empty MEMO.org

perft: normal "get_next_legal()" before movegen
perft2: is_in_check() after movegen

.dir-locals.el

@@ -1,3 +1,3 @@
 ((nil . ((compile-command . (concat "make -C "
                                        (vc-root-dir)
-                                       " -k -j2")))))
+                                       " -k -j4 dev")))))

.gitignore

@@ -4,6 +4,10 @@ vgcore.*
 *.i
 *.old
 *.save
+perf.data
+/GPATH
+/GRTAGS
+/GTAGS
 /.ccls-root
 /.ccls-cache/
 /obj/
@@ -14,4 +18,5 @@ vgcore.*
 /tmp/
 /notused/
 valgrind.out
+gmon.out
 compile_commands.json

COPYING

@@ -0,0 +1,674 @@
+                    GNU GENERAL PUBLIC LICENSE
+                       Version 3, 29 June 2007
+
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+  15. Disclaimer of Warranty.
+
+  THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
+APPLICABLE LAW.  EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
+HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY
+OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
+THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+PURPOSE.  THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM
+IS WITH YOU.  SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
+ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
+
+  16. Limitation of Liability.
+
+  IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
+WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
+THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
+GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
+USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
+DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
+PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
+EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
+SUCH DAMAGES.
+
+  17. Interpretation of Sections 15 and 16.
+
+  If the disclaimer of warranty and limitation of liability provided
+above cannot be given local legal effect according to their terms,
+reviewing courts shall apply local law that most closely approximates
+an absolute waiver of all civil liability in connection with the
+Program, unless a warranty or assumption of liability accompanies a
+copy of the Program in return for a fee.
+
+                     END OF TERMS AND CONDITIONS
+
+            How to Apply These Terms to Your New Programs
+
+  If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+  To do so, attach the following notices to the program.  It is safest
+to attach them to the start of each source file to most effectively
+state the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+    <one line to give the program's name and a brief idea of what it does.>
+    Copyright (C) <year>  <name of author>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+Also add information on how to contact you by electronic and paper mail.
+
+  If the program does terminal interaction, make it output a short
+notice like this when it starts in an interactive mode:
+
+    <program>  Copyright (C) <year>  <name of author>
+    This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+    This is free software, and you are welcome to redistribute it
+    under certain conditions; type `show c' for details.
+
+The hypothetical commands `show w' and `show c' should show the appropriate
+parts of the General Public License.  Of course, your program's commands
+might be different; for a GUI interface, you would use an "about box".
+
+  You should also get your employer (if you work as a programmer) or school,
+if any, to sign a "copyright disclaimer" for the program, if necessary.
+For more information on this, and how to apply and follow the GNU GPL, see
+<https://www.gnu.org/licenses/>.
+
+  The GNU General Public License does not permit incorporating your program
+into proprietary programs.  If your program is a subroutine library, you
+may consider it more useful to permit linking proprietary applications with
+the library.  If this is what you want to do, use the GNU Lesser General
+Public License instead of this License.  But first, please read
+<https://www.gnu.org/licenses/why-not-lgpl.html>.

MEMO.org

@@ -0,0 +1,2 @@
+** Some current ideas
+- hmmm. Empty brain.

Makefile

@@ -1,6 +1,6 @@
-# Makefile - GNU make only.
+# Makefile - brchess Makefile, **GNU make only**
 #
-# Copyright (C) 2021-2023 Bruno Raoult ("br")
+# Copyright (C) 2021-2024 Bruno Raoult ("br")
 # Licensed under the GNU General Public License v3.0 or later.
 # Some rights reserved. See COPYING.
 #
@@ -11,23 +11,33 @@
 #
 
 SHELL     := /bin/bash
-CC        := gcc
-LD        := ld
+
+ifeq ($(CC),)
+        CC = gcc
+endif
+ifeq ($(CC),cc)
+        CC = gcc
+endif
+ifeq ($(BUILD),)
+        BUILD = dev
+endif
+
 BEAR      := bear
 TOUCH     := touch
 RM        := rm
 RMDIR     := rmdir
+MAKE      := make
 
 SRCDIR    := ./src
-INCDIR    := ./include
+INCDIR    := ./src                                          # used by ./test sources
 OBJDIR    := ./obj
-
-LIBSRCDIR := ./libsrc
-LIBOBJDIR := ./libobj
-
 BINDIR    := ./bin
-LIBDIR    := ./lib
 DEPDIR    := ./dep
+TSTDIR    := ./test
+
+BRLIB     := ./brlib
+BRINCDIR  := $(BRLIB)/include
+BRLIBDIR  := $(BRLIB)/lib
 
 CCLSROOT  := .ccls-root
 CCLSFILE  := compile_commands.json
@@ -36,74 +46,198 @@ SRC       := $(wildcard $(SRCDIR)/*.c)                      # project sources
 SRC_FN    := $(notdir $(SRC))                               # source basename
 OBJ       := $(addprefix $(OBJDIR)/,$(SRC_FN:.c=.o))
 
-LIBSRC    := $(wildcard $(LIBSRCDIR)/*.c)                   # lib sources
-LIBSRC_FN := $(notdir $(LIBSRC))                            # lib sources basename
-LIBOBJ    := $(addprefix $(LIBOBJDIR)/,$(LIBSRC_FN:.c=.o))  # and lib obj ones
+TSTSRC    := $(wildcard $(TSTDIR)/*.c)
 
 LIB       := br_$(shell uname -m)                           # library name
-SLIB      := $(addsuffix .a, $(LIBDIR)/lib$(LIB))           # static lib
-DLIB      := $(addsuffix .so, $(LIBDIR)/lib$(LIB))          # dynamic lib
+LIBS      := $(strip -l$(LIB))
 
-DEP_FN    := $(SRC_FN) $(LIBSRC_FN)
+DEP_FN    := $(SRC_FN)
 DEP       := $(addprefix $(DEPDIR)/,$(DEP_FN:.c=.d))
 
 TARGET_FN := brchess
 TARGET    := $(addprefix $(BINDIR)/,$(TARGET_FN))
 
-LDFLAGS   := -L$(LIBDIR)
-LIBS      := -l$(LIB) -lreadline -lncurses
+ASMFILES  := $(SRC:.c=.s) $(TSTSRC:.c=.s)
+CPPFILES  := $(SRC:.c=.i) $(TSTSRC:.c=.i)
+
+##################################### set a version string
+# inspired from:
+#  https://eugene-babichenko.github.io/blog/2019/09/28/nightly-versions-makefiles/
+
+# last commit and date
+COMMIT    := $(shell git rev-parse --short HEAD)
+DATE      := $(shell git log -1 --format=%cd --date=format:"%Y%m%d")
+
+# get last commit w/ tag & associated tag, if any
+TAG_COMM  := $(shell git rev-list --abbrev-commit --tags --max-count=1)
+ifneq ($(TAG_COMMIT),)
+TAG       := $(shell git describe --abbrev=0 --tags ${TG_COMM} 2>/dev/null || true)
+VERSION   := $(TAG:v%=%)
+endif
+
+# if no version, use last commit and date.
+# else, if last commit != last tag commit, add commit and date to version number
+ifeq ($(VERSION),)
+  VERSION := build-$(COMMIT)-$(DATE)
+else ifneq ($(COMMIT), $(TAG_COMMIT))
+  VERSION := $(VERSION)-next-$(COMMIT)-$(DATE)
+endif
+# if uncommited changes, add "dirty" indicator
+ifneq ($(shell git status --porcelain),)
+  VERSION := $(VERSION)-dirty
+endif
 
 ##################################### pre-processor flags
-CPPFLAGS  := -I$(INCDIR)
-#CPPFLAGS  += -DDEBUG                         # global
-CPPFLAGS  += -DDEBUG_DEBUG                   # enable log() functions
-#CPPFLAGS  += -DDEBUG_DEBUG_C                # enable verbose log() settings
-CPPFLAGS  += -DDEBUG_POOL                    # memory pools management
-CPPFLAGS  += -DDEBUG_FEN                     # FEN decoding
-CPPFLAGS  += -DDEBUG_MOVE                    # move generation
-CPPFLAGS  += -DDEBUG_EVAL                    # eval functions
-CPPFLAGS  += -DDEBUG_PIECE                   # piece list management
-CPPFLAGS  += -DDEBUG_SEARCH                  # move search
+CPPFLAGS  := -I$(BRINCDIR) -I$(INCDIR) -DVERSION=\"$(VERSION)\"
+
+ifeq ($(BUILD),release)
+        CPPFLAGS  += -DNDEBUG                               # assert (unused)
+else # ifeq ($(BUILD),dev)
+        CPPFLAGS  += -DWARN_ON                              # brlib bug.h
+        CPPFLAGS  += -DBUG_ON                               # brlib bug.h
+
+        #CPPFLAGS  += -DDEBUG                               # global - unused
+        #CPPFLAGS  += -DDEBUG_DEBUG                         # enable log() functions
+        #CPPFLAGS  += -DDEBUG_DEBUG_C                       # enable log() settings
+        #CPPFLAGS  += -DDEBUG_POOL                          # memory pools management
+        #CPPFLAGS  += -DDEBUG_POS                           # position.c
+        #CPPFLAGS  += -DDEBUG_MOVE                          # move generation
+        #        fen.c
+        #CPPFLAGS  += -DDEBUG_FEN                           # FEN decoding
+        #        hash / TT
+        #CPPFLAGS  += -DZOBRIST_VERIFY                      # double chk zobrist
+        #CPPFLAGS  += -DPERFT_MOVE_HISTORY                  # perft, keep prev moves
+        #        attack.c
+        #CPPFLAGS  += -DDEBUG_ATTACK_ATTACKERS              # sq_attackers
+        #CPPFLAGS  += -DDEBUG_ATTACK_PINNERS                # sq_pinners details
+        #       CPPFLAGS  += -DDEBUG_EVAL                   # eval functions
+        #CPPFLAGS  += -DDEBUG_PIECE                         # piece list management
+        #CPPFLAGS  += -DDEBUG_SEARCH                        # move search
+endif
+
+CPPFLAGS  += -DDIAGRAM_SYM                                  # UTF8 symbols in diagrams
 
 # remove extraneous spaces (due to spaces before comments)
 CPPFLAGS  := $(strip $(CPPFLAGS))
 
 ##################################### compiler flags
 CFLAGS    := -std=gnu11
-#CFLAGS    += -O2
-CFLAGS    += -g
+
 CFLAGS    += -Wall
 CFLAGS    += -Wextra
-CFLAGS    += -march=native
+CFLAGS    += -Wshadow
 CFLAGS    += -Wmissing-declarations
-# for gprof
-# CFLAGS += -pg
-# Next one may be useful for valgrind (when invalid instructions)
-# CFLAGS += -mno-tbm
+CFLAGS    += -march=native
+
+### dev OR release
+ifeq ($(BUILD),release)
+        CFLAGS    += -O3
+        CFLAGS    += -g
+        CFLAGS    += -ginline-points                   # inlined funcs debug info
+        CFLAGS    += -funroll-loops
+        CFLAGS    += -flto
+else ifeq ($(BUILD),dev)
+        CFLAGS    += -Og
+        CFLAGS    += -g                                # symbols (gdb, perf, etc.)
+        CFLAGS    += -ginline-points                   # inlined funcs debug info
+        #CFLAGS += -pg                                 # gprof
+        # Next one may be useful for valgrind (when invalid instructions)
+        #CFLAGS += -mno-tbm
+else ifeq ($(BUILD),perf)
+        CFLAGS    += -O3
+        CFLAGS    += -g                                # symbols (gdb, perf, etc.)
+        CFLAGS    += -ginline-points                   # inlined funcs debug info
+        CFLAGS    += -funroll-loops
+else ifeq ($(BUILD),debug)
+        CFLAGS    += -O0
+        CFLAGS    += -g                                # symbols (gdb, perf, etc.)
+        # for gprof
+        #CFLAGS += -pg
+        # Next one may be useful for valgrind (when invalid instructions)
+        #CFLAGS += -mno-tbm
+endif
 
 CFLAGS    := $(strip $(CFLAGS))
 
-##################################### archiver/linker/dependency flags
+##################################### linker flags
+LDFLAGS   := --static
+LDFLAGS   += -L$(BRLIBDIR)
+
+ifeq ($(BUILD),release)
+        LDFLAGS   += -flto
+endif
+
+LDFLAGS   := $(strip $(LDFLAGS))
+
+##################################### archiver/dependency flags
 ARFLAGS   := rcs
-LDFLAGS   := -L$(LIBDIR)
-DEPFLAGS  = -MMD -MP -MF $(DEPDIR)/$*.d
+DEPFLAGS   = -MMD -MP -MF $(DEPDIR)/$*.d
+
+##################################### archiver/dependency flags
+ALL_CFLAGS  = $(DEPFLAGS) $(CPPFLAGS) $(CFLAGS)
+ALL_LDFLAGS = $(LDFLAGS) $(LIBS)
+
+##################################### Multi-targets
+# We can have an issue with Make's "-j" option, in some situations,
+# for example "make -j2 clean testing".
+# See https://stackoverflow.com/a/8496333/3079831
+
+# Check if job server supported:
+ifeq ($(filter jobserver, $(.FEATURES)),)
+# Job server not supported: sub-makes will only start one job unless
+# you specify a higher number here.  Here we use a MS Windows environment
+# variable specifying number of processors.
+JOBSARG := -j $(NUMBER_OF_PROCESSORS)
+else
+# Job server is supported; let GNU Make work as normal.
+JOBSARG :=
+endif
+
+# .FEATURES only works in GNU Make 3.81+.
+# If GNU make is older, assume job server support.
+ifneq ($(firstword $(sort 3.81 $(MAKE_VERSION))),3.81)
+# If you are using GNU Make < 3.81 that does not support job servers, you
+# might want to specify -jN parameter here instead.
+JOBSARG :=
+endif
+
+ifneq ($(words $(MAKECMDGOALS)),1)
+.NOTPARALLEL:
+# The "all" target is required in the list,
+# in case user invokes make with no targets.
+$(sort all $(MAKECMDGOALS)):
+	@$(MAKE) $(JOBSARG) -f $(firstword $(MAKEFILE_LIST)) $@
+else
 
 ##################################### General targets
-.PHONY: all compile clean cleanall
+.PHONY: all release dev perf debug compile clean cleanall
 
-all: $(TARGET)
+all: testing $(TARGET)
 
-compile: libobjs objs
+release:
+	$(MAKE) BUILD=release clean all
 
-clean: cleandep cleanobj cleanlib cleanlibobj cleanbin
+dev:
+	$(MAKE) BUILD=dev clean all
 
-cleanall: clean cleandepdir cleanobjdir cleanlibdir cleanlibobjdir cleanbindir
+perf:
+	$(MAKE) BUILD=perf clean all
+
+debug:
+	$(MAKE) BUILD=debug clean all
+
+compile: brlib objs
+
+libs: brlib
+
+clean: cleandep cleanasmcpp cleanobj cleanbin
+
+cleanall: clean cleandepdir cleanobjdir cleanallbrlib cleanbindir
 
 ##################################### cleaning functions
-# rmfiles - deletes a list of files in a directory if they exist.
+# rmfiles - delete a list of files if they exist.
 # $(1): the directory
-# $(2): the list of files to delete
-# $(3): The string to include in action output - "cleaning X files."
+# $(2): The string to include in action output - "cleaning X files."
 # see: https://stackoverflow.com/questions/6783243/functions-in-makefiles
 #
 # Don't use wildcard like "$(DIR)/*.o", so we can control mismatches between
@@ -119,7 +253,7 @@ define rmfiles
 	fi
 endef
 
-# rmdir - deletes a directory if it exists.
+# rmdir - delete a directory if it exists.
 # $(1): the directory
 # $(2): The string to include in action output - "removing X dir."
 #
@@ -138,7 +272,7 @@ endef
 ##################################### dirs creation
 .PHONY: alldirs
 
-ALLDIRS   := $(DEPDIR) $(OBJDIR) $(LIBDIR) $(LIBOBJDIR) $(BINDIR)
+ALLDIRS   := $(DEPDIR) $(OBJDIR) $(BINDIR)
 
 alldirs: $(ALLDIRS)
 
@@ -179,44 +313,20 @@ cleanobjdir: cleanobj
 # The part right of '|' are "order-only prerequisites": They are build as
 # "normal" ones, but do not imply to rebuild target.
 $(OBJDIR)/%.o: $(SRCDIR)/%.c | $(OBJDIR) $(DEPDIR)
-	@echo compiling brchess $< "->" $@.
-	@$(CC) -c $(DEPFLAGS) $(CPPFLAGS) $(CFLAGS) $< -o $@
-
-##################################### brlib objects
-.PHONY: libobjs cleanlibobj cleanlibobjdir
-
-libobjs: $(LIBOBJ)
-
-cleanlibobj:
-	$(call rmfiles,$(LIBOBJ),brlib object)
-
-cleanlibobjdir:
-	$(call rmdir,$(LIBOBJDIR),brlib objects)
-
-$(LIBOBJDIR)/%.o: $(LIBSRCDIR)/%.c | $(LIBOBJDIR) $(DEPDIR)
-	@echo compiling library $< "->" $@.
-	$(CC) -c $(DEPFLAGS) $(CPPFLAGS) $(CFLAGS) $< -o $@
+	@echo compiling brchess module: $< "->" $@.
+	@$(CC) -c $(ALL_CFLAGS) $< -o $@
 
 ##################################### brlib libraries
-.PHONY: libs cleanlib cleanlibdir
+.PHONY: cleanbrlib cleanallbrlib brlib
 
-cleanlib:
-	$(call rmfiles,$(DLIB) $(SLIB),library)
+cleanbrlib:
+	$(MAKE) -C $(BRLIB) clean
 
-cleanlibdir:
-	$(call rmdir,$(LIBDIR),libraries)
+cleanallbrlib:
+	$(MAKE) -C $(BRLIB) cleanall
 
-libs: $(DLIB) $(SLIB)
-
-$(DLIB): CFLAGS += -fPIC
-$(DLIB): LDFLAGS += -shared
-$(DLIB): $(LIBOBJ) | $(LIBDIR)
-	@echo building $@ shared library.
-	@$(CC) $(CFLAGS) $(LDFLAGS) $^ -o $@
-
-$(SLIB): $(LIBOBJ) | $(LIBDIR)
-	@echo building $@ static library.
-	$(AR) $(ARFLAGS) $@ $^
+brlib:
+	$(MAKE) -C $(BRLIB) libs
 
 ##################################### brchess binaries
 .PHONY: targets cleanbin cleanbindir
@@ -229,19 +339,23 @@ cleanbin:
 cleanbindir:
 	$(call rmdir,$(BINDIR),binaries)
 
-# We don't use static lib, but we could build it here
-$(TARGET): $(DLIB) $(OBJ) | $(BINDIR) $(SLIB)
-	@echo generating $@ executable.
-	@$(CC) $(LDFLAGS) $(OBJ) $(LIBS) -o $@
+$(TARGET): libs $(OBJ) | $(BINDIR)
+	@echo linking $@.
+	$(CC) $(LDFLAGS) $(OBJ) $(LIBS) -o $@
 
 ##################################### pre-processed (.i) and assembler (.s) output
+.PHONY: cleanasmcpp
+
+cleanasmcpp:
+	@$(call rmfiles,$(ASMFILES) $(CPPFILES),asm and pre-processed)
+
 %.i: %.c
-	@echo generating $@
+	@echo "generating $@ (cpp processed)."
 	@$(CC) -E $(CPPFLAGS) $(CFLAGS) $< -o $@
 
 %.s: %.c
-	@echo generating $@
-	@$(CC) -S -fverbose-asm $(CPPFLAGS) $(CFLAGS) $< -o $@
+	@echo "generating $@ (asm)."
+	$(CC) -S -fverbose-asm $(CPPFLAGS) $(CFLAGS) $< -o $@
 
 ##################################### LSP (ccls)
 .PHONY: ccls
@@ -253,17 +367,13 @@ $(CCLSROOT):
 	@$(TOUCH) $@
 
 # generate compile_commands.json.
-# Need to add includes and Makefile dependencies.
+# TODO: add Makefile dependencies.
 # also, if cclsfile is newer than sources, no need to clean objects file
 # (and to run bear).
 # maybe run cleanobj cleanlibobj in commands ?
-$(CCLSFILE): cleanobj cleanlibobj $(SRC) $(LIBSRC) | $(CCLSROOT)
+$(CCLSFILE): cleanobj cleanbrlib libs | $(CCLSROOT)
 	@echo "Generating ccls compile commands file ($@)."
-	@$(BEAR) -- make compile
-
-#.PHONY: bear
-#bear: cleanobj cleanlibobj Makefile | $(CCLSROOT)
-#    @$(BEAR) -- make compile
+	@$(BEAR) -- $(MAKE)
 
 ##################################### valgrind (mem check)
 .PHONY: memcheck
@@ -280,21 +390,94 @@ VALGRINDFLAGS += --suppressions=etc/libreadline.supp
 memcheck: targets
 	@$(VALGRIND) $(VALGRINDFLAGS) $(BINDIR)/brchess
 
+##################################### test binaries
+.PHONY: testing test
+
+TEST          := piece-test fen-test bitboard-test movegen-test attack-test
+TEST          += movedo-test perft-test tt-test
+
+PIECE_OBJS    := piece.o
+FEN_OBJS      := $(PIECE_OBJS) fen.o position.o bitboard.o board.o \
+	hyperbola-quintessence.o attack.o hash.o init.o misc.o move.o
+BB_OBJS       := $(FEN_OBJS)
+MOVEGEN_OBJS  := $(BB_OBJS) move-gen.o
+ATTACK_OBJS   := $(MOVEGEN_OBJS)
+MOVEDO_OBJS   := $(ATTACK_OBJS) move-do.o
+PERFT_OBJS    := $(MOVEDO_OBJS) search.o
+TT_OBJS       := $(MOVEDO_OBJS)
+
+TEST          := $(addprefix $(BINDIR)/,$(TEST))
+
+PIECE_OBJS    := $(addprefix $(OBJDIR)/,$(PIECE_OBJS))
+FEN_OBJS      := $(addprefix $(OBJDIR)/,$(FEN_OBJS))
+BB_OBJS       := $(addprefix $(OBJDIR)/,$(BB_OBJS))
+MOVEGEN_OBJS  := $(addprefix $(OBJDIR)/,$(MOVEGEN_OBJS))
+ATTACK_OBJS   := $(addprefix $(OBJDIR)/,$(ATTACK_OBJS))
+MOVEDO_OBJS   := $(addprefix $(OBJDIR)/,$(MOVEDO_OBJS))
+PERFT_OBJS    := $(addprefix $(OBJDIR)/,$(PERFT_OBJS))
+TT_OBJS       := $(addprefix $(OBJDIR)/,$(TT_OBJS))
+
+test:
+	echo TEST=$(TEST)
+	echo FEN_OBJS=$(FEN_OBJS)
+
+testing: $(TEST)
+
+bin/piece-test: test/piece-test.c $(FEN_OBJS)
+	@echo linking $@ test executable.
+	@$(CC) $(ALL_CFLAGS) $< $(FEN_OBJS) $(ALL_LDFLAGS) -o $@
+
+bin/fen-test: test/fen-test.c test/common-test.h $(FEN_OBJS)
+	@echo linking $@ test executable.
+	@$(CC) $(ALL_CFLAGS) $< $(FEN_OBJS) $(ALL_LDFLAGS) -o $@
+
+bin/bitboard-test: test/bitboard-test.c test/common-test.h $(BB_OBJS)
+	@echo linking $@ test executable.
+	@$(CC) $(ALL_CFLAGS) $< $(BB_OBJS) $(ALL_LDFLAGS) -o $@
+
+bin/movegen-test: test/movegen-test.c test/common-test.h $(MOVEGEN_OBJS)
+	@echo linking $@ test executable.
+	@$(CC) $(ALL_CFLAGS) $< $(MOVEGEN_OBJS) $(ALL_LDFLAGS) -o $@
+
+bin/attack-test: test/attack-test.c test/common-test.h $(ATTACK_OBJS)
+	@echo linking $@ test executable.
+	@$(CC) $(ALL_CFLAGS) $< $(ATTACK_OBJS) $(ALL_LDFLAGS) -o $@
+
+bin/movedo-test: test/movedo-test.c test/common-test.h $(MOVEDO_OBJS)
+	@echo linking $@ test executable.
+	@$(CC) $(ALL_CFLAGS) $< $(MOVEDO_OBJS) $(ALL_LDFLAGS) -o $@
+
+bin/perft-test: test/perft-test.c test/common-test.h $(PERFT_OBJS)
+	@echo linking $@ test executable.
+	@$(CC) $(ALL_CFLAGS) $< $(PERFT_OBJS) $(ALL_LDFLAGS) -o $@
+
+bin/tt-test: test/tt-test.c test/common-test.h $(TT_OBJS)
+	@echo linking $@ test executable.
+	@$(CC) $(ALL_CFLAGS) $< $(TT_OBJS) $(ALL_LDFLAGS) -o $@
+
 ##################################### Makefile debug
 .PHONY: showflags wft
 
-showflags:
-	@echo CFLAGS: "$(CFLAGS)"
-	@echo CPPFLAGS: $(CPPFLAGS)
-	@echo DEPFLAGS: $(DEPFLAGS)
-	@echo LDFLAGS: $(LDFLAGS)
-	@echo DEPFLAGS: $(DEPFLAGS)
+info:
+	@printf "CFLAGS:   +%s+\n" "$(CFLAGS)"
+	@printf "CPPFLAGS: +%s+\n" "$(CPPFLAGS)"
+	@printf "DEPFLAGS: +%s+\n" "$(DEPFLAGS)"
+	@printf "LDFLAGS:  +%s+\n" "$(LDFLAGS)"
+	@printf "DEPFLAGS: +%s+\n" "$(DEPFLAGS)"
+	@printf "VERSION:  +%s+\n" "$(VERSION)"
 
 wtf:
-	@printf "LIBOBJDIR=%s\n\n" "$(LIBOBJDIR)"
-	@printf "LIBOBJ=%s\n\n" "$(LIBOBJ)"
-	@printf "OBJDIR=%s\n\n" "$(OBJDIR)"
-	@printf "OBJ=%s\n\n" "$(OBJ)"
+	@printf "BRLIBDIR=%s\n" "$(BRLIBDIR)"
+	@printf "LDFLAGS=%s\n\n" "$(LDFLAGS)"
+	@#printf "LIBOBJ=%s\n\n" "$(LIBOBJ)"
+	@#printf "OBJDIR=%s\n\n" "$(OBJDIR)"
+	@#printf "OBJ=%s\n\n" "$(OBJ)"
 	@#echo LIBOBJ=$(LIBOBJ)
 	@#echo DEP=$(DEP)
 	@#echo LIBSRC=$(LIBSRC)
+
+zob:
+	@#$(CC) $(LDFLAGS) $(CPPFLAGS) $(CFLAGS) $< $(LIBS) src/util.c -o util
+
+##################################### End of multi-targets
+endif

README.org

@@ -1 +1,40 @@
-A basic chess program. The goal is not to make it good, but at least to be able to play a full game - Far to be the case !
+#+OPTIONS: toc:nil
+#+OPTIONS: num:2
+**This is not a working chess program !!**
+
+/I am only experimenting some chess programming concepts./
+
+** License
+~SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>~~
+
+This work is Copyright (C) 2021-2024 Bruno Raoult ("br"), and licensed under
+the GNU General Public License v3.0 or later.
+
+Some rights reserved. See COPYING.
+
+** Installation (don't do it until version 0.9)
+*** dependencire
+- GCC 10 or newer
+- libreadline
+*** clone repository
+*user...**
+#+BEGIN_EXAMPLE
+$ git clone https://github.com/braoult/brchess.git
+or
+$ git clone https://git.raoult.com/bruno/brchess.git
+#+END_EXAMPLE
+
+*OR ...developer*
+#+BEGIN_EXAMPLE
+$ git clone git@git.raoult.com:bruno/brchess.git
+$ cd brchess
+$ git remote add github git@github.com:braoult/brchess.git
+$ git fetch --all
+#+END_EXAMPLE
+
+*** add "brlib" submodule
+#+BEGIN_EXAMPLE
+$ cd brchess
+$ git submodule init
+$ git submodule update
+#+END_EXAMPLE

scripts/env.sh

@@ -17,10 +17,17 @@
 # environment.
 
 if [[ ! -v _BRCHESS_ENV_ ]]; then
-    export _BRCHESS_ENV_=1 BRCHESS_ROOT BRLIB_DIR LD_LIBRARY_PATH
+    export _BRCHESS_ENV_=1 BRCHESS_ROOT LD_LIBRARY_PATH
     BRCHESS_ROOT=$(realpath -L "$(dirname "${BASH_SOURCE[0]}")/..")
-    BRLIB_DIR="$BRCHESS_ROOT/brlib/lib"
-    LD_LIBRARY_PATH=/mypath${LD_LIBRARY_PATH:+:$LD_LIBRARY_PATH}
+
+    BRCHESS_SCRIPTDIR="$BRCHESS_ROOT/scripts"
+    BRCHESS_BINDIR="$BRCHESS_ROOT/bin"
+    PATH="$PATH:$BRCHESS_BINDIR:$BRCHESS_SCRIPTDIR"
+
+    BRCHESS_BRLIBDIR="$BRCHESS_ROOT/brlib"
+    BRCHESS_LIBDIR="$BRCHESS_BRLIBDIR/lib"
+    LD_LIBRARY_PATH="${BRCHESS_LIBDIR}${LD_LIBRARY_PATH:+:$LD_LIBRARY_PATH}"
     #printf "R=%s L=%s LD=%s\n" "$BRCHESS_ROOT" "$BRLIB_DIR" "$LD_LIBRARY_PATH"
-    printf "Chess environment complete.\n"
+    unset BRCHESS_SCRIPTDIR BRCHESS_BINDIR BRCHESS_LIBDIR
+    printf "brchess environment complete.\n"
 fi

scripts/fetch-all.sh

@@ -0,0 +1,44 @@
+#!/usr/bin/env bash
+#
+# Fetch all branches from remotes, and track missing ones.
+#
+# The value of variable ORIGIN is used for repository origin. If
+# not set, the default is "origin".
+
+default_origin=origin
+
+origin=${ORIGIN:-$default_origin}
+
+declare -a local_b
+declare -A alocal_b
+
+# fetch all remotes
+git fetch --all --tags
+
+# get local branches, and build reverse associative array
+readarray -t local_b < <(git for-each-ref --format='%(refname:short)' refs/heads/)
+for ref in "${local_b[@]}"; do
+    alocal_b[$ref]=1
+done
+
+# get "origin" branches
+readarray -t orig_b  < <(git for-each-ref --format='%(refname:short)' \
+                             refs/remotes/"$origin"/)
+
+# find-out missing local branches and track them.
+# bugs:
+#  - We only check local branch existence, not tracking information correctness.
+#  - What about sub-branches ? Like remote/a and remote/a/b not being tracked ?
+for remote_b in "${orig_b[@]}"; do
+    short=${remote_b#"$origin"/};
+    # OR (??): short=${remote_b##*/}
+
+    if ! [[ -v alocal_b[$short] ]]; then
+        printf "local branch %s set to track %s.\n" "$short" "$remote_b"
+        git branch --track "$short" "$remote_b"
+    else
+        printf "skipping %s.\n" "$remote_b"
+    fi
+done
+
+git pull -a

scripts/git-split.sh

@@ -0,0 +1,35 @@
+#!/usr/bin/env bash
+#
+# Duplicate file, with history (well, sort of)
+#
+# Copy a git file, keeping history.
+# Sources:
+#   https://stackoverflow.com/a/53849613/3079831
+#   https://stackoverflow.com/a/75942970/3079831
+
+CMDNAME=${0##*/}                                  # script name
+
+if (( $# != 2 )); then
+   printf "Usage: %s original copy\n" "$CMDNAME"
+   exit 1
+fi
+
+from="$1"
+to="$2"
+branch="split-file"
+
+printf "Dup from=[%s] to=[%s] branch=[%s]\n" "$from" "$to" "$branch"
+
+git checkout -b "$branch"                         # create and switch to branch
+
+git mv "$from" "$to"                              # make the duplicate
+git commit -m "Duplicate $from to $to"
+
+git checkout HEAD~ "$from"                        # bring back the original
+git commit -m "Restore duplicated $from"
+
+git checkout -                                    # switch back to source branch
+git merge --no-ff "$branch" -m "Merge $branch"    # merge dup into source branch
+
+
+exit 0

scripts/submodules-upd.sh

@@ -0,0 +1,3 @@
+#!/usr/bin/env bash
+
+git submodule update --remote --merge

src/attack.c

@@ -0,0 +1,216 @@
+/* attack.c - attack functions.
+ *
+ * Copyright (C) 2024 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#include <stdio.h>
+#include <stdarg.h>
+
+#include "chessdefs.h"
+#include "bitboard.h"
+#include "position.h"
+#include "hyperbola-quintessence.h"
+#include "attack.h"
+
+
+/**
+ * sq_is_attacked() - find if a square is attacked
+ * @pos: position
+ * @occ: occupation mask used
+ * @sq:  square to test
+ * @c:   attacker color
+ *
+ * Find if a @c piece attacks @sq.
+ *
+ * Algorithm:  We perform a reverse attack, and check if any given
+ * piece type on @sq can attack a @c piece of same type.
+ *
+ * For example, if @c is white, we test for all T in P,N,B,R,Q,K if
+ * T on @sq could attack a white T piece.
+ *
+ * @Return: true if @sq is attacked by a @c piece, false otherwise.
+ */
+bool sq_is_attacked(const pos_t *pos, const bitboard_t occ, const square_t sq, const color_t c)
+{
+    color_t opp = OPPONENT(c);
+
+    /*
+     * return (hyperbola_bishop_moves(occ, sq) & (pos->bb[c][BISHOP] | pos->bb[c][QUEEN])
+     *      || hyperbola_rook_moves(occ, sq) & (pos->bb[c][ROOK] | pos->bb[c][QUEEN])
+     *      || bb_pawn_attacks[opp][sq] & pos->bb[c][PAWN]
+     *      || bb_knight_moves(pos->bb[c][KNIGHT], sq)
+     *      || bb_king_moves(pos->bb[c][KING], sq)
+     *  )
+     */
+
+    /* bishop / queen */
+    if (hyperbola_bishop_moves(occ, sq) & (pos->bb[c][BISHOP] | pos->bb[c][QUEEN]))
+        return true;
+
+    /* rook / queen */
+    if (hyperbola_rook_moves(occ, sq) & (pos->bb[c][ROOK] | pos->bb[c][QUEEN]))
+        return true;
+
+    /* knight */
+    if (bb_knight_moves(pos->bb[c][KNIGHT], sq))
+        return true;
+
+    /* pawn */
+    if (bb_pawn_attacks[opp][sq] & pos->bb[c][PAWN])
+        return true;
+
+    /* king */
+    if (bb_king_moves(pos->bb[c][KING], sq))
+        return true;
+
+    return false;
+}
+
+/**
+ * is_in_check() - find if a king is in check.
+ * @pos:   position
+ * @color: king color
+ *
+ * Find if a @c king is in check. This function is a wrapper over @sq_is_attacked().
+ *
+ * @Return: true if @sq is attacked by a @c piece, false otherwise.
+ */
+bool is_in_check(const pos_t *pos, const color_t color)
+{
+    bitboard_t occ = pos_occ(pos);
+    return sq_is_attacked(pos, occ, pos->king[color], OPPONENT(color));
+}
+
+/**
+ * sq_attackers() - find attackers on a square
+ * @pos: position
+ * @occ: occupation mask used
+ * @sq:  square to test
+ * @c:   attacker color
+ *
+ * Find all @c attacks on @sq. En-passant is not considered.
+ *
+ * Algorithm:  We perform a reverse attack, and check if any given
+ * piece type on @sq can attack a @c piece of same type.
+ *
+ * For example, if @c is white, we test for all T in P,N,B,R,Q,K if
+ * T on @sq could attack a white T piece.
+ *
+ * @Return: a bitboard of attackers.
+ */
+bitboard_t sq_attackers(const pos_t *pos, const bitboard_t occ, const square_t sq, const color_t c)
+{
+    bitboard_t attackers = 0, tmp;
+    bitboard_t sqbb = BIT(sq);
+    bitboard_t to;
+    color_t opp = OPPONENT(c);
+
+    /* pawn */
+    to =  pos->bb[c][PAWN];
+    tmp = bb_pawns_attacks(sqbb, sq_up(opp)) & to;
+    attackers |= tmp;
+#   ifdef DEBUG_ATTACK_ATTACKERS
+    bb_print("att pawn", tmp);
+#   endif
+
+    /* knight & king */
+    to = pos->bb[c][KNIGHT];
+    tmp = bb_knight_moves(to, sq);
+    attackers |= tmp;
+#   ifdef DEBUG_ATTACK_ATTACKERS
+    bb_print("att knight", tmp);
+#   endif
+    to = pos->bb[c][KING];
+    tmp = bb_king_moves(to, sq);
+    attackers |= tmp;
+#   ifdef DEBUG_ATTACK_ATTACKERS
+    bb_print("att king", tmp);
+#   endif
+
+    /* bishop / queen */
+    to = pos->bb[c][BISHOP] | pos->bb[c][QUEEN];
+    tmp = hyperbola_bishop_moves(occ, sq) & to;
+    attackers |= tmp;
+#   ifdef DEBUG_ATTACK_ATTACKERS
+    bb_print("att bishop/queen", tmp);
+#   endif
+
+    /* rook / queen */
+    to = pos->bb[c][ROOK] | pos->bb[c][QUEEN];
+    tmp = hyperbola_rook_moves(occ, sq) & to;
+    attackers |= tmp;
+#   ifdef DEBUG_ATTACK_ATTACKERS
+    bb_print("att rook/queen", tmp);
+    bb_print("ATTACKERS", attackers);
+#   endif
+
+    return attackers;
+}
+
+/**
+ * sq_pinners() - get "pinners" on a square
+ * @pos: position
+ * @sq:  square to test
+ * @color:   attacker color
+ *
+ * Find all @c pieces which are separated from @sq by only one piece (of
+ * any color).
+ *
+ * @Return: bitboard of pinners.
+ */
+bitboard_t sq_pinners(const pos_t *pos, const square_t sq, const color_t color)
+{
+    bitboard_t attackers, pinners = 0;
+    bitboard_t occ = pos_occ(pos);
+    bitboard_t maybe_pinner, tmp, lines;
+
+    /* bishop type */
+    attackers = pos->bb[color][BISHOP] | pos->bb[color][QUEEN];
+    /* occupancy on sq diag and antidiag */
+    lines = (bb_sqdiag[sq] | bb_sqanti[sq]) & occ;
+    bit_for_each64(maybe_pinner, tmp, attackers) {
+        bitboard_t between = bb_between_excl[maybe_pinner][sq];
+        /* keep only squares between AND on sq diag/anti */
+        if (popcount64(between & lines) == 1)
+            pinners |= BIT(maybe_pinner);
+    }
+
+    /* same for rook type */
+    attackers = pos->bb[color][ROOK] | pos->bb[color][QUEEN];
+    lines = (bb_sqrank[sq] | bb_sqfile[sq]) & occ;
+    bit_for_each64(maybe_pinner, tmp, attackers) {
+        bitboard_t between = bb_between_excl[maybe_pinner][sq];
+        if (popcount64(between & lines) == 1)
+            pinners |= BIT(maybe_pinner);
+    }
+#   ifdef DEBUG_ATTACK_ATTACKERS1
+    char str[32];
+    printf("pinners : %s\n", pos_pinners2str(pos, str, sizeof(str)));
+    printf("pinners : %lx\n", pinners);
+#   endif
+    return pinners;
+}
+
+/**
+ * sq_attackers() - find all attackers on a square
+ * @pos: position
+ * @sq:  square to test
+ *
+ * Find all attacks on @sq. En-passant is not considered.
+ * Just a wrapper over @sq_attackers().
+ *
+ * @Return: a bitboard of attackers.
+ */
+bitboard_t sq_attackers_all(const pos_t *pos, const square_t sq)
+{
+    bitboard_t occ = pos_occ(pos);
+    return sq_attackers(pos, occ, sq, WHITE) | sq_attackers(pos, occ, sq, BLACK);
+}

src/attack.h

@@ -0,0 +1,26 @@
+/* attack.h - attack functions.
+ *
+ * Copyright (C) 2024 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#ifndef _ATTACK_H
+#define _ATTACK_H
+
+#include "chessdefs.h"
+#include "bitboard.h"
+
+bool sq_is_attacked(const pos_t *pos, const bitboard_t occ, const square_t sq, const color_t c);
+bool is_in_check(const pos_t *pos, const color_t color);
+
+bitboard_t sq_attackers(const pos_t *pos, const bitboard_t occ, const square_t sq, const color_t c);
+bitboard_t sq_attackers_all(const pos_t *pos, const square_t sq);
+bitboard_t sq_pinners(const pos_t *pos, const square_t sq, const color_t c);
+#endif

src/bitboard.c

@@ -0,0 +1,330 @@
+/* bitboard.c - bitboard functions.
+ *
+ * Copyright (C) 2024 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#include <stdio.h>
+#include <stdarg.h>
+
+#include <brlib.h>
+
+#include "chessdefs.h"
+#include "piece.h"
+#include "board.h"
+#include "bitboard.h"
+
+bitboard_t bb_sq[64];
+bitboard_t bb_sqrank[64], bb_sqfile[64], bb_sqdiag[64], bb_sqanti[64];
+bitboard_t bb_between_excl[64][64];
+bitboard_t bb_between[64][64];
+bitboard_t bb_line[64][64];
+
+bitboard_t bb_knight[64], bb_king[64], bb_pawn_attacks[2][64];
+
+/*  vectors are clockwise from N */
+static int knight_vector[] = {
+    NORTH_EAST + NORTH, NORTH_EAST + EAST,
+    SOUTH_EAST + EAST,  SOUTH_EAST + SOUTH,
+    SOUTH_WEST + SOUTH, SOUTH_WEST + WEST,
+    NORTH_WEST + WEST,  NORTH_WEST + NORTH
+};
+static int king_vector[8] = {
+    NORTH, NORTH_EAST, EAST, SOUTH_EAST,
+    SOUTH, SOUTH_WEST, WEST, NORTH_WEST
+};
+
+/**
+ * bitboard_between_excl() - get bitboard of squares between two squares.
+ * @sq1, @sq2: The two square_t squares
+ *
+ * From: http://www.talkchess.com/forum3/viewtopic.php?f=7&t=12499&start=14
+ * This function may be used instead of bb_XXX arrays if cache pressure is high.
+ *
+ * @Return: bitboard_t, squares between @sq1 and @sq2 (excl. @sq1 and @sq2).
+ */
+bitboard_t bitboard_between_excl(square_t sq1, square_t sq2)
+{
+    const bitboard_t m1 = -1;
+    const bitboard_t a2a7 = U64(0x0001010101010100);
+    const bitboard_t b7h1 = U64(0x0002040810204080);
+    bitboard_t btwn_bits, ray_bits;
+    u32 rank_diff, file_diff, anti_diff, diag_diff;
+
+    btwn_bits  =  (m1 << sq1) ^ (m1 << sq2);      /* includes sq1 and sq2 */
+    rank_diff  = ((sq2 | 7) - sq1) >> 3,          /* signed */
+        file_diff  =  (sq2 & 7) - (sq1 & 7);          /* signed */
+
+    anti_diff  =  rank_diff  + file_diff;
+    rank_diff  =  rank_diff  & 15;
+    file_diff  =  file_diff  & 15;
+    anti_diff  =  anti_diff  & 15;
+    diag_diff  =  rank_diff  ^ file_diff;
+    ray_bits   =  2 * ((rank_diff - 1) >> 26);
+
+    ray_bits  |=  bswap64((m1 + diag_diff) & b7h1);
+    ray_bits  |=  (m1 + anti_diff) & b7h1;
+    ray_bits  |=  (m1 + file_diff) & a2a7;
+    ray_bits  *=  btwn_bits  &  -btwn_bits;
+    return ray_bits & btwn_bits;
+}
+
+/**
+ * bitboard_init() - initialize general bitboards
+ *
+ * Generate the following bitboards :
+ *   bb_sq[64]: square to bitboard
+ *   bb_sqrank[64]: square to rank
+ *   bb_sqfile[64]: square to file
+ *   bb_sqdiag[64]: square to diagonal
+ *   bb_sqanti[64]: square to antidiagonal
+ *
+ *   bb_between_excl[64][64]: strict squares between two squares
+ *   bb_between[64][64]: squares between two squares including second square
+ *
+ * And the following pseudo move masks:
+ *   bb_knight[64]: knight moves
+ *   bb_king[64]: king moves
+ *
+ */
+void bitboard_init(void)
+{
+    /*  for each square, the 4 masks: file, rank, diagonal, antidiagonal */
+    struct { int df, dr; } vecs[4] = {
+        { 0,  1 },                                /* vertical/file */
+        { 1,  0 },                                /* horizontal/rank */
+        { 1,  1 },                                /* diagonal */
+        { 1, -1 },                                /* antidiagonal */
+    } ;
+    bitboard_t tmpbb[64][4] = { 0 };
+
+    /* 1) square to bitboard
+     *    in-between, sq2 excluded
+     */
+    for (square_t sq1 = A1; sq1 <= H8; ++sq1) {
+        bb_sq[sq1] = BIT(sq1);
+        for (square_t sq2 = A1; sq2 <= H8; ++sq2)
+            bb_between_excl[sq1][sq2] = bitboard_between_excl(sq1, sq2);
+    }
+
+    /* 2) sq1-to-sq2 mask, sq2 included
+     *    square to file/rank/dia/anti bitmaps
+     */
+    for (square_t sq = 0; sq < 64; ++sq) {
+        file_t f = sq_file(sq);
+        rank_t r = sq_rank(sq);
+        for (int vec = 0; vec < 4; ++vec) {
+            tmpbb[sq][vec] |= BIT(sq_make(f, r));
+            for (int dir = -1; dir <= 1; dir += 2) {
+                file_t df = dir * vecs[vec].df, f2 = f + df;
+                rank_t dr = dir * vecs[vec].dr, r2 = r + dr;
+                bitboard_t mask_between = 0;
+                while (sq_coord_ok(f2) && sq_coord_ok(r2)) {
+                    square_t dest = sq_make(f2, r2);
+                    tmpbb[sq][vec] |= BIT(dest);
+                    mask_between |= BIT(dest);
+                    bb_between[sq][dest] = mask_between;
+                    f2 += df, r2 += dr;
+                }
+            }
+        }
+    }
+    for (square_t sq = 0; sq < 64; ++sq) {
+        bb_sqfile[sq] = tmpbb[sq][0];
+        bb_sqrank[sq] = tmpbb[sq][1];
+        bb_sqdiag[sq] = tmpbb[sq][2];
+        bb_sqanti[sq] = tmpbb[sq][3];
+    }
+    for (square_t sq1 = 0; sq1 < 64; ++sq1) {
+        for (square_t sq2 = 0; sq2 < 64; ++sq2) {
+            if (sq1 != sq2) {
+                if (bb_sqfile[sq1] == bb_sqfile[sq2])
+                    bb_line[sq1][sq2] = bb_sqfile[sq1];
+                else if (bb_sqrank[sq1] == bb_sqrank[sq2])
+                    bb_line[sq1][sq2] = bb_sqrank[sq1];
+                else if (bb_sqdiag[sq1] == bb_sqdiag[sq2])
+                    bb_line[sq1][sq2] = bb_sqdiag[sq1];
+                else if (bb_sqanti[sq1] == bb_sqanti[sq2])
+                    bb_line[sq1][sq2] = bb_sqanti[sq1];
+            }
+        }
+    }
+
+    /* 3) pawn, knight and king attacks
+     */
+    for (square_t sq = A1; sq <= H8; ++sq) {
+         if (sq <= H7)
+             bb_pawn_attacks[WHITE][sq] = bb_pawns_attacks(BIT(sq), sq_up(WHITE));
+         if (sq >= A2)
+             bb_pawn_attacks[BLACK][sq] = bb_pawns_attacks(BIT(sq), sq_up(BLACK));
+
+        for (int vec = 0; vec < 8; ++vec) {
+            int dst = sq + knight_vector[vec];
+            if (sq_ok(dst)) {
+                if (sq_dist(dst, sq) == 2) {
+                    bb_knight[sq] |= bb_sq[dst];
+                }
+            }
+            dst = sq + king_vector[vec];
+            if (sq_ok(dst)) {
+                if (sq_dist(dst, sq) == 1) {
+                    bb_king[sq] |= bb_sq[dst];
+                }
+            }
+        }
+    }
+}
+
+
+/**
+ * bb_knight_moves() - get bitboard of knight pseudo-moves
+ * @notmine: bitboard_t of squares not occupied by own pieces
+ * @sq: knight square
+ *
+ * @Return: bitboard of available moves.
+ */
+bitboard_t bb_knight_moves(bitboard_t notmine, square_t sq)
+{
+    return bb_knight[sq] & notmine;
+}
+
+/**
+ * bb_king_moves() - get bitboard of king pseudo-moves
+ * @notmine: bitboard_t of squares not occupied by own pieces
+ * @sq: king square
+ *
+ * @Return: bitboard of available moves.
+ */
+bitboard_t bb_king_moves(bitboard_t notmine, square_t sq)
+{
+    return bb_king[sq] & notmine;
+}
+
+/**
+ * bb_print() - print simple bitboard representation
+ * @title: a string or NULL
+ * @bitboard: the bitboard
+ */
+void bb_print(const char *title, const bitboard_t bitboard)
+{
+    //char c = p? p: 'X';
+    if (title)
+        printf("%s\n", title);
+    for (rank_t r = RANK_8; r >= RANK_1; --r) {
+        printf("%d ", r + 1);
+        for (file_t f = FILE_A; f <= FILE_H; ++f) {
+            printf(" %c", bitboard & bb_sq[sq_make(f, r)] ? 'X': '.');
+        }
+        printf("\n");
+    }
+    printf("   a b c d e f g h\n");
+    return;
+}
+
+/**
+ * bb_print_multi() - print multiple bitboards horizontally
+ * @title: a string or NULL
+ * @n: number of bitboards
+ * @bb_ptr...: pointers to bitboards
+ *
+ * @n is the number of bitboards to print. If @n > 10, it is reduced to 10
+ */
+void bb_print_multi(const char *title, int n, ...)
+{
+    bitboard_t bb[8];
+    va_list ap;
+
+    n = min(n, 10);
+
+    va_start(ap, n);
+    for (int i = 0; i < n; ++i) {                 /* save all bitboards */
+        bb[i] = va_arg(ap, bitboard_t);
+    }
+    va_end(ap);
+
+    if (title)
+        printf("%s\n", title);
+
+    for (rank_t r = RANK_8; r >= RANK_1; --r) {
+        for (int i = 0; i < n; ++i) {
+            printf("%d ", r + 1);
+            for (file_t f = FILE_A; f <= FILE_H; ++f) {
+                printf(" %c", bb[i] & bb_sq[sq_make(f, r)] ? 'X': '.');
+            }
+            printf("    ");
+        }
+        printf("\n");
+    }
+    for (int i = 0; i < n; ++i) {
+        printf("   a b c d e f g h");
+        printf("    ");
+    }
+    printf("\n");
+    return;
+}
+
+/**
+ * bb_rank_sprint() - print an u8 rank binary representation
+ * @str: the destination string
+ * @bb8: the uchar to print
+ *
+ * @return: @str, filled with ascii representation
+ */
+char *bb_rank_sprint(char *str, const uchar bb8)
+{
+    file_t f;
+    for (f = FILE_A; f <= FILE_H; ++f) {
+        *(str + f) = bb8 & BIT(f) ? '1': '.';
+    }
+    *(str + f) = 0;
+    //printf(" 0 1 2 3 4 5 6 7\n");
+    //printf("\n");
+    return str;
+}
+
+/**
+ * bb_sq2str() - convert bitboard to a string with a list of squares.
+ * @bb:  bitboard
+ * @str: destination string
+ * @len: max @str length
+ *
+ * @str will be filled with the list of string representation of @bb, up to @len
+ * characters.
+ * 3 characters are used per square, so, for example, @str len should be :
+ * - For a valid position checkers (two checkers max): 2*3 + 1 = 7.
+ * - For a valid position pinners (8 pinners): 8*3 + 1 = 25.
+ * - for a full bitboard: 64*3 + 1 = 193.
+ *
+ * If @len is not enough to fill all moves, the last fitting move is replaced by "...".
+ *
+ * @return: The string.
+ */
+char *bb_sq2str(const bitboard_t bb, char *str, const int len)
+{
+    bitboard_t tmp, sq;
+    int nocc = popcount64(bb);
+    int needed = 3 * nocc + 1;
+    int willdo = (int) len >= needed ? nocc: (len - 1) / 3 - 1;
+    int current = 0;
+
+    //printf("sq2str bb=%lx len=%d willdo=%d\n", bb, len, willdo);
+    bit_for_each64(sq, tmp, bb) {
+        if (current == willdo) {
+            strcpy(str + current * 3, "...");
+        } else {
+            strcpy(str + current * 3, sq_to_string(sq));
+            str[current * 3 + 2] = ' ';
+        }
+        if (++current > willdo)
+            break;
+    }
+    str[current * 3] = 0;
+    return str;
+}

src/bitboard.h

@@ -1,6 +1,6 @@
 /* bitboard.h - bitboard definitions.
  *
- * Copyright (C) 2021 Bruno Raoult ("br")
+ * Copyright (C) 2021-2024 Bruno Raoult ("br")
  * Licensed under the GNU General Public License v3.0 or later.
  * Some rights reserved. See COPYING.
  *
@@ -11,60 +11,293 @@
  *
  */
 
-#ifndef BITBOARD_H
-#define BITBOARD_H
+#ifndef _BITBOARD_H
+#define _BITBOARD_H
 
-#include <bits.h>
+#include <brlib.h>
+#include <bitops.h>
 
 #include "chessdefs.h"
+#include "board.h"
 #include "piece.h"
 
-enum bb_square {
-    A1 = 1UL <<  0, B1 = 1UL <<  1, C1 = 1UL <<  2, D1 = 1UL <<  3,
-    E1 = 1UL <<  4, F1 = 1UL <<  5, G1 = 1UL <<  6, H1 = 1UL <<  7,
+/* mapping square -> bitboard */
+extern bitboard_t bb_sq[64];
+/* squares between sq1 and sq2, exclusing both */
+extern bitboard_t bb_between_excl[64][64];
+/* squares between sq1 and sq2, including sq2 */
+extern bitboard_t bb_between[64][64];
 
-    A2 = 1UL <<  8, B2 = 1UL <<  9, C2 = 1UL << 10, D2 = 1UL << 11,
-    E2 = 1UL << 12, F2 = 1UL << 13, G2 = 1UL << 14, H2 = 1UL << 15,
+/**
+ * bb_sqrank[64]: square to rank
+ * bb_sqfile[64]: square to file
+ * bb_sqdiag[64]: square to diagonal
+ * bb_sqanti[64]: square to antidiagonal
+ */
+extern bitboard_t bb_sqrank[64], bb_sqfile[64], bb_sqdiag[64], bb_sqanti[64];
 
-    A3 = 1UL << 16, B3 = 1UL << 17, C3 = 1UL << 18, D3 = 1UL << 19,
-    E3 = 1UL << 20, F3 = 1UL << 21, G3 = 1UL << 22, H3 = 1UL << 23,
+/* line (rank, file, diagonal or anti-diagonal) between two squares */
+extern bitboard_t bb_line[64][64];
 
-    A4 = 1UL << 24, B4 = 1UL << 25, C4 = 1UL << 26, D4 = 1UL << 27,
-    E4 = 1UL << 28, F4 = 1UL << 29, G4 = 1UL << 30, H4 = 1UL << 31,
+/* pawn, knight and king attacks */
+extern bitboard_t bb_knight[64], bb_king[64], bb_pawn_attacks[2][64];
 
-    A5 = 1UL << 32, B5 = 1UL << 33, C5 = 1UL << 34, D5 = 1UL << 35,
-    E5 = 1UL << 36, F5 = 1UL << 37, G5 = 1UL << 38, H5 = 1UL << 39,
+/* TODO (maybe C23?) when we can ensure an enum can be u64
+ *
+ * enum {
+ *     A1bb = mask(A1), A2bb = mask(A2), A3bb = mask(A3), A4bb = mask(A4),
+ *     A5bb = mask(A5), A6bb = mask(A6), A7bb = mask(A7), A8bb = mask(A8),
+ *     B1bb = mask(B1), B2bb = mask(B2), B3bb = mask(B3), B4bb = mask(B4),
+ *     B5bb = mask(B5), B6bb = mask(B6), B7bb = mask(B7), B8bb = mask(B8),
+ *     C1bb = mask(C1), C2bb = mask(C2), C3bb = mask(C3), C4bb = mask(C4),
+ *     C5bb = mask(C5), C6bb = mask(C6), C7bb = mask(C7), C8bb = mask(C8),
+ *     D1bb = mask(D1), D2bb = mask(D2), D3bb = mask(D3), D4bb = mask(D4),
+ *     D5bb = mask(D5), D6bb = mask(D6), D7bb = mask(D7), D8bb = mask(D8),
+ *     E1bb = mask(E1), E2bb = mask(E2), E3bb = mask(E3), E4bb = mask(E4),
+ *     E5bb = mask(E5), E6bb = mask(E6), E7bb = mask(E7), E8bb = mask(E8),
+ *     F1bb = mask(F1), F2bb = mask(F2), F3bb = mask(F3), F4bb = mask(F4),
+ *     F5bb = mask(F5), F6bb = mask(F6), F7bb = mask(F7), F8bb = mask(F8),
+ *     G1bb = mask(G1), G2bb = mask(G2), G3bb = mask(G3), G4bb = mask(G4),
+ *     G5bb = mask(G5), G6bb = mask(G6), G7bb = mask(G7), G8bb = mask(G8),
+ *     H1bb = mask(H1), H2bb = mask(H2), H3bb = mask(H3), H4bb = mask(H4),
+ *     H5bb = mask(H5), H6bb = mask(H6), H7bb = mask(H7), H8bb = mask(H8),
+ * };
+ *
+ * enum {
+ *     FILE_Abb = 0x0101010101010101ull, FILE_Bbb = 0x0202020202020202ull,
+ *     FILE_Cbb = 0x0404040404040404ull, FILE_Dbb = 0x0808080808080808ull,
+ *     FILE_Ebb = 0x1010101010101010ull, FILE_Fbb = 0x2020202020202020ull,
+ *     FILE_Gbb = 0x4040404040404040ull, FILE_Hbb = 0x8080808080808080ull,
+ *
+ *     RANK_1bb = 0x00000000000000ffull, RANK_2bb = 0x000000000000ff00ull,
+ *     RANK_3bb = 0x0000000000ff0000ull, RANK_4bb = 0x00000000ff000000ull,
+ *     RANK_5bb = 0x000000ff00000000ull, RANK_6bb = 0x0000ff0000000000ull,
+ *     RANK_7bb = 0x00ff000000000000ull, RANK_8bb = 0xff00000000000000ull
+ * };
+ */
 
-    A6 = 1UL << 40, B6 = 1UL << 41, C6 = 1UL << 42, D6 = 1UL << 43,
-    E6 = 1UL << 44, F6 = 1UL << 45, G6 = 1UL << 46, H6 = 1UL << 47,
+/* generated with bash:
+ * R="ABCDEFGH"
+ * F="12345678"
+ * for i in {0..63}; do
+ *   printf "#define  %c%cbb %#018llxull\n" ${R:i/8:1} ${F:i%8:1} $((1 << i))
+ * done
+ */
+#define A1bb     0x0000000000000001ull
+#define A2bb     0x0000000000000002ull
+#define A3bb     0x0000000000000004ull
+#define A4bb     0x0000000000000008ull
+#define A5bb     0x0000000000000010ull
+#define A6bb     0x0000000000000020ull
+#define A7bb     0x0000000000000040ull
+#define A8bb     0x0000000000000080ull
+#define B1bb     0x0000000000000100ull
+#define B2bb     0x0000000000000200ull
+#define B3bb     0x0000000000000400ull
+#define B4bb     0x0000000000000800ull
+#define B5bb     0x0000000000001000ull
+#define B6bb     0x0000000000002000ull
+#define B7bb     0x0000000000004000ull
+#define B8bb     0x0000000000008000ull
+#define C1bb     0x0000000000010000ull
+#define C2bb     0x0000000000020000ull
+#define C3bb     0x0000000000040000ull
+#define C4bb     0x0000000000080000ull
+#define C5bb     0x0000000000100000ull
+#define C6bb     0x0000000000200000ull
+#define C7bb     0x0000000000400000ull
+#define C8bb     0x0000000000800000ull
+#define D1bb     0x0000000001000000ull
+#define D2bb     0x0000000002000000ull
+#define D3bb     0x0000000004000000ull
+#define D4bb     0x0000000008000000ull
+#define D5bb     0x0000000010000000ull
+#define D6bb     0x0000000020000000ull
+#define D7bb     0x0000000040000000ull
+#define D8bb     0x0000000080000000ull
+#define E1bb     0x0000000100000000ull
+#define E2bb     0x0000000200000000ull
+#define E3bb     0x0000000400000000ull
+#define E4bb     0x0000000800000000ull
+#define E5bb     0x0000001000000000ull
+#define E6bb     0x0000002000000000ull
+#define E7bb     0x0000004000000000ull
+#define E8bb     0x0000008000000000ull
+#define F1bb     0x0000010000000000ull
+#define F2bb     0x0000020000000000ull
+#define F3bb     0x0000040000000000ull
+#define F4bb     0x0000080000000000ull
+#define F5bb     0x0000100000000000ull
+#define F6bb     0x0000200000000000ull
+#define F7bb     0x0000400000000000ull
+#define F8bb     0x0000800000000000ull
+#define G1bb     0x0001000000000000ull
+#define G2bb     0x0002000000000000ull
+#define G3bb     0x0004000000000000ull
+#define G4bb     0x0008000000000000ull
+#define G5bb     0x0010000000000000ull
+#define G6bb     0x0020000000000000ull
+#define G7bb     0x0040000000000000ull
+#define G8bb     0x0080000000000000ull
+#define H1bb     0x0100000000000000ull
+#define H2bb     0x0200000000000000ull
+#define H3bb     0x0400000000000000ull
+#define H4bb     0x0800000000000000ull
+#define H5bb     0x1000000000000000ull
+#define H6bb     0x2000000000000000ull
+#define H7bb     0x4000000000000000ull
+#define H8bb     0x8000000000000000ull
 
-    A7 = 1UL << 48, B7 = 1UL << 49, C7 = 1UL << 50, D7 = 1UL << 51,
-    E7 = 1UL << 52, F7 = 1UL << 53, G7 = 1UL << 54, H7 = 1UL << 55,
+#define FILE_Abb 0x0101010101010101ull
+#define FILE_Bbb 0x0202020202020202ull
+#define FILE_Cbb 0x0404040404040404ull
+#define FILE_Dbb 0x0808080808080808ull
+#define FILE_Ebb 0x1010101010101010ull
+#define FILE_Fbb 0x2020202020202020ull
+#define FILE_Gbb 0x4040404040404040ull
+#define FILE_Hbb 0x8080808080808080ull
 
-    A8 = 1UL << 56, B8 = 1UL << 57, C8 = 1UL << 58, D8 = 1UL << 59,
-    E8 = 1UL << 60, F8 = 1UL << 61, G8 = 1UL << 62, H8 = 1UL << 63,
-};
+#define RANK_1bb 0x00000000000000ffull
+#define RANK_2bb 0x000000000000ff00ull
+#define RANK_3bb 0x0000000000ff0000ull
+#define RANK_4bb 0x00000000ff000000ull
+#define RANK_5bb 0x000000ff00000000ull
+#define RANK_6bb 0x0000ff0000000000ull
+#define RANK_7bb 0x00ff000000000000ull
+#define RANK_8bb 0xff00000000000000ull
 
-enum bb_files {
-    F_1 = A1 | A2 | A3 | A4 | A5 | A6 | A7 | A8,
-    F_2 = B1 | B2 | B3 | B4 | B5 | B6 | B7 | B8,
-    F_3 = C1 | C2 | C3 | C4 | C5 | C6 | C7 | C8,
-    F_4 = D1 | D2 | D3 | D4 | D5 | D6 | D7 | D8,
-    F_5 = E1 | E2 | E3 | E4 | E5 | E6 | E7 | E8,
-    F_6 = F1 | F2 | F3 | F4 | F5 | F6 | F7 | F8,
-    F_7 = G1 | G2 | G3 | G4 | G5 | G6 | G7 | G8,
-    F_8 = H1 | H2 | H3 | H4 | H5 | H6 | H7 | H8,
-};
 
-enum bb_ranges {
-    R_1 = A1 | B1 | C1 | D1 | E1 | F1 | G1 | H1,
-    R_2 = A2 | B2 | C2 | D2 | E2 | F2 | G2 | H2,
-    R_3 = A3 | B3 | C3 | D3 | E3 | F3 | G3 | H3,
-    R_4 = A4 | B4 | C4 | D4 | E4 | F4 | G4 | H4,
-    R_5 = A5 | B5 | C5 | D5 | E5 | F5 | G5 | H5,
-    R_6 = A6 | B6 | C6 | D6 | E6 | F6 | G6 | H6,
-    R_7 = A7 | B7 | C7 | D7 | E7 | F7 | G7 | H7,
-    R_8 = A8 | B8 | C8 | D8 | E8 | F8 | G8 | H8,
-};
+/*
+static __always_inline bitboard_t bb_rank(int rank)
+{
+    return RANK_1bb << (rank * 8);
+}
+static __always_inline bitboard_t bb_rel_rank(int rank, color)
+{
+    return RANK_1bb << (rank * 8);
+}
+static __always_inline bitboard_t bb_file(int file)
+{
+    return FILE_Abb << file;
+}
+*/
 
-#endif  /* BOARD_H */
+/**
+ * bb_first_bb() - return bitboard of first square of a bitboard.
+ * @bb: bitboard
+ *
+ * bb must be non-zero.
+ *
+ * @return: bitboard of first square (lsb) of @bb.
+ */
+static __always_inline square_t bb_first_bb(bitboard_t bb)
+{
+    return bb & -bb;
+}
+
+/**
+ * bb_next() - clear and return next (lsb) square of a bitboard.
+ * @bb: &bitboard
+ *
+ * The bitboard addressed by @bb must be non-zero.
+ *
+ * @return: first bit (lsb) of @bb.
+ */
+static __always_inline square_t bb_next(bitboard_t *bb)
+{
+    square_t sq = ctz64(*bb);
+    *bb &= *bb - 1;
+    return sq;
+}
+
+/**
+ * bb_multiple() - test if a bitboard has multiple bits.
+ * @bb: bitboard
+ *
+ * @return: true if @bb has more than 1 bit, false otherwise.
+ */
+static __always_inline bool bb_multiple(bitboard_t bb)
+{
+    return !!(bb & (bb - 1));
+}
+
+/**
+ * bb_shift() - shift bitboard
+ * @bb: bitboard
+ *
+ * No control is done on off-board shifting (i.e. shifting -1 from A2 gives H3).
+ *
+ * @return: true if @bb has more than 1 bit, false otherwise.
+ */
+static __always_inline bitboard_t bb_shift(bitboard_t bb, int shift)
+{
+   return shift >= 0 ? bb << shift : bb >> -shift;
+}
+
+/**
+ * bb_pawns_attacks() - shift up pawns on both diagonals (attacks)
+ * @bb:      pawns bitboard
+ * @push:    shift value for pawn up
+ *
+ * Get the possible attacks for all @bb pawns.
+ *
+ * @return: squares attacked by @bbpawns
+ */
+static __always_inline bitboard_t bb_pawns_attacks(const bitboard_t bb, int push)
+{
+    return bb_shift(bb & ~FILE_Abb, push - 1) | bb_shift(bb & ~FILE_Hbb, push + 1);
+}
+
+#define bb_rank(r)        ((u64) RANK_1bb << ((r) * 8))
+#define bb_file(f)        ((u64) FILE_Abb << (f))
+
+#define bb_rel_rank(r, c) bb_rank(sq_rel_rank(r, c))
+#define bb_rel_file(f, c) bb_file(sq_rel_rank(f, c)) /* likely useless */
+
+/**
+ * bb_sq_aligned() - check if two squares are aligned (same file or rank).
+ * @sq1, @sq2:  the two squares.
+ *
+ * @return: true if @sq1 and @sq2 are on same line, false otherwise.
+ */
+static __always_inline bool bb_sq_aligned(square_t sq1, square_t sq2)
+{
+    return bb_line[sq1][sq2];
+}
+
+/**
+ * bb_sq_aligned3() - check if 3 squares are aligned (same file or rank).
+ * @sq1, @sq2, @sq3:  the three squares.
+ *
+ * @return: true if @sq1, @sq2, and @sq3 are aligned, false otherwise.
+ */
+static __always_inline bool bb_sq_aligned3(square_t sq1, square_t sq2, square_t sq3)
+{
+    return bb_line[sq1][sq2] & BIT(sq3);
+}
+
+/**
+ * bb_sq_between() - check if a square is between two squares
+ * @sq:  the possibly "in-between" square
+ * @sq1: square 1
+ * @sq2: square 2
+ *
+ * @return: bitboard of @sq if between @sq1 and @sq2.
+ */
+static __always_inline bitboard_t bb_sq_between(square_t sq, square_t sq1, square_t sq2)
+{
+    return bb_between_excl[sq1][sq2] & BIT(sq);
+}
+
+bitboard_t bitboard_between_excl(square_t sq1, square_t sq2);
+void bitboard_init(void);
+
+bitboard_t bb_knight_moves(bitboard_t notmine, square_t sq);
+bitboard_t bb_king_moves(bitboard_t notmine, square_t sq);
+
+void bb_print(const char *title, const bitboard_t bitboard);
+void bb_print_multi(const char *title, const int n, ...);
+char *bb_rank_sprint(char *str, const uchar bb8);
+char *bb_sq2str(const bitboard_t bb, char *str, int len);
+
+#endif  /* _BITBOARD_H */

src/board.c

@@ -0,0 +1,129 @@
+/* board.c - 8x8 functions.
+ *
+ * Copyright (C) 2024 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#include <stdio.h>
+#include <ctype.h>
+
+#include <brlib.h>
+
+#include "board.h"
+#include "bitboard.h"
+
+static const char *sq_strings[] = {
+    "a1", "b1", "c1", "d1", "e1", "f1", "g1", "h1",
+    "a2", "b2", "c2", "d2", "e2", "f2", "g2", "h2",
+    "a3", "b3", "c3", "d3", "e3", "f3", "g3", "h3",
+    "a4", "b4", "c4", "d4", "e4", "f4", "g4", "h4",
+    "a5", "b5", "c5", "d5", "e5", "f5", "g5", "h5",
+    "a6", "b6", "c6", "d6", "e6", "f6", "g6", "h6",
+    "a7", "b7", "c7", "d7", "e7", "f7", "g7", "h7",
+    "a8", "b8", "c8", "d8", "e8", "f8", "g8", "h8",
+};
+
+/**
+ * sq_to_string() - return a square string
+ * @square: square (0-64)
+ *
+ * @Return: Pointer to @square string representation ("a1"-"h8").
+ */
+const char *sq_to_string(const square_t square)
+{
+    return sq_strings[square];
+}
+
+/**
+ * sq_from_string() - return a square from a string
+ * @sqstr: the square representation (a1-h8)
+ *
+ * @Return: square_t representation of str.
+ */
+square_t sq_from_string(const char *sqstr)
+{
+    file_t f = C2FILE(sqstr[0]);
+    rank_t r = C2RANK(sqstr[1]);
+    return sq_coord_ok(f) && sq_coord_ok(r) ? sq_make(f, r): SQUARE_NONE;
+}
+
+/**
+ * board_print() - Print a board
+ * @board:  &board_t to print
+ */
+void board_print(const piece_t *board)
+{
+    printf("  +---+---+---+---+---+---+---+---+\n");
+    for (int rank = 7; rank >= 0; --rank) {
+        printf("%c |", rank + '1');
+        for (int file = 0; file < 8; ++file) {
+            piece_t pc = board[sq_make(file, rank)];
+#           ifdef DIAGRAM_SYM
+            printf(" %s |", pc? piece_to_sym(pc): " ");
+#           else
+            printf(" %s |", pc? piece_to_fen(pc): " ");
+#           endif
+        }
+        printf("\n  +---+---+---+---+---+---+---+---+\n");
+    }
+    printf("    A   B   C   D   E   F   G   H\n");
+}
+
+/**
+ * board_print_mask() - Print a board position with some reversed squares
+ * @board:  &board_t to print
+ * @mask:   a bitboard indicating reverse color displayed squares
+ *
+ * Squares corresponding to @mask will be displayed in reverse colors.
+ */
+void board_print_mask(const piece_t *board, const bitboard_t mask)
+{
+    // 6: blink
+#   define REVERSE "\e[7m▌"
+#   define RESET   "▐\e[0m"
+    printf("  +---+---+---+---+---+---+---+---+\n");
+    for (int rank = 7; rank >= 0; --rank) {
+        printf("%c |", rank + '1');
+        for (int file = 0; file < 8; ++file) {
+            square_t sq = sq_make(file, rank);
+            piece_t pc = board[sq];
+            bitboard_t set = BIT(sq) & mask;
+            printf("%s", set? REVERSE : " ");
+#           ifdef DIAGRAM_SYM
+            printf("%s", pc? piece_to_sym(pc): " ");
+#           else
+            printf("%s", pc? piece_to_char_color(pc): " ");
+#           endif
+            printf("%s|", set? RESET : " ");
+        }
+        printf("\n  +---+---+---+---+---+---+---+---+\n");
+    }
+    printf("    A   B   C   D   E   F   G   H\n");
+}
+
+/**
+ * board_print_raw - print raw (octal or FEN symbol) board
+ * @bb: the bitboard
+ * @type: int, 0 for octal, 1 for fen symbol
+ */
+void board_print_raw(const piece_t *board, const int type)
+{
+    for (rank_t r = RANK_8; r >= RANK_1; --r) {
+        for (file_t f = FILE_A; f <= FILE_H; ++f) {
+            piece_t p = board[sq_make(f, r)];
+            if (type) {
+                printf("%s ", p == EMPTY? ".": piece_to_char(p));
+            } else {
+                printf("%02o ", p);
+            }
+        }
+        printf("\n");
+    }
+}

src/board.h

@@ -1,6 +1,6 @@
-/* board.h - board definitions.
+/* board.h - 8x8 board definitions.
  *
- * Copyright (C) 2021 Bruno Raoult ("br")
+ * Copyright (C) 2021-2024 Bruno Raoult ("br")
  * Licensed under the GNU General Public License v3.0 or later.
  * Some rights reserved. See COPYING.
  *
@@ -11,70 +11,83 @@
  *
  */
 
-#ifndef BOARD_H
-#define BOARD_H
+#ifndef _BOARD_H
+#define _BOARD_H
+
+#include <brlib.h>
 
-#include <stdint.h>
 #include "chessdefs.h"
 #include "piece.h"
+#include "bitboard.h"
 
-typedef struct board_s {
-    piece_t piece;
-    piece_list_t *s_piece;
-    //struct list_head *s_piece;
-} board_t;                                        /* 0x88 board */
-#define BOARDSIZE    (8*8*2)
+/* from human to machine */
+#define C2FILE(c)          (tolower(c) - 'a')
+#define C2RANK(c)          (tolower(c) - '1')
+/* from machine to human */
+#define FILE2C(f)          ((f) + 'a')
+#define RANK2C(r)          ((r) + '1')
 
-/* definitions for 0x88 representation
+/* a square is defined as
+ * rrrfff
  */
-#define SQ88(f, r)  (((r) << 4) | (f))            /* from rank,file to sq88 */
-#define F88(s)      ((s) & 0x0f)                  /* from sq88 to file */
-#define R88(s)      ((s) >> 4)                    /* from sq88 to rank */
+#define SQ_FILEMASK (007)                         /* warning, octal */
+#define SQ_RANKMASK (070)
 
-#define SETF88(s, r) ((s) &= 0xf0, (s) |= (r))
-#define SETR88(s, f) ((s) &= 0x0f, (s) |= (f)<<4)
 
-#define SQ88_NOK(s)  ((s) & 0x88)                 /* invalid square */
-#define SQ88_OK(s)   (!SQ88_NOK(s))
-
-/* definitions for bitboard representation
+/* flip a 0-63 square:
+ * Vertical:   G8 (62) becomes G1 (6)
+ * Horizontal: G8 (62) becomes B8 (57)
  */
-#define BB(f, r)     (1ULL << (8 * (r) + (f)))    /* from rank,file to bitboard */
-#define SQ88_2_BB(s) (BB(F88(s), R88(s)))         /* from sq88 to bitboard */
-#define FILEBB(b)    ((b) % 8)                    /* from sq88 to file */
-#define RANKBB(b)    ((b) / 8)                    /* from sq88 to rank */
+#define FLIP_V(sq)      ((sq) ^ 56)
+#define FLIP_H(sq)      ((sq) ^ 7)
+#define FLIP_HV(sq)     ((sq) ^ 63)               /* FLIP_V ^ FLIP_H */
 
-#define SQ88_NOK(s)  ((s) & 0x88)                 /* invalid square */
-#define SQ88_OK(s)   (!SQ88_NOK(s))
+/* TODO: revert to macros after bitboard migration */
+static __always_inline square_t sq_make(file_t file, rank_t rank)
+{
+    return (rank << 3) + file;
+}
+static __always_inline file_t sq_file(square_t square)
+{
+    return square & SQ_FILEMASK;
+}
+static __always_inline rank_t sq_rank(square_t square)
+{
+    return square >> 3;
+}
 
-/* piece human notation
+#define sq_ok(sq)       ((sq) >= A1 && (sq) <= H8)
+#define sq_coord_ok(c)  ((c) >= 0 && (c) < 8)
+
+/**
+ * sq_dist() - Chebyshev (king) distance between two squares (macro).
+ * @sq1, @sq2: The two squares.
+ *
+ * See: https://www.chessprogramming.org/Distance
+ * Distance is max( |r2 - r1|, |f2 - f1| )
+ *
+ * @Return: the Chebyshev distance.
  */
-#define CHAR_EMPTY   ' '
-#define CHAR_PAWN    'P'
-#define CHAR_KNIGHT  'N'
-#define CHAR_BISHOP  'B'
-#define CHAR_ROOK    'R'
-#define CHAR_QUEEN   'Q'
-#define CHAR_KING    'K'
+#define sq_dist(sq1, sq2) (max(abs(sq_file(sq2) - sq_file(sq1)),  \
+                               abs(sq_rank(sq2) - sq_rank(sq1))))
 
-/* from human to machine
+/**
+ * sq_taxi() - Manhattan (taxi) distance between two squares (macro).
+ * @sq1, @sq2: The two squares.
+ *
+ * See: https://www.chessprogramming.org/Distance
+ * Distance is |r2 - r1| + |f2 - f1|.
+ *
+ * @Return: the Manhattan distance.
  */
-#define C2FILE(c)    (tolower(c) - 'a')
-#define C2RANK(c)    (tolower(c) - '1')
-/* from machine to human
- */
-#define FILE2C(f)    ((f) + 'a')
-#define RANK2C(r)    ((r) + '1')
+#define sq_taxi(sq1, sq2) (abs(sq_file(sq2) - sq_file(sq1)) +     \
+                           abs(sq_rank(sq2) - sq_rank(sq1)))
 
-enum x88_square {
-    x88_A1=0x00, x88_B1, x88_C1, x88_D1, x88_E1, x88_F1, x88_G1, x88_H1,
-    x88_A2=0x10, x88_B2, x88_C2, x88_D2, x88_E2, x88_F2, x88_G2, x88_H2,
-    x88_A3=0x20, x88_B3, x88_C3, x88_D3, x88_E3, x88_F3, x88_G3, x88_H3,
-    x88_A4=0x30, x88_B4, x88_C4, x88_D4, x88_E4, x88_F4, x88_G4, x88_H4,
-    x88_A5=0x40, x88_B5, x88_C5, x88_D5, x88_E5, x88_F5, x88_G5, x88_H5,
-    x88_A6=0x50, x88_B6, x88_C6, x88_D6, x88_E6, x88_F6, x88_G6, x88_H6,
-    x88_A7=0x60, x88_B7, x88_C7, x88_D7, x88_E7, x88_F7, x88_G7, x88_H7,
-    x88_A8=0x70, x88_B8, x88_C8, x88_D8, x88_E8, x88_F8, x88_G8, x88_H8,
-};
+extern const char *sq_to_string(const square_t sq);
+extern square_t sq_from_string(const char *sq_string);
 
-#endif  /* BOARD_H */
+extern void board_print(const piece_t *board);
+extern void board_print_mask(const piece_t *board, const bitboard_t mask);
+extern void board_print_raw(const piece_t *board, const int type);
+
+#endif  /* _BOARD_H */

src/brchess.c

@@ -1,6 +1,6 @@
 /* brchess.c - main loop.
  *
- * Copyright (C) 2021-2023 Bruno Raoult ("br")
+ * Copyright (C) 2021-2024 Bruno Raoult ("br")
  * Licensed under the GNU General Public License v3.0 or later.
  * Some rights reserved. See COPYING.
  *
@@ -12,25 +12,23 @@
  */
 
 
-#include <err.h>
+#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <readline/readline.h>
-#include <readline/history.h>
+#include <ctype.h>
+#include <unistd.h>
 
-#include <br.h>
-#include <list.h>
-#include <debug.h>
+#include <brlib.h>
 
-#include "brchess.h"
 #include "chessdefs.h"
-#include "board.h"
-#include "piece.h"
-#include "move.h"
+#include "position.h"
+#include "brchess.h"
+#include "hash.h"
 #include "fen.h"
-#include "eval.h"
-#include "eval-simple.h"
 #include "search.h"
+#include "hist.h"
+#include "move-gen.h"
+#include "move-do.h"
 
 struct command {
     char *name;                                   /* User printable name */
@@ -38,289 +36,159 @@ struct command {
     char *doc;                                    /* function doc */
 };
 
-/* readline example inspired by :
- * - https://thoughtbot.com/blog/tab-completion-in-gnu-readline
- * - http://web.mit.edu/gnu/doc/html/rlman_2.html
- */
-char **commands_completion(const char *, int, int);
-char *commands_generator(const char *, int);
-char *escape(const char *);
-int quote_detector(char *, int);
-int execute_line (pos_t *, char *line);
+int execute_line (pos_t *, struct command *, char *);
 struct command *find_command (char *);
-char *stripwhite (char *string);
+int string_trim (char *str);
 
 /* The names of functions that actually do the manipulation. */
-int do_help(pos_t *, char*);
-int do_fen(pos_t *, char*);
-int do_init(pos_t *, char*);
-int do_pos(pos_t *, char*);
-int do_genmoves(pos_t *, char*);
-int do_prmoves(pos_t *, char*);
-//int do_prmovepos(pos_t *pos, char *arg);
-int do_prpieces(pos_t *pos, char *arg);
-int do_memstats(pos_t *, char*);
-int do_eval(pos_t *, char*);
-int do_simple_eval(pos_t *, char*);
-int do_move(pos_t *, char*);
-int do_quit(pos_t *, char*);
-int do_debug(pos_t *, char*);
-int do_depth(pos_t *, char*);
-int do_search(pos_t *, char*);
-int do_pvs(pos_t *, char*);
+int do_ucinewgame(pos_t *, char *);
+int do_uci(pos_t *, char *);
+int do_isready(pos_t *, char *);
+
+int do_position(pos_t *, char *);
+int do_moves(pos_t *, char *);
+int do_diagram(pos_t *, char *);
+int do_perft(pos_t *, char *);
+
+int do_hist(pos_t *, char *);
+int do_help(pos_t *, char *);
+int do_quit(pos_t *, char *);
 
 struct command commands[] = {
-    { "help", do_help, "Display this text" },
-    { "?", do_help, "Synonym for 'help'" },
-    { "fen", do_fen, "Set position to FEN" },
-    { "init", do_init, "Set position to normal start position" },
-    { "pos", do_pos, "Print current position" },
-    { "quit", do_quit, "Quit" },
-    { "genmove", do_genmoves, "Generate move list for " },
-    { "prmoves", do_prmoves, "Print position move list" },
-//    { "prmovepos", do_prmovepos, "Print Nth move resulting position" },
-    { "prpieces", do_prpieces, "Print Pieces (from pieces lists)" },
-    { "memstats", do_memstats, "Generate next move list" },
-    { "eval", do_eval, "Eval current position" },
-    { "simple-eval", do_simple_eval, "Simple eval current position" },
-    { "do_move", do_move, "execute nth move on current position" },
-    { "debug", do_debug, "Set log level to LEVEL" },
-    { "depth", do_depth, "Set search depth to N" },
-    { "search", do_search, "Search best move (negamax)" },
-    { "pvs", do_pvs, "Search best move (Principal Variation Search)" },
+    { "help",       do_help, "(not UCI) This help" },
+    { "?",          do_help, "(not UCI) This help" },
+    { "quit",       do_quit, "Quit" },
+
+    { "uci",        do_uci, "" },
+    { "ucinewgame", do_ucinewgame, "" },
+    { "isready",    do_isready, "" },
+
+    { "position",   do_position, "position startpos|fen [moves ...]" },
+
+    { "perft",      do_perft, "(not UCI) perft [divide] [alt] depth" },
+    { "moves",      do_moves, "(not UCI) moves ..." },
+    { "diagram",    do_diagram, "(not UCI) print current position diagram" },
+    { "hist",       do_hist, "(not UCI) print history states" },
+
+ /*
+ *     { "init", do_init, "Set position to normal start position" },
+
+ *     { "genmove", do_genmoves, "Generate move list for " },
+ *     { "prmoves", do_prmoves, "Print position move list" },
+ * //    { "prmovepos", do_prmovepos, "Print Nth move resulting position" },
+ *     { "prpieces", do_prpieces, "Print Pieces (from pieces lists)" },
+ *     { "memstats", do_memstats, "Generate next move list" },
+ *     { "eval", do_eval, "Eval current position" },
+ *     { "simple-eval", do_simple_eval, "Simple eval current position" },
+ *     { "do_move", do_move, "execute nth move on current position" },
+ *     { "debug", do_debug, "Set log level to LEVEL" },
+ *     { "depth", do_depth, "Set search depth to N" },
+ *     { "search", do_search, "Search best move (negamax)" },
+ *     { "pvs", do_pvs, "Search best move (Principal Variation Search)" },
+ */
     { NULL, (int(*)()) NULL, NULL }
 };
 
-static int done=0;
-static int depth=1;
+static int done = 0;
 
 int brchess(pos_t *pos)
 {
-    char *buffer, *s;
+    char *str = NULL, *saveptr, *token, *args;
+    int len;
+    size_t lenstr = 0;
+    struct command *command;
 
-    rl_attempted_completion_function = commands_completion;
-    rl_completer_quote_characters = "'\"";
-    rl_completer_word_break_characters = " ";
-    rl_char_is_quoted_p = &quote_detector;
-
-    while (!done) {
-        buffer = readline("chess> ");
-        if (!buffer)
-            break;
-        /* Remove leading and trailing whitespace from the line.
-         * Then, if there is anything left, add it to the history list
-         * and execute it.
-         */
-        s = stripwhite(buffer);
-
-        if (*s) {
-            add_history(s);
-            execute_line(pos, s);
+    while (!done && getline(&str, &lenstr, stdin) >= 0) {
+        if (!(len = string_trim(str)))
+            continue;
+        token = strtok_r(str, " ", &saveptr);
+        if (! (command= find_command(token))) {
+            fprintf(stderr, "Unknown [%s] command. Try 'help'.\n", token);
+            continue;
         }
-        free(buffer);
+        args = strtok_r(NULL, "", &saveptr);
+        execute_line(pos, command, args);
     }
 
+    if (str)
+        free(str);
+
     return 0;
 }
 
-//char **commands_completion(const char *text, int start, int end)
-char **commands_completion(const char *text, __unused int start, __unused int end)
-{
-    rl_attempted_completion_over = 1;
-    return rl_completion_matches(text, commands_generator);
-}
-
-char *commands_generator(const char *text, int state)
-{
-    static int list_index, len;
-    char *name;
-
-    if (!state) {
-        list_index = 0;
-        len = strlen(text);
-    }
-
-    while ((name = commands[list_index++].name)) {
-        if (rl_completion_quote_character) {
-            name = strdup(name);
-        } else {
-            name = escape(name);
-        }
-
-        if (strncmp(name, text, len) == 0) {
-            return name;
-        } else {
-            free(name);
-        }
-    }
-
-    return NULL;
-}
-
-char *escape(const char *original)
-{
-    size_t original_len;
-    size_t i, j;
-    char *escaped, *resized_escaped;
-
-    original_len = strlen(original);
-
-    if (original_len > SIZE_MAX / 2) {
-        errx(1, "string too long to escape");
-    }
-
-    if ((escaped = malloc(2 * original_len + 1)) == NULL) {
-        err(1, NULL);
-    }
-
-    for (i = 0, j = 0; i < original_len; ++i, ++j) {
-        if (original[i] == ' ') {
-            escaped[j++] = '\\';
-        }
-        escaped[j] = original[i];
-    }
-    escaped[j] = '\0';
-
-    if ((resized_escaped = realloc(escaped, j)) == NULL) {
-        free(escaped);
-        resized_escaped = NULL;
-        err(1, NULL);
-    }
-
-    return resized_escaped;
-}
-
-int quote_detector(char *line, int index)
-{
-    return index > 0
-            && line[index - 1] == '\\'
-            &&!quote_detector(line, index - 1);
-}
-
 /* Execute a command line. */
-int execute_line(pos_t *pos, char *line)
+int execute_line(pos_t *pos, struct command *command, char *args)
 {
-    register int i;
-    struct command *command;
-    char *word;
-
-    /* Isolate the command word. */
-    i = 0;
-    while (line[i] && whitespace(line[i]))
-        i++;
-    word = line + i;
-
-    while (line[i] && !whitespace(line[i]))
-        i++;
-
-    if (line[i])
-        line[i++] = '\0';
-
-    command = find_command(word);
-
-    if (!command) {
-        fprintf(stderr, "%s: Unknown command.\n", word);
-        return -1;
-    }
-
-    /* Get argument to command, if any. */
-    while (whitespace(line[i]))
-        i++;
-
-    word = line + i;
-
-    /* return command number */
-    return (*command->func)(pos, word);
+    return (*command->func)(pos, args);
 }
 
-/* Look up NAME as the name of a command, and return a pointer to that
-   command.  Return a NULL pointer if NAME isn't a command name. */
+/**
+ * find_command - lookup UCI command.
+ * @name: &command string
+ *
+ * Look up NAME as the name of a command, and return a pointer to that
+ *   command.  Return a NULL pointer if NAME isn't a command name.
+ */
 struct command *find_command(char *name)
 {
     register int i;
 
     for (i = 0; commands[i].name; i++)
-        if (strcmp(name, commands[i].name) == 0)
-            return &commands[i];
+        if (!strcmp(name, commands[i].name))
+            return commands + i;
 
-    return (struct command *)NULL;
+    return NULL;
 }
 
-/* Strip whitespace from the start and end of STRING.  Return a pointer
-   into STRING. */
-char *stripwhite(char *string)
-{
-    register char *s, *t;
+/*
+ * int do_eval(__unused pos_t *pos, __unused char *arg)
+ * {
+ *     eval_t material[2], control[2], mobility[2];
+ *     for (int color = WHITE; color <= BLACK; ++color) {
+ *         material[color] = eval_material(pos, color);
+ *         control[color] = eval_square_control(pos, color);
+ *         mobility[color] = eval_mobility(pos, color);
+ *         printf("%s: material=%d mobility=%d controlled=%d\n",
+ *                color? "Black": "White", material[color],
+ *                mobility[color], control[color]);
+ *     }
+ *     eval_t res = eval(pos);
+ *     printf("eval = %d centipawns\n", res);
+ *     return 1;
+ * }
+ *
+ * int do_simple_eval(__unused pos_t *pos, __unused char *arg)
+ * {
+ *     eval_t eval = eval_simple(pos);
+ *     printf("eval = %d centipawns\n", eval);
+ *     return 1;
+ * }
+ */
 
-    for (s = string; whitespace(*s); s++)
-        ;
+/*
+ * int do_init(pos_t *pos, __unused char *arg)
+ * {
+ *     startpos(pos);
+ *     return 1;
+ * }
+ */
 
-    if (*s == 0)
-        return s;
-
-    t = s + strlen(s) - 1;
-    while (t > s && whitespace(*t))
-        t--;
-    *++t = '\0';
-
-    return s;
-}
-
-int do_eval(__unused pos_t *pos, __unused char *arg)
-{
-    eval_t material[2], control[2], mobility[2];
-    for (int color = WHITE; color <= BLACK; ++color) {
-        material[color] = eval_material(pos, color);
-        control[color] = eval_square_control(pos, color);
-        mobility[color] = eval_mobility(pos, color);
-        printf("%s: material=%d mobility=%d controlled=%d\n",
-               color? "Black": "White", material[color],
-               mobility[color], control[color]);
-    }
-    eval_t res = eval(pos);
-    printf("eval = %d centipawns\n", res);
-    return 1;
-}
-
-int do_simple_eval(__unused pos_t *pos, __unused char *arg)
-{
-    eval_t eval = eval_simple(pos);
-    printf("eval = %d centipawns\n", eval);
-    return 1;
-}
-
-int do_fen(pos_t *pos, char *arg)
-{
-    fen2pos(pos, arg);
-    return 1;
-}
-
-int do_init(pos_t *pos, __unused char *arg)
-{
-    pos_startpos(pos);
-    return 1;
-}
-
-int do_pos(pos_t *pos, __unused char *arg)
-{
-    pos_print(pos);
-    return 1;
-}
-
-int do_genmoves(pos_t *pos, __unused char *arg)
-{
-    moves_gen_all(pos);
-    return 1;
-}
-
-int do_prmoves(pos_t *pos, __unused char *arg)
-{
-    uint debug_level = debug_level_get();
-    debug_level_set(1);
-    moves_print(pos, M_PR_SEPARATE | M_PR_NUM | M_PR_LONG);
-    debug_level_set(debug_level);
-    return 1;
-}
+/*
+ * int do_genmoves(pos_t *pos, __unused char *arg)
+ * {
+ *     moves_gen_all(pos);
+ *     return 1;
+ * }
+ *
+ * int do_prmoves(pos_t *pos, __unused char *arg)
+ * {
+ *     uint debug_level = debug_level_get();
+ *     debug_level_set(1);
+ *     moves_print(pos, M_PR_SEPARATE | M_PR_NUM | M_PR_LONG);
+ *     debug_level_set(debug_level);
+ *     return 1;
+ * }
+ */
 
 /*
  * int do_prmovepos(pos_t *pos, char *arg)
@@ -342,43 +210,193 @@ int do_prmoves(pos_t *pos, __unused char *arg)
  * }
  */
 
-int do_prpieces(pos_t *pos, __unused char *arg)
+/*
+ * int do_prpieces(pos_t *pos, __unused char *arg)
+ * {
+ *     log_f(1, "%s\n", arg);
+ *     pos_pieces_print(pos);
+ *     return 1;
+ * }
+ *
+ * int do_memstats(__unused pos_t *pos,__unused char *arg)
+ * {
+ *     moves_pool_stats();
+ *     piece_pool_stats();
+ *     pos_pool_stats();
+ *     return 1;
+ * }
+ */
+
+/*
+ * int do_move(__unused pos_t *pos, __unused char *arg)
+ * {
+ *     int i = 1, nmove = atoi(arg);
+ *     move_t *move;
+ *     pos_t *newpos;
+ *
+ *     if (list_empty(&pos->moves[pos->turn])) {
+ *         log_f(1, "No moves list.\n");
+ *         return 0;
+ *     }
+ *     list_for_each_entry(move, &pos->moves[pos->turn], list) {
+ *         if (i == nmove)
+ *             goto doit;
+ *         i++;
+ *     }
+ *     log_f(1, "Invalid <%d> move, should be <1-%d>.\n", nmove, i);
+ *     return 0;
+ * doit:
+ *     newpos = move_do(pos, move);
+ *     pos_print(newpos);
+ *
+ *     return 1;
+ * }
+ */
+
+int do_ucinewgame(__unused pos_t *pos, __unused char *arg)
 {
-    log_f(1, "%s\n", arg);
-    pos_pieces_print(pos);
+    pos_clear(pos);
+    tt_clear();
     return 1;
 }
 
-int do_memstats(__unused pos_t *pos,__unused char *arg)
+int do_uci(__unused pos_t *pos, __unused char *arg)
 {
-    moves_pool_stats();
-    piece_pool_stats();
-    pos_pool_stats();
+    printf("id name brchess " VERSION "\n");
+    printf("id author Bruno Raoult\n");
+    printf("option option name Hash type spin default %d min %d max %d\n",
+           hash_tt.mb, HASH_SIZE_MIN, HASH_SIZE_MAX);
+    printf("uciok\n");
     return 1;
 }
 
-int do_move(__unused pos_t *pos, __unused char *arg)
+int do_isready(__unused pos_t *pos, __unused char *arg)
 {
-    int i = 1, nmove = atoi(arg);
-    move_t *move;
-    pos_t *newpos;
+    printf("readyok\n");
+    return 1;
+}
 
-    if (list_empty(&pos->moves[pos->turn])) {
-        log_f(1, "No moves list.\n");
-        return 0;
+int do_position(pos_t *pos, char *arg)
+{
+    char *saveptr, *token, *fen, *moves;
+
+    hist_init();
+
+    /* separate "moves" section */
+    if ((moves = strstr(arg, "moves"))) {
+        *(moves - 1) = 0;
     }
-    list_for_each_entry(move, &pos->moves[pos->turn], list) {
-        if (i == nmove)
-            goto doit;
-        i++;
+    saveptr = NULL;
+    token = strtok_r(arg, " ", &saveptr);
+    if (!strcmp(token, "startpos")) {
+        startpos(pos);
+        do_diagram(pos, "");
+    } else if (!strcmp(token, "fen")) {
+        fen = strtok_r(NULL, "", &saveptr);       /* full fen (till '\0') */
+        //printf("fen=%s\n", fen);
+        if (!fen)
+            return 1;
+        if (!fen2pos(pos, fen))
+            return 1;
+        //do_diagram(pos, "");
+    } else {
+        return 1;
     }
-    log_f(1, "Invalid <%d> move, should be <1-%d>.\n", nmove, i);
+    //puts("zob");
+    //move_t move_none = MOVE_NONE;
+    //hist_push(&pos->state, &move_none);
+
+    if (moves) {
+        //puts("zobi");
+        saveptr = NULL;
+        moves = strtok_r(moves, " ", &saveptr);   /* skip "moves" */
+        moves = strtok_r(NULL, "", &saveptr);     /* all moves (till '\0') */
+        //printf("moves = %s\n", moves);
+        do_moves(pos, moves);
+    }
+    /* link last position t history */
+    //hist_pop();
+    hist_link(pos);
+    return 1;
+}
+
+int do_moves(__unused pos_t *pos, char *arg)
+{
+    char *saveptr = NULL, *token, check[8];
+    move_t move;
+    state_t state;
+    movelist_t movelist;
+    saveptr = NULL;
+    token = strtok_r(arg, " ", &saveptr);
+    while (token) {
+        move = move_from_str(token);
+        move_to_str(check, move, 0);
+
+        printf("move: [%s] %s\n", token, check);
+        pos_set_checkers_pinners_blockers(pos);
+        pos_legal(pos, pos_gen_pseudo(pos, &movelist));
+        move = move_find_in_movelist(move, &movelist);
+        if (move == MOVE_NONE) {
+            /* should we reset here ? */
+            return 1;
+        }
+        //printf("move: %s\n", move_to_str(check, move, 0));
+        hist_push(&pos->state);                   /* push previous state */
+        move_do(pos, move, &state);
+        pos_print(pos);
+        hist_static_print();
+        token = strtok_r(NULL, " ", &saveptr);
+    }
+    //hist_static_print();
+    return 1;
+}
+
+int do_diagram(pos_t *pos, __unused char *arg)
+{
+    pos_print(pos);
+    return 1;
+}
+
+int do_perft(__unused pos_t *pos, __unused char *arg)
+{
+    char *saveptr, *token;
+    int divide = 0, depth = 6, alt = 0;
+
+    token = strtok_r(arg, " ", &saveptr);
+    if (!strcmp(token, "divide")) {
+        divide = 1;
+        token = strtok_r(NULL, " ", &saveptr);
+    }
+    if (!strcmp(token, "alt")) {
+        alt = 1;
+        token = strtok_r(NULL, " ", &saveptr);
+    }
+    depth = atoi(token);
+    printf("perft: divide=%d alt=%d depth=%d\n", divide, alt, depth);
+    if (depth > 0) {
+        if (!alt)
+            perft(pos, depth, 1, divide);
+        else
+            perft_alt(pos, depth, 1, divide);
+    }
+    return 1;
+}
+
+
+int do_hist(__unused pos_t *pos, __unused char *arg)
+{
+    hist_static_print();
     return 0;
-doit:
-    newpos = move_do(pos, move);
-    pos_print(newpos);
+}
 
-    return 1;
+int do_help(__unused pos_t *pos, __unused char *arg)
+{
+    for (struct command *cmd = commands; cmd->name; ++cmd) {
+        printf("%12s:\t%s\n", cmd->name, cmd->doc);
+        /* Print in six columns. */
+    }
+
+    return 0;
 }
 
 int do_quit(__unused pos_t *pos, __unused char *arg)
@@ -386,101 +404,108 @@ int do_quit(__unused pos_t *pos, __unused char *arg)
     return done = 1;
 }
 
-int do_debug(__unused pos_t *pos, __unused char *arg)
-{
-    debug_level_set(atoi(arg));
-    return 1;
-}
+/*
+ * int do_depth(__unused pos_t *pos, char *arg)
+ * {
+ *     depth = atoi(arg);
+ *     printf("depth = %d\n", depth);
+ *     return 1;
+ *
+ * }
+ *
+ * int do_search(pos_t *pos, __unused char *arg)
+ * {
+ *     int debug_level = debug_level_get();
+ *     float timer1, timer2, nodes_sec;
+ *
+ *     timer1 = debug_timer_elapsed();
+ *     negamax(pos, depth, pos->turn == WHITE ? 1 : -1);
+ *     timer2 = debug_timer_elapsed();
+ *     nodes_sec = (float) pos->node_count / ((float) (timer2 - timer1) / (float)NANOSEC);
+ *     log(1, "best=");
+ *     debug_level_set(1);
+ *     move_print(0, pos->bestmove, 0);
+ *     debug_level_set(debug_level);
+ *     log(1, " negamax=%d\n", pos->bestmove->negamax);
+ *     printf("Depth:%d Nodes:%luK time:%.02fs (%.0f kn/s)\n", depth,
+ *            pos->node_count / 1000, (timer2 - timer1)/NANOSEC, nodes_sec/1000);
+ *     return 1;
+ * }
+ */
 
-/* Print out help for ARG, or for all of the commands if ARG is
-   not present. */
-int do_help(__unused pos_t *pos, __unused char *arg)
-{
-    int i;
-    int printed = 0;
+/*
+ * int do_pvs(pos_t *pos, __unused char *arg)
+ * {
+ *     int debug_level = debug_level_get();
+ *     float timer1, timer2, nodes_sec;
+ *     eval_t _pvs;
+ *
+ *     timer1 = debug_timer_elapsed();
+ *     moves_gen_eval_sort(pos);
+ *     _pvs = pvs(pos, depth, EVAL_MIN, EVAL_MAX, pos->turn == WHITE ? 1 : -1);
+ *     timer2 = debug_timer_elapsed();
+ *     nodes_sec = (float) pos->node_count / ((float) (timer2 - timer1) / (float)NANOSEC);
+ *     log(1, "best=");
+ *     if (pos->bestmove) {
+ *         debug_level_set(1);
+ *         move_print(0, pos->bestmove, 0);
+ *         debug_level_set(debug_level);
+ *         log(1, " pvs=%d stored=%d\n", _pvs, pos->bestmove->negamax);
+ *     } else {
+ *         log(1, "<no-best-move>");
+ *     }
+ *     printf("Depth:%d Nodes:%luK time:%.02fs (%.0f kn/s)\n", depth,
+ *            pos->node_count / 1000, (timer2 - timer1)/NANOSEC, nodes_sec/1000);
+ *     return 1;
+ * }
+ */
 
-    for (i = 0; commands[i].name; i++) {
-        if (!*arg || (strcmp(arg, commands[i].name) == 0)) {
-            printf("%-11.11s%s.\n", commands[i].name, commands[i].doc);
-            printed++;
+/**
+ * string_trim - cleanup (trim) blank characters in string.
+ * @str: &string to clean
+ *
+ * str is cleaned and packed with the following rules:
+ * - Leading and trailing blank characters are removed.
+ * - consecutive blank characters are replaced by one space.
+ * - non printable characters are removed.
+ *
+ * "blank" means characters as understood by isspace(3): space, form-feed ('\f'),
+ * newline ('\n'), carriage return ('\r'), horizontal tab  ('\t'), and vertical
+ * tab ('\v').
+ *
+ * @return: new @str len.
+ */
+int string_trim(char *str)
+{
+    char *to = str, *from = str;
+    int state = 1;
+
+    while (*from) {
+        switch (state) {
+            case 1:                               /* blanks */
+                while (*from && isspace(*from))
+                    from++;
+                state = 0;
+                break;
+            case 0:                               /* token */
+                while (*from && !isspace(*from)) {
+                    if (isprint(*from))
+                        *to++ = *from;
+                    from++;
+                }
+                *to++ = ' ';
+                state = 1;
         }
     }
-
-    if (!printed) {
-        printf("No commands match `%s'.  Possibilties are:\n", arg);
-
-        for (i = 0; commands[i].name; i++) {
-            /* Print in six columns. */
-            if (printed == 6) {
-                printed = 0;
-                printf("\n");
-            }
-
-            printf("%s\t", commands[i].name);
-            printed++;
-        }
-
-        if (printed)
-            printf("\n");
-    }
-    return 0;
+    if (to > str)
+        to--;
+    *to = 0;
+    return to - str;
 }
 
-int do_depth(__unused pos_t *pos, char *arg)
-{
-    depth = atoi(arg);
-    printf("depth = %d\n", depth);
-    return 1;
 
-}
-
-int do_search(pos_t *pos, __unused char *arg)
-{
-    int debug_level = debug_level_get();
-    float timer1, timer2, nodes_sec;
-
-    timer1 = debug_timer_elapsed();
-    negamax(pos, depth, pos->turn == WHITE ? 1 : -1);
-    timer2 = debug_timer_elapsed();
-    nodes_sec = (float) pos->node_count / ((float) (timer2 - timer1) / (float)NANOSEC);
-    log(1, "best=");
-    debug_level_set(1);
-    move_print(0, pos->bestmove, 0);
-    debug_level_set(debug_level);
-    log(1, " negamax=%d\n", pos->bestmove->negamax);
-    printf("Depth:%d Nodes:%luK time:%.02fs (%.0f kn/s)\n", depth,
-           pos->node_count / 1000, (timer2 - timer1)/NANOSEC, nodes_sec/1000);
-    return 1;
-}
-
-int do_pvs(pos_t *pos, __unused char *arg)
-{
-    int debug_level = debug_level_get();
-    float timer1, timer2, nodes_sec;
-    eval_t _pvs;
-
-    timer1 = debug_timer_elapsed();
-    moves_gen_eval_sort(pos);
-    _pvs = pvs(pos, depth, EVAL_MIN, EVAL_MAX, pos->turn == WHITE ? 1 : -1);
-    timer2 = debug_timer_elapsed();
-    nodes_sec = (float) pos->node_count / ((float) (timer2 - timer1) / (float)NANOSEC);
-    log(1, "best=");
-    if (pos->bestmove) {
-        debug_level_set(1);
-        move_print(0, pos->bestmove, 0);
-        debug_level_set(debug_level);
-        log(1, " pvs=%d stored=%d\n", _pvs, pos->bestmove->negamax);
-    } else {
-        log(1, "<no-best-move>");
-    }
-    printf("Depth:%d Nodes:%luK time:%.02fs (%.0f kn/s)\n", depth,
-           pos->node_count / 1000, (timer2 - timer1)/NANOSEC, nodes_sec/1000);
-    return 1;
-}
-
-/** main()
- * options:
- int brchess(pos_t *pos)
+/**
+ * usage - brchess usage function.
  *
  */
 static int usage(char *prg)
@@ -489,24 +514,28 @@ static int usage(char *prg)
     return 1;
 }
 
-#include <unistd.h>
-
 int main(int ac, char **av)
 {
     pos_t *pos;
     int opt;
 
-    piece_pool_init();
-    moves_pool_init();
-    pos_pool_init();
-    pos = pos_get();
-    debug_init(1, stderr, true);
-    eval_simple_init();
+    init_all();
+    pos = pos_new();
+    hist_link(pos);
+    printf("\nWelcome to brchess " VERSION "\nEngine ready.\n");
 
+    // size_t len = 0;
+    // char *str = NULL;
+    //while (getline(&str, &len, stdin) >= 0) {
+    //    printf("[%s] -> ", str);
+    //    int newlen = string_trim(str);
+    //    printf("%d [%s]\n", newlen, str);
+    //}
+    //exit(0);
     while ((opt = getopt(ac, av, "d:f:")) != -1) {
         switch (opt) {
             case 'd':
-                debug_level_set(atoi(optarg));
+                //debug_level_set(atoi(optarg));
                 break;
             case 'f':
                 fen2pos(pos, optarg);

src/brchess.h

@@ -1,6 +1,6 @@
-/* bodichess.h - main loop.
+/* brchess.h - main loop.
  *
- * Copyright (C) 2021 Bruno Raoult ("br")
+ * Copyright (C) 2021-2024 Bruno Raoult ("br")
  * Licensed under the GNU General Public License v3.0 or later.
  * Some rights reserved. See COPYING.
  *

src/chessdefs.h

@@ -1,6 +1,6 @@
-/* chessdefs.h - generic chess definitions.
+/* chessdefs.h - generic/catchall chess definitions.
  *
- * Copyright (C) 2021 Bruno Raoult ("br")
+ * Copyright (C) 2021-2024 Bruno Raoult ("br")
  * Licensed under the GNU General Public License v3.0 or later.
  * Some rights reserved. See COPYING.
  *
@@ -11,98 +11,73 @@
  *
  */
 
-#ifndef CHESSDEFS_H
-#define CHESSDEFS_H
+#ifndef _CHESSDEFS_H
+#define _CHESSDEFS_H
 
-#include <bits.h>
+#include <brlib.h>                                /* brlib types */
 
-/* piece_t bits structure
- * MSB 8 7 6 5 4 3 2 1 LSB
- * 1: color (0 for white)
- * 2-7: bit set for pawn (2), knight, bishop, rook, queen, king (7)
+#define ONE                1ul
+#define U64(const_u64)     const_u64##UL
+#define BIT(i)             ( (u64) (ONE << (i)) )
+
+#define BOARDSIZE          (8*8)
+#define GAMESIZE           1024                   /* max game size (512 moves) */
+
+/**
+ * sq_rel - get relative square
+ * @sq: white point of view square
+ * @c:  color
+ *
+ * Get relative (mirrored if @c is BLACK) square.
+ * Example: sq_rel(A1, WHITE) = A1, sq_rel(B2, BLACK) = B7
+ *
+ * @return: Relative square.
  */
-typedef u8 piece_t;
+#define sq_rel(sq, c)      ((square_t)((sq) ^ (56 * (c))))
 
-enum {
-    E_EMPTY = 0,
-    E_COLOR,                                      /* LSB */
-    E_PAWN,
-    E_KNIGHT,
-    E_BISHOP,
-    E_ROOK,
-    E_QUEEN,
-    E_KING,
-};
-
-/* pos_t bitboards tables
+/**
+ * sq_rel_rank - get relative rank
+ * @rank: white point of view rank
+ * @c:  color
+ *
+ * Get relative (mirrored if @c is BLACK) rank.
+ * Example: sq_rel(RANK_2, WHITE) = RANK_2, sq_rel(RANK_6, BLACK) = RANK_3
+ *
+ * @return: Relative rank.
  */
-enum {
-    BB_ALL = 0,                                   /* OR of all bitboards */
-    BB_UNUSED,                                    /* future use ? */
-    BB_PAWN = E_PAWN,
-    BB_KNIGHT,
-    BB_BISHOP,
-    BB_ROOK,
-    BB_QUEEN,
-    BB_KING,
-    BB_END
-};
-
-/* piece bitmask in piece_t
- */
-enum {
-    EMPTY  = 0,
-    PAWN   = 1 << (E_PAWN - 1),                   /* 1<<(2-1) = 0x02 00000010 */
-    KNIGHT = 1 << (E_KNIGHT - 1),                 /* 0x04 00000100 */
-    BISHOP = 1 << (E_BISHOP - 1),                 /* 0x08 00001000 */
-    ROOK   = 1 << (E_ROOK - 1),                   /* 0x10 00010000 */
-    QUEEN  = 1 << (E_QUEEN - 1),                  /* 0x20 00100000 */
-    KING   = 1 << (E_KING - 1),                   /* 0x40 01000000 */
-};
-
-#define PIECETOBB(p)    (ffs64(PIECE(p)))         /* from piece_t to bb piece array */
-
-#define WHITE           0                         /* 0x00 00000000 */
-#define BLACK           1                         /* 0x01 00000001 */
-#define OPPONENT(p)     !(p)
-
-#define MASK_COLOR      0x01                      /* 00000001 */
-#define MASK_PIECE      0x7E                      /* 01111110 */
-
-#define COLOR(p)        ((p) & MASK_COLOR)        /* bitmask */
-#define PIECE(p)        ((p) & MASK_PIECE)
-#define E_PIECE(p)      (ffs64(PIECE(p)))         /* convert mask to E_XX */
-
-#define IS_WHITE(p)     (!COLOR(p))
-#define IS_BLACK(p)     (COLOR(p))
-
-#define SET_WHITE(p)    ((p) &= ~MASK_COLOR)
-#define SET_BLACK(p)    ((p) |= MASK_COLOR)
-#define SET_COLOR(p, c) (!(c)? SET_WHITE(p): SET_BLACK(p))
-
-/* flip a 0-63 square:
- * Vertical:   G8 (62) becomes G1 (6)
- * Horizontal: G8 (62) becomes B8 (57)
- */
-#define FLIP_V(sq)      ((sq) ^ 56)
-#define FLIP_H(sq)      ((sq) ^ 7)
-/* square_t bits structure : rrrrffff
- * ffff: file
- * rrrr: rank
- */
-typedef unsigned char square_t;
+#define sq_rel_rank(rank, c)  ((rank_t)((7 * (c)) ^ rank))
+#define sq_rel_file(file, c)  ((file_t)((7 * (c)) ^ file))
 
 /* castle_t bits structure
  */
-typedef unsigned char castle_t;
+typedef enum {
+    CASTLE_NONE = 0,
+    CASTLE_WK   = (1 << 0),                       /* 0001 */
+    CASTLE_WQ   = (1 << 1),                       /* 0010 */
+    CASTLE_BK   = (1 << 2),                       /* 0100 */
+    CASTLE_BQ   = (1 << 3),                       /* 1000 */
 
-#define CASTLE_WK       (1 << 0)                  /* 0x01 00000001 */
-#define CASTLE_WQ       (1 << 1)                  /* 0x02 00000010 */
-#define CASTLE_BK       (1 << 2)                  /* 0x04 00000100 */
-#define CASTLE_BQ       (1 << 3)                  /* 0x08 00001000 */
+    CASTLE_W    = (CASTLE_WK | CASTLE_WQ),        /* 0011 =  3 = W castle mask */
+    CASTLE_B    = (CASTLE_BK | CASTLE_BQ),        /* 1100 = 12 = B castle mask */
+    CASTLE_ALL  = (CASTLE_W | CASTLE_B),          /* 1111 = 15 */
 
-#define CASTLE_W        (CASTLE_WK | CASTLE_WQ)   /* 00000011 W castle mask */
-#define CASTLE_B        (CASTLE_BK | CASTLE_BQ)   /* 00001100 B castle mask */
+    CASTLE_K  = (1 << 0),                         /* generic K/Q, bits 0 and 1 */
+    CASTLE_Q  = (1 << 1),
+    CASTLE_KQ = (CASTLE_K |CASTLE_Q),
+} castle_rights_t;
+
+/* determine is oo or ooo is possible with castle flags f and color c
+ */
+//#define NORM_CASTLE(f, c)  ((f) >> (2 * (c)))      /* shift  flags to bits 0/1 */
+//#define
+//(NORM_CASTLE(f, c) & CASTLE_Q)
+#define can_oo(f, c)     ((f) & (CASTLE_K  << ((c) * 2)))
+#define can_ooo(f, c)    ((f) & (CASTLE_Q  << ((c) * 2)))
+#define can_castle(f, c) ((f) & (CASTLE_KQ << ((c) * 2)))
+
+#define clr_oo(f, c)     ((f) & ~(CASTLE_K  << (2 * (c))))
+#define clr_ooo(f, c)    ((f) & ~(CASTLE_Q  << (2 * (c))))
+#define clr_castle(f, c) ((f) & ~(CASTLE_KQ << (2 * (c)) ))
 
 /* game phases
  */
@@ -110,20 +85,103 @@ typedef unsigned char castle_t;
 #define MIDDLEGAME 1
 #define ENDGAME    2
 
-/* bitboard
+/* forward defs */
+typedef struct __pos_s pos_t;
+typedef struct __movelist_s movelist_t;
+
+/* basic types
  */
 typedef u64 bitboard_t;
 
-
 /* eval type
  */
-typedef s32 eval_t;
+//typedef s32 eval_t;
 
-/* forward typedefs
+/* forward enum definition is impossible in C11.
+ * To simplify cross-dependancies, all important enum are moved here.
  */
-typedef struct piece_list_s piece_list_t;
-typedef struct board_s board_t;
-typedef struct pos_s pos_t;
-typedef struct move_s move_t;
 
-#endif
+typedef enum {
+    _SSQUARE_ = -1,                               /* force signed enum */
+    A1 = 0, B1, C1, D1, E1, F1, G1, H1,
+    A2,     B2, C2, D2, E2, F2, G2, H2,
+    A3,     B3, C3, D3, E3, F3, G3, H3,
+    A4,     B4, C4, D4, E4, F4, G4, H4,
+    A5,     B5, C5, D5, E5, F5, G5, H5,
+    A6,     B6, C6, D6, E6, F6, G6, H6,
+    A7,     B7, C7, D7, E7, F7, G7, H7,
+    A8,     B8, C8, D8, E8, F8, G8, H8,
+    SQUARE_MAX = 64,
+    SQUARE_NONE = 64
+} square_t;
+
+typedef enum {
+    _SFILE_ = -1,                                 /* force signed enum */
+    FILE_A = 0, FILE_B, FILE_C, FILE_D, FILE_E, FILE_F, FILE_G, FILE_H,
+    FILE_MAX,
+} file_t;
+
+typedef enum {
+    _SRANK_ = -1,                                 /* force signed enum */
+    RANK_1 = 0, RANK_2, RANK_3, RANK_4, RANK_5, RANK_6, RANK_7, RANK_8,
+    RANK_MAX,
+} rank_t;
+
+typedef enum {
+    NORTH = 8,
+    EAST =  1,
+    SOUTH = -NORTH,
+    WEST = -EAST,
+
+    NORTH_EAST = (NORTH + EAST),
+    SOUTH_EAST = (SOUTH + EAST),
+    SOUTH_WEST = (SOUTH + WEST),
+    NORTH_WEST = (NORTH + WEST),
+} dir_t;
+
+/* define diff for relative squares */
+#define sq_up(c)          ((c) == WHITE ? NORTH: SOUTH)
+/* Attention here: We mix "up" (color dependent) and W/E, color independant.
+ */
+#define sq_upwest(up)     ((up) - 1)
+#define sq_upeast(up)     ((up) + 1)
+
+#include <time.h>
+
+typedef struct mclock {
+    clockid_t clocktype;
+    ulong elapsed_l;
+    double elapsed_f;
+    struct timespec start;
+} mclock_t;
+
+#define CLOCK_WALL    CLOCK_REALTIME
+#define CLOCK_SYSTEM  CLOCK_MONOTONIC_RAW
+#define CLOCK_PROCESS CLOCK_PROCESS_CPUTIME_ID
+#define CLOCK_THREAD  CLOCK_THREAD_CPUTIME_ID
+
+/**
+ * CLOCK_DEFINE - define a clock type.
+ * @name: clock name
+ * @type: clock type
+ *
+ * This macro is equivalent to:
+ *   mclock_t name;
+ *   clock_init(&name, type);
+ */
+#define CLOCK_DEFINE(name, type) struct mclock name = { .clocktype = type }
+
+void clock_init(mclock_t *clock, clockid_t type);
+void clock_start(mclock_t *clock);
+s64 clock_elapsed_μs(mclock_t *clock);
+s64 clock_elapsed_ms(mclock_t *clock);
+double clock_elapsed_sec(mclock_t *clock);
+
+#define RAND_SEED_DEFAULT U64(0xb0d1ccea)
+
+void rand_init(u64 seed);
+u64 rand64(void);
+
+void init_all(void);
+
+#endif  /* _CHESSDEFS_H */

src/eval-simple.c

@@ -1,199 +1,201 @@
-/* eval-simple.c - simple position evaluation.
- *
- * Copyright (C) 2023 Bruno Raoult ("br")
- * Licensed under the GNU General Public License v3.0 or later.
- * Some rights reserved. See COPYING.
- *
- * You should have received a copy of the GNU General Public License along with this
- * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
- *
- * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
- *
- */
-
-#include <bits.h>
-#include <debug.h>
-
-#include "piece.h"
-#include "eval-simple.h"
-#include "position.h"
-
 /*
- * Tables are from https://www.chessprogramming.org/Simplified_Evaluation_Function
+ * /\* eval-simple.c - simple position evaluation.
+ *  *
+ *  * Copyright (C) 2023 Bruno Raoult ("br")
+ *  * Licensed under the GNU General Public License v3.0 or later.
+ *  * Some rights reserved. See COPYING.
+ *  *
+ *  * You should have received a copy of the GNU General Public License along with this
+ *  * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *  *
+ *  * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *  *
+ *  *\/
  *
- * Attention! Tables are black point of view (to be visually easier to read).
- */
-
-static int mg_pawn[] = {
-    0,   0,   0,   0,   0,   0,  0,  0,
-    50, 50,  50,  50,  50,  50, 50, 50,
-    10, 10,  20,  30,  30,  20, 10, 10,
-    5,   5,  10,  25,  25,  10,  5,  5,
-    0,   0,   0,  20,  20,   0,  0,  0,
-    5,  -5, -10,   0,   0, -10, -5,  5,
-    5,  10,  10, -20, -20,  10, 10,  5,
-    0,   0,   0,   0,   0,   0,  0,  0
-};
-
-static int mg_knight[] = {
-    -50, -40, -30, -30, -30, -30, -40, -50,
-    -40, -20,   0,   0,   0,   0, -20, -40,
-    -30,   0,  10,  15,  15,  10,   0, -30,
-    -30,   5,  15,  20,  20,  15,   5, -30,
-    -30,   0,  15,  20,  20,  15,   0, -30,
-    -30,   5,  10,  15,  15,  10,   5, -30,
-    -40, -20,   0,   5,   5,   0, -20, -40,
-    -50, -40, -30, -30, -30, -30, -40, -50
-};
-
-static int mg_bishop[] = {
-    -20, -10, -10, -10, -10, -10, -10, -20,
-    -10,   0,   0,   0,   0,   0,   0, -10,
-    -10,   0,   5,  10,  10,   5,   0, -10,
-    -10,   5,   5,  10,  10,   5,   5, -10,
-    -10,   0,  10,  10,  10,  10,   0, -10,
-    -10,  10,  10,  10,  10,  10,  10, -10,
-    -10,   5,   0,   0,   0,   0,   5, -10,
-    -20, -10, -10, -10, -10, -10, -10, -20
-};
-
-static int mg_rook[] = {
-    0,   0,  0,  0,  0,  0,  0,  0,
-    5,  10, 10, 10, 10, 10, 10,  5,
-    -5,  0,  0,  0,  0,  0,  0, -5,
-    -5,  0,  0,  0,  0,  0,  0, -5,
-    -5,  0,  0,  0,  0,  0,  0, -5,
-    -5,  0,  0,  0,  0,  0,  0, -5,
-    -5,  0,  0,  0,  0,  0,  0, -5,
-    0,   0,  0,  5,  5,  0,  0,  0
-};
-
-static int mg_queen[] = {
-    -20, -10, -10, -5, -5, -10, -10, -20,
-    -10,   0,   0,  0,  0,   0,   0, -10,
-    -10,   0,   5,  5,  5,   5,   0, -10,
-    -5,    0,   5,  5,  5,   5,   0,  -5,
-    0,     0,   5,  5,  5,   5,   0,  -5,
-    -10,   5,   5,  5,  5,   5,   0, -10,
-    -10,   0,   5,  0,  0,   0,   0, -10,
-    -20, -10, -10, -5, -5, -10, -10, -20
-};
-
-static int mg_king[] = {
-    -30, -40, -40, -50, -50, -40, -40, -30,
-    -30, -40, -40, -50, -50, -40, -40, -30,
-    -30, -40, -40, -50, -50, -40, -40, -30,
-    -30, -40, -40, -50, -50, -40, -40, -30,
-    -20, -30, -30, -40, -40, -30, -30, -20,
-    -10, -20, -20, -20, -20, -20, -20, -10,
-    20,  20,   0,   0,   0,   0,  20,  20,
-    20,  30,  10,   0,   0,  10,  30,  20
-};
-
-static int eg_king[] = {
-    -50, -40, -30, -20, -20, -30, -40, -50,
-    -30, -20, -10,   0,   0, -10, -20, -30,
-    -30, -10,  20,  30,  30,  20, -10, -30,
-    -30, -10,  30,  40,  40,  30, -10, -30,
-    -30, -10,  30,  40,  40,  30, -10, -30,
-    -30, -10,  20,  30,  30,  20, -10, -30,
-    -30, -30,   0,   0,   0,   0, -30, -30,
-    -50, -30, -30, -30, -30, -30, -30, -50
-};
-
-/* as pieces bitboard tables start at position 2; we make these tables
- * bigger.
- */
-static int *mg_tables[] = {
-    NULL,
-    NULL,
-    mg_pawn,
-    mg_knight,
-    mg_bishop,
-    mg_rook,
-    mg_queen,
-    mg_king
-};
-
-static int *eg_tables[] = {
-    NULL,
-    NULL,
-    mg_pawn,
-    mg_knight,
-    mg_bishop,
-    mg_rook,
-    mg_queen,
-    eg_king
-};
-
-/* to flip vertically a square, we need to XOR it with 56
- */
-static int mg_table[2][6 + 2][64];
-static int eg_table[2][6 + 2][64];
-
-void eval_simple_init(void)
-{
-#   ifdef DEBUG_EVAL
-    log_f(1, "initializing piece tables\n");
-#   endif
-    for (int piece = BB_PAWN; piece <= BB_KING; ++piece) {
-        for (int square = 0; square < 64; ++square) {
-            mg_table[WHITE][piece][square] = mg_tables[piece][FLIP_V(square)];
-            eg_table[WHITE][piece][square] = eg_tables[piece][FLIP_V(square)];
-            mg_table[BLACK][piece][square] = mg_tables[piece][square];
-            eg_table[BLACK][piece][square] = eg_tables[piece][square];
-        }
-    }
-}
-
-/**
- * eval_simple() - simple and fast position evaluation
- * @pos: &position to evaluate
+ * #include "br.h"
+ * #include "debug.h"
  *
- * This function is normally used only during initialization,
- * or when changing phase (middlegame <--> endgame), as the eval
- * will be done increntally when doing moves.
+ * #include "piece.h"
+ * #include "eval-simple.h"
+ * #include "position.h"
  *
- * @return: the @pos evaluation in centipawns
+ * /\*
+ *  * Tables are from https://www.chessprogramming.org/Simplified_Evaluation_Function
+ *  *
+ *  * Attention! Tables are black point of view (to be visually easier to read).
+ *  *\/
+ *
+ * static int mg_pawn[] = {
+ *     0,   0,   0,   0,   0,   0,  0,  0,
+ *     50, 50,  50,  50,  50,  50, 50, 50,
+ *     10, 10,  20,  30,  30,  20, 10, 10,
+ *     5,   5,  10,  25,  25,  10,  5,  5,
+ *     0,   0,   0,  20,  20,   0,  0,  0,
+ *     5,  -5, -10,   0,   0, -10, -5,  5,
+ *     5,  10,  10, -20, -20,  10, 10,  5,
+ *     0,   0,   0,   0,   0,   0,  0,  0
+ * };
+ *
+ * static int mg_knight[] = {
+ *     -50, -40, -30, -30, -30, -30, -40, -50,
+ *     -40, -20,   0,   0,   0,   0, -20, -40,
+ *     -30,   0,  10,  15,  15,  10,   0, -30,
+ *     -30,   5,  15,  20,  20,  15,   5, -30,
+ *     -30,   0,  15,  20,  20,  15,   0, -30,
+ *     -30,   5,  10,  15,  15,  10,   5, -30,
+ *     -40, -20,   0,   5,   5,   0, -20, -40,
+ *     -50, -40, -30, -30, -30, -30, -40, -50
+ * };
+ *
+ * static int mg_bishop[] = {
+ *     -20, -10, -10, -10, -10, -10, -10, -20,
+ *     -10,   0,   0,   0,   0,   0,   0, -10,
+ *     -10,   0,   5,  10,  10,   5,   0, -10,
+ *     -10,   5,   5,  10,  10,   5,   5, -10,
+ *     -10,   0,  10,  10,  10,  10,   0, -10,
+ *     -10,  10,  10,  10,  10,  10,  10, -10,
+ *     -10,   5,   0,   0,   0,   0,   5, -10,
+ *     -20, -10, -10, -10, -10, -10, -10, -20
+ * };
+ *
+ * static int mg_rook[] = {
+ *     0,   0,  0,  0,  0,  0,  0,  0,
+ *     5,  10, 10, 10, 10, 10, 10,  5,
+ *     -5,  0,  0,  0,  0,  0,  0, -5,
+ *     -5,  0,  0,  0,  0,  0,  0, -5,
+ *     -5,  0,  0,  0,  0,  0,  0, -5,
+ *     -5,  0,  0,  0,  0,  0,  0, -5,
+ *     -5,  0,  0,  0,  0,  0,  0, -5,
+ *     0,   0,  0,  5,  5,  0,  0,  0
+ * };
+ *
+ * static int mg_queen[] = {
+ *     -20, -10, -10, -5, -5, -10, -10, -20,
+ *     -10,   0,   0,  0,  0,   0,   0, -10,
+ *     -10,   0,   5,  5,  5,   5,   0, -10,
+ *     -5,    0,   5,  5,  5,   5,   0,  -5,
+ *     0,     0,   5,  5,  5,   5,   0,  -5,
+ *     -10,   5,   5,  5,  5,   5,   0, -10,
+ *     -10,   0,   5,  0,  0,   0,   0, -10,
+ *     -20, -10, -10, -5, -5, -10, -10, -20
+ * };
+ *
+ * static int mg_king[] = {
+ *     -30, -40, -40, -50, -50, -40, -40, -30,
+ *     -30, -40, -40, -50, -50, -40, -40, -30,
+ *     -30, -40, -40, -50, -50, -40, -40, -30,
+ *     -30, -40, -40, -50, -50, -40, -40, -30,
+ *     -20, -30, -30, -40, -40, -30, -30, -20,
+ *     -10, -20, -20, -20, -20, -20, -20, -10,
+ *     20,  20,   0,   0,   0,   0,  20,  20,
+ *     20,  30,  10,   0,   0,  10,  30,  20
+ * };
+ *
+ * static int eg_king[] = {
+ *     -50, -40, -30, -20, -20, -30, -40, -50,
+ *     -30, -20, -10,   0,   0, -10, -20, -30,
+ *     -30, -10,  20,  30,  30,  20, -10, -30,
+ *     -30, -10,  30,  40,  40,  30, -10, -30,
+ *     -30, -10,  30,  40,  40,  30, -10, -30,
+ *     -30, -10,  20,  30,  30,  20, -10, -30,
+ *     -30, -30,   0,   0,   0,   0, -30, -30,
+ *     -50, -30, -30, -30, -30, -30, -30, -50
+ * };
+ *
+ * /\* as pieces bitboard tables start at position 2; we make these tables
+ *  * bigger.
+ *  *\/
+ * static int *mg_tables[] = {
+ *     NULL,
+ *     NULL,
+ *     mg_pawn,
+ *     mg_knight,
+ *     mg_bishop,
+ *     mg_rook,
+ *     mg_queen,
+ *     mg_king
+ * };
+ *
+ * static int *eg_tables[] = {
+ *     NULL,
+ *     NULL,
+ *     mg_pawn,
+ *     mg_knight,
+ *     mg_bishop,
+ *     mg_rook,
+ *     mg_queen,
+ *     eg_king
+ * };
+ *
+ * /\* to flip vertically a square, we need to XOR it with 56
+ *  *\/
+ * static int mg_table[2][6 + 2][64];
+ * static int eg_table[2][6 + 2][64];
+ *
+ * void eval_simple_init(void)
+ * {
+ * #   ifdef DEBUG_EVAL
+ *     log_f(1, "initializing piece tables\n");
+ * #   endif
+ *     for (int piece = BB_PAWN; piece <= BB_KING; ++piece) {
+ *         for (int square = 0; square < 64; ++square) {
+ *             mg_table[WHITE][piece][square] = mg_tables[piece][FLIP_V(square)];
+ *             eg_table[WHITE][piece][square] = eg_tables[piece][FLIP_V(square)];
+ *             mg_table[BLACK][piece][square] = mg_tables[piece][square];
+ *             eg_table[BLACK][piece][square] = eg_tables[piece][square];
+ *         }
+ *     }
+ * }
+ *
+ * /\**
+ *  * eval_simple() - simple and fast position evaluation
+ *  * @pos: &position to evaluate
+ *  *
+ *  * This function is normally used only during initialization,
+ *  * or when changing phase (middlegame <--> endgame), as the eval
+ *  * will be done increntally when doing moves.
+ *  *
+ *  * @return: the @pos evaluation in centipawns
+ *  *\/
+ * eval_t eval_simple(pos_t *pos)
+ * {
+ *     eval_t eval[2] = { 0, 0 };
+ *     int eg = simple_is_endgame(pos);
+ *     int (*gg)[6 + 2][64]= eg? eg_table: mg_table;
+ *
+ *     pos->eval_simple_phase = ENDGAME;
+ * #   ifdef DEBUG_EVAL
+ *     log_f(5, "phase = %s.\n", eg? "endgame": "midgame");
+ * #   endif
+ *
+ *     for (int color = WHITE; color <= BLACK; ++color) {
+ *         for (uint piece = PAWN; piece <= KING; piece <<= 1) {
+ *             int bb = PIECETOBB(piece), cur;
+ *             u64 _t;
+ *
+ * #           ifdef DEBUG_EVAL
+ *             log_f(5, "p=%u bb=%d %s %s: count=%d val=%ld ", piece, bb, color? "black": "white",
+ *                   P_SYM(piece), popcount64(pos->bb[color][bb]),
+ *                   popcount64(pos->bb[color][bb]) * P_VALUE(piece));
+ * #           endif
+ *
+ *             eval[color] += popcount64(pos->bb[color][bb]) * P_LETTER(piece);
+ *             bit_for_each64(cur, _t, pos->bb[color][bb]) {
+ * #               ifdef DEBUG_EVAL
+ *                 log(5, "sq=%d:%d ", cur, gg[color][bb][cur]);
+ * #               endif
+ *                 eval[color] += gg[color][bb][cur];
+ *             }
+ * #           ifdef DEBUG_EVAL
+ *             log(5, "\n");
+ * #           endif
+ *         }
+ *     }
+ * #   ifdef DEBUG_EVAL
+ *     log_f(2, "eval:%d white:%d black:%d\n", eval[WHITE] - eval[BLACK],
+ *           eval[WHITE], eval[BLACK]);
+ * #   endif
+ *
+ *     return eval[WHITE] - eval[BLACK];
+ * }
  */
-eval_t eval_simple(pos_t *pos)
-{
-    eval_t eval[2] = { 0, 0 };
-    int eg = simple_is_endgame(pos);
-    int (*gg)[6 + 2][64]= eg? eg_table: mg_table;
-
-    pos->eval_simple_phase = ENDGAME;
-#   ifdef DEBUG_EVAL
-    log_f(5, "phase = %s.\n", eg? "endgame": "midgame");
-#   endif
-
-    for (int color = WHITE; color <= BLACK; ++color) {
-        for (uint piece = PAWN; piece <= KING; piece <<= 1) {
-            int bb = PIECETOBB(piece), cur;
-            u64 _t;
-
-#           ifdef DEBUG_EVAL
-            log_f(5, "p=%u bb=%d %s %s: count=%d val=%ld ", piece, bb, color? "black": "white",
-                  P_SYM(piece), popcount64(pos->bb[color][bb]),
-                  popcount64(pos->bb[color][bb]) * P_VALUE(piece));
-#           endif
-
-            eval[color] += popcount64(pos->bb[color][bb]) * P_LETTER(piece);
-            bit_for_each64_2(cur, _t, pos->bb[color][bb]) {
-#               ifdef DEBUG_EVAL
-                log(5, "sq=%d:%d ", cur, gg[color][bb][cur]);
-#               endif
-                eval[color] += gg[color][bb][cur];
-            }
-#           ifdef DEBUG_EVAL
-            log(5, "\n");
-#           endif
-        }
-    }
-#   ifdef DEBUG_EVAL
-    log_f(2, "eval:%d white:%d black:%d\n", eval[WHITE] - eval[BLACK],
-          eval[WHITE], eval[BLACK]);
-#   endif
-
-    return eval[WHITE] - eval[BLACK];
-}

src/eval.c

@@ -1,95 +1,97 @@
-/* eval.c - static position evaluation.
+/*
+ * /\* eval.c - static position evaluation.
+ *  *
+ *  * Copyright (C) 2021-2023 Bruno Raoult ("br")
+ *  * Licensed under the GNU General Public License v3.0 or later.
+ *  * Some rights reserved. See COPYING.
+ *  *
+ *  * You should have received a copy of the GNU General Public License along with this
+ *  * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *  *
+ *  * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *  *
+ *  *\/
  *
- * Copyright (C) 2021-2023 Bruno Raoult ("br")
- * Licensed under the GNU General Public License v3.0 or later.
- * Some rights reserved. See COPYING.
+ * #include <stdio.h>
  *
- * You should have received a copy of the GNU General Public License along with this
- * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ * #include <list.h>
+ * #include <debug.h>
  *
- * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ * #include "position.h"
+ * #include "eval.h"
+ * #include "eval-simple.h"
  *
+ * inline eval_t eval_material(pos_t *pos, bool color)
+ * {
+ *     eval_t res = 0;
+ *
+ *     /\* I need to do something about the king, if it can be potentially taken
+ *      * if pseudo-moves include a pinned piece on King.
+ *      *\/
+ *     for (uint piece = PAWN; piece < KING; piece <<= 1) {
+ *         uint bb = PIECETOBB(piece);
+ * #       ifdef DEBUG_EVAL
+ *         log_f(2, "color=%u piece=%u bb=%u=%c count=%ul val=%ld\n",
+ *               color, piece, bb, P_LETTER(piece), popcount64(pos->bb[color][bb]),
+ *               P_VALUE(piece));
+ * #       endif
+ *         /\* attention here *\/
+ *         res += popcount64(pos->bb[color][bb]) * P_VALUE(piece);
+ *     }
+ *     return res;
+ * }
+ *
+ * inline eval_t eval_mobility(pos_t *pos, bool color)
+ * {
+ *     return pos->mobility[color];
+ * }
+ *
+ * inline eval_t eval_square_control(pos_t *pos, bool color)
+ * {
+ *     return popcount64(pos->controlled[color]);
+ * }
+ *
+ * eval_t eval(pos_t *pos)
+ * {
+ *     eval_t simple = 0, control[2] = {0};
+ *
+ *     if (pos->eval != EVAL_INVALID)
+ *         return pos->eval;
+ *
+ *     /\* 1) pieces value *\/
+ *     //material[WHITE] = eval_material(pos, WHITE);
+ *     //material[BLACK] = eval_material(pos, BLACK);
+ *     simple = eval_simple(pos);
+ *
+ * #   ifdef DEBUG_EVAL
+ *     log_f(2, "eval_simple=%d\n", simple);
+ * #   endif
+ *
+ *     /\* 2) square control: 10 square controls diff = 1 pawn *\/
+ *     control[WHITE] = eval_square_control(pos, WHITE);
+ *     control[BLACK] = eval_square_control(pos, BLACK);
+ *
+ * #   ifdef DEBUG_EVAL
+ *     log_f(2, "square control: W:%d B:%d diff=%d\n",
+ *           control[WHITE], control[BLACK],
+ *           (control[WHITE] - control[BLACK]) * 10);
+ * #   endif
+ *
+ *     /\* 3) mobility: 10 mobility diff = 1 pawn
+ *      *\/
+ * #   ifdef DEBUG_EVAL
+ *     log_f(2, "mobility: W:%u B:%u diff=%d\n",
+ *           pos->mobility[WHITE], pos->mobility[BLACK],
+ *           (pos->mobility[WHITE] - pos->mobility[BLACK]) * 10);
+ * #   endif
+ *
+ *     eval_t res = simple +
+ *         (control[WHITE] - control[BLACK]) * 10 +
+ *         (pos->mobility[WHITE] - pos->mobility[BLACK]) * 10;
+ * #   ifdef DEBUG_EVAL
+ *     log_f(2, "eval: %d\n", res);
+ * #   endif
+ *     pos->eval = res;
+ *     return res;
+ * }
  */
-
-#include <stdio.h>
-
-#include <list.h>
-#include <debug.h>
-
-#include "position.h"
-#include "eval.h"
-#include "eval-simple.h"
-
-inline eval_t eval_material(pos_t *pos, bool color)
-{
-    eval_t res = 0;
-
-    /* I need to do something about the king, if it can be potentially taken
-     * if pseudo-moves include a pinned piece on King.
-     */
-    for (uint piece = PAWN; piece < KING; piece <<= 1) {
-        uint bb = PIECETOBB(piece);
-#       ifdef DEBUG_EVAL
-        log_f(2, "color=%u piece=%u bb=%u=%c count=%ul val=%ld\n",
-              color, piece, bb, P_LETTER(piece), popcount64(pos->bb[color][bb]),
-              P_VALUE(piece));
-#       endif
-        /* attention here */
-        res += popcount64(pos->bb[color][bb]) * P_VALUE(piece);
-    }
-    return res;
-}
-
-inline eval_t eval_mobility(pos_t *pos, bool color)
-{
-    return pos->mobility[color];
-}
-
-inline eval_t eval_square_control(pos_t *pos, bool color)
-{
-    return popcount64(pos->controlled[color]);
-}
-
-eval_t eval(pos_t *pos)
-{
-    eval_t simple = 0, control[2] = {0};
-
-    if (pos->eval != EVAL_INVALID)
-        return pos->eval;
-
-    /* 1) pieces value */
-    //material[WHITE] = eval_material(pos, WHITE);
-    //material[BLACK] = eval_material(pos, BLACK);
-    simple = eval_simple(pos);
-
-#   ifdef DEBUG_EVAL
-    log_f(2, "eval_simple=%d\n", simple);
-#   endif
-
-    /* 2) square control: 10 square controls diff = 1 pawn */
-    control[WHITE] = eval_square_control(pos, WHITE);
-    control[BLACK] = eval_square_control(pos, BLACK);
-
-#   ifdef DEBUG_EVAL
-    log_f(2, "square control: W:%d B:%d diff=%d\n",
-          control[WHITE], control[BLACK],
-          (control[WHITE] - control[BLACK]) * 10);
-#   endif
-
-    /* 3) mobility: 10 mobility diff = 1 pawn
-     */
-#   ifdef DEBUG_EVAL
-    log_f(2, "mobility: W:%u B:%u diff=%d\n",
-          pos->mobility[WHITE], pos->mobility[BLACK],
-          (pos->mobility[WHITE] - pos->mobility[BLACK]) * 10);
-#   endif
-
-    eval_t res = simple +
-        (control[WHITE] - control[BLACK]) * 10 +
-        (pos->mobility[WHITE] - pos->mobility[BLACK]) * 10;
-#   ifdef DEBUG_EVAL
-    log_f(2, "eval: %d\n", res);
-#   endif
-    pos->eval = res;
-    return res;
-}

src/eval.h

@@ -1,6 +1,6 @@
 /* eval.h - static position evaluation.
  *
- * Copyright (C) 2021 Bruno Raoult ("br")
+ * Copyright (C) 2021-2024 Bruno Raoult ("br")
  * Licensed under the GNU General Public License v3.0 or later.
  * Some rights reserved. See COPYING.
  *

src/fen.c

@@ -1,6 +1,6 @@
-/* fen.c - fen notation.
+/* fen.c - fen parsing/generation/test.
  *
- * Copyright (C) 2021 Bruno Raoult ("br")
+ * Copyright (C) 2021-2024 Bruno Raoult ("br")
  * Licensed under the GNU General Public License v3.0 or later.
  * Some rights reserved. See COPYING.
  *
@@ -18,158 +18,337 @@
 #include <ctype.h>
 
 #include <debug.h>
+#include <bug.h>
 
 #include "chessdefs.h"
+#include "misc.h"
 #include "position.h"
-#include "board.h"
 #include "fen.h"
-#include "piece.h"
 
-/* Starting Position :
- * rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1
- * After 1.e4 :
- * rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq e3 0 1
- * After 1... c5 :
- * rnbqkbnr/pp1ppppp/8/2p5/4P3/8/PPPP1PPP/RNBQKBNR w KQkq c6 0 2
- * After 2. Nf3:
- * rnbqkbnr/pp1ppppp/8/2p5/4P3/5N2/PPPP1PPP/RNBQKB1R b KQkq - 1 2
- *
- * 1 : White uppercase
+/* FEN description:
+ * 1 : pieces on board (no space allowed):
+ *   - rank 8 first, '/' between ranks
+ *   - piece is usual piece notation(PNBRQK), black lowercase.
+ *   - empty: number of consecutive empty squares (digit)
  * 2 : next move (w or b)
  * 3 : Castling capabilities: "-" if none, KQ/kq if white/black can castle
  *     on K or Q side
- * 4 : en-passant: if pawn just moved 2 squares, indicate target square (e.g.
- *     for e2-e4 this field is e3)
+ * 4 : en-passant: "-" if none. If pawn just moved 2 squares, indicate target
+ *     en-passant square (e.g. for e2-e4 this field is e3)
  * 5 : half moves since last capture or pawn advance (for 50 moves rule)
  * 6 : full moves, starts at 1, increments after black move
  *
+ * Examples:
+ *
+ * starting position:
+ * rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1
+ * after 1.e4 e6 2.e5 d5
+ * rnbqkbnr/ppp2ppp/4p3/3pP3/8/8/PPPP1PPP/RNBQKBNR w KQkq d6 0 3
+ * 3.Nc3 Nc6 4.Rb1 Rb8 5.Nf3 h5 6.Be2
+ * 1rbqkbnr/ppp2pp1/2n1p3/3pP2p/8/2N2N2/PPPPBPPP/1RBQK2R b Kk - 1 6
+ * 6...Be7
+ * 1rbqk1nr/ppp1bpp1/2n1p3/3pP2p/8/2N2N2/PPPPBPPP/1RBQK2R w Kk - 2 7
+ * 7.Nxd5 h4 8.g4
+ * 1rbqk1nr/ppp1bpp1/2n1p3/3NP3/6Pp/5N2/PPPPBP1P/1RBQK2R b Kk g3 0 8
  */
 
-// warning, we expect a valid fen input
-pos_t *fen2pos(pos_t *pos, char *fen)
+/*  chess startup position FEN */
+const char *startfen="rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1";
+static const char *castle_str = "KQkq";
+
+#define SKIP_BLANK(p) for(;isspace(*(p)); (p)++)
+
+/**
+ * fen_ok() - test (and try to fix) fen-generated position.
+ * @pos:    &position
+ * @fixit:  action flag
+ *
+ * Test and possibly fix the following:
+ * - inconsistent castle flags (if K & R are not in correct position)
+ * - inconsistent en-passant square (turn, bad pawns positions)
+ *
+ * if @fixit is true, any error above will be fixed, and pos_ok() will
+ is also called, leading to fatal errors if something is wrong.
+ *
+ * @return: 0 if OK, 1 if OK after fix, -1 if fatal issue.
+ */
+int fen_ok(pos_t *pos, bool fixit)
 {
-    char *p = fen;
-    short rank, file, skip, color, bbpiece;
-    piece_t piece;
-    board_t *board = pos->board;
-#   define SKIP_BLANK(p) for(;*(p) == ' '; (p)++)
+    char *colstr[2] = { "white", "black"};
+    int warning = 0;
+    color_t us = pos->turn, them = OPPONENT(us);
+    int up = sq_up(us);                           /* pawn up */
+    square_t ep = pos->en_passant;
 
-    pos_clear(pos);
-    /* 1) get piece placement information
-     */
-    for (rank = 7, file = 0; *p && *p != ' '; ++p) {
-        color = isupper(*p)? WHITE: BLACK;
-        char cp = toupper(*p);
-        switch (cp) {
-            case CHAR_PAWN:
-                bbpiece = BB_PAWN;
-                piece = PAWN;
-                goto set_square;
-            case CHAR_KNIGHT:
-                bbpiece = BB_KNIGHT;
-                piece = KNIGHT;
-                goto set_square;
-            case CHAR_BISHOP:
-                bbpiece = BB_BISHOP;
-                piece = BISHOP;
-                goto set_square;
-            case CHAR_ROOK:
-                bbpiece = BB_ROOK;
-                piece = ROOK;
-                goto set_square;
-            case CHAR_QUEEN:
-                bbpiece = BB_QUEEN;
-                piece = QUEEN;
-                goto set_square;
-            case CHAR_KING:
-                bbpiece = BB_KING;
-                piece = KING;
-                //pos->bb[color][BB_KING] = BB(file, rank);
-                //goto set_square;
-            set_square:
-#               ifdef DEBUG_FEN
-                log_i(5, "f=%d r=%d *p=%c piece=%c color=%d\n",
-                      file, rank, *p, cp, color);
-#               endif
-                pos->bb[color][bbpiece] |= BB(file, rank);
-                pos->occupied[color] |= BB(file, rank);
-                SET_COLOR(piece, color);
-                board[SQ88(file, rank)].piece = piece;
-                board[SQ88(file, rank)].s_piece =
-                    piece_add(pos, piece, SQ88(file, rank));
-                file++;
-                break;
-            case '/':
-                rank--;
-                file = 0;
-                break;
-            default:
-                skip = cp - '0';
-                while (skip--) {
-                    board[SQ88(file++, rank)].piece = EMPTY;
-                }
-        }
-    }
-#   ifdef DEBUG_FEN
-    for (rank = 7; rank >= 0; --rank) {
-        for (file = 0; file < 8; ++file) {
-            log(5, "%02x ", board[SQ88(file, rank)].piece);
-        }
-        log(5, "\n");
-    }
-#   endif
+    /* en passant, depends on who plays next */
+    if (ep != SQUARE_NONE) {
+        rank_t eprank = sq_rank(ep);
+        rank_t rank6 = sq_rel_rank(RANK_6, us);
+        piece_t pawn = MAKE_PIECE(PAWN, them);
+        bitboard_t att = bb_pawn_attacks[them][ep] & pos->bb[us][PAWN];
 
-    /* 2) next move color
-     */
-    SKIP_BLANK(p);
-    SET_COLOR(pos->turn, *p == 'w' ? WHITE : BLACK);
-    p++;
+        if (eprank != rank6 ||
+            pos->board[ep - up] != pawn ||
+            pos->board[ep] != EMPTY ||
+            pos->board[ep + up] != EMPTY ||
+            att == 0ull) {
 
-    /* 3) castle status
-     */
-    SKIP_BLANK(p);
-    pos->castle = 0;
-    if (*p != '-') {
-        for (; *p && *p != ' '; ++p) {
-            switch (*p) {
-                case 'K':
-                    pos->castle |= CASTLE_WK;
-                    break;
-                case 'k':
-                    pos->castle |= CASTLE_BK;
-                    break;
-                case 'Q':
-                    pos->castle |= CASTLE_WQ;
-                    break;
-                case 'q':
-                    pos->castle |= CASTLE_BQ;
-                    break;
+            warning++;
+            if (fixit) {
+                warn(true, "pos warn: wrong en-passant settings (fixed).\n");
+                pos->en_passant = SQUARE_NONE;
             }
         }
     }
-    p++;
+
+    for (int color = WHITE; color <= BLACK; ++color) {
+        rank_t rank1 = sq_rel_rank(RANK_1, color);
+
+        /* castling */
+        /* where K and R should be for valid castle flag */
+        bitboard_t k    = bb_sq[sq_make(FILE_E, rank1)];
+        bitboard_t r_k  = bb_sq[sq_make(FILE_H, rank1)];
+        bitboard_t r_q  = bb_sq[sq_make(FILE_A, rank1)];
+
+       /* where they are */
+        bitboard_t kingbb = pos->bb[color][KING];
+        bitboard_t rookbb = pos->bb[color][ROOK];
+        castle_rights_t castle_k = color == WHITE? CASTLE_WK: CASTLE_BK;
+        castle_rights_t castle_q = color == WHITE? CASTLE_WQ: CASTLE_BQ;
+        if (pos->castle & castle_k && !(k & kingbb && r_k & rookbb)) {
+            warning++;
+            if (fixit) {
+                warn(true, "fen warn: wrong %s short castling (fixed)\n",
+                     colstr[color]);
+                pos->castle &= ~castle_k;
+            }
+        }
+        if (pos->castle & castle_q && !(k & kingbb && r_q & rookbb)) {
+            warning++;
+            if (fixit) {
+                warn(true, "fen warn: wrong %s long castling (fixed)\n",
+                     colstr[color]);
+                pos->castle &= ~castle_q;
+            }
+        }
+    }
+    return warning;
+}
+
+/**
+ * startpos - create a game start position
+ * @pos: a position pointer or NULL
+ *
+ * See @fen2pos function.
+ *
+ * @return: the pos position.
+ */
+pos_t *startpos(pos_t *pos)
+{
+    return fen2pos(pos, startfen);
+}
+
+/**
+ * fen2pos - make a position from a fen string
+ * @pos: a position pointer or NULL
+ * @fen: a valid fen string
+ *
+ * If @pos is NULL, a position will be allocated with @pos_new(),
+ * that should be freed by caller.
+ *
+ * @return: the pos position, or NULL if error.
+ */
+pos_t *fen2pos(pos_t *pos, const char *fen)
+{
+    const char *cur = fen;
+    char *p;
+    short rank, file, tmp;
+    piece_t piece;
+    int consumed, err_line = 0, err_pos = 0, err_char = 0;
+    pos_t tmppos;
+
+    pos_clear(&tmppos);
+    /* 1) get piece placement information
+     */
+    for (rank = 7, file = 0; *cur && !isspace(*cur); ++cur) {
+        if (*cur == '/') {                        /* next rank */
+            rank--;
+            file = 0;
+            continue;
+        }
+        if (isdigit(*cur)) {                      /* empty square(s) */
+            file += *cur - '0';
+            continue;
+        }
+        if ((piece = piece_from_fen(*cur)) != EMPTY) {
+#           ifdef DEBUG_FEN
+            printf("f=%d r=%d *p=%c piece=%#04x t=%d c=%d\n", file, rank, *cur,
+                  piece, PIECE(piece), COLOR(piece));
+#           endif
+            pos_set_sq(&tmppos, sq_make(file, rank), piece);
+            if (PIECE(piece) == KING)
+                tmppos.king[COLOR(piece)] = sq_make(file, rank);
+            file++;
+        } else {                                  /* error */
+            err_line = __LINE__, err_char = *cur, err_pos = cur - fen;
+            goto end;
+        }
+    }
+    SKIP_BLANK(cur);
+
+    /* 2) next turn color
+     */
+    tmppos.turn = *cur++ == 'w' ? WHITE : BLACK;
+    SKIP_BLANK(cur);
+
+    /* 3) castle rights
+     */
+    if (*cur == '-') {
+        cur++;
+    } else {
+        for (; *cur && !isspace(*cur); ++cur) {
+            if ((p = strchr(castle_str, *cur))) { /* valid castle letter */
+                tmppos.castle |= 1 << (p - castle_str);
+            } else {
+                err_line = __LINE__, err_char = *cur, err_pos = cur - fen;
+                goto end;
+            }
+        }
+    }
+    SKIP_BLANK(cur);
 
     /* 4) en passant
      */
-    SKIP_BLANK(p);
-    pos->en_passant = 0;
-    if (*p != '-') {
-        //SET_F(pos->en_passant, C2FILE(*p++));
-        //SET_R(pos->en_passant, C2RANK(*p++));
-        pos->en_passant = SQ88(C2FILE(*p), C2RANK(*(p+1)));
-        pos += 2;
+    if (*cur == '-') {
+        cur++;
     } else {
-        p++;
+        tmppos.en_passant = sq_from_string(cur);
+        cur += 2;
+    }
+    SKIP_BLANK(cur);
+
+    /* 5) half moves since last capture or pawn move (50 moves rule)
+     */
+    tmppos.clock_50 = 0;
+    tmppos.plycount = 1;
+    if (sscanf(cur, "%hd%n", &tmp, &consumed) != 1)
+        goto end;                                 /* early end, ignore w/o err */
+
+    tmppos.clock_50 = tmp;
+    cur += consumed;
+    SKIP_BLANK(cur);
+
+    /* 6) current full move number, starting with 1
+     */
+    if (sscanf(cur, "%hd", &tmp) != 1)
+        goto end;
+    if (tmp <= 0)                                 /* fix faulty numbers*/
+        tmp = 1;
+    tmp = 2 * (tmp - 1) + (tmppos.turn == BLACK); /* plies, +1 if black turn */
+    tmppos.plycount = tmp;
+
+end:
+    if (warn(err_line, "FEN error line %d: charpos=%d char=%#x(%c)\n",
+             err_line, err_pos, err_char, err_char)) {
+        return NULL;
     }
 
-    /* 5) half moves since last capture or pawn move and
-     * 6) current move number
-     */
-    SKIP_BLANK(p);
-    //log_i(5, "pos=%d\n", (int)(p-fen));
-    sscanf(p, "%hd %hd", &pos->clock_50, &pos->curmove);
+    fen_ok(&tmppos, true);                        /* fix e.p & castling flags */
+    if (!pos_ok(&tmppos, false))
+        return NULL;                              /* invalid position: ignored */
+
+    tmppos.key = zobrist_calc(&tmppos);
+    if (!pos)
+        pos = pos_new();
+    pos_copy(&tmppos, pos);
 #   ifdef DEBUG_FEN
-    log_i(5, "50 rule=%d current move=%d\n", pos->clock_50, pos->curmove);
+    pos_print_raw(&tmppos, 1);
 #   endif
+
     return pos;
 }
+
+/**
+ * pos2fen - make a FEN string from a position.
+ * @pos: a position pointer
+ * @fen: destination FEN char*, or NULL
+ *
+ * If @fen is NULL, a 92 bytes memory will be allocated with malloc(1),
+ * that should be freed by caller.
+ *
+ * Note: If @fen is given, no check is done on its length, but to
+ * be on secure side, it should be at least 90 bytes. See:
+ * https://chess.stackexchange.com/questions/30004/longest-possible-fen
+ * For convenience, use FENSTRLEN.
+ *
+ * @return: the pos position, or NULL if error.
+ */
+char *pos2fen(const pos_t *pos, char *fen)
+{
+    int cur = 0;
+
+    if (!fen)
+        fen = safe_malloc(92);
+
+    /*  1) position
+     */
+    for (rank_t r = RANK_8; r >= RANK_1; --r) {
+        for (file_t f = FILE_A; f <= FILE_H;) {
+            square_t sq = sq_make(f, r);
+            piece_t piece = pos->board[sq];
+#           ifdef DEBUG_FEN
+            printf("r=%d f=%d p=%d pos=%d\n", r, f, piece, cur);
+#           endif
+            if (piece == EMPTY) {
+                int len = 0;
+                for (; f <= FILE_H && pos->board[sq_make(f, r)] == EMPTY; f++)
+                    len++;
+#               ifdef DEBUG_FEN
+                printf("empty=%d char=%c\n", len, '0' + len);
+#               endif
+                fen[cur++] = '0' + len;
+            } else {
+                fen[cur++] = *piece_to_fen(piece);
+#               ifdef DEBUG_FEN
+                printf("f1=%d r=%d c=%c t=%d c=%d \n", f, r,
+                       *(piece_to_fen(piece)), PIECE(piece), COLOR(piece));
+#               endif
+                f++;
+            }
+        }
+        fen[cur++] = r == RANK_1? ' ': '/';
+    }
+
+    /* 2) next turn color
+     */
+    fen[cur++] = pos->turn == WHITE? 'w': 'b';
+    fen[cur++] = ' ';
+
+    /*  3) castle rights
+     */
+    if (pos->castle == 0) {
+        fen[cur++] = '-';
+    } else {
+        for (int i = 0; i < 4; ++i)
+            if (pos->castle & BIT(i))
+                fen[cur++] = castle_str[i];
+    }
+    fen[cur++] = ' ';
+
+    /* 4) en passant
+     */
+    if (pos->en_passant == SQUARE_NONE) {
+        fen[cur++] = '-';
+    } else {
+        strcpy(fen+cur, sq_to_string(pos->en_passant));
+        cur += 2;
+    }
+    fen[cur++] = ' ';
+
+    /* 5) moves since last capture or pawn move (50 moves rule)
+     * 6) current full move number, starting with 1
+     */
+    sprintf(fen+cur, "%d %d", pos->clock_50,
+            1 + (pos->plycount - (pos->turn == BLACK)) / 2);
+    return fen;
+}

src/fen.h

@@ -1,6 +1,6 @@
 /* fen.h - fen notation.
  *
- * Copyright (C) 2021 Bruno Raoult ("br")
+ * Copyright (C) 2021-2024 Bruno Raoult ("br")
  * Licensed under the GNU General Public License v3.0 or later.
  * Some rights reserved. See COPYING.
  *
@@ -14,8 +14,15 @@
 #ifndef FEN_H
 #define FEN_H
 
-#include "position.h"
+#include "chessdefs.h"
 
-pos_t *fen2pos(pos_t *pos, char *fen);
+#define FENSTRLEN 92                              /* secure FEN string size */
+
+extern const char *startfen;                      /* startup position */
+
+extern int fen_ok(pos_t *pos, bool fixit);
+extern pos_t *startpos(pos_t *pos);
+extern pos_t *fen2pos(pos_t *pos, const char *fen);
+extern char *pos2fen(const pos_t *pos, char *fen);
 
 #endif /* FEN_H */

src/hash.c

@@ -0,0 +1,422 @@
+/* hash.c - hash management.
+ *
+ * Copyright (C) 2024 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#include <string.h>
+#include <assert.h>
+
+#include <brlib.h>
+#include <bitops.h>
+
+#include "chessdefs.h"
+#include "misc.h"
+#include "position.h"
+#include "piece.h"
+#include "hash.h"
+
+u64 zobrist_pieces[16][64];
+u64 zobrist_castling[4 * 4 + 1];
+u64 zobrist_turn;                                 /* for black, XOR each ply */
+u64 zobrist_ep[9];                                /* 0-7: ep file, 8: SQUARE_NONE */
+
+hasht_t hash_tt;                                  /* main transposition table */
+
+/**
+ * zobrist_init() - initialize zobrist tables.
+ *
+ * Initialize all zobrist random bitmasks. Must be called before any other
+ * zobrist function, and can be called once only (further calls will be ignored).
+ */
+void zobrist_init(void)
+{
+    static bool called = false;
+    if (!called) {
+        called = true;
+        for (color_t c = WHITE; c <= BLACK; ++c) {
+            for (piece_type_t p = PAWN; p <= KING; ++p)
+                for (square_t sq = A1; sq <= H8; ++sq)
+                    zobrist_pieces[MAKE_PIECE(p, c)][sq] = rand64();
+        }
+        for (castle_rights_t c = CASTLE_NONE; c <= CASTLE_ALL; ++c)
+            zobrist_castling[c] = rand64();
+        for (file_t f = FILE_A; f <= FILE_H; ++f)
+            zobrist_ep[f] = rand64();
+        zobrist_ep[8] = 0;                        /* see EP_ZOBRIST_IDX macro */
+        zobrist_turn = rand64();
+    }
+}
+
+/**
+ * zobrist_calc() - calculate a position zobrist hash.
+ * @pos: &position
+ *
+ * Normally, Zobrist keys are incrementally calculated when doing or
+ * undoing a move.
+ * This function should normally only be called:
+ * - When starting a new position
+ * - To verify incremental Zobrist calculation is correct
+ *
+ * @return: @pos Zobrist key
+ */
+hkey_t zobrist_calc(pos_t *pos)
+{
+    hkey_t key = 0;
+
+    if (pos->turn == BLACK)
+        key ^= zobrist_turn;
+
+    for (color_t c = WHITE; c <= BLACK; ++c) {
+        for (piece_type_t pt = PAWN; pt <= KING; ++pt) {
+            piece_t piece = MAKE_PIECE(pt, c);
+            bitboard_t bb = pos->bb[c][pt];
+            while (bb) {
+                square_t sq = bb_next(&bb);
+                key ^= zobrist_pieces[piece][sq];
+            }
+        }
+    }
+    key ^= zobrist_castling[pos->castle];
+    key ^= zobrist_ep[EP_ZOBRIST_IDX(pos->en_passant)];
+
+    return key;
+}
+
+/**
+ * zobrist_verify() - verify current position Zobrist key.
+ * @pos: &position
+ *
+ * Verify that position Zobrist key matches a full Zobrist calculation.
+ * This function cannot be called if ZOBRIST_VERIFY is not set.
+ *
+ * @return: True if Zobrist key is OK.
+ */
+#ifdef ZOBRIST_VERIFY
+
+#pragma push_macro("BUG_ON")                      /* force BUG_ON and WARN_ON */
+#pragma push_macro("WARN_ON")
+#undef BUG_ON
+#define BUG_ON
+#undef WARN_ON
+#define WARN_ON
+
+bool zobrist_verify(pos_t *pos)
+{
+    hkey_t diff, key = zobrist_calc(pos);
+    if (pos->key == key)
+        return true;
+
+    printf("key verify: cur=%#lx != %#lx\n", pos->key, key);
+
+    /* try to find-out the key in different zobrist tables */
+    diff = pos->key ^ key;
+
+    for (color_t c = WHITE; c <= BLACK; ++c) {
+        for (piece_type_t p = PAWN; p <= KING; ++p)
+            for (square_t sq = A1; sq <= H8; ++sq)
+                if (diff == zobrist_pieces[MAKE_PIECE(p, c)][sq]) {
+                    warn(true, "zobrist difference is piece:[%s][%s]\n",
+                         piece_to_fen(MAKE_PIECE(p, c)), sq_to_string(sq));
+                    goto end;
+                }
+    }
+    for (castle_rights_t c = CASTLE_NONE; c <= CASTLE_ALL; ++c) {
+        if (diff == zobrist_castling[c]) {
+            warn(true, "zobrist difference is castling:[%d]\n", c);
+            goto end;
+        }
+    }
+
+    for (file_t f = FILE_A; f <= FILE_H; ++f) {
+        if (diff == zobrist_ep[f]) {
+            warn(true, "zobrist difference is ep:[%d]\n", f);
+            goto end;
+        }
+    }
+    if (diff == zobrist_turn) {
+        warn(true, "zobrist difference is turn\n");
+        goto end;
+    }
+    warn(true, "zobrist diff %lx is unknown\n", diff);
+end:
+    bug_on(false);
+    /* not reached */
+    return true;
+}
+#pragma pop_macro("WARN_ON")
+#pragma pop_macro("BUG_ON")
+
+#endif
+
+/**
+ * tt_create() - create transposition table
+ * @sizemb: s32 size of hash table in Mb
+ *
+ * Create a hash table of max @sizemb (or HASH_SIZE_MBif @sizemb <= 0) Mb size.
+ * This function must be called at startup.
+ *
+ * The number of bucket_t entries fitting in @sizemb is calculated, and rounded
+ * (down) to a power of 2.
+ * This means the actual size could be lower than @sizemb (nearly halved in
+ * worst case).
+ *
+ * If transposition hashtable already exists and new size would not change,
+ * the old one is cleared.
+ * If transposition hashtable already exists and new size is different,
+ * the old one is destroyed first (old data is not preserved).
+ *
+ * TODO:
+ * - Rebuild old hashtable data ?
+ *
+ * @return: hash table size in Mb. If memory allocation fails, the function does
+ * not return.
+ */
+int tt_create(s32 sizemb)
+{
+    size_t bytes, target_nbuckets;
+    u32 nbits;
+
+    static_assert(sizeof(hentry_t) == 16, "fatal: hentry_t size != 16");
+
+    //printf("mb = %'7u ", sizemb);
+    /* adjust tt size */
+    if (sizemb <= 0)
+        sizemb = HASH_SIZE_DEFAULT;
+    sizemb = clamp(sizemb, HASH_SIZE_MIN, HASH_SIZE_MAX);
+
+    bytes = sizemb * 1024ull * 1024ull;           /* bytes wanted */
+    target_nbuckets = bytes / sizeof(bucket_t);   /* target buckets */
+
+    nbits = msb64(target_nbuckets);               /* adjust to power of 2 */
+
+    if (hash_tt.nbits != nbits) {
+        if (hash_tt.keys)
+            tt_delete();
+
+        hash_tt.nbits    = nbits;
+
+        hash_tt.nbuckets = BIT(hash_tt.nbits);
+        hash_tt.nkeys    = hash_tt.nbuckets * ENTRIES_PER_BUCKET;
+
+        hash_tt.bytes    = hash_tt.nbuckets * sizeof(bucket_t);
+        hash_tt.mb       = hash_tt.bytes / 1024 / 1024;
+
+        hash_tt.mask     = -1ull >> (64 - nbits);
+
+        hash_tt.keys     = safe_malloc(hash_tt.bytes);
+
+        //printf("bits=%2d size=%'15lu/%'6d Mb/%'14lu buckets ",
+        //       hash_tt.nbits, hash_tt.bytes, hash_tt.mb, hash_tt.nbuckets);
+        //printf("mask=%9x\n", hash_tt.mask);
+    }
+    //else {
+    //    printf("unchanged (cleared)\n");
+    //}
+    /* attention - may fail ! */
+    tt_clear();
+
+    return hash_tt.nbits;
+}
+
+/**
+ * tt_clear() - clear transposition table
+ *
+ * Reset hashtable entries (if available) and statistic information.
+ */
+void tt_clear()
+{
+    if (hash_tt.keys)
+        memset(hash_tt.keys, 0, hash_tt.bytes);
+
+    hash_tt.used_keys = 0;
+    hash_tt.collisions = 0;
+    hash_tt.hits = 0;
+    hash_tt.misses = 0;
+}
+
+/**
+ * tt_delete() - delete transposition table
+ *
+ * free hashtable data.
+ */
+void tt_delete()
+{
+    if (hash_tt.keys) {
+        safe_free(hash_tt.keys);
+        hash_tt.keys = NULL;
+    }
+    tt_clear();
+}
+
+/**
+ * tt_probe() - probe tt for an entry
+ *
+ *
+ */
+hentry_t *tt_probe(hkey_t key)
+{
+    bucket_t *bucket;
+    hentry_t *entry;
+    int i;
+
+    bug_on(!hash_tt.keys);
+    bucket = hash_tt.keys + (key & hash_tt.mask);
+
+    /* find key in buckets */
+    for (i = 0; i < ENTRIES_PER_BUCKET; ++i) {
+        entry = bucket->entry + i;
+        if (key == entry->key)
+            break;
+    }
+    if (i < ENTRIES_PER_BUCKET)
+        return entry;
+    return NULL;
+}
+
+/**
+ * tt_probe_perft() - probe tt for an entry (perft version)
+ * @key:   Zobrist (hkey_t) key
+ * @depth: depth from search root
+ *
+ * Search transposition for @key entry with @depth depth.
+ *
+ * @return: @hentry_t address is found, TT_MISS otherwise.
+ */
+hentry_t *tt_probe_perft(const hkey_t key, const u16 depth)
+{
+    bucket_t *bucket;
+    hentry_t *entry;
+    int i;
+
+    bug_on(!hash_tt.keys);
+    bucket = hash_tt.keys + (key & hash_tt.mask);
+
+    /* find key in buckets */
+    for (i = 0; i < ENTRIES_PER_BUCKET; ++i) {
+        entry = bucket->entry + i;
+        if (key == entry->key && HASH_PERFT_DEPTH(entry->data) == depth) {
+            hash_tt.hits++;
+            /*
+             * printf("tt hit: key=%lx depth=%d bucket=%lu entry=%d!\n",
+             *        key, depth, bucket - hash_tt.keys, i);
+             */
+            return entry;
+        }
+    }
+    /*
+     * printf("tt miss: key=%lx depth=%d ucket=%lu\n",
+     *        key, depth, bucket - hash_tt.keys);
+     */
+    hash_tt.misses++;
+    return TT_MISS;
+}
+
+/**
+ * tt_store_perft() - store a transposition table entry (perft version)
+ * @key:   Zobrist (hkey_t) key
+ * @depth: depth from search root
+ * @nodes: value to store
+ *
+ */
+hentry_t *tt_store_perft(const hkey_t key, const u16 depth, const u64 nodes)
+{
+    bucket_t *bucket;
+    hentry_t *entry;
+    int replace = -1;
+    uint mindepth = 1024;
+    u64 data = HASH_PERFT(depth, nodes);
+
+    //printf("tt_store: key=%lx data=%lx depth=%d=%d nodes=%lu=%lu\n",
+    //       key, data, depth, HASH_PERFT_DEPTH(data), nodes, HASH_PERFT_VAL(data));
+    /*
+     * printf("tt_store: key=%lx depth=%d nodes=%lu ",
+     *        key, depth, nodes);
+     */
+    bug_on(!hash_tt.keys);
+    bucket = hash_tt.keys + (key & hash_tt.mask);
+
+    /* find key in buckets */
+    for (int i = 0; i < ENTRIES_PER_BUCKET; ++i) {
+        entry = bucket->entry + i;
+        //if (!entry->key) {
+        //    replace = i;
+            //hash_tt.used_keys++;
+        //    break;
+        //}
+        if (key == entry->key) {
+            if (depth == HASH_PERFT_DEPTH(entry->data)) {
+                printf("tt_store: dup key=%lx depth=%d, this should not happen!\n",
+                       key, depth);
+                return NULL;
+            }
+        }
+        /* always keep higher nodes */
+        if (HASH_PERFT_DEPTH(entry->data) < mindepth) {
+            mindepth = HASH_PERFT_DEPTH(entry->data);
+            replace = i;
+        }
+    }
+
+    if (replace >= 0) {
+        entry = bucket->entry + replace;
+
+        hash_tt.used_keys  += entry->key == 0;
+        hash_tt.collisions += entry->key && (key != entry->key);
+        /*
+         * if (HASH_PERFT_VAL(entry->data)) {
+         *     printf("REPL entry=%lu[%d] key=%lx->%lx val=%lu->%lu\n",
+         *            bucket - hash_tt.keys, replace,
+         *            entry->key, key,
+         *            HASH_PERFT_VAL(entry->data), nodes);
+         * } else {
+         *     printf("NEW entry=%lu[%d] key=%lx val=%lu\n",
+         *            bucket - hash_tt.keys, replace,
+         *            entry->key, nodes);
+         * }
+         */
+        entry->key = key;
+        entry->data = data;
+        return entry;
+    } else {
+        //printf("TT full, skip\n");
+    }
+    return NULL;
+}
+
+/**
+ * tt_info() - print hash-table information.
+ */
+void tt_info()
+{
+    if (hash_tt.keys) {
+        printf("TT: Mb:%d buckets:%'lu (bits:%u mask:%#x) entries:%'lu\n",
+               hash_tt.mb, hash_tt.nbuckets, hash_tt.nbits,
+               hash_tt.mask, hash_tt.nkeys);
+    } else {
+        printf("TT: not set.\n");
+    }
+}
+
+/**
+ * tt_stats() - print hash-table usage.
+ */
+void tt_stats()
+{
+    if (hash_tt.keys) {
+        float percent = 100.0 * hash_tt.used_keys / hash_tt.nkeys;
+        printf("hash: used:%'lu/%'lu (%.2f%%) hit:%'lu miss:%'lu coll:%'lu\n",
+               hash_tt.used_keys, hash_tt.nkeys, percent,
+               hash_tt.hits, hash_tt.misses,
+               hash_tt.collisions);
+    } else {
+        printf("hash: not set.\n");
+    }
+}

src/hash.h

@@ -0,0 +1,145 @@
+/* hash.h - hash management.
+ *
+ * Copyright (C) 2024 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#ifndef HASH_H
+#define HASH_H
+
+#include <brlib.h>
+#include <bug.h>
+
+#include "chessdefs.h"
+#include "move.h"
+
+#define ENTRIES_PER_BUCKET   4                    /* buckets per hash table entry */
+
+#define HASH_SIZE_DEFAULT   32                    /* default: 32Mb */
+#define HASH_SIZE_MIN        1
+#define HASH_SIZE_MAX    32768                    /* 32Gb */
+
+#define TT_MISS   NULL
+#define TT_DUP    (void *) U64(0x01)
+#define TT_OK(p)  ((p) > (void *)U64(0xF))
+
+typedef u64 hkey_t;                               /* cannot use typedef for key_t */
+
+/**
+ * hash_short: get the most significant 7 nibble of a 64 bits value.
+ */
+#define hash_short(hash)  ((hash) >> (64 - 4 * 7))
+
+/**
+ * hentry_t: hashtable bucket.
+ *
+ * Size should be exactly 16 bytes. If impossible to fit necessary data in
+ * 16 bytes in future, it should be updated to be exactly 32 bytes.
+ */
+typedef struct {
+    hkey_t key;                                   /* zobrist */
+    union {
+        u64 data;
+        struct {
+            u16 depth;                            /* ply in search */
+            s16 eval;
+            move_t move;
+            //u8 flags;                             /* maybe for locking, etc... */
+            //u8 filler;
+        };
+    };
+} hentry_t;
+
+/* hentry perft data:
+ * 0-47:  perft value
+ * 48-63: depth
+ */
+#define HASH_PERFT_MASK        U64(0xffffffffffff)
+#define HASH_PERFT(depth, val) ((((u64) depth) << 48) | ((val) & HASH_PERFT_MASK))
+#define HASH_PERFT_VAL(data)   ((data) & HASH_PERFT_MASK)
+#define HASH_PERFT_DEPTH(data) ((u16)((data) >> 48))
+
+
+typedef struct {
+    hentry_t entry[ENTRIES_PER_BUCKET];
+} bucket_t;
+
+typedef struct {
+    bucket_t *keys;                               /* &hashtable entries */
+
+    /* memory size in bytes/mb */
+    size_t bytes;
+    u32  mb;
+
+    /* size in buckets/keys */
+    size_t nbuckets;
+    size_t nkeys;                                 /* nbuckets * NBUCKETS */
+
+    /* internal representation */
+    u32  nbits;                                   /* #buckets in bits, power of 2 */
+    u32  mask;                                    /* nbuckets - 1, key mask */
+
+    /* stats - unsure about usage */
+    //size_t used_buckets;
+    size_t used_keys;
+    u64 collisions;
+    u64 hits;
+    u64 misses;
+} hasht_t;
+
+/* hack:
+ *  ep zobrist key index is 0-7 for each en-passant file, 8 for SQUARE_NONE.
+ * To transform :
+ *   - ep == 64 (SQUARE_NONE) to id = 8
+ *   - ep == 0~63 to idx = sq_file(ep), i.e. (ep & 7)
+ * we use the formula:
+ * idx = ( ( ep & SQUARE_NONE ) >> 3 ) | sq_file(ep);
+ */
+#define EP_ZOBRIST_IDX(ep) ( ( ( ep & SQUARE_NONE ) >> 3 ) | sq_file(ep) )
+
+extern hkey_t zobrist_pieces[16][64];
+extern hkey_t zobrist_castling[4 * 4 + 1];
+extern hkey_t zobrist_turn;                        /* for black, XOR each ply */
+extern hkey_t zobrist_ep[9];                       /* 0-7: ep file, 8: SQUARE_NONE */
+
+extern hasht_t hash_tt;                           /* main transposition table */
+
+void zobrist_init(void);
+hkey_t zobrist_calc(pos_t *pos);
+
+#ifdef ZOBRIST_VERIFY
+bool zobrist_verify(pos_t *pos);
+#else
+#define zobrist_verify(p) true
+#endif
+
+/**
+ * tt_prefetch() - prefetch hash table entry
+ * @hash: u64 key
+ *
+ * Prefetch memory for @key.
+ */
+static inline void tt_prefetch(hkey_t key)
+{
+    bug_on(!hash_tt.keys);
+    __builtin_prefetch(hash_tt.keys + (key & hash_tt.mask));
+}
+
+int tt_create(int Mb);
+void tt_clear(void);
+void tt_delete(void);
+
+hentry_t *tt_probe(hkey_t key);
+hentry_t *tt_probe_perft(const hkey_t key, const u16 depth);
+hentry_t *tt_store_perft(const hkey_t key, const u16 depth, const u64 nodes);
+void tt_info(void);
+void tt_stats(void);
+
+#endif  /* HASH_H */

src/hist.c

@@ -0,0 +1,165 @@
+/* hist.c - history management.
+ *
+ * Copyright (C) 2024 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#include <brlib.h>
+#include <bug.h>
+
+#include "position.h"
+#include "hash.h"
+#include "move.h"
+#include "hist.h"
+
+hist_t hist = {
+    .nstates = 1,
+    { { .move = MOVE_NONE, .key = U64(0), .prev = &hist.state[0] } },
+};
+
+/**
+ * hist_init() - initialize history states data.
+ *
+ * This should be done every time a new position must be handled.
+ */
+void hist_init(void)
+{
+    hist.nstates       = 1;
+    hist.state[0].key  = U64(0);
+    hist.state[0].move = MOVE_NONE;
+    hist.state[0].prev = &hist.state[0];
+}
+
+/**
+ * hist_push() - add a state to hist list
+ * @st:   &state_t to add
+ *
+ * Used to add moves when the UCI "position" command includes moves.
+ * These moves, but last one, should be pushed. Last move should be
+ * linked to hist with @hist_link().
+ */
+void hist_push(state_t *st) //, move_t *move)
+{
+    int last = hist.nstates++;
+
+    bug_on(last >= HIST_SIZE);
+    hist.state[last] = *st;
+    hist.state[last].prev = &hist.state[last - 1];
+    // hist.state[last].move = *move;
+}
+
+/**
+ * hist_link() - link a position to last hist element.
+ * @pos:   &pos_t to link
+ *
+ * Used to add position resulting from last "move" in UCI "position" command.
+ * All other moves in UCI "position" command should be pushed instead, with
+ * hist_push().
+ */
+void hist_link(pos_t *pos)
+{
+    pos->prev = hist_last();
+}
+
+/**
+ * hist_pop() - return last state from hist entry, and remove it from list
+ *
+ * Not used, only for debug.
+ */
+state_t *hist_pop(void)
+{
+    if (hist.nstates > 1)
+        hist.nstates--;
+    return hist_last();
+}
+
+/**
+ * hist_last() - return last state from hist.
+ */
+state_t *hist_last(void)
+{
+    return hist.state + hist.nstates - 1;
+}
+
+/**
+ * hist_prev() - return a state's ancestor.
+ * @st: &state_t state
+ *
+ * No test is done on ancestor. Caller should check it is different
+ * from HIST_START.
+ */
+state_t *hist_prev(state_t *st)
+{
+    return st->prev;
+}
+
+/**
+ * hist_prev2() - return a state's second ancestor.
+ * @st: &state_t state
+ *
+ * No test is done on ancestors. Caller should check it is different
+ * from HIST_START.
+ */
+state_t *hist_prev2(state_t *st)
+{
+    return st->prev->prev;
+}
+
+/**
+ * hist_prev4() - return a state's 4th ancestor.
+ * @st: &state_t state
+ *
+ * No test is done on ancestors. Caller should check it is different
+ * from HIST_START.
+ */
+state_t *hist_prev4(state_t *st)
+{
+    return st->prev->prev->prev->prev;
+}
+
+/**
+ * hist_static_print() - print hist entries
+ */
+void hist_static_print(void)
+{
+    char movestr[8];
+    state_t *st =  hist_last();
+
+    printf("UCI state history: ");
+    while (true) {
+        printf("%s(#%lx) ",
+               move_to_str(movestr, st->move, 0),
+               hash_short(st->key));
+        if (st == HIST_START)
+            break;
+        st = hist_prev(st);
+    }
+    printf("\n");
+}
+
+/**
+ * hist_print() - print position history
+ * @pos: &pos to start from
+ */
+void hist_print(pos_t *pos)
+{
+    char movestr[8];
+    state_t *st = &pos->state;
+    printf("position states history: ");
+    while (true) {
+        printf("%s(#%lx) ",
+               move_to_str(movestr, st->move, 0),
+               hash_short(st->key));
+        if (st == HIST_START)
+            break;
+        st = hist_prev(st);
+    }
+    printf("\n");
+}

src/hist.h

@@ -0,0 +1,61 @@
+/* hist.h - history management.
+ *
+ * Copyright (C) 2024 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#ifndef HIST_H
+#define HIST_H
+
+#include <brlib.h>
+#include <bug.h>
+
+#include "position.h"
+#include "hash.h"
+
+#define HIST_SIZE 4096                            /* I know, I know... */
+
+/**
+ * hist - history states data.
+ *
+ * This variable is of type hist_t, which contains:
+ * @state:    state_t array, size HIST_SIZE
+ * @nstates:  current number of @state
+ *
+ * hist contains moves already played.
+ *
+ * Only HIST_SIZE - 1 hist elements are available, as the first element is
+ * used as a sentinel value (hist[0].state.prev = &hist[0].state).
+ * This first element allows multiple backards searches (p->prev->prev).
+ *
+ * hist is only written by main thread, and read by other threads/processes,
+ * therefore is never duplicated (even after a fork(), due to COW).
+ */
+typedef struct {
+    int nstates;
+    state_t state[HIST_SIZE];
+} hist_t;
+
+extern hist_t hist;
+
+#define HIST_START  (hist.state)
+
+void hist_init(void);
+void hist_push(state_t *st); //, move_t *move);
+void hist_link(pos_t *pos);
+state_t *hist_pop(void);
+state_t *hist_last(void);
+state_t *hist_prev(state_t *st);
+state_t *hist_prev2(state_t *st);
+state_t *hist_prev4(state_t *st);
+void hist_static_print(void);
+void hist_print(pos_t *pos);
+
+#endif  /* HIST_H */

src/hyperbola-quintessence.c

@@ -0,0 +1,210 @@
+/* hyperbola-quintessence.c - hyperbola quintessence functions.
+ *
+ * Copyright (C) 2024 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#include <stdio.h>
+#include <stdarg.h>
+
+#include <brlib.h>
+
+#include "chessdefs.h"
+#include "board.h"
+#include "bitboard.h"
+#include "hyperbola-quintessence.h"
+
+
+uchar bb_rank_attacks[64 * 8];
+
+/**
+ * hyperbola_init() - init hyperbola quintessence attack bitboards
+ *
+ * See: https://www.chessprogramming.org/Kindergarten_Bitboards
+ * and  https://www.chessprogramming.org/Hyperbola_Quintessence
+ *
+ *
+ * Rank attacks table:
+ * bb_rank_hyperbola[512 = 9 bits], indexed by oooooofff where:
+ *   - O = oooooo: occupation of inner 6 bits on rank
+ *   - F = fff:    file of sliding piece
+ * The index is built as (oooooo << 3 + fff), = ((O << 3) + F), where:
+ *   - O = all combinations of 6 bits (loop from 0 to 64)
+ *   - F = all files (loop from 0 to 7)
+ * To retrieve the index, given an 8 bits mask M=XooooooX, and a file F=fff,
+ * we get O from M with:
+ *   1) remove bits 'X' (O = M & 01111110)
+ *   2) shift left result 2 more bits, as bit 0 is unused and already cleared:
+ *      (O <<= 2)
+ *
+ * TODO ? create masks excluding slider (eg. bb_diag ^ bb_sq[square]),
+ * to save one operation in hyperbola_moves().
+ * TODO ? replace rank attack with this idea, mapping rank to diagonal ?
+ * See http://timcooijmans.blogspot.com/2014/04/
+ */
+void hyperbola_init()
+{
+    /* generate rank attacks, not handled by HQ
+     */
+    for (int occ = 0; occ < 64; ++occ) {
+        for (int file = 0; file < 8; ++file) {
+            int attacks = 0;
+            //int o = mask << 1;                    /* skip right square */
+
+            /* set f left attacks */
+            for (int slide = file - 1; slide >= 0; --slide) {
+                int b = bb_sq[slide];             /* bit to consider */
+                attacks |= b;                     /* add to attack mask */
+                if ((occ << 1) & b)               /* piece on b, we stop */
+                    break;
+            }
+            /* set f right attacks */
+            for (int slide = file + 1; slide < 8; ++slide) {
+                int b = bb_sq[slide];
+                attacks |= b;
+                if ((occ << 1) & b)               /* piece on b, we stop */
+                    //if ((o & b) == b)
+                    break;
+            }
+            bb_rank_attacks[(occ << 3) + file] = attacks;
+
+            //if (((occ << 3) + file) == 171) {
+            //char str[64], str2[64];
+               //printf("mask=%x=%s file=%d att=%x=%s\n",
+               //       occ, bitboard_rank_sprint(str, occ), file,
+               //       attacks, bitboard_rank_sprint(str2, attacks));
+            //}
+        }
+    }
+}
+
+/**
+ * hyperbola_rank_moves() - get rank moves for a sliding piece.
+ * @pieces: occupation bitboard
+ * @sq: piece square
+ *
+ * Rank attacks are not handled by HQ, so this function uses a pre-calculated
+ * rank attacks table (@bb_rank_attacks).
+ *
+ * @Return: bitboard of @piece available pseudo-moves.
+ */
+bitboard_t hyperbola_rank_moves(bitboard_t occ, square_t sq)
+{
+    u32 rank = sq & SQ_RANKMASK;
+    u32 file = sq & SQ_FILEMASK;
+    u64 o = (occ >> rank) & 0176;                 /* 01111110 clear bits 0 & 7 */
+    //char zob[128], zob2[128];
+    //printf("rank_moves: occ=%lx=%s file=%d o=%lx=%s index=%ld=%ld attack=%lx=%s\n", occ,
+    //       bitboard_rank_sprint(zob, occ), file, o,
+    //       bitboard_rank_sprint(zob, o), (o << 2) + file, (o * 4) + file,
+    //       (bitboard_t)bb_rank_attacks[(o << 2) + file] << rank,
+    //       bitboard_rank_sprint(zob2, (bitboard_t)bb_rank_attacks[(o << 2) + file] << rank));
+    return ((bitboard_t)bb_rank_attacks[(o << 2) + file]) << rank;
+}
+
+/**
+ * hyperbola_moves() - get hyperbola pseudo-moves for a sliding piece
+ * @pieces: occupation bitboard
+ * @sq: piece square
+ * @mask: the appropriate mask (pre-calculated)
+ *
+ * This function can be used for files, diagonal, and anti-diagonal attacks.
+ * @mask is the corresponding pre-calculated table (@bb_sqfile, @bb_sqdiag,
+ * or @bb_sqanti).
+ * See https://www.chessprogramming.org/Hyperbola_Quintessence for details.
+ *
+ * @Return: bitboard of piece available pseudo-moves.
+ */
+bitboard_t hyperbola_moves(const bitboard_t pieces, const square_t sq,
+                                   const bitboard_t mask)
+{
+    bitboard_t o = pieces & mask;
+    bitboard_t r = bswap64(o);
+    square_t  r_sq = FLIP_V(sq);
+
+    return (         (o - 2 * BIT(sq)   )
+            ^ bswap64(r - 2 * BIT(r_sq)))
+        & mask;
+}
+
+/**
+ * hyperbola_file_moves() - get file pseudo-moves for a sliding piece.
+ * @pieces: occupation bitboard
+ * @sq: piece square
+ *
+ * @Return: bitboard of piece available pseudo-moves on its file.
+ */
+bitboard_t hyperbola_file_moves(const bitboard_t occ, const square_t sq)
+{
+    return hyperbola_moves(occ, sq, bb_sqfile[sq]);
+}
+
+/**
+ * hyperbola_diag_moves() - get diagonal pseudo-moves for a sliding piece.
+ * @pieces: occupation bitboard
+ * @sq: piece square
+ *
+ * @Return: bitboard of piece available pseudo-moves on its diagonal.
+ */
+bitboard_t hyperbola_diag_moves(const bitboard_t occ, const square_t sq)
+{
+    return hyperbola_moves(occ, sq, bb_sqdiag[sq]);
+}
+
+/**
+ * hyperbola_anti_moves() - get anti-diagonal pseudo-moves for a sliding piece.
+ * @pieces: occupation bitboard
+ * @sq: piece square
+ *
+ * @Return: bitboard of piece available pseudo-moves on its anti-diagonal.
+ */
+bitboard_t hyperbola_anti_moves(const bitboard_t occ, const square_t sq)
+{
+    return hyperbola_moves(occ, sq, bb_sqanti[sq]);
+}
+
+/**
+ * hyperbola_bishop_moves() - get bitboard of bishop pseudo-moves
+ * @occ: occupation bitboard
+ * @sq: bishop square
+ *
+ * @Return: bitboard of bishop available pseudo-moves.
+ */
+bitboard_t hyperbola_bishop_moves(const bitboard_t occ, const square_t sq)
+{
+    return hyperbola_diag_moves(occ, sq) | hyperbola_anti_moves(occ, sq);
+}
+
+/**
+ * hyperbola_rook_moves() - get bitboard of rook pseudo-moves
+ * @occ: occupation bitboard
+ * @sq: rook square
+ *
+ * @Return: bitboard of rook available pseudo-moves.
+ */
+bitboard_t hyperbola_rook_moves(const bitboard_t occ, const square_t sq)
+{
+    return hyperbola_file_moves(occ, sq) | hyperbola_rank_moves(occ, sq);
+}
+
+/**
+ * hyperbola_queen_moves() - get bitboard of queen pseudo-moves
+ * @occ: occupation bitboard
+ * @sq: queen square
+ *
+ * This function is a wrapper over @hyperbola_bishop_moves() and
+ * @hyperbola_rook_moves().
+ *
+ * @Return: bitboard of queen available pseudo-moves.
+ */
+bitboard_t hyperbola_queen_moves(const bitboard_t occ, const square_t sq)
+{
+    return hyperbola_bishop_moves(occ, sq) | hyperbola_rook_moves(occ, sq);
+}

src/hyperbola-quintessence.h

@@ -0,0 +1,33 @@
+/* hyperbola-quintessence.h - hyperbola-quintessence definitions.
+ *
+ * Copyright (C) 2024 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#ifndef _HYPERBOLA_QUINTESSENCE_H
+#define _HYPERBOLA_QUINTESSENCE_H
+
+#include "board.h"
+#include "bitboard.h"
+
+void hyperbola_init(void);
+
+bitboard_t hyperbola_rank_moves(const bitboard_t occ, const square_t sq);
+bitboard_t hyperbola_moves(const bitboard_t pieces, const square_t sq,
+                           const bitboard_t mask);
+bitboard_t hyperbola_file_moves(const bitboard_t occ, const square_t sq);
+bitboard_t hyperbola_diag_moves(const bitboard_t occ, const square_t sq);
+bitboard_t hyperbola_anti_moves(const bitboard_t occ, const square_t sq);
+
+bitboard_t hyperbola_bishop_moves(const bitboard_t occ, const square_t sq);
+bitboard_t hyperbola_rook_moves(const bitboard_t occ, const square_t sq);
+bitboard_t hyperbola_queen_moves(const bitboard_t occ, const square_t sq);
+
+#endif  /* _HYPERBOLA_QUINTESSENCE_H */

src/init.c

@@ -0,0 +1,56 @@
+/* init.c - initialize all.
+ *
+ * Copyright (C) 2024 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <locale.h>
+
+#include "chessdefs.h"
+
+#include "bitboard.h"
+#include "hyperbola-quintessence.h"
+
+#include "hash.h"
+#include "hist.h"
+
+#define printff(x) ({ printf(x); fflush(stdout); })
+void init_all(void)
+{
+    /* line-buffered stdout */
+    printff("initiazing stdout buffering... ");
+    setlinebuf(stdout);
+
+    /* for printf() numeric thousands separator */
+    printff("locale... ");
+    setlocale(LC_NUMERIC, "");
+
+    /* pseudo random generator seed */
+    printff("random generator... ");
+    rand_init(RAND_SEED_DEFAULT);
+
+    /* bitboards & hq */
+    printff("bitboards... ");
+    bitboard_init();
+
+    printff("hq bitboards... ");
+    hyperbola_init();
+
+    /* zobrist tables & default tt hashtable */
+    printff("zobrist tables... ");
+    zobrist_init();
+
+    printff("transposition tables... ");
+    tt_create(HASH_SIZE_DEFAULT);
+
+    printf("done.\n");
+}

src/misc.c

@@ -0,0 +1,152 @@
+/* misc.c - generic/catchall functions.
+ *
+ * Copyright (C) 2024 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#include <time.h>
+#include <stdlib.h>
+
+#include <bug.h>
+
+#include "chessdefs.h"
+
+/*
+ * 1 sec      = 1000 millisec
+ * 1 millisec = 1000 microsec
+ * 1 microsec = 1000 nanosec
+ * milli = sec * 1000 + nanosec / 1000000
+ *
+ */
+
+/* We use microsec for all intermediate calcluation */
+#define NANO_IN_MICRO  1000ll                     /* nanosecond in millisecond */
+#define MICRO_IN_SEC   1000000ll                  /* millisecond in second */
+
+#define MILLI_IN_SEC   1000ll                     /* millisecond in second */
+
+#define MICRO_IN_MILLI 1000ll
+
+//#define NANO_IN_MILLI  1000000ll                         /* nanosecond in millisecond */
+//#define NANO_IN_SEC    (NANOS_IN_MS * MS_IN_SEC)
+
+
+/**
+ * clock_start - start or restart a clock.
+ * @clock: &mclock_t clock
+ *
+ * Save current time according to @clock type.
+ */
+void clock_start(mclock_t *clock)
+{
+    clock_gettime(clock->clocktype, &clock->start);
+}
+
+/**
+ * clock_init - initializes a clock type.
+ * @clock: &mclock_t clock
+ * @type: clock type
+ *
+ * See the clock_gettime(2) for details.
+ * CLOCK_WALL (a.k.a CLOCK_REALTIME): Wall clock.
+ * CLOCK_SYSTEM (a.k.a CLOCK_MONOTONIC_RAW): System clock.
+ * CLOCK_PROCESS (a.k.a CLOCK_PROCESS_CPUTIME_ID): Process CPU clock (incl. threads).
+ * CLOCK_THREAD  (a.k.a CLOCK_THREAD_CPUTIME_ID): Thread CPU clock.
+ */
+void clock_init(mclock_t *clock, clockid_t type)
+{
+    clock->clocktype = type;
+    clock_start(clock);
+}
+
+/**
+ * clock_elapsed_μs - return a mclock_t elapsed time in microseconds.
+ * @clock: &mclock_t clock
+ *
+ * The elapsed time is calculated between current time and last clock_start(@clock)
+ * call time.
+ *
+ * @return: microseconds elapsed since last clock_start().
+ */
+s64 clock_elapsed_μs(mclock_t *clock)
+{
+    struct timespec current;
+    s64 μs;
+
+    clock_gettime(clock->clocktype, &current);
+    μs = ((s64)current.tv_sec - (s64)clock->start.tv_sec) * MICRO_IN_SEC +
+        ((s64)current.tv_nsec - (s64)clock->start.tv_nsec) / NANO_IN_MICRO ;
+    return μs;
+}
+
+/**
+ * clock_elapsed_ms - return a mclock_t elapsed time in milliseconds.
+ * @clock: &mclock_t clock
+ *
+ * The elapsed time is calculated between current time and last clock_start(@clock)
+ * call time.
+ *
+ * @return: milliseconds elapsed since last clock_start().
+ */
+s64 clock_elapsed_ms(mclock_t *clock)
+{
+    return clock_elapsed_μs(clock) / MICRO_IN_MILLI;
+}
+
+/**
+ * clock_elapsed_sec - return a mclock_t elapsed time in seconds.
+ * @clock: &mclock_t clock
+ *
+ * The elapsed time is calculated between current time and last clock_start(@clock)
+ * call time.
+ *
+ * @return: seconds elapsed since last clock_start().
+ */
+double clock_elapsed_sec(mclock_t *clock)
+{
+    return (double) clock_elapsed_μs(clock) / (double) MICRO_IN_SEC;
+}
+
+static u64 rand_seed = 1ull;
+
+/**
+ * rand_init() - initialize random generator seed.
+ * @seed: u64, the random generator seed.
+ *
+ * No change is made is performed if If @seed is zero. By default, @seed is
+ * 1.
+ * This seed is used by rand64().
+ */
+void rand_init(u64 seed)
+{
+    if (seed)
+        rand_seed = seed;
+}
+
+/**
+ * rand64() - get a random number, xorshift method.
+ *
+ * Source:
+ *   https://en.wikipedia.org/wiki/Xorshift#xorshift*
+ * We do not want true random numbers, like those offered by getrandom(2), as we
+ * need to be able to get predictable results.
+ * Note: For predictable results in MT, we should use separate seeds.
+ *
+ * @return: a 64 bits random number.
+ */
+u64 rand64(void)
+{
+    bug_on(rand_seed == 0ull);
+
+    rand_seed ^= rand_seed >> 12;
+    rand_seed ^= rand_seed << 25;
+    rand_seed ^= rand_seed >> 27;
+    return rand_seed * 0x2545f4914f6cdd1dull;
+}

src/misc.h

@@ -0,0 +1,47 @@
+/* util.h - various util functions.
+ *
+ * Copyright (C) 2024 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#ifndef _UTIL_H
+#define _UTIL_H
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "chessdefs.h"
+
+#undef safe_malloc
+#undef safe_free
+
+/* force BUG_ON, to get a program abort for failed malloc/free
+ */
+#pragma push_macro("BUG_ON")
+#undef BUG_ON
+#define BUG_ON
+#include <bug.h>
+
+#define safe_malloc(size) ({                   \
+            void *_ret = malloc(size);         \
+            bug_on(_ret == NULL);              \
+            _ret;                              \
+        })
+
+#define safe_free(ptr) do {                    \
+        bug_on(ptr == NULL);                   \
+        free(ptr);                             \
+    } while (0)
+
+/* restore BUG_ON
+ */
+#pragma pop_macro("BUG_ON")
+
+#endif  /* UTIL_H */

src/move-do.c

@@ -0,0 +1,365 @@
+/* move-do.c - move do/undo.
+ *
+ * Copyright (C) 2021-2024 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#include <malloc.h>
+#include <ctype.h>
+#include <stdlib.h>
+
+#include <brlib.h>
+#include <likely.h>
+#include <bug.h>
+
+#include "chessdefs.h"
+#include "move.h"
+#include "position.h"
+#include "move-do.h"
+#include "hash.h"
+
+/**
+ * move_do() - do move.
+ * @pos:    &pos_t position
+ * @move:   move to apply
+ * @state:  &state_t address where irreversible changes will be saved
+ *
+ * @move is applied to @pos:
+ * - bitboards and board are updated
+ * - counters are updated:
+ *   - move count
+ *   - 50-moves rule count
+ * - flags are possibly updated:
+ *   - castling
+ *   - en-passant
+ * - captured piece (excl. en-passant)
+ * - tt hash values are updated for:
+ *   - side-to-move
+ *   - en-passant
+ *   - castling rights.
+ *
+ * @return: updated pos.
+ */
+pos_t *move_do(pos_t *pos, const move_t move, state_t *state)
+{
+    color_t us = pos->turn, them = OPPONENT(us);
+    square_t from = move_from(move), to = move_to(move);
+    piece_t piece = pos->board[from];
+    piece_t captured = pos->board[to];
+    piece_type_t ptype = PIECE(piece);
+    piece_t new_piece = piece;
+    int up = sq_up(us);
+    hkey_t key = pos->key;
+
+    *state = pos->state;                          /* save irreversible changes */
+
+    /* update key: switch turn, reset castling and ep */
+    key ^= zobrist_turn;
+    key ^= zobrist_castling[pos->castle];
+    key ^= zobrist_ep[EP_ZOBRIST_IDX(pos->en_passant)];
+
+    ++pos->clock_50;
+    ++pos->plycount;
+    pos->en_passant = SQUARE_NONE;
+    pos->turn = them;
+    pos->captured = captured;
+    pos->move = move;
+
+    bug_on(COLOR(piece) != us);
+
+    if (is_promotion(move)) {
+        bug_on(sq_rank(to) != sq_rel_rank(RANK_8, us));
+        new_piece = MAKE_PIECE(move_promoted(move), us);
+    }
+
+    if (captured != EMPTY) {
+        pos->clock_50 = 0;
+        bug_on(pos->board[to] == EMPTY || COLOR(pos->captured) != them);
+        key ^= zobrist_pieces[captured][to];
+        pos_clr_sq(pos, to);                      /* clear square */
+    } else if (is_castle(move)) {                 /* handle rook move */
+        square_t rookfrom, rookto;
+        if (to > from) {
+            rookfrom = sq_rel(H1, us);
+            rookto = sq_rel(F1, us);
+        } else {
+            rookfrom = sq_rel(A1, us);
+            rookto = sq_rel(D1, us);
+        }
+        key ^= zobrist_pieces[pos->board[rookfrom]][rookto] ^
+            zobrist_pieces[pos->board[rookfrom]][rookfrom];
+        pos_set_sq(pos, rookto, pos->board[rookfrom]);
+        pos_clr_sq(pos, rookfrom);
+        pos->castle = clr_castle(pos->castle, us);
+    } else if (ptype == PAWN) {                   /* pawn non capture or e.p. */
+        pos->clock_50 = 0;
+        if (from + up + up == to) {               /* if pawn double push, set e.p. */
+            square_t ep = from + up;
+            if (bb_pawn_attacks[us][ep] & pos->bb[them][PAWN]) {
+                pos->en_passant = ep;
+                key ^= zobrist_ep[EP_ZOBRIST_IDX(pos->en_passant)];
+            }
+        } else if (is_enpassant(move)) {          /* clear grabbed pawn */
+            square_t grabbed = to - up;
+            piece_t pc = pos->board[grabbed];
+            key ^= zobrist_pieces[pc][grabbed];
+            pos_clr_sq(pos, grabbed);
+        }
+    }
+
+    key ^= zobrist_pieces[piece][from] ^ zobrist_pieces[new_piece][to];
+    pos_clr_sq(pos, from);                        /* clear "from" and set "to" */
+    pos_set_sq(pos, to, new_piece);
+
+    if (ptype == KING)
+        pos->king[us] = to;
+
+    /* update castling flags
+     * As we always consider flags are valid, we :
+     * - adjust our flags if relative from is "E1", "A1", H1"
+     * - adjust opp flags if relative to   if "A8", H8"
+     */
+    if (can_castle(pos->castle, us)) {            /* do we save time with this test ? */
+        square_t rel_e1 = sq_rel(E1, us);
+        square_t rel_a1 = sq_rel(A1, us);
+        square_t rel_h1 = sq_rel(H1, us);
+        if (from == rel_e1)
+            pos->castle = clr_castle(pos->castle, us);
+        else if (from == rel_a1)
+            pos->castle = clr_ooo(pos->castle, us);
+        else if (from == rel_h1)
+            pos->castle = clr_oo(pos->castle, us);
+    }
+    if (can_castle(pos->castle, them)) {
+        square_t rel_a8 = sq_rel(A8, us);
+        square_t rel_h8 = sq_rel(H8, us);
+        if (to == rel_a8)
+            pos->castle = clr_ooo(pos->castle, them);
+        else if (to == rel_h8)
+            pos->castle = clr_oo(pos->castle, them);
+    }
+
+    /* update castling rights key */
+    key ^= zobrist_castling[pos->castle];
+
+    pos->key = key;
+
+    zobrist_verify(pos);
+
+    return pos;
+}
+
+/**
+ * move_undo() - undo move.
+ * @pos:    &pos_t position
+ * @move:   move to undo
+ * @state:  &state_t address where irreversible changes were saved
+ *
+ * @move is applied to @pos:
+ * - bitboards and board are updated
+ * - previous information is restored:
+ *   - castling
+ *   - en-passant
+ *   - captured piece (excl. en-passant)
+ *   - move count
+ *   - 50-moves rule count
+ *
+ * @return: pos.
+ */
+pos_t *move_undo(pos_t *pos, const move_t move, const state_t *state)
+{
+    color_t them = pos->turn, us = OPPONENT(them);
+    square_t from = move_from(move), to = move_to(move);
+    piece_t piece = pos->board[to];
+    int up = sq_up(them);
+
+    if (is_promotion(move))
+        piece = MAKE_PIECE(PAWN, us);
+
+    pos_clr_sq(pos, to);                          /* always clear "to" ... */
+    pos_set_sq(pos, from, piece);                 /* ... and set "from" */
+
+    if (PIECE(piece) == KING)
+        pos->king[us] = from;
+
+    if (pos->captured != EMPTY) {
+        pos_set_sq(pos, to, pos->captured);       /* restore captured piece */
+    } else if (is_castle(move)) {                 /* make reverse rook move */
+        square_t rookfrom, rookto;
+        if (to > from) {
+            rookfrom = sq_rel(F1, us);
+            rookto = sq_rel(H1, us);
+        } else {
+            rookfrom = sq_rel(D1, us);
+            rookto = sq_rel(A1, us);
+        }
+        pos_set_sq(pos, rookto, pos->board[rookfrom]);
+        pos_clr_sq(pos, rookfrom);
+    } else if (is_enpassant(move)) {              /* restore grabbed pawn */
+        square_t grabbed = to + up;
+        pos_set_sq(pos, grabbed, MAKE_PIECE(PAWN, them));
+    }
+
+    pos->state = *state;                          /* restore irreversible changes */
+    pos->turn = us;
+    return pos;
+}
+
+/**
+ * move_{do,undo}_alt - alternative move_do/move_undo (to experiment)
+ */
+pos_t *move_do_alt(pos_t *pos, const move_t move, state_t *state)
+{
+    color_t us = pos->turn, them = OPPONENT(us);
+    square_t from = move_from(move), to = move_to(move);
+    piece_t piece = pos->board[from];
+    piece_t captured = pos->board[to];
+    piece_type_t ptype = PIECE(piece);
+    piece_t new_piece = piece;
+    int up = sq_up(us);
+    hkey_t key = pos->key;
+
+    *state = pos->state;                          /* save irreversible changes */
+
+    /* update key: switch turn, reset castling and ep */
+    key ^= zobrist_turn;
+    key ^= zobrist_castling[pos->castle];
+    key ^= zobrist_ep[EP_ZOBRIST_IDX(pos->en_passant)];
+
+    ++pos->clock_50;
+    ++pos->plycount;
+    pos->en_passant = SQUARE_NONE;
+    pos->turn = them;
+    pos->captured = captured;
+    pos->move = move;
+
+    bug_on(COLOR(piece) != us);
+
+    if (is_promotion(move)) {
+        bug_on(sq_rank(to) != sq_rel_rank(RANK_8, us));
+        new_piece = MAKE_PIECE(move_promoted(move), us);
+    }
+
+    if (captured != EMPTY) {
+        pos->clock_50 = 0;
+        //pos->captured = pos->board[to];           /* save capture info */
+        bug_on(pos->board[to] == EMPTY || COLOR(pos->captured) != them);
+        key ^= zobrist_pieces[captured][to];
+        pos_clr_sq(pos, to);                      /* clear square */
+    } else if (is_castle(move)) {                 /* handle rook move */
+        square_t rookfrom, rookto;
+        if (to > from) {
+            rookfrom = sq_rel(H1, us);
+            rookto = sq_rel(F1, us);
+        } else {
+            rookfrom = sq_rel(A1, us);
+            rookto = sq_rel(D1, us);
+        }
+        key ^= zobrist_pieces[pos->board[rookfrom]][rookto] ^
+            zobrist_pieces[pos->board[rookfrom]][rookfrom];
+        pos_set_sq(pos, rookto, pos->board[rookfrom]);
+        pos_clr_sq(pos, rookfrom);
+        pos->castle = clr_castle(pos->castle, us);
+    } else if (ptype == PAWN) {                   /* pawn non capture or e.p. */
+        pos->clock_50 = 0;
+        if (from + up + up == to) {               /* if pawn double push, set e.p. */
+            square_t ep = from + up;
+            if (bb_pawn_attacks[us][ep] & pos->bb[them][PAWN]) {
+                pos->en_passant = ep;
+                key ^= zobrist_ep[EP_ZOBRIST_IDX(pos->en_passant)];
+            }
+        } else if (is_enpassant(move)) {          /* clear grabbed pawn */
+            square_t grabbed = to - up;
+            piece_t pc = pos->board[grabbed];
+            key ^= zobrist_pieces[pc][grabbed];
+            pos_clr_sq(pos, grabbed);
+        }
+    }
+
+    key ^= zobrist_pieces[piece][from] ^ zobrist_pieces[new_piece][to];
+    pos_clr_sq(pos, from);                        /* clear "from" and set "to" */
+    pos_set_sq(pos, to, new_piece);
+
+    if (ptype == KING)
+        pos->king[us] = to;
+
+    /* update castling flags
+     * As we always consider flags are valid, we :
+     * - adjust our flags if relative from is "E1", "A1", H1"
+     * - adjust opp flags if relative to   if "A8", H8"
+     */
+    if (can_castle(pos->castle, us)) {            /* do we save time with this test ? */
+        square_t rel_e1 = sq_rel(E1, us);
+        square_t rel_a1 = sq_rel(A1, us);
+        square_t rel_h1 = sq_rel(H1, us);
+        if (from == rel_e1)
+            pos->castle = clr_castle(pos->castle, us);
+        else if (from == rel_a1)
+            pos->castle = clr_ooo(pos->castle, us);
+        else if (from == rel_h1)
+            pos->castle = clr_oo(pos->castle, us);
+    }
+    if (can_castle(pos->castle, them)) {
+        square_t rel_a8 = sq_rel(A8, us);
+        square_t rel_h8 = sq_rel(H8, us);
+        if (to == rel_a8)
+            pos->castle = clr_ooo(pos->castle, them);
+        else if (to == rel_h8)
+            pos->castle = clr_oo(pos->castle, them);
+    }
+
+    /* update castling rights key */
+    key ^= zobrist_castling[pos->castle];
+
+    pos->key = key;
+
+    zobrist_verify(pos);
+
+    return pos;
+}
+
+pos_t *move_undo_alt(pos_t *pos, const move_t move, const state_t *state)
+{
+    color_t them = pos->turn, us = OPPONENT(them);
+    square_t from = move_from(move), to = move_to(move);
+    piece_t piece = pos->board[to];
+    int up = sq_up(them);
+
+    if (is_promotion(move))
+        piece = MAKE_PIECE(PAWN, us);
+
+    pos_clr_sq(pos, to);                          /* always clear "to" ... */
+    pos_set_sq(pos, from, piece);                 /* ... and set "from" */
+
+    if (PIECE(piece) == KING)
+        pos->king[us] = from;
+
+    if (pos->captured != EMPTY) {
+        pos_set_sq(pos, to, pos->captured);       /* restore captured piece */
+    } else if (is_castle(move)) {                 /* make reverse rook move */
+        square_t rookfrom, rookto;
+        if (to > from) {
+            rookfrom = sq_rel(F1, us);
+            rookto = sq_rel(H1, us);
+        } else {
+            rookfrom = sq_rel(D1, us);
+            rookto = sq_rel(A1, us);
+        }
+        pos_set_sq(pos, rookto, pos->board[rookfrom]);
+        pos_clr_sq(pos, rookfrom);
+    } else if (is_enpassant(move)) {              /* restore grabbed pawn */
+        square_t grabbed = to + up;
+        pos_set_sq(pos, grabbed, MAKE_PIECE(PAWN, them));
+    }
+
+    pos->state = *state;                          /* restore irreversible changes */
+    pos->turn = us;
+    return pos;
+}

src/move-do.h

@@ -0,0 +1,26 @@
+/* move-do.h - move do/undo.
+ *
+ * Copyright (C) 2021-2024 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#ifndef MOVE_DO_H
+#define MOVE_DO_H
+
+#include "position.h"
+
+pos_t *move_do(pos_t *pos, const move_t move, state_t *state);
+pos_t *move_undo(pos_t *pos, const move_t move, const state_t *state);
+
+/* new version testing */
+pos_t *move_do_alt(pos_t *pos, const move_t move, state_t *state);
+pos_t *move_undo_alt(pos_t *pos, const move_t move, const state_t *state);
+
+#endif  /* MOVE_DO_H */

src/move-gen.c

@@ -0,0 +1,482 @@
+/* move-gen.c - move generation
+ *
+ * Copyright (C) 2024 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#include <stdio.h>
+
+#include "bitops.h"
+#include "bug.h"
+
+#include "chessdefs.h"
+#include "board.h"
+#include "bitboard.h"
+#include "piece.h"
+#include "position.h"
+#include "move.h"
+#include "hyperbola-quintessence.h"
+#include "attack.h"
+#include "move-gen.h"
+
+/**
+ * pseudo_is_legal() - check if a move is legal.
+ * @pos:  position
+ * @move: move_t to verify
+ *
+ * @return: true if move is valid, false otherwise.
+ */
+bool pseudo_is_legal(const pos_t *pos, const move_t move)
+{
+    color_t  us       = pos->turn;
+    color_t them      = OPPONENT(us);
+    square_t from     = move_from(move);
+    square_t to       = move_to(move);
+    square_t kingsq   = pos->king[us];
+    square_t ep       = pos->en_passant;
+    bitboard_t kingbb = pos->bb[us][KING];
+    bitboard_t occ    = pos_occ(pos);
+    u64 pinned        = BIT(from) & pos->blockers;
+    u64 checkers      = pos->checkers;
+
+    bug_on(pos->board[from] == NO_PIECE || COLOR(pos->board[from]) != us);
+
+    /* (1) - Castling & King
+     * For castling, we need to check intermediate squares attacks only.
+     * Attention: To test if K is in check after moving, we need to exclude
+     * king from occupation bitboard (to catch king moving away from checker
+     * on same line) !
+     */
+    if (is_castle(move)) {
+        int dir = to > from? 1: -1;
+        if (sq_is_attacked(pos, occ, from + dir, them))
+            return false;
+    }
+    if (from == kingsq) {
+        return !sq_is_attacked(pos, occ ^ kingbb, to, them);
+    }
+
+    /* (2) - King is in check
+     * Double-check is already handled in (1), as only K moves were generated
+     * by pseudo legal move generator.
+     * Special cases (illegal):
+     *   - e.p., if the grabbed pawn is *not* giving check
+     *   - piece is pinned
+     */
+    if (checkers) {
+        if (pinned)
+            return false;
+        if (is_enpassant(move)) {
+            return ep + sq_up(them) == ctz64(checkers);
+        }
+        return true;
+    }
+
+    /* (3) - pinned pieces
+     * We verify here that pinned piece P stays on line between K & dest square.
+     */
+    if (pinned) {
+        return bb_line[from][kingsq] & BIT(to);   /* is to on pinner line ? */
+    }
+
+    /* (4) - En-passant
+     * pinned piece is already handled in (3).
+     * One case not handled anywhere else: when the two "disappearing" pawns
+     * would discover a R/Q horizontal check.
+     * Note: grabbed pawn *cannot* discover a check (impossible position).
+     */
+    if (is_enpassant(move)) {
+        bitboard_t rank5 = bb_rel_rank(RANK_5, us);
+
+        if (kingbb & rank5) {
+            bitboard_t exclude = BIT(ep + sq_up(them)) | BIT(from);
+            bitboard_t rooks = (pos->bb[them][ROOK] | pos->bb[them][QUEEN]) & rank5;
+
+            return !(hyperbola_rank_moves(occ ^ exclude, kingsq) & rooks);
+        }
+    }
+    return true;
+}
+
+/**
+ * pos_next_legal() - get next legal move in position.
+ * @pos:  position
+ * @movelist: &pseudo-legal movelist
+ * @start:  &int, starting position in @movelist
+ *
+ * Get next valid move in @pos move list, from move @start, or MOVE_NONE.
+ * @start is set to next non-checked move in pseudo-legal list.
+ * Position pseudo-legal moves must be already calculated before calling this function.
+ *
+ * @return: move, or MOVE_NONE if no move.
+ */
+move_t pos_next_legal(const pos_t *pos, movelist_t *movelist, int *start)
+{
+    const int nmoves = movelist->nmoves;
+    const move_t *moves = movelist->move;
+    move_t move;
+
+    while (*start < nmoves) {
+        if (pseudo_is_legal(pos, (move = moves[(*start)++] )))
+            return  move;
+    }
+    return MOVE_NONE;
+}
+
+/**
+ * pos_legal_dup() - get legal moves from pseudo-legal ones in new list.
+ * @pos:  position
+ * @pseudo: &movelist_t pseudo-legal moves list
+ * @legal: &movelist_t legal moves
+ *
+ * The pseudo-legal moves must be already calculated before calling this function.
+ * No check is done on @legal limits.
+ * This function is similar to pos_legal(), but creates a new list for legal moves.
+ * It should only be used for debug purpose, when we want to keep a copy of
+ * pseudo-legal moves.
+ *
+ * @return: @legal
+ */
+movelist_t *pos_legal_dup(const pos_t *pos, movelist_t *pseudo, movelist_t *legal)
+{
+    int tmp = legal->nmoves = 0;
+    move_t move;
+
+    while ((move = pos_next_legal(pos, pseudo, &tmp)) != MOVE_NONE)
+        legal->move[legal->nmoves++] = move;
+    return legal;
+}
+
+/**
+ * pos_legal() - get legal moves from pseudo-legal ones in new list.
+ * @pos:  position
+ * @list: &movelist_t pseudo-legal moves list
+ *
+ * The pseudo-legal moves must be already calculated before calling this function.
+ * @list is replaced by legal moves.
+ *
+ * @return: @list
+ */
+movelist_t *pos_legal(const pos_t *pos, movelist_t *list)
+{
+    move_t *cur = list->move, *last = list->move + list->nmoves;
+
+    while (cur < last) {
+        if (pseudo_is_legal(pos, *cur))
+            cur++;
+        else {
+            *cur = *--last;
+        }
+    }
+    list->nmoves = last - list->move;
+    return list;
+}
+
+/**
+ * gen_pseudo_king() - generate king pseudo-legal moves.
+ * @pos: position
+ * @movelist: &movelist_t array to store pseudo-moves
+ *
+ */
+static inline __unused move_t *gen_pseudo_king(move_t *moves, square_t from,
+                                               bitboard_t mask)
+{
+    //color_t us    = pos->turn;
+    //square_t from = pos->king[us];
+    //bitboard_t not_my_pieces     = ~pos->bb[us][ALL_PIECES];
+    bitboard_t to_bb = bb_king_moves(mask, from);
+    square_t to;
+    while (moves) {
+        to = bb_next(&to_bb);
+        *moves++ = move_make(from, to);
+    }
+    return moves;
+}
+
+/**
+ * pos_gen_check_pseudomoves() - generate position pseudo-legal moves when in check
+ * @pos: position
+ * @movelist: &movelist_t array to store pseudo-moves
+ *
+ * Generate all @pos pseudo moves for player-to-move.
+ * @movelist is filled with the moves.
+ *
+ * Only a few validity checks are done here (i.e. moves are not generated):
+ *  - castling, if king is in check
+ *  - castling, if king passes an enemy-controlled square (not final square).
+ * When immediately known, a few move flags are also applied in these cases:
+ *  - castling: M_CASTLE_{K,Q}
+ *  - capture (excl. en-passant): M_CAPTURE
+ *  - en-passant: M_EN_PASSANT
+ *  - pawn double push: M_DPUSH
+ *  - promotion: M_PROMOTION
+ *  - promotion and capture
+ *
+ * TODO: move code to specific functions (especially castling, pawn push/capture)
+ *
+ * @Return: The total number of moves.
+ */
+
+/**
+ * gen_pseudo_escape() - generate position pseudo-legal moves when in check
+ * @pos: square_t king position
+ * @mask: possible destinations to consider
+ * @moves: &move_t array to store pseudo-moves
+ *
+ * Generate all @pos pseudo moves for player-to-move, when in check.
+ * @movelist is filled with the moves.
+ *
+ * If king is doubles-checked, only King moves will be generated.
+ * Otherwise, only moves where destination in between King or checker, or checker
+ * square.
+ *
+ */
+/*
+ * static void __always_inline gen_pseudo_escape(pos_t *pos, movelist_t *movelist)
+ * {
+ *     color_t us               = pos->turn;
+ *     color_t them             = OPPONENT(us);
+ *     square_t king            = pos->king[us];
+ *
+ *     gen_pseudo_king(pos, movelist);
+ *
+ * }
+ */
+
+/**
+ * moves_gen_flags() - generate all moves from square to bitboard (with flags).
+ * @moves: &move_t array where to store moves
+ * @from: square_t piece position
+ * @to_bb: destination bitboard
+ * @flags: flags to apply
+ *
+ * Generate (at address @moves) moves from square @from to each square in @to_bb,
+ * with flags @flags.
+ *
+ * @Return: New @moves.
+ */
+static inline __unused move_t *moves_gen_flags(move_t *moves, square_t from, bitboard_t to_bb,
+    __unused move_flags_t flags)
+{
+    square_t to;
+    while(to_bb) {
+        to = bb_next(&to_bb);
+        *moves++ = move_make_flags(from, to, flags);
+    }
+    return moves;
+}
+
+/**
+ * move_gen_promotions() - generate all promotions for given pawn and dest.
+ * @moves: &move_t array where to store moves
+ * @from: pawn position
+ * @to: promotion square
+ *
+ * Generate  (at address @moves) all promotion (Q/R/B/N) moves on @to for
+ * pawn @from.
+ *
+ * @Return: New @moves.
+ */
+static inline move_t *move_gen_promotions(move_t *moves, square_t from, square_t to)
+{
+    for (piece_type_t pt = QUEEN; pt >= KNIGHT; --pt)
+        *moves++ = move_make_promote(from, to, pt);
+    return moves;
+}
+
+/**
+ * moves_gen() - generate all moves from square to bitboard.
+ * @moves: &move_t array where to store moves
+ * @from: square_t piece position
+ * @to_bb: destination bitboard
+ *
+ * Generate (at address @moves) moves from square @from to each square in @to_bb.
+ *
+ * @Return: New @moves.
+ */
+static inline move_t *moves_gen(move_t *moves, square_t from, bitboard_t to_bb)
+{
+    square_t to;
+    // bb_print(sq_to_string(from), to_bb);
+    while(to_bb) {
+        to = bb_next(&to_bb);
+        *moves++ = move_make(from, to);
+    }
+    return moves;
+}
+
+/**
+ * pos_gen_pseudo() - generate position pseudo-legal moves
+ * @pos: position
+ * @movelist: &movelist_t array to store pseudo-moves
+ *
+ * Generate all @pos pseudo moves for player-to-move.
+ * @movelist is filled with the moves.
+ *
+ * Only a few validity checks are done here (i.e. moves are not generated):
+ *  - castling, if king is in check
+ *  - castling, if king passes an enemy-controlled square (not final square).
+ * When immediately known, a few move flags are also applied in these cases:
+ *  - castling: M_CASTLE_{K,Q}
+ *  - capture (excl. en-passant): M_CAPTURE
+ *  - en-passant: M_EN_PASSANT
+ *  - pawn double push: M_DPUSH
+ *  - promotion: M_PROMOTION
+ *  - promotion and capture
+ *
+ * TODO: move code to specific functions (especially castling, pawn push/capture)
+ *
+ * @Return: movelist
+ */
+movelist_t *pos_gen_pseudo(pos_t *pos, movelist_t *movelist)
+{
+    color_t us               = pos->turn;
+    color_t them             = OPPONENT(us);
+
+    bitboard_t my_pieces     = pos->bb[us][ALL_PIECES];
+    bitboard_t enemy_pieces  = pos->bb[them][ALL_PIECES];
+    bitboard_t dest_squares  = ~my_pieces;
+    bitboard_t occ           = my_pieces | enemy_pieces;
+    bitboard_t empty         = ~occ;
+    move_t *moves            = movelist->move;
+    square_t king = pos->king[us];
+
+    bitboard_t from_bb, to_bb;
+    bitboard_t tmp_bb;
+    square_t from, to;
+
+    /* king - MUST BE FIRST */
+    to_bb = bb_king_moves(dest_squares, king);
+    moves = moves_gen(moves, king, to_bb);
+
+    if (bb_multiple(pos->checkers))               /* double check, we stop here */
+        goto finish;
+
+    if (pos->checkers) {
+        /* one checker: we limit destination squares to line between
+         * checker and king + checker square (think: knight).
+         */
+        square_t checker = ctz64(pos->checkers);
+        dest_squares &= bb_between[king][checker] | pos->checkers;
+        enemy_pieces &= dest_squares;
+    } else {
+        /* no checker: castling moves
+         * Attention ! Castling flags are assumed correct
+         */
+        bitboard_t rel_rank1 = bb_rel_rank(RANK_1, us);
+        /* For castle, we check the opponent attacks on squares between from and to.
+         * To square attack check will be done in gen_is_legal.
+         */
+        if (can_oo(pos->castle, us)) {
+
+            /* CHANGE HERE, either with bitmask >> or direct sq check */
+            bitboard_t occmask = rel_rank1 & (FILE_Fbb | FILE_Gbb);
+            if (!(occ & occmask)) {
+                *moves++ = move_make_flags(king, king + 2, M_CASTLE);
+            }
+        }
+        if (can_ooo(pos->castle, us)) {
+            bitboard_t occmask = rel_rank1 & (FILE_Bbb | FILE_Cbb | FILE_Dbb);
+            if (!(occ & occmask)) { // &&
+                *moves++ = move_make_flags(king, king - 2, M_CASTLE);
+            }
+        }
+    }
+
+    /* sliding pieces */
+    from_bb = pos->bb[us][BISHOP] | pos->bb[us][QUEEN];
+    while (from_bb) {
+        from = bb_next(&from_bb);
+        to_bb = hyperbola_bishop_moves(occ, from) & dest_squares;
+        moves = moves_gen(moves, from, to_bb);
+    }
+    from_bb = pos->bb[us][ROOK] | pos->bb[us][QUEEN];
+    while (from_bb) {
+        from = bb_next(&from_bb);
+        to_bb = hyperbola_rook_moves(occ, from) & dest_squares;
+        moves = moves_gen(moves, from, to_bb);
+    }
+
+    /* knight */
+    from_bb = pos->bb[us][KNIGHT];
+    while (from_bb) {
+        from = bb_next(&from_bb);
+        to_bb = bb_knight_moves(dest_squares, from);
+        moves = moves_gen(moves, from, to_bb);
+    }
+
+    /* pawn: relative rank and files */
+    bitboard_t rel_rank8 = bb_rel_rank(RANK_8, us);
+    bitboard_t rel_rank3 = bb_rel_rank(RANK_3, us);
+
+    /* pawn: push */
+    int shift = sq_up(us);
+    tmp_bb = bb_shift(pos->bb[us][PAWN], shift) & empty;
+
+    to_bb = tmp_bb & ~rel_rank8 & dest_squares;   /* non promotion */
+    while(to_bb) {
+        to = bb_next(&to_bb);
+        from = to - shift;
+        *moves++ = move_make(from, to);
+    }
+    to_bb = tmp_bb & rel_rank8 & dest_squares;    /* promotions */
+    while(to_bb) {
+        to = bb_next(&to_bb);
+        from = to - shift;
+        moves = move_gen_promotions(moves, from, to);
+    }
+
+    /* possible second push */
+    to_bb = bb_shift(tmp_bb & rel_rank3, shift) & empty & dest_squares;
+    while(to_bb) {
+        to = bb_next(&to_bb);
+        from = to - shift - shift;
+        *moves++ = move_make(from, to);
+    }
+
+    /* pawn: captures */
+    tmp_bb = bb_pawns_attacks(pos->bb[us][PAWN], shift) & enemy_pieces;
+    to_bb = tmp_bb & ~rel_rank8;
+    while (to_bb) {
+        to = bb_next(&to_bb);
+        from_bb = bb_pawn_attacks[them][to] & pos->bb[us][PAWN];
+        while (from_bb) {
+            from = bb_next(&from_bb);
+            *moves++ = move_make(from, to);
+        }
+    }
+    to_bb = tmp_bb & rel_rank8;
+    while (to_bb) {
+        to = bb_next(&to_bb);
+        from_bb = bb_pawn_attacks[them][to] & pos->bb[us][PAWN];
+        while (from_bb) {
+            from = bb_next(&from_bb);
+            moves = move_gen_promotions(moves, from, to);
+        }
+    }
+
+    /* pawn: en-passant
+     * TODO: special case when in-check here ?
+     */
+    if ((to = pos->en_passant) != SQUARE_NONE) {
+        from_bb = bb_pawn_attacks[them][to] & pos->bb[us][PAWN];
+        while (from_bb) {
+            from = bb_next(&from_bb);
+            *moves++ = move_make_enpassant(from, to);
+        }
+    }
+
+    /* TODO: add function per piece, and type, for easier debug
+     */
+finish:
+    movelist->nmoves = moves - movelist->move;
+    return movelist;
+    //return movelist->nmoves = moves - movelist->move;
+}

src/move-gen.h

@@ -0,0 +1,31 @@
+/* move-gen.h - move generation
+ *
+ * Copyright (C) 2024 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#ifndef MOVEGEN_H
+#define MOVEGEN_H
+
+#include "bitops.h"
+
+#include "bitboard.h"
+#include "hyperbola-quintessence.h"
+#include "piece.h"
+#include "move.h"
+
+bool pseudo_is_legal(const pos_t *pos, const move_t move);
+move_t pos_next_legal(const pos_t *pos, movelist_t *movelist, int *start);
+movelist_t *pos_legal_dup(const pos_t *pos, movelist_t *pseudo, movelist_t *legal);
+movelist_t *pos_legal(const pos_t *pos, movelist_t *list);
+
+movelist_t *pos_gen_pseudo(pos_t *pos, movelist_t *movelist);
+
+#endif  /* MOVEGEN_H */

src/move.h

@@ -1,6 +1,6 @@
 /* move.h - move management.
  *
- * Copyright (C) 2021 Bruno Raoult ("br")
+ * Copyright (C) 2021-2024 Bruno Raoult ("br")
  * Licensed under the GNU General Public License v3.0 or later.
  * Some rights reserved. See COPYING.
  *
@@ -15,20 +15,122 @@
 #define MOVE_H
 
 #include "chessdefs.h"
-#include "position.h"
-#include "pool.h"
 #include "piece.h"
+#include "board.h"
 
-/* move flags
+/* move structure:
+ * 1  1 1 1 1
+ * 8  5 4 2 1    6 5    0
+ * FFFF ppp tttttt ffffff
+ *
+ * bits    len off range         type      mask        get  desc
+ * ffffff    6   0   0-5     square_t       077        &077 from
+ * tttttt    6   6  6-11     square_t     07700 (>>6)  &077 to
+ * ppp       3  12 12-14 piece_type_t    070000 (>>12) &07  promoted
+ * FFF       3  15 15-17 move_flags_t   0700000 (>>15) &07  flags
+ */
+typedef u32 move_t;
+
+enum {
+    M_OFF_FROM     = 0,
+    M_OFF_TO       = 6,
+    M_OFF_PROMOTED = 12,
+    M_OFF_FLAGS    = 15
+};
+
+typedef enum {
+    M_PROMOTION  =  070000,
+    M_FLAGS_MASK = 0700000,
+    M_ENPASSANT  = (1 << M_OFF_FLAGS),
+    M_CASTLE     = (2 << M_OFF_FLAGS),            /* maybe only one ? */
+//  M_CHECK      = (3 << M_OFF_FLAGS)             /* maybe unknown/useless ? */
+} move_flags_t;
+
+/* special move_t values */
+#define MOVE_NULL    0                            /* hack: from = to = A1 */
+#define MOVE_NONE    07777                        /* hack: from = to = H8 */
+// #define MOVE_NO_MOVE 01010                        /* hack: from = to = A2 */
+
+#define move_set_flags(move, flags) ((move) | (flags))
+#define move_flags(move)            ((move) & M_FLAGS_MASK)
+
+#define is_promotion(m)             ((m) &  M_PROMOTION)
+#define is_enpassant(m)             (move_flags(m) == M_ENPASSANT)
+#define is_castle(m)                (move_flags(m) == M_CASTLE)
+#define is_check(m)                 (move_flags(m) == M_CHECK)
+
+#define MOVES_MAX   256
+
+typedef struct __movelist_s {
+    move_t move[MOVES_MAX];
+    int nmoves;                                   /* total moves (fill) */
+} movelist_t;
+
+static inline square_t move_from(move_t move)
+{
+    return move & 077;
+}
+
+static inline square_t move_to(move_t move)
+{
+    return (move >> M_OFF_TO) & 077;
+}
+
+static inline piece_type_t move_promoted(move_t move)
+{
+    return (move >> M_OFF_PROMOTED) & 07;
+}
+
+/*
+ * static inline piece_type_t move_captured(move_t move)
+ * {
+ *     return (move >> M_OFF_CAPTURED) & 07;
+ * }
+ */
+
+static inline move_t move_make(square_t from, square_t to)
+{
+    return (to << M_OFF_TO) | from;
+}
+
+static inline move_t move_make_flags(square_t from, square_t to, move_flags_t flags)
+{
+    return (to << M_OFF_TO) | from | flags;
+    //move_set_flags(move_make(from, to), flags);
+}
+
+/*
+ * static inline move_t move_make_capture(square_t from, square_t to)
+ * {
+ *     return move_make_flags(from, to, M_CAPTURE);
+ * }
+ */
+
+static inline move_t move_make_enpassant(square_t from, square_t to)
+{
+    return move_make_flags(from, to, M_ENPASSANT);
+}
+
+static inline move_t move_make_promote(square_t from, square_t to,
+                                       piece_type_t promoted)
+{
+    return move_make(from, to) | (promoted << M_OFF_PROMOTED);
+}
+
+/*
+ * static inline move_t move_make_promote_capture(square_t from, square_t to,
+ *                                                piece_type_t promoted)
+ * {
+ *     return move_make_promote(from, to, promoted) | M_CAPTURE;
+ * }
+ */
+
+/*
+ * static inline move_t move_set_captured(move_t move, piece_type_t captured)
+ * {
+ *     return move | (captured << M_OFF_CAPTURED);
+ * }
  */
-typedef unsigned char move_flags_t;
-#define M_NORMAL       0x00
-#define M_CHECK        0x01                       /* unsure if we know */
-#define M_CAPTURE      0x02
-#define M_EN_PASSANT   0x04
-#define M_PROMOTION    0x08
-#define M_CASTLE_K     0x10
-#define M_CASTLE_Q     0x20
 
 /* moves_print flags
  */
@@ -36,44 +138,15 @@ typedef unsigned char move_flags_t;
 #define M_PR_NCAPT     0x02
 #define M_PR_NUM       0x04
 #define M_PR_NL        0x08
+#define M_UCI          0x10                       /* UCI style - e7e8q */
 #define M_PR_EVAL      0x20                       /* separate captures */
 #define M_PR_SEPARATE  0x40                       /* separate captures */
 #define M_PR_LONG      0x80
 
-typedef struct move_s {
-    piece_t piece;
-    square_t from, to;
-    piece_t capture;                              /* captured piece */
-    piece_t promotion;                            /* promoted piece */
-    move_flags_t flags;
-    eval_t negamax;
-    eval_t eval;
-    eval_t eval_simple;
-    pos_t *pos;
-    struct list_head list;                        /* next move */
-} move_t;
-
-pool_t *moves_pool_init();
-void moves_pool_stats();
-int move_print(int movenum, move_t *move, move_flags_t flags);
-void moves_print(pos_t *move, move_flags_t flags);
-
-void move_del(struct list_head *ptr);
-int moves_del(pos_t *pos);
-
-int pseudo_moves_castle(pos_t *pos, bool color, bool doit, bool do_king);
-int pseudo_moves_gen(pos_t *pos, piece_list_t *piece, bool doit, bool do_king);
-int pseudo_moves_pawn(pos_t *pos, piece_list_t *piece, bool doit);
-int moves_gen(pos_t *pos, bool color, bool doit, bool do_king);
-int moves_gen_king_moves(pos_t *pos, bool color, bool doit);
-
-void moves_sort(pos_t *pos);
-void moves_gen_eval_sort(pos_t *pos);
-
-void moves_gen_all(pos_t *pos);
-void moves_gen_all_nomoves(pos_t *pos);
-
-pos_t *move_do(pos_t *pos, move_t *move);
-void move_undo(pos_t *pos, move_t *move);
+char *move_to_str(char *dst, const move_t move, __unused const int flags);
+move_t move_from_str(const char *str);
+move_t move_find_in_movelist(move_t target, movelist_t *list);
+void moves_print(movelist_t *moves, int flags);
+void move_sort_by_sq(movelist_t *moves);
 
 #endif  /* MOVE_H */

src/piece.c

@@ -1,6 +1,6 @@
 /* piece.c - piece list management.
  *
- * Copyright (C) 2021 Bruno Raoult ("br")
+ * Copyright (C) 2021-2024 Bruno Raoult ("br")
  * Licensed under the GNU General Public License v3.0 or later.
  * Some rights reserved. See COPYING.
  *
@@ -13,106 +13,87 @@
 
 #include <malloc.h>
 #include <ctype.h>
+#include <string.h>
+#include <assert.h>
 
-#include <debug.h>
-#include <pool.h>
-#include <list.h>
+#include "bug.h"
 
 #include "chessdefs.h"
 #include "piece.h"
-#include "board.h"
-#include "bitboard.h"
-#include "position.h"
 
-static pool_t *pieces_pool;
-
-struct piece_details piece_details[] = {
-    [E_EMPTY]  = { ' ', ' ', " ", " ", "",       0 },
-    [E_PAWN]   = { 'P', 'p', "♙", "♟", "Pawn",   PAWN_VALUE },
-    [E_KNIGHT] = { 'N', 'n', "♘", "♞", "Knight", KNIGHT_VALUE },
-    [E_BISHOP] = { 'B', 'b', "♗", "♝", "Bishop", BISHOP_VALUE },
-    [E_ROOK]   = { 'R', 'r', "♖", "♜", "Rook",   ROOK_VALUE },
-    [E_QUEEN]  = { 'Q', 'q', "♕", "♛", "Queen",  QUEEN_VALUE },
-    [E_KING]   = { 'K', 'k', "♔", "♚", "King",   KING_VALUE }
+/**
+ * piece_details
+ */
+const struct piece_details piece_details[PIECE_MAX] = {
+    /*             cap  low  fen  sym  name      values */
+    [EMPTY]    = { "",  "",  "",  "",  "",       0, 0, 0 },
+    [W_PAWN]   = { "",  "",  "P", "♙", "Pawn",   P_VAL_OPN, P_VAL_MID, P_VAL_END },
+    [W_KNIGHT] = { "N", "n", "N", "♘", "Knight", N_VAL_OPN, N_VAL_MID, N_VAL_END },
+    [W_BISHOP] = { "B", "b", "B", "♗", "Bishop", B_VAL_OPN, B_VAL_MID, B_VAL_END },
+    [W_ROOK]   = { "R", "r", "R", "♖", "Rook",   R_VAL_OPN, R_VAL_MID, R_VAL_END },
+    [W_QUEEN]  = { "Q", "q", "Q", "♕", "Queen",  Q_VAL_OPN, Q_VAL_MID, Q_VAL_END },
+    [W_KING]   = { "K", "k", "K", "♔", "King",   K_VAL_OPN, K_VAL_MID, K_VAL_END },
+    [7]        = { "",  "",  "",  "",  "",       0, 0, 0 },
+    [8]        = { "",  "",  "",  "",  "",       0, 0, 0 },
+    [B_PAWN]   = { "",  "",  "p", "♟", "Pawn",   P_VAL_OPN, P_VAL_MID, P_VAL_END },
+    [B_KNIGHT] = { "N", "n", "n", "♞", "Knight", P_VAL_OPN, N_VAL_MID, N_VAL_END },
+    [B_BISHOP] = { "B", "b", "b", "♝", "Bishop", P_VAL_OPN, B_VAL_MID, B_VAL_END },
+    [B_ROOK]   = { "R", "r", "r", "♜", "Rook",   P_VAL_OPN, R_VAL_MID, R_VAL_END },
+    [B_QUEEN]  = { "Q", "q", "q", "♛", "Queen",  P_VAL_OPN, Q_VAL_MID, Q_VAL_END },
+    [B_KING]   = { "K", "k", "k", "♚", "King",   P_VAL_OPN, K_VAL_MID, K_VAL_END },
 };
 
-void piece_list_print(struct list_head *list)
+const char pieces_str[6+6+1] = "PNBRQKpnbrqk";
+
+bool piece_ok(piece_t p)
 {
-    struct list_head *p_cur, *tmp;
-    piece_list_t *piece;
+    piece_type_t pt = PIECE(p);
+    return !(p & ~(MASK_COLOR | MASK_PIECE)) && pt && (pt <= KING);
+}
 
-    list_for_each_safe(p_cur, tmp, list) {
-        piece = list_entry(p_cur, piece_list_t, list);
+char *piece_to_cap(piece_t p)
+{
+    return piece_details[p].cap;
+}
 
-        printf("%s%c%c ", P_SYM(piece->piece),
-               FILE2C(F88(piece->square)),
-               RANK2C(R88(piece->square)));
+char *piece_to_char(piece_t p)
+{
+    return piece_details[p].fen;
+}
+
+char *piece_to_low(piece_t p)
+{
+    return piece_details[p].low;
+}
+
+char *piece_to_sym(piece_t p)
+{
+    return piece_details[p].sym;
+}
+
+char *piece_to_name(piece_t p)
+{
+    return piece_details[p].name;
+}
+
+piece_type_t piece_t_from_char(char c)
+{
+    char *p;
+    piece_type_t pt = NO_PIECE_TYPE;
+    if (c && (p = strchr(pieces_str, c))) {
+        pt = (p - pieces_str) % 6 + 1;
     }
-    printf("\n");
+    return pt;
 }
 
-pool_t *piece_pool_init()
+//piece_type_t piece_from_promotion(char c, color_t color)
+//{
+//    piece_type_t piece = piece_t_from_char(c);
+//    return piece? SET_COLOR()p? (p - pieces_str) % 6 + 1: NO_PIECE_TYPE;
+//}
+
+piece_t piece_from_char(char c)
 {
-    if (!pieces_pool)
-        pieces_pool = pool_create("pieces", 128, sizeof(piece_list_t));
-    return pieces_pool;
-}
-
-void piece_pool_stats()
-{
-    if (pieces_pool)
-        pool_stats(pieces_pool);
-}
-
-piece_list_t *piece_add(pos_t *pos, piece_t piece, square_t square)
-{
-    piece_list_t *new;
-    short color = COLOR(piece);
-
-#   ifdef DEBUG_PIECE
-    log_f(3, "piece=%02x square=%02x\n", piece, square);
-    log_f(5, "Adding %s %s on %c%c\n", color? "Black": "White",
-          P_NAME(piece), FILE2C(F88(square)), RANK2C(R88(square)));
-#   endif
-    if ((new = pool_get(pieces_pool))) {
-        /* first piece is always king */
-        if (PIECE(piece) == KING)
-            list_add(&new->list, &pos->pieces[color]);
-        else
-            list_add_tail(&new->list, &pos->pieces[color]);
-        new->piece = piece;
-        new->square = square;
-        new->castle = 0;
-        new-> value = piece_details[PIECE(piece)].value;
-    }
-
-    return new;
-}
-
-void piece_del(struct list_head *ptr)
-{
-    piece_list_t *piece = list_entry(ptr, piece_list_t, list);
-#   ifdef DEBUG_PIECE
-    log_f(3, "piece=%02x square=%02x\n", piece->piece, piece->square);
-#   endif
-    list_del(ptr);
-    pool_add(pieces_pool, piece);
-    return;
-}
-
-int pieces_del(pos_t *pos, short color)
-{
-    struct list_head *p_cur, *tmp, *head;
-    int count = 0;
-
-    head = &pos->pieces[color];
-
-    list_for_each_safe(p_cur, tmp, head) {
-        piece_del(p_cur);
-        count++;
-    }
-#   ifdef DEBUG_PIECE
-    log_f(3, "color=%d removed=%d\n", color, count);
-#   endif
-    return count;
+    piece_type_t piece = piece_t_from_char(c);
+    return isupper(c)? SET_WHITE(piece): SET_BLACK(piece);
 }

src/piece.h

@@ -1,6 +1,6 @@
 /* piece.h - piece definitions.
  *
- * Copyright (C) 2021 Bruno Raoult ("br")
+ * Copyright (C) 2021-2024 Bruno Raoult ("br")
  * Licensed under the GNU General Public License v3.0 or later.
  * Some rights reserved. See COPYING.
  *
@@ -14,58 +14,127 @@
 #ifndef PIECE_H
 #define PIECE_H
 
-#include <ctype.h>
+#include <string.h>
 
 #include "chessdefs.h"
-#include "list.h"
-#include "pool.h"
 
-#define PIECE_DEFAULT_VALUE 0
+/* piece_t bits structure
+ * piece is on bits 1-3, color on bit 4:
+ * .... CPPP
+ * C: 0 for white, 1: black
+ * PPP: pawn (1), knight, bishop, rook, queen, king (6)
+ */
+typedef enum {
+    WHITE, BLACK,
+    COLOR_MAX
+} color_t;
 
-/* initial default values */
-#define PAWN_VALUE    100
-#define KNIGHT_VALUE  300
-#define BISHOP_VALUE  300
-#define ROOK_VALUE    500
-#define QUEEN_VALUE   900
-#define KING_VALUE    20000
+typedef enum {
+    ALL_PIECES = 0,                               /* 'all pieces' bitboard */
+    NO_PIECE_TYPE = 0,
+    PAWN = 1, KNIGHT, BISHOP, ROOK, QUEEN, KING,
+    PIECE_TYPE_MAX = 7                            /* bit 4 */
+} piece_type_t;
 
-typedef struct piece_list_s {
-    piece_t piece;
-    square_t square;
-    short castle;
-    s64 value;
-    struct list_head list;
-} piece_list_t;
+typedef enum __piece_e {
+    EMPTY = 0,
+    NO_PIECE = 0,
+    W_PAWN = PAWN, W_KNIGHT, W_BISHOP, W_ROOK, W_QUEEN, W_KING,
+    B_PAWN = PAWN | 8, B_KNIGHT, B_BISHOP, B_ROOK, B_QUEEN, B_KING,
+    PIECE_MAX
+} piece_t;
+
+/* default values for opening, midgame, endgame
+ */
+#define E_VAL_OPN    0                            /* empty */
+#define P_VAL_OPN    100
+#define N_VAL_OPN    300
+#define B_VAL_OPN    300
+#define R_VAL_OPN    500
+#define Q_VAL_OPN    900
+#define K_VAL_OPN    20000
+
+#define E_VAL_MID    0
+#define P_VAL_MID    100
+#define N_VAL_MID    300
+#define B_VAL_MID    300
+#define R_VAL_MID    500
+#define Q_VAL_MID    900
+#define K_VAL_MID    20000
+
+#define E_VAL_END    0
+#define P_VAL_END    100
+#define N_VAL_END    300
+#define B_VAL_END    300
+#define R_VAL_END    500
+#define Q_VAL_END    900
+#define K_VAL_END    20000
 
 /* some default values for pieces
+ * @abbr:   char, piece capital letter (used for game notation)
+ * @abbr_c: char, capital for white, lowercase for black
+ * char *sym;
+ *  char *sym_c;
+ *  char *name;
+ *  s64  opn_value;
+ *  s64  mid_value;
+ *  s64  end_value;
  */
-extern struct piece_details {
-    char abbrev_w;                                /* used for game notation */
-    char abbrev_b;
-    char *symbol_w;
-    char *symbol_b;                               /* used for game notation */
-    char *name;
-    s64  value;
-} piece_details[];
+extern const struct piece_details {
+    char *cap;                                    /* used for game notation */
+    char *low;                                    /* used also for UCI promotion */
+    char *fen;                                    /* cap=white, low=black */
+    char *sym;                                    /* UTF-8 symbol */
+    char *name;                                   /* piece name */
+    s64  opn_value;                               /* value opening */
+    s64  mid_value;                               /* value midgame */
+    s64  end_value;                               /* value endgame */
+} piece_details[PIECE_MAX];
+
+extern const char pieces_str[6+6+1];              /* to search from fen/user input */
+
+#define OPPONENT(color)   !(color)
+
+#define MASK_PIECE        0x07                      /* 00000111 */
+#define MASK_COLOR        0x08                      /* 00001000 */
+
+#define COLOR(p)          ((p) >> 3)              /* bitmask */
+#define PIECE(p)          ((p) & MASK_PIECE)
+#define MAKE_PIECE(p, c)  ((p) | (c) << 3)
+
+#define IS_WHITE(p)       (!COLOR(p))
+#define IS_BLACK(p)       (COLOR(p))
+
+#define SET_WHITE(p)      (piece_t)((p) &= ~MASK_COLOR)
+#define SET_BLACK(p)      (piece_t)((p) |= MASK_COLOR)
+#define SET_COLOR(p, c)   (piece_t)(!(c)? SET_WHITE(p): SET_BLACK(p))
+
+bool piece_ok(piece_t p);
+
+char *piece_to_cap(piece_t p);
+char *piece_to_low(piece_t p);
+char *piece_to_fen(piece_t p);
+char *piece_to_sym(piece_t p);
+char *piece_to_name(piece_t p);
+
+#define piece_to_char(c) piece_to_fen(c)
+//#define piece_to_char_t(p) piece_to_uci(p)
+
+//piece_type_t char_to_piece(char c);
+piece_type_t piece_t_from_char(char c);
+piece_t piece_from_fen(char c);
+
+#define piece_from_char(c) piece_from_fen(c)
 
-#define P_NAME(p)      piece_details[E_PIECE(p)].name
-#define P_LETTER(p)    piece_details[E_PIECE(p)].abbrev_w
-#define P_SYM(p)       piece_details[E_PIECE(p)].symbol_b
-#define P_CSHORT(p)    (IS_WHITE(p)? piece_details[E_PIECE(p)].abbrev_w: \
-                        piece_details[E_PIECE(p)].abbrev_b)
-#define P_CSYM(p)      (IS_WHITE(p)? piece_details[E_PIECE(p)].symbol_w: \
-                        piece_details[E_PIECE(p)].symbol_b)
-#define P_VALUE(p)     (piece_details[E_PIECE(p)].value)
 /* use short name or symbol - no effect
  */
 #define P_USE_UTF      1
 
-void piece_list_print(struct list_head *list);
-pool_t *piece_pool_init();
-void piece_pool_stats();
-piece_list_t *piece_add(pos_t *pos, piece_t piece, square_t square);
-void piece_del(struct list_head *ptr);
-int pieces_del(pos_t *pos, short color);
+//void piece_list_print(struct list_head *list);
+//pool_t *piece_pool_init();
+//void piece_pool_stats();
+//piece_list_t *piece_add(pos_t *pos, piece_t piece, square_t square);
+//void piece_del(struct list_head *ptr);
+//int pieces_del(pos_t *pos, short color);
 
 #endif

src/position.c

@@ -1,6 +1,6 @@
 /* position.c - position management.
  *
- * Copyright (C) 2021 Bruno Raoult ("br")
+ * Copyright (C) 2021-2024 Bruno Raoult ("br")
  * Licensed under the GNU General Public License v3.0 or later.
  * Some rights reserved. See COPYING.
  *
@@ -16,308 +16,479 @@
 #include <stdbool.h>
 #include <string.h>
 #include <ctype.h>
+#include <assert.h>
+
+#include <brlib.h>
+#include <bitops.h>
 
 #include "chessdefs.h"
 #include "position.h"
-#include "move.h"
+#include "bitboard.h"
+#include "hyperbola-quintessence.h"
 #include "fen.h"
 #include "piece.h"
-#include "eval.h"
-
-static pool_t *pos_pool;
-
-#define BYTE_PRINT "%c%c%c%c%c%c%c%c"
-#define BYTE2BIN(b) ((b) & 0x01 ? '1' : '0'),  \
-        ((b) & 0x02 ? '1' : '0'),              \
-        ((b) & 0x04 ? '1' : '0'),              \
-        ((b) & 0x08 ? '1' : '0'),              \
-        ((b) & 0x10 ? '1' : '0'),              \
-        ((b) & 0x20 ? '1' : '0'),              \
-        ((b) & 0x40 ? '1' : '0'),              \
-        ((b) & 0x80 ? '1' : '0')
-
-inline void bitboard_print(bitboard_t bb)
-{
-    int i;
-    printf("%#018lx\n", bb);
-    for (i=56; i>=0; i-=8)
-        printf("\t"BYTE_PRINT"\n",
-               BYTE2BIN(bb>>i));
-}
-
-inline void bitboard_print2(bitboard_t bb1, bitboard_t bb2)
-{
-    int i;
-    printf("\tW: %#018lx\tB: %#018lx\n", bb1, bb2);
-    for (i=56; i>=0; i-=8)
-        printf("\t"BYTE_PRINT"\t\t"BYTE_PRINT"\n",
-               BYTE2BIN(bb1>>i),
-               BYTE2BIN(bb2>>i));
-}
+#include "misc.h"
+#include "board.h"
+#include "attack.h"
+#include "hist.h"
 
 /**
- * pos_pieces_print() - Print position pieces
- * @pos:  &position
+ * pos_new() - allocate a new position
+ *
+ * Position is not initialized.
+ * If BUG_ON compilation is defined, the program will fail.
+ *
+ * @Return: The new position or NULL.
  */
-void pos_pieces_print(pos_t *pos)
+pos_t *pos_new(void)
 {
-    printf("White pieces (%d): \t", popcount64(pos->occupied[WHITE]));
-    piece_list_print(&pos->pieces[WHITE]);
-    printf("Black pieces (%d): \t", popcount64(pos->occupied[BLACK]));
-    piece_list_print(&pos->pieces[BLACK]);
-}
-
-/**
- * pos_bitboards_print() - Print position bitboards
- * @pos:  &position
- */
-void pos_bitboards_print(pos_t *pos)
-{
-    printf("Bitboards occupied :\n");
-    bitboard_print2(pos->occupied[WHITE], pos->occupied[BLACK]);
-    printf("Bitboards controlled :\n");
-    bitboard_print2(pos->controlled[WHITE], pos->controlled[BLACK]);
-
-}
-
-/**
- * pos_print() - Print position on stdout.
- * @pos:  &position
- */
-void pos_print(pos_t *pos)
-{
-    int rank, file;
-    piece_t piece;
-    board_t *board = pos->board;
-    piece_list_t *wk = list_first_entry(&pos->pieces[WHITE], piece_list_t, list),
-        *bk = list_first_entry(&pos->pieces[BLACK], piece_list_t, list);
-
-
-    printf("  +---+---+---+---+---+---+---+---+\n");
-    for (rank = 7; rank >= 0; --rank) {
-        printf("%c |", rank + '1');
-        for (file = 0; file < 8; ++file) {
-            piece = board[SQ88(file, rank)].piece;
-            printf(" %s |", P_CSYM(piece));
-        }
-        printf("\n  +---+---+---+---+---+---+---+---+\n");
-    }
-    printf("    A   B   C   D   E   F   G   H\n\n");
-    printf("Turn: %s.\n", IS_WHITE(pos->turn) ? "white" : "black");
-    printf("Kings: W:%c%c B:%c%c\n",
-           FILE2C(F88(wk->square)),
-           RANK2C(R88(wk->square)),
-           FILE2C(F88(bk->square)),
-           RANK2C(R88(bk->square)));
-    printf("Possible en-passant: [%#x] ", pos->en_passant);
-    if (pos->en_passant == 0)
-        printf("None.\n");
-    else
-        printf("%d %d = %c%c\n",
-               F88(pos->en_passant),
-               R88(pos->en_passant),
-               FILE2C(F88(pos->en_passant)),
-               RANK2C(R88(pos->en_passant)));
-
-    printf("castle [%#x] : ", pos->castle);
-
-    if (pos->castle & CASTLE_WK)
-        printf("K");
-    if (pos->castle & CASTLE_WQ)
-        printf("Q");
-    if (pos->castle & CASTLE_BK)
-        printf("k");
-    if (pos->castle & CASTLE_BQ)
-        printf("q");
-
-    printf("\n50 half-moves-rule = %d\n", pos->clock_50);
-    printf("Current move = %d\n", pos->curmove);
-    printf("Squares controlled: W:%d B:%d\n", popcount64(pos->controlled[WHITE]),
-           popcount64(pos->controlled[BLACK]));
-    printf("Mobility: W:%u B:%u\n", pos->mobility[WHITE],
-           pos->mobility[BLACK]);
-}
-
-/**
- * pos_check() - extensive position consistenci check.
- * @pos:  &position
- */
-void pos_check(pos_t *pos)
-{
-    int rank, file;
-    piece_t piece;
-    board_t *board = pos->board;
-
-    /* check that board and bitboard reflect same information */
-    for (rank = 7; rank >= 0; --rank) {
-        for (file = 0; file < 8; ++file) {
-            piece_list_t *ppiece;
-            printf("checking %c%c ", file+'a', rank+'1');
-
-            piece = board[SQ88(file, rank)].piece;
-            ppiece= board[SQ88(file, rank)].s_piece;
-            printf("piece=%s ", P_CSYM(piece));
-            if (ppiece)
-                printf("ppiece=%s/sq=%#x ", P_CSYM(ppiece->piece), ppiece->square);
-            switch(PIECE(piece)) {
-                case PAWN:
-                    printf("pawn" );
-                    break;
-                case KNIGHT:
-                    printf("knight ");
-                    break;
-                case BISHOP:
-                    printf("bishop ");
-                    break;
-                case ROOK:
-                    printf("rook ");
-                    break;
-                case QUEEN:
-                    printf("queen ");
-                    break;
-                case KING:
-                    printf("king ");
-                    break;
-            }
-            printf("\n");
-        }
-    }
-}
-
-pos_t *pos_clear(pos_t *pos)
-{
-    int file, rank;
-    board_t *board = pos->board;
-
-    for (file = 0; file < 8; ++file) {
-        for (rank = 0; rank < 8; ++rank) {
-            /*printf("file = %d rank = %d SQ88 = %#2x = %d addr=%p\n", file, rank,
-                   SQ88(file, rank), SQ88(file, rank),
-                   &board[SQ88(file, rank)].piece);
-            */
-            board[SQ88(file, rank)].piece = EMPTY;
-        }
-    }
-
-    SET_WHITE(pos->turn);
-    pos->node_count = 0;
-    pos->castle = 0;
-    pos->clock_50 = 0;
-    pos->curmove = 0;
-    pos->eval = 0;
-    pos->en_passant = 0;
-    pos->occupied[WHITE] = 0;
-    pos->occupied[BLACK] = 0;
-    for (int color=0; color<2; ++color)
-        for (int piece = BB_ALL; piece < BB_END; ++piece)
-            pos->bb[color][piece] = 0;
-    pos->controlled[WHITE] = 0;
-    pos->controlled[BLACK] = 0;
-    pos->mobility[WHITE] = 0;
-    pos->mobility[BLACK] = 0;
-    pos->moves_generated = false;
-    pos->moves_counted = false;
-    /* remove pieces / moves */
-    pieces_del(pos, WHITE);
-    pieces_del(pos, BLACK);
-    moves_del(pos);
-
-    return pos;
-}
-
-/**
- * pos_del() - delete a position.
- * @pos: &position.
- */
-void pos_del(pos_t *pos)
-{
-    pieces_del(pos, WHITE);
-    pieces_del(pos, BLACK);
-    moves_del(pos);
-    pool_add(pos_pool, pos);
-}
-
-pos_t *pos_startpos(pos_t *pos)
-{
-    static char *startfen="rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1";
-
-    return fen2pos(pos, startfen);
-}
-
-pos_t *pos_get()
-{
-    pos_t *pos = pool_get(pos_pool);
-    if (pos) {
-        INIT_LIST_HEAD(&pos->pieces[WHITE]);
-        INIT_LIST_HEAD(&pos->pieces[BLACK]);
-
-        INIT_LIST_HEAD(&pos->moves[WHITE]);
-        INIT_LIST_HEAD(&pos->moves[BLACK]);
-        pos_clear(pos);
-    } else {
-        fprintf(stderr, "zobaaa\n");
-    }
-    return pos;
+    return safe_malloc(sizeof(pos_t));
 }
 
 /**
  * pos_dup() - duplicate a position.
  * @pos: &position to duplicate.
  *
- * New position is the same as source one (with duplicated pieces list),
- * except:
- * - moves list is empty
- * - bestmove is NULL
- * - nodecount is set to zero
- * - eval is set to EVAL_INVALID
- * - moves_generated ans moves_counted are unset
- * - check is set to zero
+ * Return a copy, allocated with malloc(1), of @pos.
  *
- * @return: The new position.
+ * @Return: The new position.
  *
- * TODO: merge with pos_get - NULL for init, non null for duplicate
+ * TODO: merge with pos_new - NULL for init, non null for duplicate
  */
-pos_t *pos_dup(pos_t *pos)
+pos_t *pos_dup(const pos_t *pos)
 {
-    struct list_head *p_cur, *piece_list;
-    piece_list_t *oldpiece;
-    board_t *board;
-    pos_t *new = pool_get(pos_pool);
+    pos_t *newpos = safe_malloc(sizeof(pos_t));
 
-    if (new) {
-        board = new->board;
-        *new = *pos;
-        for (int color = 0; color < 2; ++color) {
-            INIT_LIST_HEAD(&new->pieces[color]);
-            INIT_LIST_HEAD(&new->moves[color]);
-            /* duplicate piece list */
-            piece_list = &pos->pieces[color];     /* white/black piece list */
+    *newpos = *pos;
+    return newpos;
+}
 
-            list_for_each(p_cur, piece_list) {
-                oldpiece = list_entry(p_cur, piece_list_t, list);
-                board[oldpiece->square].s_piece =
-                    piece_add(new, oldpiece->piece, oldpiece->square);
-            }
-        }
-        new->bestmove = NULL;
-        new->node_count = 0;
-        new->eval = EVAL_INVALID;
-        new->moves_generated = false;
-        new->moves_counted = false;
-        new->check[WHITE] = new->check[BLACK] = 0;
+/**
+ * pos_copy() - copy a position into another one.
+ * @from: &position to duplicate.
+ * @to: &destination position.
+ *
+ * Return a copy of @from into @to.
+ *
+ * @Return: @to.
+ */
+pos_t *pos_copy(const pos_t *from, pos_t *to)
+{
+    *to = *from;
+    return to;
+}
+
+/**
+ * pos_del() - delete a position.
+ * @pos: &position.
+ *
+ */
+void pos_del(pos_t *pos)
+{
+    safe_free(pos);
+}
+
+/**
+ * pos_clear() - clear a position.
+ * @pos: &position.
+ *
+ * @return: @pos.
+ */
+pos_t *pos_clear(pos_t *pos)
+{
+#   ifdef DEBUG_POS
+    printf("size(pos_board=%lu elt=%lu\n", sizeof(pos->board), sizeof(int));
+#   endif
+    pos->node_count = 0;
+    pos->turn = WHITE;
+
+    /* move_do/undo position state */
+    pos->key = 0;
+    pos->en_passant = SQUARE_NONE;
+    pos->castle = 0;
+    pos->clock_50 = 0;
+    pos->plycount = 0;
+    pos->move = MOVE_NONE;
+    pos->captured = NO_PIECE;
+
+    for (square_t sq = A1; sq <= H8; ++sq)
+        pos->board[sq] = EMPTY;
+
+    for (color_t color = WHITE; color <= BLACK; ++color) {
+        for (piece_type_t piece = 0; piece <= KING; ++piece)
+            pos->bb[color][piece] = 0;
+        //pos->controlled[color] = 0;
+        pos->king[color] = SQUARE_NONE;
     }
-    return new;
+
+    pos->checkers = 0;
+    pos->pinners = 0;
+    pos->blockers = 0;
+
+    return pos;
 }
 
-pool_t *pos_pool_init()
+/**
+ * pos_cmp() - compare two positions..
+ * @pos1, @pos2: The two &position.
+ *
+ * Used only for move_{do,undo} test/debug.
+ *
+ * @return: true if equal, false otherwise.
+ */
+bool pos_cmp(const pos_t *pos1, const pos_t *pos2)
 {
-    if (!pos_pool)
-        pos_pool = pool_create("positions", 128, sizeof(pos_t));
-    return pos_pool;
+#define _cmpf(a) (pos1->a != pos2->a)
+    bool ret = false;
+
+    if (_cmpf(node_count) || _cmpf(turn))
+        goto end;
+
+    /* move_do/undo position state */
+    if (_cmpf(key) || _cmpf(en_passant) || _cmpf(castle) ||
+        _cmpf(clock_50) || _cmpf(plycount) || _cmpf(captured))
+        goto end;
+
+    if (_cmpf(checkers) || _cmpf(pinners) || _cmpf(blockers))
+        goto end;
+
+    for (square_t sq = A1; sq <= H8; ++sq)
+        if (_cmpf(board[sq]))
+            goto end;
+
+    for (color_t color = WHITE; color <= BLACK; ++color) {
+        for (piece_type_t piece = ALL_PIECES; piece <= KING; ++piece)
+            if (_cmpf(bb[color][piece]))
+                goto end;
+        if (_cmpf(king[color]))
+            goto end;
+    }
+
+    if (_cmpf(checkers) ||_cmpf(pinners) || _cmpf(blockers))
+        goto end;
+
+    /*
+     * if (_cmpf(repeat.moves) ||
+     *     memcmp(pos1->repeat.key, pos2->repeat.key,
+     *            pos1->repeat.moves * sizeof pos1->repeat.key))
+     *     goto end;
+     */
+
+    ret = true;
+end:
+    return ret;
+#undef _cmpf
 }
 
-void pos_pool_stats()
+/**
+ * pos_checkers() - find all checkers on a king.
+ * @pos:   &position
+ * @color: king color
+ *
+ * Get a bitboard of all checkers on @color king.
+ * Just a wrapper over @sq_attackers().
+ *
+ * @return: a bitboard of checkers.
+ */
+bitboard_t pos_checkers(const pos_t *pos, const color_t color)
 {
-    if (pos_pool)
-        pool_stats(pos_pool);
+    bitboard_t occ = pos_occ(pos);
+    return sq_attackers(pos, occ, pos->king[color], OPPONENT(color));
+}
+
+/**
+ * pos_set_checkers_pinners_blockers() - calculate checkers, pinners and blockers.
+ * @pos:   &position
+ *
+ * Set position checkers, pinners and blockers on player-to-play king.
+ * It should be slightly faster than @pos_checkers + @pos_set_pinners_blockers, as
+ * some calculation will be done once.
+ */
+void pos_set_checkers_pinners_blockers(pos_t *pos)
+{
+    int us = pos->turn, them = OPPONENT(us);
+    bitboard_t occ = pos_occ(pos);
+    bitboard_t attackers;
+    bitboard_t checkers = 0, blockers = 0, pinners = 0;
+    bitboard_t targets, tmpcheckers, maybeblockers, tmppinners;
+    square_t king = pos->king[us];
+    int pinner;
+
+    /* bishop type - we attack with a bishop from king position */
+    attackers = pos->bb[them][BISHOP] | pos->bb[them][QUEEN];
+
+    /* targets is all "target" pieces if K was a bishop */
+    targets = hyperbola_bishop_moves(occ, king) & occ;
+
+    /* checkers = only opponent B/Q */
+    tmpcheckers = targets & attackers;
+    checkers |= tmpcheckers;
+
+    /* maybe blockers = we remove checkers, to look "behind" */
+    maybeblockers = targets & ~tmpcheckers;
+
+    /* we find second targets, by removing first ones (excl. checkers) */
+    if (maybeblockers) {
+        targets = hyperbola_bishop_moves(occ ^ maybeblockers, king) ^ tmpcheckers;
+
+        /* pinners = only B/Q */
+        tmppinners = targets & attackers;
+
+        /* blockers = we find occupied squares between pinner and king */
+        while (tmppinners) {
+            pinner = bb_next(&tmppinners);
+            pinners |= BIT(pinner);
+            blockers |= bb_between[pinner][king] & maybeblockers;
+        }
+    }
+
+    /* same for rook type */
+    attackers = pos->bb[them][ROOK] | pos->bb[them][QUEEN];
+    targets = hyperbola_rook_moves(occ, king) & occ;
+
+    tmpcheckers = targets & attackers;
+    checkers |= tmpcheckers;
+
+    maybeblockers = targets & ~tmpcheckers;
+    if (maybeblockers) {
+        targets = hyperbola_rook_moves(occ ^ maybeblockers, king) ^ tmpcheckers;
+        tmppinners = targets & attackers;
+        while (tmppinners) {
+            pinner = bb_next(&tmppinners);
+            pinners |= BIT(pinner);
+            blockers |= bb_between[pinner][king] & maybeblockers;
+        }
+    }
+
+    /* pawns & knights */
+    checkers |= bb_pawn_attacks[us][king] & pos->bb[them][PAWN];
+    checkers |= bb_knight[king] & pos->bb[them][KNIGHT];
+
+    pos->checkers = checkers;
+    pos->pinners = pinners;
+    pos->blockers = blockers;
+}
+
+/**
+ * pos_set_pinners_blockers() - set position pinners and blockers.
+ * @pos:   &position
+ *
+ * set position pinners and blockers on player-to-play king.
+ */
+void pos_set_pinners_blockers(pos_t *pos)
+{
+    color_t color = pos->turn;
+    square_t king = pos->king[color];
+    bitboard_t tmp, occ = pos_occ(pos), blockers = 0;
+    int pinner;
+
+    pos->pinners = sq_pinners(pos, king, OPPONENT(pos->turn));
+    bit_for_each64(pinner, tmp, pos->pinners) {
+        //bitboard_t blocker =
+        // warn_on(popcount64(blocker) != 1);
+        blockers |= bb_between_excl[pinner][king] & occ;
+    }
+    pos->blockers = blockers;
+    return;
+}
+
+/**
+ * pos_king_pinners() - get the "pinners" on a king "pinners".
+ * @pos:   &position
+ * @color: king color.
+ *
+ * get position "pinners" on @color king. Here, pinner means a piece separated from king
+ * by one piece (any color) only.
+ * This is just a wrapper over @sq_pinners().
+ *
+ * @return: pinners bitboard.
+ */
+bitboard_t pos_king_pinners(const pos_t *pos, const color_t color)
+{
+    return sq_pinners(pos, pos->king[color], OPPONENT(pos->turn));
+}
+
+/**
+ * pos_king_blockers() - get the pin blockers on a king.
+ * @pos:   &position
+ * @color: king color.
+ * @pinners: pinners bitboard.
+ *
+ * get @pinners blockers pieces on @color king.
+ *
+ * @return: blockers bitboard.
+ */
+bitboard_t pos_king_blockers(const pos_t *pos, const color_t color, const bitboard_t pinners)
+{
+    bitboard_t tmp, blockers = 0, occ = pos_occ(pos);
+    square_t pinner, king = pos->king[color];
+
+    bit_for_each64(pinner, tmp, pinners) {
+        //warn_on(popcount64(blocker) != 1);
+        //if (popcount64(blocker) != 1) {
+        //    printf("n blockers = %d\n", popcount64(blocker));
+        //    bb_print("blockers", blocker);
+        //}
+        blockers |= bb_between_excl[pinner][king] & occ;
+    }
+    return blockers;
+}
+
+/**
+ * pos_ok() - extensive position consistency check.
+ * @pos:    &position
+ * @strict: if true, call bug_on() on any error.
+ *
+ * Perform some validity check on position @pos:
+ * - pawns on 1st or 8th rank
+ * - number of pawns > 8 (per color)
+ * - total number of pieces > 16 or zero (per color)
+ * - number of kings != 1 (per color)
+ * - discrepancy between board and king (per color)
+ * - discrepancy between bitboards and board (per color)
+ * - side-to-move already checking opponent king
+ * - side-to-move in check more than twice
+ * - kings distance is 1
+ * - TODO: - castling / e.p. flags
+ *
+ * In case of errors, and @strict is true, @bug_on() is called, and program will
+ * be terminated.
+ * This function should be called with @strict == false during initialization phase
+ * (eg after fen parsing), and with @strict == true otherwise (as we have some data
+ * corruption).
+ *
+ * @return: (if @strict is false) return true if check is ok, false otherwise.
+ */
+bool pos_ok(pos_t *pos, const bool strict)
+{
+    int n, count = 0, bbcount = 0, error = 0;
+    color_t __unused us = pos->turn, __unused them = OPPONENT(us);
+
+    /* force BUG_ON and WARN_ON */
+#   pragma push_macro("BUG_ON")
+#   pragma push_macro("WARN_ON")
+#   undef BUG_ON
+#   define BUG_ON
+#   undef WARN_ON
+#   define WARN_ON
+#   include <bug.h>
+
+    /* pawns on 1st ot 8th rank */
+    error += warn_on((pos->bb[WHITE][PAWN] | pos->bb[BLACK][PAWN]) &
+                     (RANK_1bb | RANK_8bb));
+
+    for (color_t color = WHITE; color <= BLACK; ++color) {
+        /* pawn count */
+        n = popcount64(pos->bb[color][PAWN]);
+        error += warn_on(n > 8);
+        /* king count */
+        n = popcount64(pos->bb[color][KING]);
+        error += warn_on(n != 1);
+        /* king mismatch with board */
+        error += warn_on(PIECE(pos->board[pos->king[color]]) != KING);
+        /* pieces count */
+        n = popcount64(pos->bb[color][ALL_PIECES]);
+        error += warn_on(n == 0 || n > 16);
+        bbcount += n;
+    }
+    for (square_t sq = 0; sq < 64; ++sq) {
+        piece_t piece = pos->board[sq];
+        __unused bitboard_t match;
+        if (piece == EMPTY)
+            continue;
+        color_t c = COLOR(piece);
+        piece_type_t p = PIECE(piece);
+        match = pos->bb[c][p] & BIT(sq);
+        error += warn_on(!match);
+        count++;
+    }
+    /* occupied board is different from bitboards */
+    error += warn_on(count != bbcount);
+    /* is opponent already in check ? */
+    error += warn_on(pos_checkers(pos, them));
+    /* is color to play in check more than twice ? */
+    error += warn_on(popcount64(pos_checkers(pos, us)) > 2);
+    /* kings distance is less than 2 */
+    error += warn_on(sq_dist(pos->king[WHITE], pos->king[BLACK]) < 2);
+    /* e.p. and castling rights check */
+    error += fen_ok(pos, false);
+
+    if (strict) {
+        bug_on(error);
+        /* not reached */
+    }
+    return error? false: true;
+#   pragma pop_macro("WARN_ON")
+#   pragma pop_macro("BUG_ON")
+}
+
+/**
+ * pos_print() - Print position and fen on stdout.
+ * @pos:  &position
+ */
+void pos_print(const pos_t *pos)
+{
+    char str[128];
+
+    board_print(pos->board);
+    printf("fen: %s\n", pos2fen(pos, str));
+    printf("last move:%s ", move_to_str(str, pos->move, 0));
+    printf("key:%lx\n", pos->key);
+    printf("checkers:%s ", pos_checkers2str(pos, str, sizeof(str)));
+    printf("pinners: %s ", pos_pinners2str(pos, str, sizeof(str)));
+    printf("blockers: %s\n", pos_blockers2str(pos, str, sizeof(str)));
+}
+
+/**
+ * pos_print_mask() - Print position and fen on stdout, with highlighted squares.
+ * @pos:  &position
+ * @mask: mask of highlighted squares.
+ */
+void pos_print_mask(const pos_t *pos, const bitboard_t mask)
+{
+    char fen[92];
+
+    board_print_mask(pos->board, mask);
+    printf("fen %s\n", pos2fen(pos, fen));
+}
+
+/**
+ * pos_print_raw - print simple position board (octal/FEN symbol values)
+ * @bb: the bitboard
+ * @type: int, 0 for octal, 1 for fen symbol
+ */
+void pos_print_raw(const pos_t *pos, const int type)
+{
+    board_print_raw(pos->board, type);
+    return;
+}
+
+/**
+ * pos_print_pieces() - Print position pieces
+ * @pos:  &position
+ */
+void pos_print_pieces(const pos_t *pos)
+{
+    int sq, count, cur;
+    char *pname;
+    u64 tmp;
+    bitboard_t p;
+    for (int color = WHITE; color <= BLACK; ++color) {
+        for (int piece = KING; piece >= PAWN; --piece) {
+            p = pos->bb[color][piece];
+            count = popcount64(p);
+            cur = 0;
+            pname = piece_to_char(p);
+            printf("%s(%d)%s", pname, count, count? ":": "");
+            if (count) {
+                bit_for_each64(sq, tmp, p) {
+                    // char cf = sq_file(bit), cr = sq_rank(bit);
+                    printf("%s%s", cur? ",": "", sq_to_string(sq));
+                    cur++;
+                }
+            }
+            printf(" ");
+        }
+        printf("\n");
+    }
 }

src/position.h

@@ -1,6 +1,6 @@
 /* position.h - position management definitions.
  *
- * Copyright (C) 2021 Bruno Raoult ("br")
+ * Copyright (C) 2021-2024 Bruno Raoult ("br")
  * Licensed under the GNU General Public License v3.0 or later.
  * Some rights reserved. See COPYING.
  *
@@ -15,51 +15,180 @@
 #define POSITION_H
 
 #include <stdint.h>
-#include <pool.h>
-#include <list.h>
-#include <bits.h>
 
-#include "board.h"
+#include <brlib.h>
+#include <bitops.h>
+#include <struct-group.h>
+#include <bug.h>
+
 #include "chessdefs.h"
+#include "hash.h"
+#include "bitboard.h"
+#include "piece.h"
+#include "move.h"
+#include "board.h"
 
-typedef struct pos_s {
+typedef struct __pos_s {
     u64 node_count;                               /* evaluated nodes */
-    piece_t turn;                                 /* we use only color bit */
-    castle_t castle;
-    u16 clock_50;
-    u16 curmove;
-    eval_t eval;
-    int check[2];
-    int eval_simple_phase;
-    eval_t eval_simple;
-    move_t *bestmove;
-    bool moves_generated;
-    bool moves_counted;
-    board_t board[BOARDSIZE];
+    int turn;                                     /* WHITE or BLACK */
 
-    square_t en_passant;
+    /* data which cannot be recovered by move_undo (like castle_rights, ...).
+     *
+     * Attention: checkers/pinners/blockers are not included here, and
+     * are not available in move_undo or any following legality check.
+     *
+     * Following data can be accessed either directly, either via "state"
+     * structure name.
+     * For example, pos->en_passant and pos->state.en_passant are the same.
+     * This allows a memcpy on this data (to save/restore position state).
+     */
+    struct_group_tagged(state_s, state,
+                        hkey_t key;
+                        square_t en_passant;
+                        castle_rights_t castle;
+                        int clock_50;
+                        int plycount;             /* plies so far, start from 1 */
+                        piece_t captured;         /* only used in move_undo */
+                        move_t move;
+                        struct state_s *prev;
+        );
+    bitboard_t checkers;                          /* opponent checkers */
+    bitboard_t pinners;                           /* opponent pinners */
+    bitboard_t blockers;                          /* pieces blocking pin */
 
-    bitboard_t bb[2][BB_END];                     /* use: pieces[BLACK][BB_PAWN] */
-    bitboard_t occupied[2];                       /* OR of bb[COLOR][x] */
-    bitboard_t controlled[2];
-    u16 mobility[2];
-    struct list_head pieces[2];                   /* pieces list, King is first */
-    struct list_head moves[2];
+    piece_t board[BOARDSIZE];
+    bitboard_t bb[2][PIECE_TYPE_MAX];             /* bb[0][PAWN], bb[1][ALL_PIECES] */
+    square_t king[2];                             /* dup with bb, faster retrieval */
 } pos_t;
 
-void bitboard_print(bitboard_t bb);
-void bitboard_print2(bitboard_t bb1, bitboard_t bb2);
-void pos_pieces_print(pos_t *pos);
-void pos_bitboards_print(pos_t *pos);
-void pos_print(pos_t *pos);
-pos_t *pos_clear(pos_t *pos);
+typedef struct state_s state_t;
+
+#define pos_pinned(p)                  (p->blockers & p->bb[p->turn][ALL_PIECES])
+
+/**
+ * pos_set_sq - unconditionally set a piece on a square
+ * @pos: position
+ * @square: square_t to set
+ * @piece: piece_t to add
+ *
+ * Both position board and bitboards are modified.
+ */
+static __always_inline void pos_set_sq(pos_t *pos, square_t square, piece_t piece)
+{
+    color_t color = COLOR(piece);
+    piece_type_t type = PIECE(piece);
+
+    bug_on(pos->board[square] != EMPTY);
+
+    pos->board[square] = piece;
+    pos->bb[color][type] |= BIT(square);
+    pos->bb[color][ALL_PIECES] |= BIT(square);
+    //if (type == KING)
+    //    pos->king[color] = square;
+
+    //pos->key ^= zobrist_pieces[piece][square];
+}
+
+/**
+ * pos_clr_sq - unconditionally remove a piece from square
+ * @pos: position
+ * @square: square_t to clear
+ *
+ * Both position board and bitboards are modified.
+ */
+static __always_inline void pos_clr_sq(pos_t *pos, square_t square)
+{
+    piece_t piece = pos->board[square];
+    piece_type_t type = PIECE(piece);
+    color_t color = COLOR(piece);
+
+    bug_on(pos->board[square] == EMPTY);
+
+    //pos->key ^= zobrist_pieces[piece][square];
+
+    pos->board[square] = EMPTY;
+    pos->bb[color][type] &= ~BIT(square);
+    pos->bb[color][ALL_PIECES] &= ~BIT(square);
+    //if (type == KING)
+    //    pos->king[color] = SQUARE_NONE;
+}
+
+/**
+ * pos_occ() - get position occupation (all pieces)
+ * @pos: position
+ *
+ * @return: occupation bitboard.
+ */
+static __always_inline bitboard_t pos_occ(const pos_t *pos)
+{
+    return pos->bb[WHITE][ALL_PIECES] | pos->bb[BLACK][ALL_PIECES];
+}
+
+/**
+ * pos_between_occ() - find occupation between two squares.
+ * @pos:   position
+ * @sq1:   square 1
+ * @sq2:   square 2
+ *
+ * @return: bitboard of @betw if between @sq1 and @sq2.
+ */
+static __always_inline bitboard_t pos_between_occ(const pos_t *pos,
+                                                  const square_t sq1, const square_t sq2)
+{
+    return bb_between_excl[sq1][sq2] & pos_occ(pos);
+}
+
+/**
+ * pos_between_count() - count occupied squares between two squares.
+ * @pos:   position
+ * @sq1:   square 1
+ * @sq2:   square 2
+ *
+ * @return: bitboard of @betw if between @sq1 and @sq2.
+ */
+static __always_inline int pos_between_count(const pos_t *pos,
+                                             const square_t sq1, const square_t sq2)
+{
+    return popcount64(pos_between_occ(pos, sq1, sq2));
+}
+
+/**
+ * pos_checkers2str() - get of string of checkers.
+ * @p:   position
+ * @str:   destination string
+ * @len:   max @str len.
+ *
+ * A wrapper over @bb_sq2str() for checkers bitmap.
+ *
+ * @return: @str.
+ */
+#define pos_checkers2str(p, str, len)  bb_sq2str(p->checkers, str, len)
+#define pos_pinners2str(p, str, len)   bb_sq2str(p->pinners, str, len)
+#define pos_blockers2str(p, str, len)  bb_sq2str(p->blockers, str, len)
+
+//void bitboard_print(bitboard_t bb, char *title);
+//void bitboard_print2(bitboard_t bb1, bitboard_t bb2, char *title);
+
+pos_t *pos_new();
+pos_t *pos_dup(const pos_t *pos);
+pos_t *pos_copy(const pos_t *from, pos_t *to);
 void pos_del(pos_t *pos);
-pos_t *pos_startpos(pos_t *pos);
-pos_t *pos_create();
-pool_t *pos_pool_init();
-void pos_pool_stats();
-pos_t *pos_get();
-pos_t *pos_dup(pos_t *pos);
-void pos_check(pos_t *pos);
+pos_t *pos_clear(pos_t *pos);
+bool pos_cmp(const pos_t *pos1, const pos_t *pos2);
+
+void pos_set_checkers_pinners_blockers(pos_t *pos);
+void pos_set_pinners_blockers(pos_t *pos);
+bitboard_t pos_checkers(const pos_t *pos, const color_t color);
+bitboard_t pos_king_pinners(const pos_t *pos, const color_t color);
+bitboard_t pos_king_blockers(const pos_t *pos, const color_t color, const bitboard_t );
+
+bool pos_ok(pos_t *pos, const bool strict);
+
+void pos_print(const pos_t *pos);
+void pos_print_mask(const pos_t *pos, const bitboard_t mask);
+void pos_print_raw(const pos_t *pos, const int type);
+
+void pos_print_pieces(const pos_t *pos);
+
 
 #endif  /* POSITION_H */

src/search.c

@@ -1,6 +1,6 @@
-/* search.c - search good moves.
+/* search.c - perft + search.
  *
- * Copyright (C) 2023 Bruno Raoult ("br")
+ * Copyright (C) 2023-2024 Bruno Raoult ("br")
  * Licensed under the GNU General Public License v3.0 or later.
  * Some rights reserved. See COPYING.
  *
@@ -11,14 +11,141 @@
  *
  */
 
+#include <stdio.h>
 
-#include <br.h>
-#include <list.h>
-#include "debug.h"
+#include <brlib.h>
 
-#include "move.h"
-#include "eval.h"
+#include "position.h"
+#include "move-gen.h"
+#include "move-do.h"
 #include "search.h"
+#include "attack.h"
+
+/**
+ * perft() - Perform perft on position
+ * @pos:    &position to search
+ * @depth:  Wanted depth.
+ * @ply:    current perft depth level (root = 1)
+ * @output: output total for 1st level moves.
+ *
+ * Run perft on a position. This function displays the available moves at @depth
+ * level for each possible first move, and the total of moves.
+ *
+ * This version uses the algorithm:
+ *    if last depth
+ *      return 1;
+ *    gen legal moves
+ *    loop for legal move
+ *      do-move
+ *      perft (depth -1)
+ *      undo-move
+ *
+ * @return: total moves found at @depth level.
+ */
+u64 perft(pos_t *pos, int depth, int ply, bool output)
+{
+    u64 subnodes, nodes = 0;
+    movelist_t movelist;
+    move_t *move, *last;
+    state_t state;
+#   ifdef PERFT_MOVE_HISTORY
+    static movelist_t stack;
+    if (ply == 1)
+        stack.nmoves = 0;
+#   endif
+
+    pos_set_checkers_pinners_blockers(pos);
+
+    pos_legal(pos, pos_gen_pseudo(pos, &movelist));
+    last = movelist.move + movelist.nmoves;
+    for (move = movelist.move; move < last; ++move) {
+        if (depth == 1) {
+            nodes++;
+        } else {
+            move_do(pos, *move, &state);
+#           ifdef PERFT_MOVE_HISTORY
+            stack.move[stack.nmoves++] = *move;
+#           endif
+            if (depth == 2) {
+                movelist_t movelist2;
+                pos_set_checkers_pinners_blockers(pos);
+                subnodes = pos_legal(pos, pos_gen_pseudo(pos, &movelist2))->nmoves;
+            } else if (ply >= 3) {
+                hentry_t *entry = tt_probe_perft(pos->key, depth);
+                if (entry != TT_MISS) {
+                    subnodes = HASH_PERFT_VAL(entry->data);
+                } else {
+                    subnodes = perft(pos, depth - 1, ply + 1, output);
+                    tt_store_perft(pos->key, depth, subnodes);
+                }
+            } else {
+                subnodes = perft(pos, depth - 1, ply + 1, output);
+            }
+            if (output && ply == 1) {
+                char movestr[8];
+                printf("%s: %lu\n", move_to_str(movestr, *move, 0), subnodes);
+            }
+            nodes += subnodes;
+            move_undo(pos, *move, &state);
+#           ifdef PERFT_MOVE_HISTORY
+            stack.nmoves--;
+#           endif
+        }
+    }
+
+    if (output && ply == 1)
+        printf("Total: %lu\n", nodes);
+    return nodes;
+}
+
+/**
+ * perft_alt() - Perform perft on position, experimental version.
+ * @pos:    &position to search
+ * @depth:  Wanted depth.
+ * @ply:    current perft depth level (root = 1)
+ * @output: output total for 1st level moves.
+ *
+ * Run perft on a position. This function displays the available moves at @depth
+ * level for each possible first move, and the total of moves.
+ *
+ * @return: total moves found at @depth level.
+ */
+u64 perft_alt(pos_t *pos, int depth, int ply, bool output)
+{
+    u64 subnodes, nodes = 0;
+    movelist_t movelist;
+    move_t *move, *last;
+    state_t state;
+
+    pos_set_checkers_pinners_blockers(pos);
+
+    pos_legal(pos, pos_gen_pseudo(pos, &movelist));
+    last = movelist.move + movelist.nmoves;
+    for (move = movelist.move; move < last; ++move) {
+        if (depth == 1) {
+            nodes++;
+        } else {
+            move_do_alt(pos, *move, &state);
+            if (depth == 2) {
+                movelist_t movelist2;
+                pos_set_checkers_pinners_blockers(pos);
+                subnodes = pos_legal(pos, pos_gen_pseudo(pos, &movelist2))->nmoves;
+            } else {
+                subnodes = perft_alt(pos, depth - 1, ply + 1, output);
+            }
+            if (output && ply == 1) {
+                char movestr[8];
+                printf("%s: %lu\n", move_to_str(movestr, *move, 0), subnodes);
+            }
+            nodes += subnodes;
+            move_undo_alt(pos, *move, &state);
+        }
+    }
+
+    if (output && ply == 1)
+        printf("Total: %lu\n", nodes);
+    return nodes;
+}
 
 /**
  * negamax() - search position negamax.
@@ -31,32 +158,34 @@
  *
  * @return: The @pos negamax evaluation.
  */
-eval_t negamax(pos_t *pos, int depth, int color)
-{
-    move_t *move;
-    pos_t *newpos;
-    eval_t best = EVAL_MIN, score;
-
-    pos->node_count++;
-    if (depth == 0) {
-        moves_gen_all_nomoves(pos);
-        score = eval(pos) * color;
-        return score;
-    }
-    moves_gen_all(pos);
-    list_for_each_entry(move, &pos->moves[pos->turn], list) {
-        newpos = move_do(pos, move);
-        score = -negamax(newpos, depth - 1, -color);
-        pos->node_count += newpos->node_count;
-        move->negamax = score;
-        if (score > best) {
-            best = score;
-            pos->bestmove = move;
-        }
-        move_undo(newpos, move);
-    }
-    return best;
-}
+/*
+ * eval_t negamax(pos_t *pos, int depth, int color)
+ * {
+ *     move_t *move;
+ *     pos_t *newpos;
+ *     eval_t best = EVAL_MIN, score;
+ *
+ *     pos->node_count++;
+ *     if (depth == 0) {
+ *         moves_gen_all_nomoves(pos);
+ *         score = eval(pos) * color;
+ *         return score;
+ *     }
+ *     moves_gen_all(pos);
+ *     list_for_each_entry(move, &pos->moves[pos->turn], list) {
+ *         newpos = move_do(pos, move);
+ *         score = -negamax(newpos, depth - 1, -color);
+ *         pos->node_count += newpos->node_count;
+ *         move->negamax = score;
+ *         if (score > best) {
+ *             best = score;
+ *             pos->bestmove = move;
+ *         }
+ *         move_undo(newpos, move);
+ *     }
+ *     return best;
+ * }
+ */
 
 
 /**
@@ -74,74 +203,76 @@ eval_t negamax(pos_t *pos, int depth, int color)
  *
  * @return: The @pos PVS evaluation.
  */
-eval_t pvs(pos_t *pos, int depth, int alpha, int beta, int color)
-{
-    move_t *move;
-    pos_t *newpos;
-    eval_t score = EVAL_INVALID;
-    bool firstchild = true;
-
-    pos->node_count++;
-
-    if (depth == 0) {
-        //return quiesce(p, alpha, beta);           /* leaf node */
-        moves_gen_all_nomoves(pos);
-        score = eval(pos) * color;
-        log_f(2, "Terminal: depth=%d ", depth);
-        log_f(2, "score=%d alpha=%d beta=%d\n", score, alpha, beta);
-        return score;
-    }
-
-    moves_gen_all(pos);
-    //moves_print(pos, M_PR_EVAL);
-    /* do the full search for first child */
-    //move = list_first_entry_or_null(&pos->moves[pos->turn], move_t, list);
-
-    list_for_each_entry(move, &pos->moves[pos->turn], list) {
-        newpos = move_do(pos, move);
-        log(2, "%.*s", 5 - depth, "                ");
-        if (firstchild) {                               /* first child */
-            score = -pvs(newpos, depth - 1, -beta, -alpha, -color);
-            log_f(2, "First child depth=%d move=", depth);
-            //move_print(0, move, 0);
-            log(2, "score=%d alpha=%d beta=%d\n", score, alpha, beta);
-            pos->bestmove = move;
-        } else {
-            /* search with a null window */
-            score = -pvs(newpos, depth - 1, -alpha - 1, -alpha, -color);
-            log_f(2, "Other child depth=%d move=", depth);
-            //move_print(0, move, 0);
-            log_f(2, "score=%d alpha=%d beta=%d ", score, alpha, beta);
-            /* for fail-soft:  if (score > alpha && score < beta) */
-            if (score > alpha) {
-                /* if failed high, do a full re-search */
-                log_f(2, "doing full search.");
-                score = -pvs(newpos, depth - 1, -beta, -alpha, -color);
-            }
-            log(2, "\n");
-        }
-        pos->node_count += newpos->node_count;
-        move_undo(newpos, move);
-        if (score >= beta) {                      /* fail-hard hard beta cut-off */
-            log(2, "%.*s", 5 - depth, "                ");
-            log_f(2, "depth=%d score=%d alpha=%d beta=%d beta cut-off.\n",
-                  depth, score, alpha, beta);
-            return beta;
-        }
-        if (score > alpha) {
-            log(2, "%.*s", 5 - depth, "                ");
-            log_f(2, "depth=%d setting new alpha from %d to %d\n",
-                  depth, alpha, score);
-            alpha = score;
-            pos->bestmove = move;
-        }
-        move->pos = NULL;
-        move->negamax = score;
-        firstchild = false;
-    }
-
-    return alpha;
-}
+/*
+ * eval_t pvs(pos_t *pos, int depth, int alpha, int beta, int color)
+ * {
+ *     move_t *move;
+ *     pos_t *newpos;
+ *     eval_t score = EVAL_INVALID;
+ *     bool firstchild = true;
+ *
+ *     pos->node_count++;
+ *
+ *     if (depth == 0) {
+ *         //return quiesce(p, alpha, beta);           /\* leaf node *\/
+ *         moves_gen_all_nomoves(pos);
+ *         score = eval(pos) * color;
+ *         log_f(2, "Terminal: depth=%d ", depth);
+ *         log_f(2, "score=%d alpha=%d beta=%d\n", score, alpha, beta);
+ *         return score;
+ *     }
+ *
+ *     moves_gen_all(pos);
+ *     //moves_print(pos, M_PR_EVAL);
+ *     /\* do the full search for first child *\/
+ *     //move = list_first_entry_or_null(&pos->moves[pos->turn], move_t, list);
+ *
+ *     list_for_each_entry(move, &pos->moves[pos->turn], list) {
+ *         newpos = move_do(pos, move);
+ *         log(2, "%.*s", 5 - depth, "                ");
+ *         if (firstchild) {                               /\* first child *\/
+ *             score = -pvs(newpos, depth - 1, -beta, -alpha, -color);
+ *             log_f(2, "First child depth=%d move=", depth);
+ *             //move_print(0, move, 0);
+ *             log(2, "score=%d alpha=%d beta=%d\n", score, alpha, beta);
+ *             pos->bestmove = move;
+ *         } else {
+ *             /\* search with a null window *\/
+ *             score = -pvs(newpos, depth - 1, -alpha - 1, -alpha, -color);
+ *             log_f(2, "Other child depth=%d move=", depth);
+ *             //move_print(0, move, 0);
+ *             log_f(2, "score=%d alpha=%d beta=%d ", score, alpha, beta);
+ *             /\* for fail-soft:  if (score > alpha && score < beta) *\/
+ *             if (score > alpha) {
+ *                 /\* if failed high, do a full re-search *\/
+ *                 log_f(2, "doing full search.");
+ *                 score = -pvs(newpos, depth - 1, -beta, -alpha, -color);
+ *             }
+ *             log(2, "\n");
+ *         }
+ *         pos->node_count += newpos->node_count;
+ *         move_undo(newpos, move);
+ *         if (score >= beta) {                      /\* fail-hard hard beta cut-off *\/
+ *             log(2, "%.*s", 5 - depth, "                ");
+ *             log_f(2, "depth=%d score=%d alpha=%d beta=%d beta cut-off.\n",
+ *                   depth, score, alpha, beta);
+ *             return beta;
+ *         }
+ *         if (score > alpha) {
+ *             log(2, "%.*s", 5 - depth, "                ");
+ *             log_f(2, "depth=%d setting new alpha from %d to %d\n",
+ *                   depth, alpha, score);
+ *             alpha = score;
+ *             pos->bestmove = move;
+ *         }
+ *         move->pos = NULL;
+ *         move->negamax = score;
+ *         firstchild = false;
+ *     }
+ *
+ *     return alpha;
+ * }
+ */
 
 /*
  * int negascout (pos_t *pos, int depth, int alpha, int beta )
@@ -214,24 +345,24 @@ eval_t pvs(pos_t *pos, int depth, int alpha, int beta, int color)
  * @return: The @pos negamax evaluation.
  */
 /*int ab_negamax(pos_t *pos, int alpha, int beta, int depth)
-{
-    move_t *move;
-    pos_t *newpos;
-    eval_t best = EVAL_MIN, score;
+  {
+  move_t *move;
+  pos_t *newpos;
+  eval_t best = EVAL_MIN, score;
 
-    if(depth == 0) {
-       //return quiesce( alpha, beta );
-        moves_gen_all_nomoves(pos);
-       score = eval(pos) * color;
-       return score;
-    }
-   for ( all moves)  {
-      score = -alphaBeta( -beta, -alpha, depthleft - 1 );
-      if( score >= beta )
-         return beta;   //  fail hard beta-cutoff
-      if( score > alpha )
-         alpha = score; // alpha acts like max in MiniMax
-   }
-   return alpha;
-}
+  if(depth == 0) {
+  //return quiesce( alpha, beta );
+  moves_gen_all_nomoves(pos);
+  score = eval(pos) * color;
+  return score;
+  }
+  for ( all moves)  {
+  score = -alphaBeta( -beta, -alpha, depthleft - 1 );
+  if( score >= beta )
+  return beta;   //  fail hard beta-cutoff
+  if( score > alpha )
+  alpha = score; // alpha acts like max in MiniMax
+  }
+  return alpha;
+  }
 */

src/search.h

@@ -1,6 +1,6 @@
 /* search.h - search for perfect move.
  *
- * Copyright (C) 2021 Bruno Raoult ("br")
+ * Copyright (C) 2021-2024 Bruno Raoult ("br")
  * Licensed under the GNU General Public License v3.0 or later.
  * Some rights reserved. See COPYING.
  *
@@ -16,7 +16,10 @@
 
 #include "position.h"
 
-eval_t negamax(pos_t *pos, int depth, int color);
-eval_t pvs(pos_t *pos, int depth, int alpha, int beta, int color);
+//eval_t negamax(pos_t *pos, int depth, int color);
+//eval_t pvs(pos_t *pos, int depth, int alpha, int beta, int color);
+
+u64 perft(pos_t *pos, int depth, int ply, bool output);
+u64 perft_alt(pos_t *pos, int depth, int ply, bool output);
 
 #endif  /* SEARCH_H */

src/temp-migration-bitboard/bitboard.c

@@ -0,0 +1,42 @@
+/* bitboard.c - bitboard functions.
+ *
+ * Copyright (C) 2024 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#include "br.h"
+#include "bitboard.h"
+
+/*  maps are clockwise from N */
+static char knight_vector[8] = {
+    NORTH*2 + EAST, NORTH + EAST*2, SOUTH + EAST*2, SOUTH*2 + EAST,
+    SOUTH*2 + WEST, SOUTH + WEST*2, NORTH + WEST*2, NORTH*2 + WEST
+};
+static char king_vector[8] = {
+    NORTH, NORTH_EAST, EAST, SOUTH_EAST,
+    SOUTH, SOUTH_WEST, WEST, NORTH_WEST
+};
+
+static u64 knight_attacks[64], king_attacks[64];
+static int zob=0;
+
+void bitboard_init(void)
+{
+    for (int sq = SQ_0; sq < SQ_N; ++sq) {
+        /* knight/king */
+        for (int j = 0; j < 8; ++j) {
+            zob += *knight_attacks + *king_attacks + *knight_vector +
+                *king_vector;
+            //int dest_knight = sq + knight_vector[j];
+            //if ()
+        }
+
+    }
+}

src/temp-migration-bitboard/bitboard.h

@@ -0,0 +1,105 @@
+/* bitboard.h - bitboard definitions.
+ *
+ * Copyright (C) 2021-2024 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#ifndef BITBOARD_H
+#define BITBOARD_H
+
+#include "br.h"
+#include "chessdefs.h"
+#include "piece.h"
+#include "bitops.h"
+
+#define mask(s)  ( 1ULL << (s) )
+#define C64(const_u64) const_u64##ULL
+
+typedef enum square {
+    A1, B1, C1, D1, E1, F1, G1, H1,
+    A2, B2, C2, D2, E2, F2, G2, H2,
+    A3, B3, C3, D3, E3, F3, G3, H3,
+    A4, B4, C4, D4, E4, F4, G4, H4,
+    A5, B5, C5, D5, E5, F5, G5, H5,
+    A6, B6, C6, D6, E6, F6, G6, H6,
+    A7, B7, C7, D7, E7, F7, G7, H7,
+    A8, B8, C8, D8, E8, F8, G8, H8,
+    SQ_N,
+    SQ_0 = 0
+} square;
+
+typedef enum file {
+    FILE_A, FILE_B, FILE_C, FILE_D, FILE_E, FILE_F, FILE_G, FILE_H,
+    FILE_N,
+    FILE_0 = 0
+} file;
+
+typedef enum rank {
+    RANK_1, RANK_2, RANK_3, RANK_4, RANK_5, RANK_6, RANK_7, RANK_8,
+    RANK_N,
+    RANK_0 = 0
+} rank;
+
+typedef enum sq_bb {
+    //A1 = 0x01ULL, B1 = 0x02ULL, C1 = 1UL <<  2, D1 = 1UL <<  3,
+    //E1 = 1UL <<  4, F1 = 1UL <<  5, G1 = 1UL <<  6, H1 = 1UL <<
+    A1bb = mask(A1), A2bb = mask(A2), A3bb = mask(A3), A4bb = mask(A4),
+    A5bb = mask(A5), A6bb = mask(A6), A7bb = mask(A7), A8bb = mask(A8),
+    B1bb = mask(B1), B2bb = mask(B2), B3bb = mask(B3), B4bb = mask(B4),
+    B5bb = mask(B5), B6bb = mask(B6), B7bb = mask(B7), B8bb = mask(B8),
+    C1bb = mask(C1), C2bb = mask(C2), C3bb = mask(C3), C4bb = mask(C4),
+    C5bb = mask(C5), C6bb = mask(C6), C7bb = mask(C7), C8bb = mask(C8),
+    D1bb = mask(D1), D2bb = mask(D2), D3bb = mask(D3), D4bb = mask(D4),
+    D5bb = mask(D5), D6bb = mask(D6), D7bb = mask(D7), D8bb = mask(D8),
+    E1bb = mask(E1), E2bb = mask(E2), E3bb = mask(E3), E4bb = mask(E4),
+    E5bb = mask(E5), E6bb = mask(E6), E7bb = mask(E7), E8bb = mask(E8),
+    F1bb = mask(F1), F2bb = mask(F2), F3bb = mask(F3), F4bb = mask(F4),
+    F5bb = mask(F5), F6bb = mask(F6), F7bb = mask(F7), F8bb = mask(F8),
+    G1bb = mask(G1), G2bb = mask(G2), G3bb = mask(G3), G4bb = mask(G4),
+    G5bb = mask(G5), G6bb = mask(G6), G7bb = mask(G7), G8bb = mask(G8),
+    H1bb = mask(H1), H2bb = mask(H2), H3bb = mask(H3), H4bb = mask(H4),
+    H5bb = mask(H5), H6bb = mask(H6), H7bb = mask(H7), H8bb = mask(H8),
+} sq_bb;
+
+typedef enum file_bb {
+    FILE_Abb = 0x0101010101010101ULL,
+    FILE_Bbb = 0x0202020202020202ULL,
+    FILE_Cbb = 0x0404040404040404ULL,
+    FILE_Dbb = 0x0808080808080808ULL,
+    FILE_Ebb = 0x1010101010101010ULL,
+    FILE_Fbb = 0x2020202020202020ULL,
+    FILE_Gbb = 0x4040404040404040ULL,
+    FILE_Hbb = 0x8080808080808080ULL,
+} file_bb;
+
+typedef enum rank_bb {
+    RANK_1bb = 0x00000000000000ffULL,
+    RANK_2bb = 0x000000000000ff00ULL,
+    RANK_3bb = 0x0000000000ff0000ULL,
+    RANK_4bb = 0x00000000ff000000ULL,
+    RANK_5bb = 0x000000ff00000000ULL,
+    RANK_6bb = 0x0000ff0000000000ULL,
+    RANK_7bb = 0x00ff000000000000ULL,
+    RANK_8bb = 0xff00000000000000ULL
+} rank_bb;
+
+#define NORTH 8
+#define EAST  1
+#define SOUTH -NORTH
+#define WEST  -EAST
+
+#define NORTH_EAST (NORTH + EAST)
+#define SOUTH_EAST (SOUTH + EAST)
+#define SOUTH_WEST (SOUTH + WEST)
+#define NORTH_WEST (NORTH + WEST)
+
+void bitboard_init(void);
+
+#endif  /* BITBOARD_H */

src/temp-migration-bitboard/board.h

@@ -0,0 +1,80 @@
+/* board.h - board definitions.
+ *
+ * Copyright (C) 2021 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#ifndef BOARD_H
+#define BOARD_H
+
+#include <stdint.h>
+#include "chessdefs.h"
+#include "piece.h"
+
+typedef struct board_s {
+    piece_t piece;
+    piece_list_t *s_piece;
+    //struct list_head *s_piece;
+} board_t;                                        /* 0x88 board */
+#define BOARDSIZE    (8*8*2)
+
+/* definitions for 0x88 representation
+ */
+#define SQ88(f, r)  (((r) << 4) | (f))            /* from rank,file to sq88 */
+#define F88(s)      ((s) & 0x0f)                  /* from sq88 to file */
+#define R88(s)      ((s) >> 4)                    /* from sq88 to rank */
+
+#define SETF88(s, r) ((s) &= 0xf0, (s) |= (r))
+#define SETR88(s, f) ((s) &= 0x0f, (s) |= (f)<<4)
+
+#define SQ88_NOK(s)  ((s) & 0x88)                 /* invalid square */
+#define SQ88_OK(s)   (!SQ88_NOK(s))
+
+/* definitions for bitboard representation
+ */
+#define BB(f, r)     (1ULL << (8 * (r) + (f)))    /* from rank,file to bitboard */
+#define SQ88_2_BB(s) (BB(F88(s), R88(s)))         /* from sq88 to bitboard */
+#define FILEBB(b)    ((b) % 8)                    /* from sq88 to file */
+#define RANKBB(b)    ((b) / 8)                    /* from sq88 to rank */
+
+#define SQ88_NOK(s)  ((s) & 0x88)                 /* invalid square */
+#define SQ88_OK(s)   (!SQ88_NOK(s))
+
+/* piece human notation
+ */
+#define CHAR_EMPTY   ' '
+#define CHAR_PAWN    'P'
+#define CHAR_KNIGHT  'N'
+#define CHAR_BISHOP  'B'
+#define CHAR_ROOK    'R'
+#define CHAR_QUEEN   'Q'
+#define CHAR_KING    'K'
+
+/* from human to machine
+ */
+#define C2FILE(c)    (tolower(c) - 'a')
+#define C2RANK(c)    (tolower(c) - '1')
+/* from machine to human
+ */
+#define FILE2C(f)    ((f) + 'a')
+#define RANK2C(r)    ((r) + '1')
+
+enum x88_square {
+    x88_A1=0x00, x88_B1, x88_C1, x88_D1, x88_E1, x88_F1, x88_G1, x88_H1,
+    x88_A2=0x10, x88_B2, x88_C2, x88_D2, x88_E2, x88_F2, x88_G2, x88_H2,
+    x88_A3=0x20, x88_B3, x88_C3, x88_D3, x88_E3, x88_F3, x88_G3, x88_H3,
+    x88_A4=0x30, x88_B4, x88_C4, x88_D4, x88_E4, x88_F4, x88_G4, x88_H4,
+    x88_A5=0x40, x88_B5, x88_C5, x88_D5, x88_E5, x88_F5, x88_G5, x88_H5,
+    x88_A6=0x50, x88_B6, x88_C6, x88_D6, x88_E6, x88_F6, x88_G6, x88_H6,
+    x88_A7=0x60, x88_B7, x88_C7, x88_D7, x88_E7, x88_F7, x88_G7, x88_H7,
+    x88_A8=0x70, x88_B8, x88_C8, x88_D8, x88_E8, x88_F8, x88_G8, x88_H8,
+};
+
+#endif  /* BOARD_H */

src/temp-migration-bitboard/brchess.c

@@ -0,0 +1,522 @@
+/* brchess.c - main loop.
+ *
+ * Copyright (C) 2021-2023 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+
+#include <err.h>
+#include <stdlib.h>
+#include <string.h>
+#include <readline/readline.h>
+#include <readline/history.h>
+
+#include <br.h>
+#include <list.h>
+#include <debug.h>
+
+#include "brchess.h"
+#include "chessdefs.h"
+#include "board.h"
+#include "piece.h"
+#include "move.h"
+#include "fen.h"
+#include "eval.h"
+#include "eval-simple.h"
+#include "search.h"
+
+struct command {
+    char *name;                                   /* User printable name */
+    int (*func)(pos_t *, char *);                 /* function doing the job */
+    char *doc;                                    /* function doc */
+};
+
+/* readline example inspired by :
+ * - https://thoughtbot.com/blog/tab-completion-in-gnu-readline
+ * - http://web.mit.edu/gnu/doc/html/rlman_2.html
+ */
+char **commands_completion(const char *, int, int);
+char *commands_generator(const char *, int);
+char *escape(const char *);
+int quote_detector(char *, int);
+int execute_line (pos_t *, char *line);
+struct command *find_command (char *);
+char *stripwhite (char *string);
+
+/* The names of functions that actually do the manipulation. */
+int do_help(pos_t *, char*);
+int do_fen(pos_t *, char*);
+int do_init(pos_t *, char*);
+int do_pos(pos_t *, char*);
+int do_genmoves(pos_t *, char*);
+int do_prmoves(pos_t *, char*);
+//int do_prmovepos(pos_t *pos, char *arg);
+int do_prpieces(pos_t *pos, char *arg);
+int do_memstats(pos_t *, char*);
+int do_eval(pos_t *, char*);
+int do_simple_eval(pos_t *, char*);
+int do_move(pos_t *, char*);
+int do_quit(pos_t *, char*);
+int do_debug(pos_t *, char*);
+int do_depth(pos_t *, char*);
+int do_search(pos_t *, char*);
+int do_pvs(pos_t *, char*);
+
+struct command commands[] = {
+    { "help", do_help, "Display this text" },
+    { "?", do_help, "Synonym for 'help'" },
+    { "fen", do_fen, "Set position to FEN" },
+    { "init", do_init, "Set position to normal start position" },
+    { "pos", do_pos, "Print current position" },
+    { "quit", do_quit, "Quit" },
+    { "genmove", do_genmoves, "Generate move list for " },
+    { "prmoves", do_prmoves, "Print position move list" },
+//    { "prmovepos", do_prmovepos, "Print Nth move resulting position" },
+    { "prpieces", do_prpieces, "Print Pieces (from pieces lists)" },
+    { "memstats", do_memstats, "Generate next move list" },
+    { "eval", do_eval, "Eval current position" },
+    { "simple-eval", do_simple_eval, "Simple eval current position" },
+    { "do_move", do_move, "execute nth move on current position" },
+    { "debug", do_debug, "Set log level to LEVEL" },
+    { "depth", do_depth, "Set search depth to N" },
+    { "search", do_search, "Search best move (negamax)" },
+    { "pvs", do_pvs, "Search best move (Principal Variation Search)" },
+    { NULL, (int(*)()) NULL, NULL }
+};
+
+static int done=0;
+static int depth=1;
+
+int brchess(pos_t *pos)
+{
+    char *buffer, *s;
+
+    rl_attempted_completion_function = commands_completion;
+    rl_completer_quote_characters = "'\"";
+    rl_completer_word_break_characters = " ";
+    rl_char_is_quoted_p = &quote_detector;
+
+    while (!done) {
+        buffer = readline("chess> ");
+        if (!buffer)
+            break;
+        /* Remove leading and trailing whitespace from the line.
+         * Then, if there is anything left, add it to the history list
+         * and execute it.
+         */
+        s = stripwhite(buffer);
+
+        if (*s) {
+            add_history(s);
+            execute_line(pos, s);
+        }
+        free(buffer);
+    }
+
+    return 0;
+}
+
+//char **commands_completion(const char *text, int start, int end)
+char **commands_completion(const char *text, __unused int start, __unused int end)
+{
+    rl_attempted_completion_over = 1;
+    return rl_completion_matches(text, commands_generator);
+}
+
+char *commands_generator(const char *text, int state)
+{
+    static int list_index, len;
+    char *name;
+
+    if (!state) {
+        list_index = 0;
+        len = strlen(text);
+    }
+
+    while ((name = commands[list_index++].name)) {
+        if (rl_completion_quote_character) {
+            name = strdup(name);
+        } else {
+            name = escape(name);
+        }
+
+        if (strncmp(name, text, len) == 0) {
+            return name;
+        } else {
+            free(name);
+        }
+    }
+
+    return NULL;
+}
+
+char *escape(const char *original)
+{
+    size_t original_len;
+    size_t i, j;
+    char *escaped, *resized_escaped;
+
+    original_len = strlen(original);
+
+    if (original_len > SIZE_MAX / 2) {
+        errx(1, "string too long to escape");
+    }
+
+    if ((escaped = malloc(2 * original_len + 1)) == NULL) {
+        err(1, NULL);
+    }
+
+    for (i = 0, j = 0; i < original_len; ++i, ++j) {
+        if (original[i] == ' ') {
+            escaped[j++] = '\\';
+        }
+        escaped[j] = original[i];
+    }
+    escaped[j] = '\0';
+
+    if ((resized_escaped = realloc(escaped, j)) == NULL) {
+        free(escaped);
+        resized_escaped = NULL;
+        err(1, NULL);
+    }
+
+    return resized_escaped;
+}
+
+int quote_detector(char *line, int index)
+{
+    return index > 0
+            && line[index - 1] == '\\'
+            &&!quote_detector(line, index - 1);
+}
+
+/* Execute a command line. */
+int execute_line(pos_t *pos, char *line)
+{
+    register int i;
+    struct command *command;
+    char *word;
+
+    /* Isolate the command word. */
+    i = 0;
+    while (line[i] && whitespace(line[i]))
+        i++;
+    word = line + i;
+
+    while (line[i] && !whitespace(line[i]))
+        i++;
+
+    if (line[i])
+        line[i++] = '\0';
+
+    command = find_command(word);
+
+    if (!command) {
+        fprintf(stderr, "%s: Unknown command.\n", word);
+        return -1;
+    }
+
+    /* Get argument to command, if any. */
+    while (whitespace(line[i]))
+        i++;
+
+    word = line + i;
+
+    /* return command number */
+    return (*command->func)(pos, word);
+}
+
+/* Look up NAME as the name of a command, and return a pointer to that
+   command.  Return a NULL pointer if NAME isn't a command name. */
+struct command *find_command(char *name)
+{
+    register int i;
+
+    for (i = 0; commands[i].name; i++)
+        if (strcmp(name, commands[i].name) == 0)
+            return &commands[i];
+
+    return (struct command *)NULL;
+}
+
+/* Strip whitespace from the start and end of STRING.  Return a pointer
+   into STRING. */
+char *stripwhite(char *string)
+{
+    register char *s, *t;
+
+    for (s = string; whitespace(*s); s++)
+        ;
+
+    if (*s == 0)
+        return s;
+
+    t = s + strlen(s) - 1;
+    while (t > s && whitespace(*t))
+        t--;
+    *++t = '\0';
+
+    return s;
+}
+
+int do_eval(__unused pos_t *pos, __unused char *arg)
+{
+    eval_t material[2], control[2], mobility[2];
+    for (int color = WHITE; color <= BLACK; ++color) {
+        material[color] = eval_material(pos, color);
+        control[color] = eval_square_control(pos, color);
+        mobility[color] = eval_mobility(pos, color);
+        printf("%s: material=%d mobility=%d controlled=%d\n",
+               color? "Black": "White", material[color],
+               mobility[color], control[color]);
+    }
+    eval_t res = eval(pos);
+    printf("eval = %d centipawns\n", res);
+    return 1;
+}
+
+int do_simple_eval(__unused pos_t *pos, __unused char *arg)
+{
+    eval_t eval = eval_simple(pos);
+    printf("eval = %d centipawns\n", eval);
+    return 1;
+}
+
+int do_fen(pos_t *pos, char *arg)
+{
+    fen2pos(pos, arg);
+    return 1;
+}
+
+int do_init(pos_t *pos, __unused char *arg)
+{
+    pos_startpos(pos);
+    return 1;
+}
+
+int do_pos(pos_t *pos, __unused char *arg)
+{
+    pos_print(pos);
+    return 1;
+}
+
+int do_genmoves(pos_t *pos, __unused char *arg)
+{
+    moves_gen_all(pos);
+    return 1;
+}
+
+int do_prmoves(pos_t *pos, __unused char *arg)
+{
+    uint debug_level = debug_level_get();
+    debug_level_set(1);
+    moves_print(pos, M_PR_SEPARATE | M_PR_NUM | M_PR_LONG);
+    debug_level_set(debug_level);
+    return 1;
+}
+
+/*
+ * int do_prmovepos(pos_t *pos, char *arg)
+ * {
+ *     struct list_head *p_cur, *tmp;
+ *     int movenum = atoi(arg), cur = 0;             /\* starts with 0 *\/
+ *     move_t *move;
+ *
+ *     log_f(1, "%s\n", arg);
+ *     list_for_each_safe(p_cur, tmp, &pos->moves[pos->turn]) {
+ *         move = list_entry(p_cur, move_t, list);
+ *         if (cur++ == movenum) {
+ *             pos_print(move->newpos);
+ *             break;
+ *         }
+ *     }
+ *
+ *     return 1;
+ * }
+ */
+
+int do_prpieces(pos_t *pos, __unused char *arg)
+{
+    log_f(1, "%s\n", arg);
+    pos_pieces_print(pos);
+    return 1;
+}
+
+int do_memstats(__unused pos_t *pos,__unused char *arg)
+{
+    moves_pool_stats();
+    piece_pool_stats();
+    pos_pool_stats();
+    return 1;
+}
+
+int do_move(__unused pos_t *pos, __unused char *arg)
+{
+    int i = 1, nmove = atoi(arg);
+    move_t *move;
+    pos_t *newpos;
+
+    if (list_empty(&pos->moves[pos->turn])) {
+        log_f(1, "No moves list.\n");
+        return 0;
+    }
+    list_for_each_entry(move, &pos->moves[pos->turn], list) {
+        if (i == nmove)
+            goto doit;
+        i++;
+    }
+    log_f(1, "Invalid <%d> move, should be <1-%d>.\n", nmove, i);
+    return 0;
+doit:
+    newpos = move_do(pos, move);
+    pos_print(newpos);
+
+    return 1;
+}
+
+int do_quit(__unused pos_t *pos, __unused char *arg)
+{
+    return done = 1;
+}
+
+int do_debug(__unused pos_t *pos, __unused char *arg)
+{
+    debug_level_set(atoi(arg));
+    return 1;
+}
+
+/* Print out help for ARG, or for all of the commands if ARG is
+   not present. */
+int do_help(__unused pos_t *pos, __unused char *arg)
+{
+    int i;
+    int printed = 0;
+
+    for (i = 0; commands[i].name; i++) {
+        if (!*arg || (strcmp(arg, commands[i].name) == 0)) {
+            printf("%-11.11s%s.\n", commands[i].name, commands[i].doc);
+            printed++;
+        }
+    }
+
+    if (!printed) {
+        printf("No commands match `%s'.  Possibilties are:\n", arg);
+
+        for (i = 0; commands[i].name; i++) {
+            /* Print in six columns. */
+            if (printed == 6) {
+                printed = 0;
+                printf("\n");
+            }
+
+            printf("%s\t", commands[i].name);
+            printed++;
+        }
+
+        if (printed)
+            printf("\n");
+    }
+    return 0;
+}
+
+int do_depth(__unused pos_t *pos, char *arg)
+{
+    depth = atoi(arg);
+    printf("depth = %d\n", depth);
+    return 1;
+
+}
+
+int do_search(pos_t *pos, __unused char *arg)
+{
+    int debug_level = debug_level_get();
+    float timer1, timer2, nodes_sec;
+
+    timer1 = debug_timer_elapsed();
+    negamax(pos, depth, pos->turn == WHITE ? 1 : -1);
+    timer2 = debug_timer_elapsed();
+    nodes_sec = (float) pos->node_count / ((float) (timer2 - timer1) / (float)NANOSEC);
+    log(1, "best=");
+    debug_level_set(1);
+    move_print(0, pos->bestmove, 0);
+    debug_level_set(debug_level);
+    log(1, " negamax=%d\n", pos->bestmove->negamax);
+    printf("Depth:%d Nodes:%luK time:%.02fs (%.0f kn/s)\n", depth,
+           pos->node_count / 1000, (timer2 - timer1)/NANOSEC, nodes_sec/1000);
+    return 1;
+}
+
+int do_pvs(pos_t *pos, __unused char *arg)
+{
+    int debug_level = debug_level_get();
+    float timer1, timer2, nodes_sec;
+    eval_t _pvs;
+
+    timer1 = debug_timer_elapsed();
+    moves_gen_eval_sort(pos);
+    _pvs = pvs(pos, depth, EVAL_MIN, EVAL_MAX, pos->turn == WHITE ? 1 : -1);
+    timer2 = debug_timer_elapsed();
+    nodes_sec = (float) pos->node_count / ((float) (timer2 - timer1) / (float)NANOSEC);
+    log(1, "best=");
+    if (pos->bestmove) {
+        debug_level_set(1);
+        move_print(0, pos->bestmove, 0);
+        debug_level_set(debug_level);
+        log(1, " pvs=%d stored=%d\n", _pvs, pos->bestmove->negamax);
+    } else {
+        log(1, "<no-best-move>");
+    }
+    printf("Depth:%d Nodes:%luK time:%.02fs (%.0f kn/s)\n", depth,
+           pos->node_count / 1000, (timer2 - timer1)/NANOSEC, nodes_sec/1000);
+    return 1;
+}
+
+/** main()
+ * options:
+ int brchess(pos_t *pos)
+ *
+ */
+static int usage(char *prg)
+{
+    fprintf(stderr, "Usage: %s [-ilw] [file...]\n", prg);
+    return 1;
+}
+
+#include <unistd.h>
+
+int main(int ac, char **av)
+{
+    pos_t *pos;
+    int opt;
+
+    piece_pool_init();
+    moves_pool_init();
+    pos_pool_init();
+    pos = pos_get();
+    debug_init(1, stderr, true);
+    eval_simple_init();
+
+    while ((opt = getopt(ac, av, "d:f:")) != -1) {
+        switch (opt) {
+            case 'd':
+                debug_level_set(atoi(optarg));
+                break;
+            case 'f':
+                fen2pos(pos, optarg);
+                break;
+            default:
+                return usage(*av);
+        }
+    }
+    if (optind < ac)
+        return usage(*av);
+
+    return brchess(pos);
+}

src/temp-migration-bitboard/brchess.h

@@ -0,0 +1,21 @@
+/* brchess.h - main loop.
+ *
+ * Copyright (C) 2021-2024 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#ifndef BRCHESS_H
+#define BRCHESS_H
+
+#include "position.h"
+
+int brchess(pos_t *pos);
+
+#endif  /* BRCHESS_H */

src/temp-migration-bitboard/chessdefs.h

@@ -0,0 +1,129 @@
+/* chessdefs.h - generic chess definitions.
+ *
+ * Copyright (C) 2021 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#ifndef CHESSDEFS_H
+#define CHESSDEFS_H
+
+#include "br.h"
+
+/* piece_t bits structure
+ * MSB 8 7 6 5 4 3 2 1 LSB
+ * 1: color (0 for white)
+ * 2-7: bit set for pawn (2), knight, bishop, rook, queen, king (7)
+ */
+typedef u8 piece_t;
+
+enum {
+    E_EMPTY = 0,
+    E_COLOR,                                      /* LSB */
+    E_PAWN,
+    E_KNIGHT,
+    E_BISHOP,
+    E_ROOK,
+    E_QUEEN,
+    E_KING,
+};
+
+/* pos_t bitboards tables
+ */
+enum {
+    BB_ALL = 0,                                   /* OR of all bitboards */
+    BB_UNUSED,                                    /* future use ? */
+    BB_PAWN = E_PAWN,
+    BB_KNIGHT,
+    BB_BISHOP,
+    BB_ROOK,
+    BB_QUEEN,
+    BB_KING,
+    BB_END
+};
+
+/* piece bitmask in piece_t
+ */
+enum {
+    EMPTY  = 0,
+    PAWN   = 1 << (E_PAWN - 1),                   /* 1<<(2-1) = 0x02 00000010 */
+    KNIGHT = 1 << (E_KNIGHT - 1),                 /* 0x04 00000100 */
+    BISHOP = 1 << (E_BISHOP - 1),                 /* 0x08 00001000 */
+    ROOK   = 1 << (E_ROOK - 1),                   /* 0x10 00010000 */
+    QUEEN  = 1 << (E_QUEEN - 1),                  /* 0x20 00100000 */
+    KING   = 1 << (E_KING - 1),                   /* 0x40 01000000 */
+};
+
+#define PIECETOBB(p)    (ffs64(PIECE(p)))         /* from piece_t to bb piece array */
+
+#define WHITE           0                         /* 0x00 00000000 */
+#define BLACK           1                         /* 0x01 00000001 */
+#define OPPONENT(p)     !(p)
+
+#define MASK_COLOR      0x01                      /* 00000001 */
+#define MASK_PIECE      0x7E                      /* 01111110 */
+
+#define COLOR(p)        ((p) & MASK_COLOR)        /* bitmask */
+#define PIECE(p)        ((p) & MASK_PIECE)
+#define E_PIECE(p)      (ffs64(PIECE(p)))         /* convert mask to E_XX */
+
+#define IS_WHITE(p)     (!COLOR(p))
+#define IS_BLACK(p)     (COLOR(p))
+
+#define SET_WHITE(p)    ((p) &= ~MASK_COLOR)
+#define SET_BLACK(p)    ((p) |= MASK_COLOR)
+#define SET_COLOR(p, c) (!(c)? SET_WHITE(p): SET_BLACK(p))
+
+/* flip a 0-63 square:
+ * Vertical:   G8 (62) becomes G1 (6)
+ * Horizontal: G8 (62) becomes B8 (57)
+ */
+#define FLIP_V(sq)      ((sq) ^ 56)
+#define FLIP_H(sq)      ((sq) ^ 7)
+/* square_t bits structure : rrrrffff
+ * ffff: file
+ * rrrr: rank
+ */
+typedef uchar square_t;
+
+/* castle_t bits structure
+ */
+typedef unsigned char castle_t;
+
+#define CASTLE_WK       (1 << 0)                  /* 0x01 00000001 */
+#define CASTLE_WQ       (1 << 1)                  /* 0x02 00000010 */
+#define CASTLE_BK       (1 << 2)                  /* 0x04 00000100 */
+#define CASTLE_BQ       (1 << 3)                  /* 0x08 00001000 */
+
+#define CASTLE_W        (CASTLE_WK | CASTLE_WQ)   /* 00000011 W castle mask */
+#define CASTLE_B        (CASTLE_BK | CASTLE_BQ)   /* 00001100 B castle mask */
+
+/* game phases
+ */
+#define OPENING    0
+#define MIDDLEGAME 1
+#define ENDGAME    2
+
+/* bitboard
+ */
+typedef u64 bitboard_t;
+
+
+/* eval type
+ */
+typedef s32 eval_t;
+
+/* forward typedefs
+ */
+typedef struct piece_list_s piece_list_t;
+typedef struct board_s board_t;
+typedef struct pos_s pos_t;
+typedef struct move_s move_t;
+
+#endif

src/temp-migration-bitboard/eval-simple.c

@@ -0,0 +1,199 @@
+/* eval-simple.c - simple position evaluation.
+ *
+ * Copyright (C) 2023 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#include "br.h"
+#include "debug.h"
+
+#include "piece.h"
+#include "eval-simple.h"
+#include "position.h"
+
+/*
+ * Tables are from https://www.chessprogramming.org/Simplified_Evaluation_Function
+ *
+ * Attention! Tables are black point of view (to be visually easier to read).
+ */
+
+static int mg_pawn[] = {
+    0,   0,   0,   0,   0,   0,  0,  0,
+    50, 50,  50,  50,  50,  50, 50, 50,
+    10, 10,  20,  30,  30,  20, 10, 10,
+    5,   5,  10,  25,  25,  10,  5,  5,
+    0,   0,   0,  20,  20,   0,  0,  0,
+    5,  -5, -10,   0,   0, -10, -5,  5,
+    5,  10,  10, -20, -20,  10, 10,  5,
+    0,   0,   0,   0,   0,   0,  0,  0
+};
+
+static int mg_knight[] = {
+    -50, -40, -30, -30, -30, -30, -40, -50,
+    -40, -20,   0,   0,   0,   0, -20, -40,
+    -30,   0,  10,  15,  15,  10,   0, -30,
+    -30,   5,  15,  20,  20,  15,   5, -30,
+    -30,   0,  15,  20,  20,  15,   0, -30,
+    -30,   5,  10,  15,  15,  10,   5, -30,
+    -40, -20,   0,   5,   5,   0, -20, -40,
+    -50, -40, -30, -30, -30, -30, -40, -50
+};
+
+static int mg_bishop[] = {
+    -20, -10, -10, -10, -10, -10, -10, -20,
+    -10,   0,   0,   0,   0,   0,   0, -10,
+    -10,   0,   5,  10,  10,   5,   0, -10,
+    -10,   5,   5,  10,  10,   5,   5, -10,
+    -10,   0,  10,  10,  10,  10,   0, -10,
+    -10,  10,  10,  10,  10,  10,  10, -10,
+    -10,   5,   0,   0,   0,   0,   5, -10,
+    -20, -10, -10, -10, -10, -10, -10, -20
+};
+
+static int mg_rook[] = {
+    0,   0,  0,  0,  0,  0,  0,  0,
+    5,  10, 10, 10, 10, 10, 10,  5,
+    -5,  0,  0,  0,  0,  0,  0, -5,
+    -5,  0,  0,  0,  0,  0,  0, -5,
+    -5,  0,  0,  0,  0,  0,  0, -5,
+    -5,  0,  0,  0,  0,  0,  0, -5,
+    -5,  0,  0,  0,  0,  0,  0, -5,
+    0,   0,  0,  5,  5,  0,  0,  0
+};
+
+static int mg_queen[] = {
+    -20, -10, -10, -5, -5, -10, -10, -20,
+    -10,   0,   0,  0,  0,   0,   0, -10,
+    -10,   0,   5,  5,  5,   5,   0, -10,
+    -5,    0,   5,  5,  5,   5,   0,  -5,
+    0,     0,   5,  5,  5,   5,   0,  -5,
+    -10,   5,   5,  5,  5,   5,   0, -10,
+    -10,   0,   5,  0,  0,   0,   0, -10,
+    -20, -10, -10, -5, -5, -10, -10, -20
+};
+
+static int mg_king[] = {
+    -30, -40, -40, -50, -50, -40, -40, -30,
+    -30, -40, -40, -50, -50, -40, -40, -30,
+    -30, -40, -40, -50, -50, -40, -40, -30,
+    -30, -40, -40, -50, -50, -40, -40, -30,
+    -20, -30, -30, -40, -40, -30, -30, -20,
+    -10, -20, -20, -20, -20, -20, -20, -10,
+    20,  20,   0,   0,   0,   0,  20,  20,
+    20,  30,  10,   0,   0,  10,  30,  20
+};
+
+static int eg_king[] = {
+    -50, -40, -30, -20, -20, -30, -40, -50,
+    -30, -20, -10,   0,   0, -10, -20, -30,
+    -30, -10,  20,  30,  30,  20, -10, -30,
+    -30, -10,  30,  40,  40,  30, -10, -30,
+    -30, -10,  30,  40,  40,  30, -10, -30,
+    -30, -10,  20,  30,  30,  20, -10, -30,
+    -30, -30,   0,   0,   0,   0, -30, -30,
+    -50, -30, -30, -30, -30, -30, -30, -50
+};
+
+/* as pieces bitboard tables start at position 2; we make these tables
+ * bigger.
+ */
+static int *mg_tables[] = {
+    NULL,
+    NULL,
+    mg_pawn,
+    mg_knight,
+    mg_bishop,
+    mg_rook,
+    mg_queen,
+    mg_king
+};
+
+static int *eg_tables[] = {
+    NULL,
+    NULL,
+    mg_pawn,
+    mg_knight,
+    mg_bishop,
+    mg_rook,
+    mg_queen,
+    eg_king
+};
+
+/* to flip vertically a square, we need to XOR it with 56
+ */
+static int mg_table[2][6 + 2][64];
+static int eg_table[2][6 + 2][64];
+
+void eval_simple_init(void)
+{
+#   ifdef DEBUG_EVAL
+    log_f(1, "initializing piece tables\n");
+#   endif
+    for (int piece = BB_PAWN; piece <= BB_KING; ++piece) {
+        for (int square = 0; square < 64; ++square) {
+            mg_table[WHITE][piece][square] = mg_tables[piece][FLIP_V(square)];
+            eg_table[WHITE][piece][square] = eg_tables[piece][FLIP_V(square)];
+            mg_table[BLACK][piece][square] = mg_tables[piece][square];
+            eg_table[BLACK][piece][square] = eg_tables[piece][square];
+        }
+    }
+}
+
+/**
+ * eval_simple() - simple and fast position evaluation
+ * @pos: &position to evaluate
+ *
+ * This function is normally used only during initialization,
+ * or when changing phase (middlegame <--> endgame), as the eval
+ * will be done increntally when doing moves.
+ *
+ * @return: the @pos evaluation in centipawns
+ */
+eval_t eval_simple(pos_t *pos)
+{
+    eval_t eval[2] = { 0, 0 };
+    int eg = simple_is_endgame(pos);
+    int (*gg)[6 + 2][64]= eg? eg_table: mg_table;
+
+    pos->eval_simple_phase = ENDGAME;
+#   ifdef DEBUG_EVAL
+    log_f(5, "phase = %s.\n", eg? "endgame": "midgame");
+#   endif
+
+    for (int color = WHITE; color <= BLACK; ++color) {
+        for (uint piece = PAWN; piece <= KING; piece <<= 1) {
+            int bb = PIECETOBB(piece), cur;
+            u64 _t;
+
+#           ifdef DEBUG_EVAL
+            log_f(5, "p=%u bb=%d %s %s: count=%d val=%ld ", piece, bb, color? "black": "white",
+                  P_SYM(piece), popcount64(pos->bb[color][bb]),
+                  popcount64(pos->bb[color][bb]) * P_VALUE(piece));
+#           endif
+
+            eval[color] += popcount64(pos->bb[color][bb]) * P_LETTER(piece);
+            bit_for_each64(cur, _t, pos->bb[color][bb]) {
+#               ifdef DEBUG_EVAL
+                log(5, "sq=%d:%d ", cur, gg[color][bb][cur]);
+#               endif
+                eval[color] += gg[color][bb][cur];
+            }
+#           ifdef DEBUG_EVAL
+            log(5, "\n");
+#           endif
+        }
+    }
+#   ifdef DEBUG_EVAL
+    log_f(2, "eval:%d white:%d black:%d\n", eval[WHITE] - eval[BLACK],
+          eval[WHITE], eval[BLACK]);
+#   endif
+
+    return eval[WHITE] - eval[BLACK];
+}

src/temp-migration-bitboard/eval-simple.h

@@ -0,0 +1,47 @@
+/* eval-simple.h - simple position evaluation.
+ *
+ * Copyright (C) 2021 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#ifndef EVAL_SIMPLE_H
+#define EVAL_SIMPLE_H
+
+
+#include "chessdefs.h"
+
+/* no queen on board */
+#define simple_no_queen(p, c)              \
+    ( !(p)->bb[c][BB_QUEEN] )
+
+#define simple_one_queen(p, c)             \
+    ( popcount64((p)->bb[c][BB_QUEEN]) == 1 )
+
+#define simple_no_rook(p, c)               \
+    (!(p)->bb[c][BB_ROOK])
+
+#define simple_one_minor_piece(p, c)       \
+    (popcount64((p)->bb[c][BB_KNIGHT] | (p)->bb[c][BB_BISHOP]) == 1)
+
+#define simple_is_endgame(p)                  \
+    ( (simple_no_queen(p, WHITE)   ||         \
+       (simple_one_queen(p, WHITE) &&         \
+        simple_no_rook(p, WHITE)   &&         \
+        simple_one_minor_piece(p, WHITE)))    \
+      &&                                      \
+      (simple_no_queen(p, BLACK)   ||         \
+       (simple_one_queen(p, BLACK) &&         \
+        simple_no_rook(p, BLACK)   &&         \
+        simple_one_minor_piece(p, BLACK))) )
+
+void eval_simple_init(void);
+eval_t eval_simple(pos_t *pos);
+
+#endif  /* EVAL_SIMPLE_H */

src/temp-migration-bitboard/eval.c

@@ -0,0 +1,95 @@
+/* eval.c - static position evaluation.
+ *
+ * Copyright (C) 2021-2023 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#include <stdio.h>
+
+#include <list.h>
+#include <debug.h>
+
+#include "position.h"
+#include "eval.h"
+#include "eval-simple.h"
+
+inline eval_t eval_material(pos_t *pos, bool color)
+{
+    eval_t res = 0;
+
+    /* I need to do something about the king, if it can be potentially taken
+     * if pseudo-moves include a pinned piece on King.
+     */
+    for (uint piece = PAWN; piece < KING; piece <<= 1) {
+        uint bb = PIECETOBB(piece);
+#       ifdef DEBUG_EVAL
+        log_f(2, "color=%u piece=%u bb=%u=%c count=%ul val=%ld\n",
+              color, piece, bb, P_LETTER(piece), popcount64(pos->bb[color][bb]),
+              P_VALUE(piece));
+#       endif
+        /* attention here */
+        res += popcount64(pos->bb[color][bb]) * P_VALUE(piece);
+    }
+    return res;
+}
+
+inline eval_t eval_mobility(pos_t *pos, bool color)
+{
+    return pos->mobility[color];
+}
+
+inline eval_t eval_square_control(pos_t *pos, bool color)
+{
+    return popcount64(pos->controlled[color]);
+}
+
+eval_t eval(pos_t *pos)
+{
+    eval_t simple = 0, control[2] = {0};
+
+    if (pos->eval != EVAL_INVALID)
+        return pos->eval;
+
+    /* 1) pieces value */
+    //material[WHITE] = eval_material(pos, WHITE);
+    //material[BLACK] = eval_material(pos, BLACK);
+    simple = eval_simple(pos);
+
+#   ifdef DEBUG_EVAL
+    log_f(2, "eval_simple=%d\n", simple);
+#   endif
+
+    /* 2) square control: 10 square controls diff = 1 pawn */
+    control[WHITE] = eval_square_control(pos, WHITE);
+    control[BLACK] = eval_square_control(pos, BLACK);
+
+#   ifdef DEBUG_EVAL
+    log_f(2, "square control: W:%d B:%d diff=%d\n",
+          control[WHITE], control[BLACK],
+          (control[WHITE] - control[BLACK]) * 10);
+#   endif
+
+    /* 3) mobility: 10 mobility diff = 1 pawn
+     */
+#   ifdef DEBUG_EVAL
+    log_f(2, "mobility: W:%u B:%u diff=%d\n",
+          pos->mobility[WHITE], pos->mobility[BLACK],
+          (pos->mobility[WHITE] - pos->mobility[BLACK]) * 10);
+#   endif
+
+    eval_t res = simple +
+        (control[WHITE] - control[BLACK]) * 10 +
+        (pos->mobility[WHITE] - pos->mobility[BLACK]) * 10;
+#   ifdef DEBUG_EVAL
+    log_f(2, "eval: %d\n", res);
+#   endif
+    pos->eval = res;
+    return res;
+}

src/temp-migration-bitboard/eval.h

@@ -0,0 +1,37 @@
+/* eval.h - static position evaluation.
+ *
+ * Copyright (C) 2021 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#ifndef EVAL_H
+#define EVAL_H
+
+#include <limits.h>
+
+#include "chessdefs.h"
+#include "piece.h"
+
+/* max pieces eval is KING_VALUE + 9*QUEEN_VALUE + 2*ROOK_VALUE + 2*BISHOP_VALUE
+ *  + 2*KNIGHT_VALUE which around 30000.
+ * We are on secure side with -50000/+50000
+ */
+#define EVAL_MAX     (50000)
+#define EVAL_MIN     (-EVAL_MAX)
+#define EVAL_INVALID INT_MIN
+#define EVAL_MATE    EVAL_MAX
+
+eval_t eval_material(pos_t *pos, bool color);
+eval_t eval_mobility(pos_t *pos, bool color);
+eval_t eval_square_control(pos_t *pos, bool color);
+
+eval_t eval(pos_t *pos);
+
+#endif  /* EVAL_H */

src/temp-migration-bitboard/fen.c

@@ -0,0 +1,175 @@
+/* fen.c - fen notation.
+ *
+ * Copyright (C) 2021 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <ctype.h>
+
+#include <debug.h>
+
+#include "chessdefs.h"
+#include "position.h"
+#include "board.h"
+#include "fen.h"
+#include "piece.h"
+
+/* Starting Position :
+ * rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1
+ * After 1.e4 :
+ * rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq e3 0 1
+ * After 1... c5 :
+ * rnbqkbnr/pp1ppppp/8/2p5/4P3/8/PPPP1PPP/RNBQKBNR w KQkq c6 0 2
+ * After 2. Nf3:
+ * rnbqkbnr/pp1ppppp/8/2p5/4P3/5N2/PPPP1PPP/RNBQKB1R b KQkq - 1 2
+ *
+ * 1 : White uppercase
+ * 2 : next move (w or b)
+ * 3 : Castling capabilities: "-" if none, KQ/kq if white/black can castle
+ *     on K or Q side
+ * 4 : en-passant: if pawn just moved 2 squares, indicate target square (e.g.
+ *     for e2-e4 this field is e3)
+ * 5 : half moves since last capture or pawn advance (for 50 moves rule)
+ * 6 : full moves, starts at 1, increments after black move
+ *
+ */
+
+// warning, we expect a valid fen input
+pos_t *fen2pos(pos_t *pos, char *fen)
+{
+    char *p = fen;
+    short rank, file, skip, color, bbpiece;
+    piece_t piece;
+    board_t *board = pos->board;
+#   define SKIP_BLANK(p) for(;*(p) == ' '; (p)++)
+
+    pos_clear(pos);
+    /* 1) get piece placement information
+     */
+    for (rank = 7, file = 0; *p && *p != ' '; ++p) {
+        color = isupper(*p)? WHITE: BLACK;
+        char cp = toupper(*p);
+        switch (cp) {
+            case CHAR_PAWN:
+                bbpiece = BB_PAWN;
+                piece = PAWN;
+                goto set_square;
+            case CHAR_KNIGHT:
+                bbpiece = BB_KNIGHT;
+                piece = KNIGHT;
+                goto set_square;
+            case CHAR_BISHOP:
+                bbpiece = BB_BISHOP;
+                piece = BISHOP;
+                goto set_square;
+            case CHAR_ROOK:
+                bbpiece = BB_ROOK;
+                piece = ROOK;
+                goto set_square;
+            case CHAR_QUEEN:
+                bbpiece = BB_QUEEN;
+                piece = QUEEN;
+                goto set_square;
+            case CHAR_KING:
+                bbpiece = BB_KING;
+                piece = KING;
+                //pos->bb[color][BB_KING] = BB(file, rank);
+                //goto set_square;
+            set_square:
+#               ifdef DEBUG_FEN
+                log_i(5, "f=%d r=%d *p=%c piece=%c color=%d\n",
+                      file, rank, *p, cp, color);
+#               endif
+                pos->bb[color][bbpiece] |= BB(file, rank);
+                pos->occupied[color] |= BB(file, rank);
+                SET_COLOR(piece, color);
+                board[SQ88(file, rank)].piece = piece;
+                board[SQ88(file, rank)].s_piece =
+                    piece_add(pos, piece, SQ88(file, rank));
+                file++;
+                break;
+            case '/':
+                rank--;
+                file = 0;
+                break;
+            default:
+                skip = cp - '0';
+                while (skip--) {
+                    board[SQ88(file++, rank)].piece = EMPTY;
+                }
+        }
+    }
+#   ifdef DEBUG_FEN
+    for (rank = 7; rank >= 0; --rank) {
+        for (file = 0; file < 8; ++file) {
+            log(5, "%02x ", board[SQ88(file, rank)].piece);
+        }
+        log(5, "\n");
+    }
+#   endif
+
+    /* 2) next move color
+     */
+    SKIP_BLANK(p);
+    SET_COLOR(pos->turn, *p == 'w' ? WHITE : BLACK);
+    p++;
+
+    /* 3) castle status
+     */
+    SKIP_BLANK(p);
+    pos->castle = 0;
+    if (*p != '-') {
+        for (; *p && *p != ' '; ++p) {
+            switch (*p) {
+                case 'K':
+                    pos->castle |= CASTLE_WK;
+                    break;
+                case 'k':
+                    pos->castle |= CASTLE_BK;
+                    break;
+                case 'Q':
+                    pos->castle |= CASTLE_WQ;
+                    break;
+                case 'q':
+                    pos->castle |= CASTLE_BQ;
+                    break;
+            }
+        }
+    }
+    p++;
+
+    /* 4) en passant
+     */
+    SKIP_BLANK(p);
+    pos->en_passant = 0;
+    if (*p != '-') {
+        //SET_F(pos->en_passant, C2FILE(*p++));
+        //SET_R(pos->en_passant, C2RANK(*p++));
+        pos->en_passant = SQ88(C2FILE(*p), C2RANK(*(p+1)));
+        pos += 2;
+    } else {
+        p++;
+    }
+
+    /* 5) half moves since last capture or pawn move and
+     * 6) current move number
+     */
+    SKIP_BLANK(p);
+    //log_i(5, "pos=%d\n", (int)(p-fen));
+    sscanf(p, "%hd %hd", &pos->clock_50, &pos->curmove);
+#   ifdef DEBUG_FEN
+    log_i(5, "50 rule=%d current move=%d\n", pos->clock_50, pos->curmove);
+#   endif
+    return pos;
+}

src/temp-migration-bitboard/fen.h

@@ -0,0 +1,21 @@
+/* fen.h - fen notation.
+ *
+ * Copyright (C) 2021 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#ifndef FEN_H
+#define FEN_H
+
+#include "position.h"
+
+pos_t *fen2pos(pos_t *pos, char *fen);
+
+#endif /* FEN_H */

src/temp-migration-bitboard/move.c

@@ -0,0 +1,890 @@
+/* move.c - move management.
+ *
+ * Copyright (C) 2021 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#include <malloc.h>
+#include <ctype.h>
+
+#include <br.h>
+#include <list.h>
+#include <list_sort.h>
+#include <debug.h>
+
+#include "chessdefs.h"
+#include "board.h"
+#include "bitboard.h"
+#include "piece.h"
+#include "move.h"
+#include "eval.h"
+#include "eval-simple.h"
+
+static pool_t *moves_pool;
+
+static struct vector {
+    unsigned char ndirs;
+    char          slide;
+    char          dir[8];
+} vectors[] = {
+    [KNIGHT] = { 8, 0, { -33, -31, -18, -14, 14,  18,  31, 33 }},
+    [BISHOP] = { 4, 1, { -15, -17, 15,  17 }},
+    [ROOK]   = { 4, 1, { -1,  -16, 1,   16 }},
+    [QUEEN]  = { 8, 1, { -1,  -16, 1,   16,  -15, -17, 15, 17 }},
+    [KING]   = { 8, 0, { -1,  -16, 1,   16,  -15, -17, 15, 17 }}
+};
+
+
+/* squares needed to be empty & not controlled by opponent for castle.
+ * For black castle, same values 7 rows higher (>> 7*8)
+ */
+static struct can_castle {
+    bitboard_t controlled[2];
+    bitboard_t occupied[2];
+} castle_squares[2] = {
+    /*  Queen side      King side           Queen side      King side */
+    { { C1bb|D1bb|E1bb, E1bb|F1bb|G1bb }, { B1bb|C1bb|D1bb, F1bb|G1bb } },
+    { { C8bb|D8bb|E8bb, E8bb|F8bb|G8bb }, { B8bb|C8bb|D8bb, F8bb|G8bb } }
+};
+
+pool_t *moves_pool_init()
+{
+    if (!moves_pool)
+        moves_pool = pool_create("moves", 128, sizeof(move_t));
+    return moves_pool;
+}
+
+void moves_pool_stats()
+{
+    if (moves_pool)
+        pool_stats(moves_pool);
+}
+
+/**
+ * move_print() - print a move
+ * @movenum: move number
+ * @move: &move to display
+ * @flags: options to display
+ *
+ * Possible flags are:
+ * M_PR_CAPT:  print move if capture
+ * M_PR_NCAPT: print move if non capture
+ * M_PR_NUM:   print also move number
+ * M_PR_LONG:  print long notation
+ * M_PR_NL:    print a newline after move
+ * M_PR_EVAL:  print move eval
+ *
+ * @return: 0 if nothing printed, 1 otherwise
+ */
+int move_print(int movenum, move_t *move, move_flags_t flags)
+{
+    if ((flags & M_PR_CAPT) && !(move->flags & M_CAPTURE)) {
+#       ifdef DEBUG_MOVE
+        log_i(9, "skipping capture & %#04x\n", move->flags);
+#       endif
+        return 0;
+    }
+    if ((flags & M_PR_NCAPT) && (move->flags & M_CAPTURE)) {
+#       ifdef DEBUG_MOVE
+        log_i(9, "skipping !capture & %#04x\n", move->flags);
+#       endif
+        return 0;
+    }
+    if (flags & M_PR_NUM)
+        log(1, "%d:", movenum);
+    if (move->flags & M_CASTLE_K) {
+        log(1, "O-O");
+        goto end;
+    } else if (move->flags & M_CASTLE_Q) {
+        log(1, "O-O-O");
+        goto end;
+    } else {
+        log(1, "%s%c%c", P_SYM(move->piece),
+               FILE2C(F88(move->from)),
+               RANK2C(R88(move->from)));
+        if (move->flags & M_CAPTURE) {
+            log(1, "x");
+            if (flags & M_PR_LONG)
+                log(1, "%s", P_SYM(move->capture));
+        } else {
+            log(1, "-");
+        }
+        log(1, "%c%c",
+               FILE2C(F88(move->to)),
+               RANK2C(R88(move->to)));
+        if (flags & M_PR_LONG && move->flags & M_EN_PASSANT)
+            log(1, "e.p.");
+        if (move->promotion)
+            log(1, "=%s", P_SYM(move->promotion));
+        if (flags & M_PR_EVAL)
+            log(1, "[ev:%d] ", move->eval);
+    end:
+        log(1, " ");
+    }
+    if (flags & M_PR_NL)
+        log(1, "\n");
+    return 1;
+}
+
+void moves_print(pos_t *pos, move_flags_t flags)
+{
+    struct list_head *p_cur, *tmp;
+    move_t *move;
+    int movenum;
+
+    for (int color=WHITE; color <= BLACK; ++color) {
+        int verif = 0;
+        log(1, "%s pseudo-moves:\n\t", color == WHITE? "White": "Black");
+        if (! (flags & M_PR_SEPARATE)) {
+            movenum = 1;
+            list_for_each_safe(p_cur, tmp, &pos->moves[color]) {
+                move = list_entry(p_cur, move_t, list);
+                verif += move_print(movenum++, move, flags);
+            }
+        } else {
+            log(1, "captures: ");
+            movenum = 1;
+            list_for_each_safe(p_cur, tmp, &pos->moves[color]) {
+                move = list_entry(p_cur, move_t, list);
+                verif += move_print(movenum++, move, flags | M_PR_CAPT);
+            }
+            movenum = 1;
+            log(1, "\n\tothers  : ");
+            list_for_each_safe(p_cur, tmp, &pos->moves[color]) {
+                move = list_entry(p_cur, move_t, list);
+                verif += move_print(movenum++, move, flags | M_PR_NCAPT);
+            }
+        }
+        log(1, "\n\tTotal moves = %d mobility=%u\n", verif, pos->mobility[color]);
+    }
+}
+
+static move_t *move_add(pos_t *pos, piece_t piece, square_t from,
+                        square_t to)
+{
+    board_t *board = pos->board;
+    move_t *move;
+    int color = COLOR(pos->board[from].piece);
+
+#   ifdef DEBUG_MOVE
+    log_i(3, "piece_color=%d turn=%d from=%c%c to=%c%c\n",
+          color, pos->turn,
+          FILE2C(F88(from)),
+          RANK2C(R88(from)),
+          FILE2C(F88(to)),
+          RANK2C(R88(to)));
+#   endif
+    /* invalid position if opponent king is attacked
+     */
+    if (board[to].piece & KING) {
+#       ifdef DEBUG_MOVE
+        log_i(2, "invalid position: opponent king [%c%c] is in check.\n",
+              FILE2C(F88(to)), RANK2C(R88(to)));
+#       endif
+        return NULL;
+    }
+    if (!(move = pool_get(moves_pool)))
+        return NULL;
+    list_add(&move->list, &pos->moves[color]);
+
+    move->piece = piece | color;
+    move->from = from;
+    move->to = to;
+    move->capture = board[to].piece;
+    if (PIECE(move->capture) == KING)
+        pos->check[color]++;
+
+    move->flags = M_NORMAL;
+    if (move->capture)
+        move->flags |= M_CAPTURE;
+    move->pos = NULL;
+#   ifdef DEBUG_MOVE
+    log_i(3, "added %s %s move from %c%c to %c%c\n",
+          COLOR(move->piece)? "black": "white",
+          P_NAME(PIECE(move->piece)),
+          FILE2C(F88(move->from)), RANK2C(R88(move->from)),
+          FILE2C(F88(move->to)), RANK2C(R88(move->to)));
+#   endif
+    return move;
+}
+
+/**
+ * move_del() - delete a move from list.
+ * @ptr: move &list_head
+ *
+ * Remove the move whose 'list' element address is @ptr.
+ */
+void move_del(struct list_head *ptr)
+{
+    move_t *move = list_entry(ptr, move_t, list);
+
+#   ifdef DEBUG_MOVE
+    log_i(3, "delete move from %c%c to %c%c\n",
+          FILE2C(F88(move->from)), RANK2C(R88(move->from)),
+          FILE2C(F88(move->to)), RANK2C(R88(move->to)));
+#   endif
+
+    if (move->pos)
+        pos_del(move->pos);
+    list_del(ptr);
+    pool_add(moves_pool, move);
+    return;
+}
+
+/**
+ * move_del() - delete all position moves.
+ * @ppos: &position.
+ *
+ * Remove all generated moves from @pos structure.
+ */
+int moves_del(pos_t *pos)
+{
+    struct list_head *p_cur, *tmp, *head;
+    int count = 0;
+
+    for (int color = WHITE; color <= BLACK; ++color) {
+        head = &pos->moves[color];
+
+        list_for_each_safe(p_cur, tmp, head) {
+            move_del(p_cur);
+            count++;
+        }
+    }
+#   ifdef DEBUG_PIECE
+    log_f(3, "%d moves removed\n", count);
+#   endif
+    return count;
+}
+
+/* TODO: return nmoves */
+static move_t *move_pawn_add(pos_t *pos, piece_t piece, square_t from,
+                             square_t to, unsigned char rank7)
+{
+    move_t *move;
+    piece_t promote;
+    unsigned char color = COLOR(piece);
+
+    if (R88(from) == rank7) {                  /* promotion */
+        for (promote = QUEEN; promote > PAWN; promote >>= 1) {
+            if ((move = move_add(pos, piece, from, to))) {
+                move->flags |= M_PROMOTION;
+                move->promotion = promote | color;
+            }
+        }
+    } else {
+        move = move_add(pos, piece, from, to);
+    }
+    return move;
+}
+
+/**
+ * pseudo_moves_pawn() - generate moves for pawn.
+ * @pos: &position
+ * @ppiece: &piece_list pawn structure pointer
+ * @doit: add move to moves list
+ *
+ * Calculate all possible moves for @ppiece pawn.
+ * If @doit is true, add moves to @pos' moves list.
+ */
+int pseudo_moves_pawn(pos_t *pos, piece_list_t *ppiece, bool doit)
+{
+    piece_t piece = PIECE(ppiece->piece);
+    unsigned char color = COLOR(ppiece->piece);
+    square_t square = ppiece->square, new;
+    board_t *board = pos->board;
+    unsigned char rank2, rank7, rank5;
+    move_t *move = NULL;
+    char dir;
+    int count = 0;
+
+    /* setup direction */
+    if (IS_WHITE(color)) {
+        dir = 1;
+        rank2 = 1;
+        rank7 = 6;
+        rank5 = 4;
+    } else {
+        dir = -1;
+        rank2 = 6;
+        rank7 = 1;
+        rank5 = 3;
+    }
+
+#   ifdef DEBUG_MOVE
+    log_f(2, "pos:%p turn:%s piece:%d [%s %s] dir:%d at %#04x[%c%c]\n",
+          pos,
+          IS_WHITE(pos->turn)? "white": "black",
+          piece,
+          IS_WHITE(color)? "white": "black",
+          P_NAME(piece),
+          dir,
+          square,
+          FILE2C(F88(square)), RANK2C(R88(square)));
+#   endif
+
+    /* normal push. We do not test for valid destination square here,
+     * assuming position is valid. Is that correct ?
+     */
+    new = square + dir * 16;
+    if (!board[new].piece) {
+#       ifdef DEBUG_MOVE
+        log_i(4, "pushing pawn %#04x\n", square);
+#       endif
+        pos->mobility[color]++;
+        count++;
+        if (doit)
+            move_pawn_add(pos, piece | color, square, new, rank7);
+        /* push 2 squares */
+        log(4, "R88(%#x)=%d R2=%d \n", square, R88(square), rank2);
+        if (R88(square) == rank2) {
+            new += dir * 16;
+            if (SQ88_OK(new) && !board[new].piece) {
+#               ifdef DEBUG_MOVE
+                log_i(4, "pushing pawn %#04x 2 squares\n", square);
+#               endif
+                //log_f(2, "pawn move2 mobility\n");
+                pos->mobility[color]++;
+                count++;
+                if (doit)
+                    move_pawn_add(pos, piece | color, square, new, rank7);
+            }
+        }
+    }
+
+    /* en passant - not accounted for mobility. Correct ? */
+    if (pos->en_passant && R88(square) == rank5) {
+        unsigned char ep_file = F88(pos->en_passant);
+        unsigned char sq_file = F88(square);
+
+#       ifdef DEBUG_MOVE
+        log_i(4, "possible en passant on rank %#x (current = %#0x)\n", ep_file,
+              sq_file);
+#       endif
+        if (sq_file == ep_file - 1 || sq_file == ep_file + 1) {
+            square_t t_square = SQ88(ep_file, rank5); /* taken pawn square */
+            piece_t captured = board[t_square].piece;
+            move = move_pawn_add(pos, piece | color , square, pos->en_passant, rank7);
+            move->flags |= M_EN_PASSANT | M_CAPTURE;
+            move->capture = captured;
+            pos->mobility[color]++;
+            count++;
+        }
+
+    }
+
+    /* capture */
+    int two=0;
+    for (new = square + dir * 15; two < 2; new = square + dir * 17, two++) {
+#       ifdef DEBUG_MOVE
+        log_i(4, "pawn capture %#04x %#04x\n", square, new);
+#       endif
+        if (SQ88_NOK(new))
+            continue;
+        pos->controlled[color] |= SQ88_2_BB(new);
+        if (board[new].piece && COLOR(board[new].piece) != color) {
+            if (PIECE(board[new].piece) == KING)
+                pos->check[color]++;
+            //log_f(2, "pawn capture mobility\n");
+            pos->mobility[color]++;
+            count++;
+            if (doit)
+                move_pawn_add(pos, piece | color, square, new, rank7);
+        }
+    }
+#   ifdef DEBUG_MOVE
+    log_f(2, "pos:%p turn:%s piece:%d [%s %s] dir:%d at %#04x[%c%c] count=%d\n",
+          pos,
+          IS_WHITE(pos->turn)? "white": "black",
+          piece,
+          IS_WHITE(color)? "white": "black",
+          P_NAME(piece),
+          dir,
+          square,
+          FILE2C(F88(square)), RANK2C(R88(square)), count);
+#   endif
+    return count;
+}
+
+/**
+ * pseudo_moves_castle() - generate castle moves.
+ * @pos: &position
+ * @color: side for which to generate moves
+ * @doit: add move to moves list
+ * @do_king: count king moves in mobility
+ *
+ * Calculate the possible castle moves for @color side.
+ * If @doit is true, add moves to @pos' moves list.
+ * If @do_king is true, account king moves (incl. castle) to mobility.
+ *
+ * @return: The number of possible king moves.
+ */
+int pseudo_moves_castle(pos_t *pos, bool color, bool doit, bool do_king)
+{
+    board_t *board = pos->board;
+    unsigned char rank1, castle_K, castle_Q;
+    move_t *move = NULL;
+    unsigned short count=0;
+    struct can_castle *can_castle;
+    bitboard_t controlled;
+    bitboard_t occupied = pos->occupied[WHITE] | pos->occupied[BLACK];
+    //pos_t *newpos;
+
+#   ifdef DEBUG_MOVE
+    log_f(2, "pos:%p turn:%s color:%s\n",
+          pos,
+          IS_WHITE(pos->turn)? "white": "black",
+          IS_WHITE(color)? "white": "black");
+#   endif
+
+    if (IS_WHITE(color)) {
+        rank1 = 0;
+        castle_K = pos->castle & CASTLE_WK;
+        castle_Q = pos->castle & CASTLE_WQ;
+        can_castle = castle_squares+WHITE;
+        controlled = pos->controlled[BLACK];
+    } else {
+        rank1 = 7;
+        castle_K = pos->castle & CASTLE_BK;
+        castle_Q = pos->castle & CASTLE_BQ;
+        can_castle = castle_squares+BLACK;
+        controlled = pos->controlled[WHITE];
+    }
+    if (castle_K) {
+        if (occupied & can_castle->occupied[1]) {
+#           ifdef DEBUG_MOVE
+            log(5, "Cannot castle K side: occupied\n");
+#           endif
+            goto next;
+        }
+        if (controlled & can_castle->controlled[1]) {
+#           ifdef DEBUG_MOVE
+            log(5, "Cannot castle K side: controlled\n");
+#           endif
+            goto next;
+        }
+        if (do_king) {
+            pos->mobility[color]++;
+            count++;
+        }
+        if (doit) {
+            move = move_add(pos, board[SQ88(4, rank1)].piece,
+                            SQ88(4, rank1), SQ88(6, rank1));
+            if (move)
+                move->flags |= M_CASTLE_K;
+        }
+    }
+
+next:
+    if (castle_Q) {
+        if (occupied & can_castle->occupied[0]) {
+#           ifdef DEBUG_MOVE
+            log(5, "Cannot castle Q side: occupied\n");
+#           endif
+            goto end;
+        }
+        if (controlled & can_castle->controlled[0]) {
+#           ifdef DEBUG_MOVE
+            log(5, "Cannot castle Q side: controlled\n");
+#           endif
+            goto end;
+        }
+        if (do_king) {
+            pos->mobility[color]++;
+            count++;
+        }
+        if (doit) {
+            move = move_add(pos, board[SQ88(4, rank1)].piece,
+                            SQ88(4, rank1), SQ88(2, rank1));
+            if (move)
+                move->flags |= M_CASTLE_Q;
+        }
+    }
+end:
+    return count;
+}
+
+/**
+ * pseudo_moves_gen() - general move generation for non pawn pieces
+ * @pos: &position
+ * @ppiece: &piece_list structure pointer
+ * @doit: add move to moves list
+ * @do_king: count king moves
+ *
+ * Calculate all possible moves for @ppiece.
+ * If @doit is true, add moves to @pos' moves list.
+ * If @do_king is true, account king moves (incl. castle) to mobility.
+ */
+int pseudo_moves_gen(pos_t *pos, piece_list_t *ppiece, bool doit, bool do_king)
+{
+    piece_t piece = PIECE(ppiece->piece);
+    unsigned char color = COLOR(ppiece->piece);
+    struct vector *vector = vectors+piece;
+    square_t square = ppiece->square;
+    unsigned char ndirs = vector->ndirs;
+    char slide = vector->slide;
+    board_t *board = pos->board;
+    //move_t *move;
+    int count = 0;
+    u64 bb_new;
+
+#   ifdef DEBUG_MOVE
+    log_f(2, "pos:%p turn:%s piece:%d [%s %s] at %#04x[%c%c]\n",
+          pos,
+          IS_WHITE(pos->turn)? "white": "black",
+          piece,
+          IS_WHITE(color)? "white": "black",
+          P_NAME(piece),
+          square,
+          FILE2C(F88(square)), RANK2C(R88(square)));
+    log_i(5, "vector=%ld ndirs=%d slide=%d\n", vector-vectors, ndirs, slide);
+#   endif
+
+    for (int curdir = 0; curdir < ndirs; ++curdir) {
+        char dir = vector->dir[curdir];
+        for (square_t new = square + dir; ; new = new + dir) {
+            /* outside board */
+            if (SQ88_NOK(new)) {
+#               ifdef DEBUG_MOVE
+                log_i(4,"skipping %04x (invalid square)\n", new);
+#               endif
+                break;
+            }
+            bb_new = SQ88_2_BB(new);
+#           ifdef DEBUG_MOVE
+            log_i(2, "trying %#x=%c%c bb=%#lx\n",
+                  new, FILE2C(F88(new)), RANK2C(R88(new)),
+                  bb_new);
+            //bitboard_print(new_bitboard);
+#           endif
+
+            pos->controlled[color] |= bb_new;;
+
+            /* king: do not move to opponent controlled square */
+            if (piece == KING && pos->controlled[OPPONENT(color)] & bb_new) {
+#               ifdef DEBUG_MOVE
+                log_i(2, "%s king cannot move to %c%c\n",
+                      IS_WHITE(color)? "white": "black",
+                      FILE2C(F88(new)), RANK2C(R88(new)));
+#               endif
+                break;
+            }
+
+            if (bb_new & pos->occupied[color]) {
+                //bitboard_print(pos->occupied[color]);
+                //bitboard_print(pos->occupied[OPPONENT(color)]);
+#               ifdef DEBUG_MOVE
+                log_i(2, "BB: skipping %#lx [%c%c] (same color piece)\n",
+                      bb_new, FILE2C(F88(new)), RANK2C(R88(new)));
+#               endif
+                break;
+            }
+
+            /* we are sure the move is valid : we create move */
+            if (piece != KING || do_king) {
+                pos->mobility[color]++;
+                count++;
+            }
+            if (doit)
+                move_add(pos, ppiece->piece, square, new);
+            if (board[new].piece) {               /* stopper move */
+                break;
+            }
+            if (!slide)
+                break;
+        }
+    }
+#   ifdef DEBUG_MOVE
+    log_f(2, "pos:%p turn:%s piece:%d [%s %s] at %#04x[%c%c] count=%d\n",
+          pos,
+          IS_WHITE(pos->turn)? "white": "black",
+          piece,
+          IS_WHITE(color)? "white": "black",
+          P_NAME(piece),
+          square,
+          FILE2C(F88(square)), RANK2C(R88(square)), count);
+#   endif
+    return count;
+}
+
+/**
+ * moves_gen() - move generation for one color
+ * @pos: &position
+ * @color: side
+ * @doit: add move to moves list
+ * @do_king: count king moves
+ *
+ * Calculate all possible moves for @color.
+ * If @doit is true, add moves to @pos' moves list.
+ * If @do_king is true, account king moves (incl. castle) to mobility.
+ */
+int moves_gen(pos_t *pos, bool color, bool doit, bool do_king)
+{
+    struct list_head *p_cur, *tmp, *piece_list;
+    piece_list_t *piece;
+    int count = 0;
+
+#   ifdef DEBUG_MOVE
+    log_f(2, "color:%s doit:%d\n", color? "Black": "White", doit);
+#   endif
+
+    /* do not generate moves if already done for color */
+    if (!list_empty(&pos->moves[color]))
+        doit = false;
+
+    piece_list = &pos->pieces[color];
+    pos->mobility[color] = 0;
+    pos->controlled[color] = 0;
+    count += pseudo_moves_castle(pos, color, doit, do_king);
+    list_for_each_safe(p_cur, tmp, piece_list) {
+        piece = list_entry(p_cur, piece_list_t, list);
+        if (PIECE(piece->piece) != PAWN)
+            count += pseudo_moves_gen(pos, piece, doit, do_king);
+        else
+            count += pseudo_moves_pawn(pos, piece, doit);
+
+        count++;
+    }
+    return count;
+}
+
+/**
+ * moves_gen_king_moves() - adjust king mobility
+ * @pos: &position
+ * @color: king color
+ * @doit: add move to moves list
+ *
+ * Compute the number of king moves (incl. castle), after opponent controlled
+ * are known.
+ * If @doit is true, add moves to @pos' moves list.
+ *
+ * @return: The number of possible king moves.
+ */
+int moves_gen_king_moves(pos_t *pos, bool color, bool doit)
+{
+    int count = 0;
+    piece_list_t *king = list_first_entry(&pos->pieces[color], piece_list_t, list);
+    count = pseudo_moves_castle(pos, king, doit, true);
+    count += pseudo_moves_gen(pos, king, doit, true);
+    return count;
+}
+
+static int moves_cmp_eval(__unused void *data, const struct list_head *h1, const struct list_head *h2)
+{
+    move_t *m1 = list_entry(h1, move_t, list);
+    move_t *m2 = list_entry(h2, move_t, list);
+    return m2->eval_simple - m1->eval_simple;
+}
+
+/**
+ * moves_sort() sort - sort moves list, best eval first.
+ * @pos: &position.
+ */
+void moves_sort(pos_t *pos)
+{
+    list_sort(NULL, &pos->moves[pos->turn], moves_cmp_eval);
+}
+
+/**
+ * moves_gen_all_eval_sort() - calculate/generate/sort moves for side to play.
+ * @pos: &position
+ *
+ * Generate positions for each move for player to move.
+ * For each of them generate opponents moves, calculate eval, and sort the moves list.
+ */
+void moves_gen_eval_sort(pos_t *pos)
+{
+    move_t *move;
+    pos_t *newpos;
+
+    moves_gen_all(pos);
+
+    list_for_each_entry(move, &pos->moves[pos->turn], list) {
+        newpos = move_do(pos, move);
+        move->pos = newpos;
+        //move_print(0, move, 0);
+        move->eval_simple = eval_simple(newpos);
+        newpos->eval_simple = move->eval_simple;
+    }
+    moves_sort(pos);
+    //moves_print(pos, 0);
+}
+
+/**
+ * moves_gen_all() - calculate all moves, and generate moves for side to play.
+ * @pos: &position
+ *
+ * Compute pseudo moves for both sides, and generate moves for player to move.
+ */
+void moves_gen_all(pos_t *pos)
+{
+    //log_f(1, "turn=%d opponent=%d\n", pos->turn, OPPONENT(pos->turn));
+    if (!pos->moves_generated) {
+        if (!pos->moves_counted) {}
+            moves_gen(pos, OPPONENT(pos->turn), false, false);
+        moves_gen(pos, pos->turn, true, true);
+        if (!pos->moves_counted)
+            moves_gen_king_moves(pos, OPPONENT(pos->turn), false);
+        pos->moves_counted = true;
+        pos->moves_generated = true;
+    }
+}
+
+/**
+ * moves_gen_all_nomoves() - calculate number of moves for each player.
+ * @pos: &position
+ */
+void moves_gen_all_nomoves(pos_t *pos)
+{
+    //log_f(1, "turn=%d opponent=%d\n", pos->turn, OPPONENT(pos->turn));
+    if (!pos->moves_counted) {
+        moves_gen(pos, OPPONENT(pos->turn), false, false);
+        moves_gen(pos, pos->turn, false, true);
+        moves_gen_king_moves(pos, OPPONENT(pos->turn), false);
+        pos->moves_counted = true;
+    }
+}
+
+/**
+ * move_do() - execute move in a duplicated position.
+ * @pos: &pos_t struct on which move will be applied
+ * @move: &move_t struct to apply
+ *
+ * @return: &new position
+ */
+pos_t *move_do(pos_t *pos, move_t *move)
+{
+#   ifdef DEBUG_MOVE
+    //log(1, "new move: ");
+    //move_print(0, move, M_PR_NL | M_PR_LONG);
+#   endif
+
+    pos_t *new = pos_dup(pos);
+    piece_t piece = PIECE(move->piece), newpiece = piece, captured = move->capture;
+    int color = COLOR(move->piece);
+    square_t from = move->from, to = move->to;
+    u64 bb_from = SQ88_2_BB(from), bb_to = SQ88_2_BB(to);
+
+    if (move->capture || piece == PAWN)    /* 50 moves */
+        new->clock_50 = 0;
+    else
+        new->clock_50++;
+
+    if (move->flags & M_CAPTURE) {                            /* capture */
+        if (move->flags & M_EN_PASSANT) {
+            uchar ep_file = F88(pos->en_passant);
+            square_t ep_grab = color == WHITE ? SQ88(ep_file, 4): SQ88(ep_file, 3);
+            u64 bb_ep_grab = SQ88_2_BB(ep_grab);
+
+            log_f(5, "en-passant=%d,%d\n", ep_file, color == WHITE ? 4 : 3);
+            piece_del(&new->board[ep_grab].s_piece->list);
+            new->board[ep_grab].piece = 0;
+            new->occupied[OPPONENT(color)] &= ~bb_ep_grab;
+            new->bb[OPPONENT(color)][BB_PAWN] &= ~bb_ep_grab;
+
+        } else {
+            piece_del(&new->board[to].s_piece->list);
+            new->board[to].piece = 0;
+            new->occupied[OPPONENT(color)] &= ~bb_to;
+            new->bb[OPPONENT(color)][PIECETOBB(captured)] &= ~bb_to;
+        }
+
+    } else if (move->flags & M_CASTLE_Q) {
+        uchar row = R88(from);
+        square_t rook_from = SQ88(0, row);
+        square_t rook_to = SQ88(3, row);
+        u64 bb_rook_from = SQ88_2_BB(rook_from);
+        u64 bb_rook_to = SQ88_2_BB(rook_to);
+
+        new->board[rook_to] = new->board[rook_from];
+        new->board[rook_to].s_piece->square = rook_to;
+        new->occupied[color] &= ~bb_rook_from;
+        new->occupied[color] |= bb_rook_to;
+        new->bb[color][PIECETOBB(BB_ROOK)] &= ~bb_rook_from;
+        new->bb[color][PIECETOBB(BB_ROOK)] |= bb_rook_to;
+        new->board[rook_from].piece = 0;
+        new->board[rook_from].s_piece = NULL;
+        //new->castle &= color == WHITE? ~CASTLE_W: ~CASTLE_B;
+
+    } else if (move->flags & M_CASTLE_K) {
+        uchar row = R88(from);
+        square_t rook_from = SQ88(7, row);
+        square_t rook_to = SQ88(5, row);
+        u64 bb_rook_from = SQ88_2_BB(rook_from);
+        u64 bb_rook_to = SQ88_2_BB(rook_to);
+
+        new->board[rook_to] = new->board[rook_from];
+        new->board[rook_to].s_piece->square = rook_to;
+        new->occupied[color] &= ~bb_rook_from;
+        new->occupied[color] |= bb_rook_to;
+        new->bb[color][PIECETOBB(BB_ROOK)] &= ~bb_rook_from;
+        new->bb[color][PIECETOBB(BB_ROOK)] |= bb_rook_to;
+        new->board[rook_from].piece = 0;
+        new->board[rook_from].s_piece = NULL;
+        // new->castle &= color == WHITE? ~CASTLE_W: ~CASTLE_B;
+    }
+
+    new->board[to] = new->board[from];
+    /* fix dest square */
+    new->board[to].s_piece->square = to;
+    if (move->flags & M_PROMOTION) {
+        log_f(5, "promotion to %s\n", P_SYM(move->promotion));
+        log_f(5, "newpiece=%#x p=%#x\n", move->promotion, PIECE(move->promotion));
+        newpiece = PIECE(move->promotion);
+        new->board[to].piece = move->promotion;
+        new->board[to].s_piece->piece = move->promotion;
+    }
+    /* replace old occupied bitboard by new one */
+    new->occupied[color] &= ~bb_from;
+    new->occupied[color] |= bb_to;
+    new->bb[color][PIECETOBB(piece)] &= ~bb_from;
+    new->bb[color][PIECETOBB(newpiece)] |= bb_to;
+    if (move->flags & M_PROMOTION) {
+        log_f(5, "promotion color=%d bbpiece=%d\n", color, PIECETOBB(newpiece));
+        //bitboard_print(new->bb[color][PIECETOBB(newpiece)]);
+    }
+    /* set en_passant */
+    new->en_passant = 0;
+    if (piece == PAWN) {
+        if (R88(from) == 1 && R88(to) == 3)
+            pos->en_passant = SQ88(F88(from), 2);
+        else if  (R88(from) == 6 && R88(to) == 4)
+            pos->en_passant = SQ88(F88(from), 5);
+    }
+
+    /* always make "from" square empty */
+    new->board[from].piece = 0;
+    new->board[from].s_piece = NULL;
+
+    //printf("old turn=%d ", color);
+    //printf("new turn=%d\n", new->turn);
+    //fflush(stdout);
+    /* adjust castling flags */
+    if ((bb_from | bb_to) & E1bb)
+        new->castle &= ~(CASTLE_WQ | CASTLE_WK);
+    else if ((bb_from | bb_to) & A1bb)
+        new->castle &= ~CASTLE_WQ;
+    else if ((bb_from | bb_to) & H1bb)
+        new->castle &= ~CASTLE_WK;
+
+    if ((bb_from | bb_to) & E8bb)
+        new->castle &= ~(CASTLE_BQ | CASTLE_BK);
+    else if ((bb_from | bb_to) & A8bb)
+        new->castle &= ~CASTLE_BQ;
+    else if ((bb_from | bb_to) & H8bb)
+        new->castle &= ~CASTLE_BK;
+
+    SET_COLOR(new->turn, OPPONENT(color));        /* pos color */
+    return new;
+}
+
+void move_undo(pos_t *pos, __unused move_t *move)
+{
+    pos_del(pos);
+}

src/temp-migration-bitboard/move.h

@@ -0,0 +1,79 @@
+/* move.h - move management.
+ *
+ * Copyright (C) 2021 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#ifndef MOVE_H
+#define MOVE_H
+
+#include "chessdefs.h"
+#include "position.h"
+#include "pool.h"
+#include "piece.h"
+
+/* move flags
+ */
+typedef unsigned char move_flags_t;
+#define M_NORMAL       0x00
+#define M_CHECK        0x01                       /* unsure if we know */
+#define M_CAPTURE      0x02
+#define M_EN_PASSANT   0x04
+#define M_PROMOTION    0x08
+#define M_CASTLE_K     0x10
+#define M_CASTLE_Q     0x20
+
+/* moves_print flags
+ */
+#define M_PR_CAPT      0x01
+#define M_PR_NCAPT     0x02
+#define M_PR_NUM       0x04
+#define M_PR_NL        0x08
+#define M_PR_EVAL      0x20                       /* separate captures */
+#define M_PR_SEPARATE  0x40                       /* separate captures */
+#define M_PR_LONG      0x80
+
+typedef struct move_s {
+    piece_t piece;
+    square_t from, to;
+    piece_t capture;                              /* captured piece */
+    piece_t promotion;                            /* promoted piece */
+    move_flags_t flags;
+    eval_t negamax;
+    eval_t eval;
+    eval_t eval_simple;
+    pos_t *pos;
+    struct list_head list;                        /* next move */
+} move_t;
+
+pool_t *moves_pool_init();
+void moves_pool_stats();
+int move_print(int movenum, move_t *move, move_flags_t flags);
+void moves_print(pos_t *move, move_flags_t flags);
+
+void move_del(struct list_head *ptr);
+int moves_del(pos_t *pos);
+
+int pseudo_moves_castle(pos_t *pos, bool color, bool doit, bool do_king);
+int pseudo_moves_gen(pos_t *pos, piece_list_t *piece, bool doit, bool do_king);
+int pseudo_moves_pawn(pos_t *pos, piece_list_t *piece, bool doit);
+int moves_gen(pos_t *pos, bool color, bool doit, bool do_king);
+int moves_gen_king_moves(pos_t *pos, bool color, bool doit);
+
+void moves_sort(pos_t *pos);
+void moves_gen_eval_sort(pos_t *pos);
+
+void moves_gen_all(pos_t *pos);
+void moves_gen_all_nomoves(pos_t *pos);
+
+pos_t *move_do(pos_t *pos, move_t *move);
+void move_undo(pos_t *pos, move_t *move);
+
+#endif  /* MOVE_H */

src/temp-migration-bitboard/piece.c

@@ -0,0 +1,118 @@
+/* piece.c - piece list management.
+ *
+ * Copyright (C) 2021 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#include <malloc.h>
+#include <ctype.h>
+
+#include <debug.h>
+#include <pool.h>
+#include <list.h>
+
+#include "chessdefs.h"
+#include "piece.h"
+#include "board.h"
+#include "bitboard.h"
+#include "position.h"
+
+static pool_t *pieces_pool;
+
+struct piece_details piece_details[] = {
+    [E_EMPTY]  = { ' ', ' ', " ", " ", "",       0 },
+    [E_PAWN]   = { 'P', 'p', "♙", "♟", "Pawn",   PAWN_VALUE },
+    [E_KNIGHT] = { 'N', 'n', "♘", "♞", "Knight", KNIGHT_VALUE },
+    [E_BISHOP] = { 'B', 'b', "♗", "♝", "Bishop", BISHOP_VALUE },
+    [E_ROOK]   = { 'R', 'r', "♖", "♜", "Rook",   ROOK_VALUE },
+    [E_QUEEN]  = { 'Q', 'q', "♕", "♛", "Queen",  QUEEN_VALUE },
+    [E_KING]   = { 'K', 'k', "♔", "♚", "King",   KING_VALUE }
+};
+
+void piece_list_print(struct list_head *list)
+{
+    struct list_head *p_cur, *tmp;
+    piece_list_t *piece;
+
+    list_for_each_safe(p_cur, tmp, list) {
+        piece = list_entry(p_cur, piece_list_t, list);
+
+        printf("%s%c%c ", P_SYM(piece->piece),
+               FILE2C(F88(piece->square)),
+               RANK2C(R88(piece->square)));
+    }
+    printf("\n");
+}
+
+pool_t *piece_pool_init()
+{
+    if (!pieces_pool)
+        pieces_pool = pool_create("pieces", 128, sizeof(piece_list_t));
+    return pieces_pool;
+}
+
+void piece_pool_stats()
+{
+    if (pieces_pool)
+        pool_stats(pieces_pool);
+}
+
+piece_list_t *piece_add(pos_t *pos, piece_t piece, square_t square)
+{
+    piece_list_t *new;
+    short color = COLOR(piece);
+
+#   ifdef DEBUG_PIECE
+    log_f(3, "piece=%02x square=%02x\n", piece, square);
+    log_f(5, "Adding %s %s on %c%c\n", color? "Black": "White",
+          P_NAME(piece), FILE2C(F88(square)), RANK2C(R88(square)));
+#   endif
+    if ((new = pool_get(pieces_pool))) {
+        /* first piece is always king */
+        if (PIECE(piece) == KING)
+            list_add(&new->list, &pos->pieces[color]);
+        else
+            list_add_tail(&new->list, &pos->pieces[color]);
+        new->piece = piece;
+        new->square = square;
+        new->castle = 0;
+        new-> value = piece_details[PIECE(piece)].value;
+    }
+
+    return new;
+}
+
+void piece_del(struct list_head *ptr)
+{
+    piece_list_t *piece = list_entry(ptr, piece_list_t, list);
+#   ifdef DEBUG_PIECE
+    log_f(3, "piece=%02x square=%02x\n", piece->piece, piece->square);
+#   endif
+    list_del(ptr);
+    pool_add(pieces_pool, piece);
+    return;
+}
+
+int pieces_del(pos_t *pos, short color)
+{
+    struct list_head *p_cur, *tmp, *head;
+    int count = 0;
+
+    head = &pos->pieces[color];
+
+    list_for_each_safe(p_cur, tmp, head) {
+        piece_del(p_cur);
+        count++;
+    }
+#   ifdef DEBUG_PIECE
+    log_f(3, "color=%d removed=%d\n", color, count);
+#   endif
+    return count;
+}

src/temp-migration-bitboard/piece.h

@@ -0,0 +1,71 @@
+/* piece.h - piece definitions.
+ *
+ * Copyright (C) 2021 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#ifndef PIECE_H
+#define PIECE_H
+
+#include <ctype.h>
+
+#include "chessdefs.h"
+#include "list.h"
+#include "pool.h"
+
+#define PIECE_DEFAULT_VALUE 0
+
+/* initial default values */
+#define PAWN_VALUE    100
+#define KNIGHT_VALUE  300
+#define BISHOP_VALUE  300
+#define ROOK_VALUE    500
+#define QUEEN_VALUE   900
+#define KING_VALUE    20000
+
+typedef struct piece_list_s {
+    piece_t piece;
+    square_t square;
+    short castle;
+    s64 value;
+    struct list_head list;
+} piece_list_t;
+
+/* some default values for pieces
+ */
+extern struct piece_details {
+    char abbrev_w;                                /* used for game notation */
+    char abbrev_b;
+    char *symbol_w;
+    char *symbol_b;                               /* used for game notation */
+    char *name;
+    s64  value;
+} piece_details[];
+
+#define P_NAME(p)      piece_details[E_PIECE(p)].name
+#define P_LETTER(p)    piece_details[E_PIECE(p)].abbrev_w
+#define P_SYM(p)       piece_details[E_PIECE(p)].symbol_b
+#define P_CSHORT(p)    (IS_WHITE(p)? piece_details[E_PIECE(p)].abbrev_w: \
+                        piece_details[E_PIECE(p)].abbrev_b)
+#define P_CSYM(p)      (IS_WHITE(p)? piece_details[E_PIECE(p)].symbol_w: \
+                        piece_details[E_PIECE(p)].symbol_b)
+#define P_VALUE(p)     (piece_details[E_PIECE(p)].value)
+/* use short name or symbol - no effect
+ */
+#define P_USE_UTF      1
+
+void piece_list_print(struct list_head *list);
+pool_t *piece_pool_init();
+void piece_pool_stats();
+piece_list_t *piece_add(pos_t *pos, piece_t piece, square_t square);
+void piece_del(struct list_head *ptr);
+int pieces_del(pos_t *pos, short color);
+
+#endif

src/temp-migration-bitboard/position.c

@@ -0,0 +1,323 @@
+/* position.c - position management.
+ *
+ * Copyright (C) 2021 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <ctype.h>
+
+#include "chessdefs.h"
+#include "position.h"
+#include "move.h"
+#include "fen.h"
+#include "piece.h"
+#include "eval.h"
+
+static pool_t *pos_pool;
+
+#define BYTE_PRINT "%c%c%c%c%c%c%c%c"
+#define BYTE2BIN(b) ((b) & 0x01 ? '1' : '0'),  \
+        ((b) & 0x02 ? '1' : '0'),              \
+        ((b) & 0x04 ? '1' : '0'),              \
+        ((b) & 0x08 ? '1' : '0'),              \
+        ((b) & 0x10 ? '1' : '0'),              \
+        ((b) & 0x20 ? '1' : '0'),              \
+        ((b) & 0x40 ? '1' : '0'),              \
+        ((b) & 0x80 ? '1' : '0')
+
+inline void bitboard_print(bitboard_t bb)
+{
+    int i;
+    printf("%#018lx\n", bb);
+    for (i=56; i>=0; i-=8)
+        printf("\t"BYTE_PRINT"\n",
+               BYTE2BIN(bb>>i));
+}
+
+inline void bitboard_print2(bitboard_t bb1, bitboard_t bb2)
+{
+    int i;
+    printf("\tW: %#018lx\tB: %#018lx\n", bb1, bb2);
+    for (i=56; i>=0; i-=8)
+        printf("\t"BYTE_PRINT"\t\t"BYTE_PRINT"\n",
+               BYTE2BIN(bb1>>i),
+               BYTE2BIN(bb2>>i));
+}
+
+/**
+ * pos_pieces_print() - Print position pieces
+ * @pos:  &position
+ */
+void pos_pieces_print(pos_t *pos)
+{
+    printf("White pieces (%d): \t", popcount64(pos->occupied[WHITE]));
+    piece_list_print(&pos->pieces[WHITE]);
+    printf("Black pieces (%d): \t", popcount64(pos->occupied[BLACK]));
+    piece_list_print(&pos->pieces[BLACK]);
+}
+
+/**
+ * pos_bitboards_print() - Print position bitboards
+ * @pos:  &position
+ */
+void pos_bitboards_print(pos_t *pos)
+{
+    printf("Bitboards occupied :\n");
+    bitboard_print2(pos->occupied[WHITE], pos->occupied[BLACK]);
+    printf("Bitboards controlled :\n");
+    bitboard_print2(pos->controlled[WHITE], pos->controlled[BLACK]);
+
+}
+
+/**
+ * pos_print() - Print position on stdout.
+ * @pos:  &position
+ */
+void pos_print(pos_t *pos)
+{
+    int rank, file;
+    piece_t piece;
+    board_t *board = pos->board;
+    piece_list_t *wk = list_first_entry(&pos->pieces[WHITE], piece_list_t, list),
+        *bk = list_first_entry(&pos->pieces[BLACK], piece_list_t, list);
+
+
+    printf("  +---+---+---+---+---+---+---+---+\n");
+    for (rank = 7; rank >= 0; --rank) {
+        printf("%c |", rank + '1');
+        for (file = 0; file < 8; ++file) {
+            piece = board[SQ88(file, rank)].piece;
+            printf(" %s |", P_CSYM(piece));
+        }
+        printf("\n  +---+---+---+---+---+---+---+---+\n");
+    }
+    printf("    A   B   C   D   E   F   G   H\n\n");
+    printf("Turn: %s.\n", IS_WHITE(pos->turn) ? "white" : "black");
+    printf("Kings: W:%c%c B:%c%c\n",
+           FILE2C(F88(wk->square)),
+           RANK2C(R88(wk->square)),
+           FILE2C(F88(bk->square)),
+           RANK2C(R88(bk->square)));
+    printf("Possible en-passant: [%#x] ", pos->en_passant);
+    if (pos->en_passant == 0)
+        printf("None.\n");
+    else
+        printf("%d %d = %c%c\n",
+               F88(pos->en_passant),
+               R88(pos->en_passant),
+               FILE2C(F88(pos->en_passant)),
+               RANK2C(R88(pos->en_passant)));
+
+    printf("castle [%#x] : ", pos->castle);
+
+    if (pos->castle & CASTLE_WK)
+        printf("K");
+    if (pos->castle & CASTLE_WQ)
+        printf("Q");
+    if (pos->castle & CASTLE_BK)
+        printf("k");
+    if (pos->castle & CASTLE_BQ)
+        printf("q");
+
+    printf("\n50 half-moves-rule = %d\n", pos->clock_50);
+    printf("Current move = %d\n", pos->curmove);
+    printf("Squares controlled: W:%d B:%d\n", popcount64(pos->controlled[WHITE]),
+           popcount64(pos->controlled[BLACK]));
+    printf("Mobility: W:%u B:%u\n", pos->mobility[WHITE],
+           pos->mobility[BLACK]);
+}
+
+/**
+ * pos_check() - extensive position consistenci check.
+ * @pos:  &position
+ */
+void pos_check(pos_t *pos)
+{
+    int rank, file;
+    piece_t piece;
+    board_t *board = pos->board;
+
+    /* check that board and bitboard reflect same information */
+    for (rank = 7; rank >= 0; --rank) {
+        for (file = 0; file < 8; ++file) {
+            piece_list_t *ppiece;
+            printf("checking %c%c ", file+'a', rank+'1');
+
+            piece = board[SQ88(file, rank)].piece;
+            ppiece= board[SQ88(file, rank)].s_piece;
+            printf("piece=%s ", P_CSYM(piece));
+            if (ppiece)
+                printf("ppiece=%s/sq=%#x ", P_CSYM(ppiece->piece), ppiece->square);
+            switch(PIECE(piece)) {
+                case PAWN:
+                    printf("pawn" );
+                    break;
+                case KNIGHT:
+                    printf("knight ");
+                    break;
+                case BISHOP:
+                    printf("bishop ");
+                    break;
+                case ROOK:
+                    printf("rook ");
+                    break;
+                case QUEEN:
+                    printf("queen ");
+                    break;
+                case KING:
+                    printf("king ");
+                    break;
+            }
+            printf("\n");
+        }
+    }
+}
+
+pos_t *pos_clear(pos_t *pos)
+{
+    int file, rank;
+    board_t *board = pos->board;
+
+    for (file = 0; file < 8; ++file) {
+        for (rank = 0; rank < 8; ++rank) {
+            /*printf("file = %d rank = %d SQ88 = %#2x = %d addr=%p\n", file, rank,
+                   SQ88(file, rank), SQ88(file, rank),
+                   &board[SQ88(file, rank)].piece);
+            */
+            board[SQ88(file, rank)].piece = EMPTY;
+        }
+    }
+
+    SET_WHITE(pos->turn);
+    pos->node_count = 0;
+    pos->castle = 0;
+    pos->clock_50 = 0;
+    pos->curmove = 0;
+    pos->eval = 0;
+    pos->en_passant = 0;
+    pos->occupied[WHITE] = 0;
+    pos->occupied[BLACK] = 0;
+    for (int color=0; color<2; ++color)
+        for (int piece = BB_ALL; piece < BB_END; ++piece)
+            pos->bb[color][piece] = 0;
+    pos->controlled[WHITE] = 0;
+    pos->controlled[BLACK] = 0;
+    pos->mobility[WHITE] = 0;
+    pos->mobility[BLACK] = 0;
+    pos->moves_generated = false;
+    pos->moves_counted = false;
+    /* remove pieces / moves */
+    pieces_del(pos, WHITE);
+    pieces_del(pos, BLACK);
+    moves_del(pos);
+
+    return pos;
+}
+
+/**
+ * pos_del() - delete a position.
+ * @pos: &position.
+ */
+void pos_del(pos_t *pos)
+{
+    pieces_del(pos, WHITE);
+    pieces_del(pos, BLACK);
+    moves_del(pos);
+    pool_add(pos_pool, pos);
+}
+
+pos_t *pos_startpos(pos_t *pos)
+{
+    static char *startfen="rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1";
+
+    return fen2pos(pos, startfen);
+}
+
+pos_t *pos_get()
+{
+    pos_t *pos = pool_get(pos_pool);
+    if (pos) {
+        INIT_LIST_HEAD(&pos->pieces[WHITE]);
+        INIT_LIST_HEAD(&pos->pieces[BLACK]);
+
+        INIT_LIST_HEAD(&pos->moves[WHITE]);
+        INIT_LIST_HEAD(&pos->moves[BLACK]);
+        pos_clear(pos);
+    } else {
+        fprintf(stderr, "zobaaa\n");
+    }
+    return pos;
+}
+
+/**
+ * pos_dup() - duplicate a position.
+ * @pos: &position to duplicate.
+ *
+ * New position is the same as source one (with duplicated pieces list),
+ * except:
+ * - moves list is empty
+ * - bestmove is NULL
+ * - nodecount is set to zero
+ * - eval is set to EVAL_INVALID
+ * - moves_generated ans moves_counted are unset
+ * - check is set to zero
+ *
+ * @return: The new position.
+ *
+ * TODO: merge with pos_get - NULL for init, non null for duplicate
+ */
+pos_t *pos_dup(pos_t *pos)
+{
+    struct list_head *p_cur, *piece_list;
+    piece_list_t *oldpiece;
+    board_t *board;
+    pos_t *new = pool_get(pos_pool);
+
+    if (new) {
+        board = new->board;
+        *new = *pos;
+        for (int color = 0; color < 2; ++color) {
+            INIT_LIST_HEAD(&new->pieces[color]);
+            INIT_LIST_HEAD(&new->moves[color]);
+            /* duplicate piece list */
+            piece_list = &pos->pieces[color];     /* white/black piece list */
+
+            list_for_each(p_cur, piece_list) {
+                oldpiece = list_entry(p_cur, piece_list_t, list);
+                board[oldpiece->square].s_piece =
+                    piece_add(new, oldpiece->piece, oldpiece->square);
+            }
+        }
+        new->bestmove = NULL;
+        new->node_count = 0;
+        new->eval = EVAL_INVALID;
+        new->moves_generated = false;
+        new->moves_counted = false;
+        new->check[WHITE] = new->check[BLACK] = 0;
+    }
+    return new;
+}
+
+pool_t *pos_pool_init()
+{
+    if (!pos_pool)
+        pos_pool = pool_create("positions", 128, sizeof(pos_t));
+    return pos_pool;
+}
+
+void pos_pool_stats()
+{
+    if (pos_pool)
+        pool_stats(pos_pool);
+}

src/temp-migration-bitboard/position.h

@@ -0,0 +1,66 @@
+/* position.h - position management definitions.
+ *
+ * Copyright (C) 2021 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#ifndef POSITION_H
+#define POSITION_H
+
+#include <stdint.h>
+
+#include "pool.h"
+#include "list.h"
+#include "bitops.h"
+
+#include "board.h"
+#include "chessdefs.h"
+
+typedef struct pos_s {
+    u64 node_count;                               /* evaluated nodes */
+    piece_t turn;                                 /* we use only color bit */
+    castle_t castle;
+    u16 clock_50;
+    u16 curmove;
+    eval_t eval;
+    int check[2];
+    int eval_simple_phase;
+    eval_t eval_simple;
+    move_t *bestmove;
+    bool moves_generated;
+    bool moves_counted;
+    board_t board[BOARDSIZE];
+
+    square_t en_passant;
+
+    bitboard_t bb[2][BB_END];                     /* use: pieces[BLACK][BB_PAWN] */
+    bitboard_t occupied[2];                       /* OR of bb[COLOR][x] */
+    bitboard_t controlled[2];
+    u16 mobility[2];
+    struct list_head pieces[2];                   /* pieces list, King is first */
+    struct list_head moves[2];
+} pos_t;
+
+void bitboard_print(bitboard_t bb);
+void bitboard_print2(bitboard_t bb1, bitboard_t bb2);
+void pos_pieces_print(pos_t *pos);
+void pos_bitboards_print(pos_t *pos);
+void pos_print(pos_t *pos);
+pos_t *pos_clear(pos_t *pos);
+void pos_del(pos_t *pos);
+pos_t *pos_startpos(pos_t *pos);
+pos_t *pos_create();
+pool_t *pos_pool_init();
+void pos_pool_stats();
+pos_t *pos_get();
+pos_t *pos_dup(pos_t *pos);
+void pos_check(pos_t *pos);
+
+#endif  /* POSITION_H */

src/temp-migration-bitboard/search.c

@@ -0,0 +1,237 @@
+/* search.c - search good moves.
+ *
+ * Copyright (C) 2023 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+
+#include <br.h>
+#include <list.h>
+#include "debug.h"
+
+#include "move.h"
+#include "eval.h"
+#include "search.h"
+
+/**
+ * negamax() - search position negamax.
+ * @pos: &position to search
+ * @depth: Wanted depth.
+ * @color: 1 for white, -1 for black.
+ *
+ * Calculate the negamax value of @pos. This is an extensive search, with
+ * absolutely no cutoff.
+ *
+ * @return: The @pos negamax evaluation.
+ */
+eval_t negamax(pos_t *pos, int depth, int color)
+{
+    move_t *move;
+    pos_t *newpos;
+    eval_t best = EVAL_MIN, score;
+
+    pos->node_count++;
+    if (depth == 0) {
+        moves_gen_all_nomoves(pos);
+        score = eval(pos) * color;
+        return score;
+    }
+    moves_gen_all(pos);
+    list_for_each_entry(move, &pos->moves[pos->turn], list) {
+        newpos = move_do(pos, move);
+        score = -negamax(newpos, depth - 1, -color);
+        pos->node_count += newpos->node_count;
+        move->negamax = score;
+        if (score > best) {
+            best = score;
+            pos->bestmove = move;
+        }
+        move_undo(newpos, move);
+    }
+    return best;
+}
+
+
+/**
+ * pvs() - Principal Variation Search.
+ * @pos: &position to search
+ * @depth: wanted depth.
+ * @alpha: alpha value.
+ * @beta: beta value.
+ * @color: 1 for white, -1 for black.
+ *
+ * Calculate the PVS value of @pos.
+ * See https://en.wikipedia.org/wiki/Principal_variation_search
+ *
+ * Moves list should be first generated and evaluated/sorted.
+ *
+ * @return: The @pos PVS evaluation.
+ */
+eval_t pvs(pos_t *pos, int depth, int alpha, int beta, int color)
+{
+    move_t *move;
+    pos_t *newpos;
+    eval_t score = EVAL_INVALID;
+    bool firstchild = true;
+
+    pos->node_count++;
+
+    if (depth == 0) {
+        //return quiesce(p, alpha, beta);           /* leaf node */
+        moves_gen_all_nomoves(pos);
+        score = eval(pos) * color;
+        log_f(2, "Terminal: depth=%d ", depth);
+        log_f(2, "score=%d alpha=%d beta=%d\n", score, alpha, beta);
+        return score;
+    }
+
+    moves_gen_all(pos);
+    //moves_print(pos, M_PR_EVAL);
+    /* do the full search for first child */
+    //move = list_first_entry_or_null(&pos->moves[pos->turn], move_t, list);
+
+    list_for_each_entry(move, &pos->moves[pos->turn], list) {
+        newpos = move_do(pos, move);
+        log(2, "%.*s", 5 - depth, "                ");
+        if (firstchild) {                               /* first child */
+            score = -pvs(newpos, depth - 1, -beta, -alpha, -color);
+            log_f(2, "First child depth=%d move=", depth);
+            //move_print(0, move, 0);
+            log(2, "score=%d alpha=%d beta=%d\n", score, alpha, beta);
+            pos->bestmove = move;
+        } else {
+            /* search with a null window */
+            score = -pvs(newpos, depth - 1, -alpha - 1, -alpha, -color);
+            log_f(2, "Other child depth=%d move=", depth);
+            //move_print(0, move, 0);
+            log_f(2, "score=%d alpha=%d beta=%d ", score, alpha, beta);
+            /* for fail-soft:  if (score > alpha && score < beta) */
+            if (score > alpha) {
+                /* if failed high, do a full re-search */
+                log_f(2, "doing full search.");
+                score = -pvs(newpos, depth - 1, -beta, -alpha, -color);
+            }
+            log(2, "\n");
+        }
+        pos->node_count += newpos->node_count;
+        move_undo(newpos, move);
+        if (score >= beta) {                      /* fail-hard hard beta cut-off */
+            log(2, "%.*s", 5 - depth, "                ");
+            log_f(2, "depth=%d score=%d alpha=%d beta=%d beta cut-off.\n",
+                  depth, score, alpha, beta);
+            return beta;
+        }
+        if (score > alpha) {
+            log(2, "%.*s", 5 - depth, "                ");
+            log_f(2, "depth=%d setting new alpha from %d to %d\n",
+                  depth, alpha, score);
+            alpha = score;
+            pos->bestmove = move;
+        }
+        move->pos = NULL;
+        move->negamax = score;
+        firstchild = false;
+    }
+
+    return alpha;
+}
+
+/*
+ * int negascout (pos_t *pos, int depth, int alpha, int beta )
+ * {                     /\* compute minimax value of position p *\/
+ *     move_t *move;
+ *     pos_t *newpos;
+ *     eval_t best = EVAL_MIN, score;
+ *
+ *     int a, b, t, i;
+ *
+ *     if (depth == 0) {
+ *         //return quiesce(p, alpha, beta);           /\* leaf node *\/
+ *         moves_gen_all_nomoves(pos);
+ *         score = eval(pos) * color;
+ *         return score;
+ *     }
+ *     moves_gen_all(pos);
+ *     a = alpha;
+ *     b = beta;
+ *     list_for_each_entry(move, &pos->moves[pos->turn], list) {
+ *         log(1, "%.*s", 5 - depth, "                ");
+ *         newpos = move_do(pos, move);
+ * //    for ( i = 1; i <= w; i++ ) {
+ *         t = -negascout (newpos, depth - 1, -b, -alpha);
+ *         if ( (t > a) && (t < beta) && (i > 1) )
+ *             t = -NegaScout ( p_i, -beta, -alpha ); /\* re-search *\/
+ *         alpha = max( alpha, t );
+ *         if ( alpha >= beta )
+ *             return alpha;                            /\* cut-off *\/
+ *         b = alpha + 1;                  /\* set new null window *\/
+ *     }
+ *     return alpha;
+ * }
+ */
+
+/*
+ * int quiesce(pos_t *pos, int alpha, int beta)
+ * {
+ *     int stand_pat = eval(pos);
+ *
+ *     if( stand_pat >= beta )
+ *         return beta;
+ *     if( alpha < stand_pat )
+ *         alpha = stand_pat;
+ *
+ *     /\*
+ *      * until( every_capture_has_been_examined )  {
+ *      *     MakeCapture();
+ *      *     score = -Quiesce( -beta, -alpha );
+ *      *     TakeBackMove();
+ *      *
+ *      *     if( score >= beta )
+ *      *         return beta;
+ *      *     if( score > alpha )
+ *      *        alpha = score;
+ *      * }
+ *      *\/
+ *     return alpha;
+ * }
+ */
+
+/**
+ * ab_negamax() - search position negamax with alpha-beta cutoff.
+ * @pos: &position to search
+ * @depth: Wanted depth.
+ * @color: 1 for white, -1 for black.
+ *
+ * Calculate the negamax value of @pos, with alpha-beta pruning.
+ *
+ * @return: The @pos negamax evaluation.
+ */
+/*int ab_negamax(pos_t *pos, int alpha, int beta, int depth)
+{
+    move_t *move;
+    pos_t *newpos;
+    eval_t best = EVAL_MIN, score;
+
+    if(depth == 0) {
+       //return quiesce( alpha, beta );
+        moves_gen_all_nomoves(pos);
+       score = eval(pos) * color;
+       return score;
+    }
+   for ( all moves)  {
+      score = -alphaBeta( -beta, -alpha, depthleft - 1 );
+      if( score >= beta )
+         return beta;   //  fail hard beta-cutoff
+      if( score > alpha )
+         alpha = score; // alpha acts like max in MiniMax
+   }
+   return alpha;
+}
+*/

src/temp-migration-bitboard/search.h

@@ -0,0 +1,22 @@
+/* search.h - search for perfect move.
+ *
+ * Copyright (C) 2021 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#ifndef SEARCH_H
+#define SEARCH_H
+
+#include "position.h"
+
+eval_t negamax(pos_t *pos, int depth, int color);
+eval_t pvs(pos_t *pos, int depth, int alpha, int beta, int color);
+
+#endif  /* SEARCH_H */

test/attack-test.c

@@ -0,0 +1,65 @@
+/* attack-test.c - basic square attack tests.
+ *
+ * Copyright (C) 2024 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include "chessdefs.h"
+#include "fen.h"
+#include "position.h"
+#include "move-gen.h"
+#include "attack.h"
+
+#include "common-test.h"
+
+int main(int __unused ac, __unused char**av)
+{
+    int i = 0;
+    char *fen;
+    pos_t *pos;//, *fishpos = pos_new();
+    bitboard_t checkers, pinners, blockers;
+
+    setlinebuf(stdout);                           /* line-buffered stdout */
+
+    bitboard_init();
+    hyperbola_init();
+
+    while ((fen = next_fen(ATTACK))) {
+        //printf(">>>>> %s\n", test[i]);
+        printf("original fen %d: [%p][%s]\n", i, fen, fen);
+        if (!(pos = fen2pos(NULL, fen))) {
+            printf("wrong fen %d: [%s]\n", i, fen);
+            continue;
+        }
+        pos->checkers = pos_checkers(pos, pos->turn);
+        pos_set_pinners_blockers(pos);
+
+        pos_print(pos);
+
+        checkers = pos->checkers;
+        pinners = pos->pinners;
+        blockers = pos->blockers;
+
+        pos_set_checkers_pinners_blockers(pos);
+
+        printf("******* %s\n", cur_comment());
+        bb_print_multi("checkers", 2, checkers, pos->checkers);
+        bb_print_multi("pinners", 2, pinners, pos->pinners);
+        bb_print_multi("blockers", 2, blockers, pos->blockers);
+
+        pos_del(pos);
+        i++;
+    }
+    return 0;
+}

test/bitboard-test.c

@@ -0,0 +1,69 @@
+/* bitboard-test.c - basic bitboard/hyperbola tests.
+ *
+ * Copyright (C) 2024 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#include <stdio.h>
+#include <string.h>
+
+#include "bug.h"
+
+#include "chessdefs.h"
+#include "bitboard.h"
+#include "hyperbola-quintessence.h"
+
+int main(int __unused ac, __unused char**av)
+{
+    char str[256];
+    bitboard_init();
+    hyperbola_init();
+    for (int i = 0; i < 64; ++i) {
+        sprintf(str, "\n%#x:\n   %-22s%-22s%-22s%-22s%-22s%-22s%-22s", i,
+                "sliding", "diagonal", "antidiagonal", "file", "rank", "knight",
+                "king"
+                );
+        bb_print_multi(str, 7,
+                             bb_sqfile[i] | bb_sqrank[i] |
+                             bb_sqdiag[i] | bb_sqanti[i],
+                             bb_sqdiag[i], bb_sqanti[i],
+                             bb_sqfile[i], bb_sqrank[i],
+                             bb_knight[i], bb_king[i]);
+    }
+    sprintf(str, "between: %-22s%-22s%-22s%-22s%-22s%-22s",
+            "a1-a8", "a1-h8", "a1-h1", "a2-a7", "a2-g7", "a2-g2");
+    bb_print_multi(str, 6,
+                         bb_between[A1][A8], bb_between[A1][H8],
+                         bb_between[A1][H1], bb_between[A2][A7],
+                         bb_between[A2][G7], bb_between[A2][G2]);
+    sprintf(str, "between: %-22s%-22s%-22s%-22s%-22s%-22s%-22s%-22s",
+            "c3-c6", "c3-f6", "c3-f3", "c3-e1", "c3-c1", "c3-a1", "c3-a3", "c3-a5");
+    bb_print_multi(str, 8,
+                   bb_between[C3][C6], bb_between[C3][F6],
+                   bb_between[C3][F3], bb_between[C3][E1],
+                   bb_between[C3][C1], bb_between[C3][A1],
+                   bb_between[C3][A3], bb_between[C3][A5]);
+    sprintf(str, "between: %-22s%-22s%-22s%-22s%-22s%-22s%-22s%-22s",
+            "c4-c6", "c4-f6", "c4-f3", "c4-e1", "c4-c1", "c4-a1", "c4-a3", "c4-a5");
+    bb_print_multi(str, 8,
+                   bb_between[C4][C6], bb_between[C4][F6],
+                   bb_between[C4][F3], bb_between[C4][E1],
+                   bb_between[C4][C1], bb_between[C4][A1],
+                   bb_between[C4][A3], bb_between[C4][A5]);
+    sprintf(str, "Pwn att: %-22s%-22s%-22s%-22s%-22s%-22s%-22s%-22s",
+            "White a2", "Black a2", "White h7", "Black h7",
+            "White c3", "Black c3", "White e5", "Black e5");
+    bb_print_multi(str, 8,
+                   bb_pawn_attacks[WHITE][A2], bb_pawn_attacks[BLACK][A2],
+                   bb_pawn_attacks[WHITE][H7], bb_pawn_attacks[BLACK][H7],
+                   bb_pawn_attacks[WHITE][C3], bb_pawn_attacks[BLACK][C3],
+                   bb_pawn_attacks[WHITE][E5], bb_pawn_attacks[BLACK][E5]);
+    return 0;
+}

test/common-test.h

@@ -0,0 +1,493 @@
+/* common-test.h - common static vars/funcs test
+ *
+ * Copyright (C) 2024 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#include <stdio.h>
+#include "chessdefs.h"
+/* when below FENs are in a struct with selection per test */
+#define NOTEST      0
+#define FEN         1
+#define BITBOARD    2
+#define MOVEGEN     4
+#define ATTACK      8
+#define MOVEDO     16
+#define PERFT      32
+
+struct fentest {
+    int line;
+    uint modules;
+    char *comment;
+    char *fen;
+} fentest[] = {
+    /************************************************************
+     * TEMP TESTS BELOW - only run them (till sentinel below)   *
+     ************************************************************/
+
+    /*
+     * { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+     *   "startpos + 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4",
+     *   "r1bqkbnr/1ppp1ppp/p1n5/4p3/B3P3/5N2/PPPP1PPP/RNBQK2R b KQkq - 1 4"
+     * },
+     * { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+     *   "",
+     *   "r3k2r/p1ppqpb1/bn2pnp1/3PN3/1p2P3/2N2Q1p/PPPBBPPP/R3K2R w KQkq - 0 1"
+     * },
+     */
+
+    /*
+     * { __LINE__, MOVEGEN | MOVEDO | PERFT,
+     *   "from https://talkchess.com/viewtopic.php?t=74153",
+     *   "8/p7/8/1P6/K1k3p1/6P1/7P/8 w - - 0 1", // Perft(8) == 8,103,790
+     * },
+     * 8/5p2/8/2k3P1/p3K3/8/1P6/8 b - - // Perft(8) == 64,451,405
+
+     */
+    /*
+     * { __LINE__, MOVEGEN | MOVEDO | PERFT,
+     *   "from https://talkchess.com/viewtopic.php?t=74153",
+     *   "n1n5/PPPk4/8/8/8/8/4Kppp/5N1N b - - 0 1" // Perft(6) == 71,179,139
+     * },
+     * { __LINE__, MOVEGEN | MOVEDO | PERFT,
+     *   "from https://talkchess.com/viewtopic.php?t=74153",
+     *   "r3k2r/p6p/8/B7/1pp1p3/3b4/P6P/R3K2R w KQkq - 0 1" // Perft(6) == 77,054,993
+     * },
+     */
+    /*
+     * { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+     *   "from https://www.talkchess.com/forum/viewtopic.php?t=42463",
+     *   "rnbqkb1r/pp1p1ppp/2p5/4P3/2B5/8/PPP1NnPP/RNBQK2R w KQkq - 0 6"
+     * },
+     */
+    /*
+      r3k2r/pb3p2/5npp/n2p4/1p1PPB2/6P1/P2N1PBP/R3K2R w KQkq - // Perft(5) == 29,179,893
+    */
+    /******************************************************************
+     * DO NOT DELETE NEXT LINE - sentinel entry for temp tests above. *
+     *                           ignored if first array entry.        *
+     ******************************************************************/
+    { __LINE__, 0, NULL, NULL },
+
+    { __LINE__, MOVEGEN | MOVEDO | PERFT,
+      "illegal white e.p.",
+      "3k4/8/5K2/3pP3/8/2b5/8/8 w - d6 0 1",
+    },
+    { __LINE__, PERFT,
+      "only K, pawn push and ep moves",
+      "3k4/8/8/3pPK2/8/8/8/8 w - d6 0 1"
+    },
+
+    { __LINE__, MOVEGEN | MOVEDO | PERFT,
+      "illegal white e.p.",
+      "3k4/8/8/2qpPK2/8/8/8/8 w - d6 0 1",
+    },
+    { __LINE__, MOVEGEN | MOVEDO | PERFT,
+      "illegal black e.p.",
+      "8/8/8/8/2QPpk2/8/8/3K4 b - d3 0 1",
+    },
+    { __LINE__, MOVEGEN | MOVEDO | PERFT,
+      "illegal black e.p.",
+      "8/8/2B5/8/3Pp3/5k2/8/3K4 b - d3 0 1",
+    },
+
+    { __LINE__, MOVEGEN | MOVEDO | PERFT,
+      "legal white e.p.",
+      "1K1k4/8/8/3pP3/8/6b1/8/8 w - d6 0 1",
+    },
+    { __LINE__, MOVEGEN | MOVEDO | PERFT,
+      "legal black e.p.",
+      "8/8/6B1/8/3Pp3/8/8/1k1K4 b - d3 0 1",
+    },
+    { __LINE__, MOVEGEN | MOVEDO | PERFT,
+      "illegal e.p.",
+      "1nbqkbn1/ppp1pppp/8/r1rpP1K1/8/8/PPPP1PPP/RNBQ1BNR w - d6 0 1",
+    },
+    { __LINE__, MOVEGEN | MOVEDO | PERFT,
+      "illegal e.p. bug perft at depth 4",
+      "1nbqkbn1/ppp2ppp/4p3/r1rpP3/6K1/P7/1PPP1PPP/RNBQ1BNR b - - 1 2"
+    },
+    /*
+     * { __LINE__, MOVEGEN | MOVEDO | PERFT,
+     *   "illegal e.p. bug perft depth 3",
+     *   "1nbqkbn1/ppp2ppp/4p3/2rpP3/r5K1/P7/1PPP1PPP/RNBQ1BNR w - - 2 3"
+     * },
+     * { __LINE__, MOVEGEN | MOVEDO | PERFT,
+     *   "illegal e.p. bug perft depth 2",
+     *   "1nbqkbn1/ppp2ppp/4p3/2rpP3/r4PK1/P7/1PPP2PP/RNBQ1BNR b - - 0 3"
+     * },
+     * { __LINE__, MOVEGEN | MOVEDO | PERFT | PERFT,
+     *   "illegal e.p. bug perft depth 1 - fixed",
+     *   "1nb1kbn1/ppp2ppp/4p3/2rpP1q1/r4PK1/P7/1PPP2PP/RNBQ1BNR w - - 1 4"
+     * },
+     */
+    { __LINE__, ATTACK,
+      "only 3 K moves (but impossible situation)",
+      "1k6/8/8/8/8/8/8/r2K3r w - - 0 1"
+    },
+    { __LINE__, ATTACK,
+      "checkers: a8 h8",
+      "R2k3R/8/8/8/8/8/8/1K6 b - - 0 1"
+    },
+    { __LINE__, ATTACK,
+      "checkers: b3 g3",
+      "1k6/8/8/8/8/1r1K2r1/8/8 w - - 0 1"
+    },
+
+    { __LINE__, ATTACK,
+      "checkers: b6 g6",
+      "8/8/1R1k2R1/8/8/8/8/1K6 b - - 0 1"
+    },
+
+    { __LINE__, ATTACK,
+      "checkers: g2 g7",
+      "8/k5r1/8/8/6K1/8/6r1/8 w - - 0 1"
+    },
+    { __LINE__, ATTACK,
+      "checkers: g2 g7",
+      "8/6R1/8/6k1/8/8/K5R1/8 b - - 0 1"
+    },
+    { __LINE__, ATTACK,
+      "checkers: d5 e3, pinners: none (2 pieces between attacker & K)",
+      "3k4/8/8/3r3b/b7/1N2nn2/2n1B3/rNBK1Rbr w - - 0 1"
+    },
+
+    { __LINE__, ATTACK,
+      "checkers: d4 e6 pinners: h4 a5 a8 h8",
+      "Rn1k1r1R/4b3/1n2N3/B7/3R3B/8/8/3K4 b - - 0 1"
+    },
+    { __LINE__, ATTACK,
+      "checkers: d5 e3, pinners: a1 h1 a4 h5",
+      "3k4/8/8/3r3b/b7/1N2n3/4B3/rN1K1R1r w - - 0 1"
+    },
+
+    { __LINE__, MOVEGEN | MOVEDO | PERFT,
+      "only pawn captures",
+      "4k3/8/2p1p3/2PpP3/8/pp4pp/PP4PP/4K3 w - d6 0 1"
+    },
+
+    { __LINE__, FEN | ATTACK,
+      "checker: h4",
+      "4k3/8/8/8/7b/8/8/4K3 w - - 0 1"
+    },
+    /*
+     * { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+     *   "1.e3 - perft bug",
+     *   "rnbqkbnr/pppppppp/8/8/8/4P3/PPPP1PPP/RNBQKBNR b KQkq - 0 1"
+     * },
+     * { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT | PERFT,
+     *   "1.e3 Nc6 - perft bug",
+     *   "r1bqkbnr/pppppppp/2n5/8/8/4P3/PPPP1PPP/RNBQKBNR w KQkq - 1 2"
+     * },
+     * { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT | PERFT,
+     *   "1.e3 Nc6 2.Ke2 - perft bug",
+     *   "r1bqkbnr/pppppppp/2n5/8/8/4P3/PPPPKPPP/RNBQ1BNR b kq - 2 2"
+     * },
+     * { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+     *   "1.e3 Nc6 2.Ke2 Nd4+ - perft bug",
+     *   "r1bqkbnr/pppppppp/8/8/3n4/4P3/PPPPKPPP/RNBQ1BNR w kq - 3 3"
+     * },
+     */
+    // First game moves
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "startpos",
+      "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "startpos + 1.e4",
+      "rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq - 0 1"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "startpos + 1.e4 e5 2.Nf3",
+      "rnbqkbnr/pppp1ppp/8/4p3/4P3/5N2/PPPP1PPP/RNBQKB1R b KQkq - 1 2"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "startpos + 1.e4 e5 2.Nf3 Nc6",
+      "r1bqkbnr/pppp1ppp/2n5/4p3/4P3/5N2/PPPP1PPP/RNBQKB1R w KQkq - 2 3"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "startpos + 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4",
+      "r1bqkbnr/1ppp1ppp/p1n5/4p3/B3P3/5N2/PPPP1PPP/RNBQK2R b KQkq - 1 4"
+    },
+    // castling test
+    // both can castle queen only
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "no Q castling",
+      "r3k2r/8/3B4/8/8/3b4/8/R3K2R w KQkq - 0 1"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "no castling, 2 mates in 1",
+      "r3k2r/8/3BB3/8/8/3bb3/8/R3K2R w KQkq - 0 1"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "",
+      "r2bkb1r/8/8/8/8/3bb3/8/R2BKB1R w KQkq - 0 1"
+    },
+    //
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "4 castle possible, only K+R",
+      "r3k2r/8/8/8/8/8/8/R3K2R w KQkq - 0 1"
+    },
+    //
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "only kings on A1/A8, white to play",
+      "k7/8/8/8/8/8/8/K7 w - - 0 1"
+    },
+    //
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "only one move possible (Pf2xBg3)",
+      "k7/8/8/1p1p4/pPpPp3/P1PpPpb1/NBNP1P2/KBB1B3 w - - 0 1"
+    },
+    //
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "only 2 moves possible (Ph5xg6 e.p., Ph5-h6)",
+      "k7/8/8/1p1p2pP/pPpPp3/P1PpPp2/NBNP1P2/KBB1B3 w - g6 0 1"
+    },
+    //
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "2 Kings, W/B/ pawns on 7th for promotion",
+      "k4n2/4P3/8/8/8/8/4p3/K4N2 w - - 0 1"
+    },
+    // white castled, and can e.p. on c6 black can castle
+    // white is a pawn down
+    // white has 36 moves: P=11 + 1 e.p. N=6+3 B=5+5 R=1 Q=3 K=1 + 1 e.p.
+    // black has 33 moves: P=11 N=2+7 B=5 R=3 Q=3 K=1 + castle
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "",
+      "rnbqk2r/pp1pbpp1/7p/2pPp3/4n3/3B1N2/PPP2PPP/RNBQ1RK1 w kq c6 0 7"
+    },
+
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "",
+      "4k3/4p3/8/b7/1BR1p2p/1Q3P2/5N2/4K3 w - - 0 1"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "",
+      "r1bq1rk1/pppp1ppp/2n2n2/4p3/2B1P3/3PPN2/PPP3PP/RN1QK2R b KQ - 1 7"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "",
+      "6k1/6pp/R2p4/p1p5/8/1P1r3P/6P1/6K1 b - - 3 3"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "from https://www.talkchess.com/forum/viewtopic.php?t=42463",
+      "rnbqkb1r/pp1p1ppp/2p5/4P3/2B5/8/PPP1NnPP/RNBQK2R w KQkq - 0 6"
+    },
+
+    // some of tests below are from:
+    // - Rodent IV
+    // - https://www.chessprogramming.net/perfect-perft/
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "\"kiwipete\"",
+      "r3k2r/p1ppqpb1/bn2pnp1/3PN3/1p2P3/2N2Q1p/PPPBBPPP/R3K2R w KQkq - 0 1"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "",
+      "8/2p5/3p4/KP5r/1R3p1k/8/4P1P1/8 w - - 0 1"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "",
+      "8/2p5/3p4/Kp5r/1R3p1k/8/4P1P1/8 w - - 0 1"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "",
+      "4rrk1/pp1n3p/3q2pQ/2p1pb2/2PP4/2P3N1/P2B2PP/4RRK1 b - - 7 19"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "",
+      "rq3rk1/ppp2ppp/1bnpb3/3N2B1/3NP3/7P/PPPQ1PP1/2KR3R w - - 7 14"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "",
+      "r1bq1r1k/1pp1n1pp/1p1p4/4p2Q/4Pp2/1BNP4/PPP2PPP/3R1RK1 w - - 2 14"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "",
+      "r3r1k1/2p2ppp/p1p1bn2/8/1q2P3/2NPQN2/PPP3PP/R4RK1 b - - 2 15"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "",
+      "1rbqk1nr/p3ppbp/2np2p1/2p5/1p2PP2/3PB1P1/PPPQ2BP/R2NK1NR b KQk - 0 1"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "",
+      "r1bqk2r/pp1p1ppp/2n1pn2/2p5/1bPP4/2NBP3/PP2NPPP/R1BQK2R b KQkq - 0 1"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "",
+      "rnb1kb1r/ppp2ppp/1q2p3/4P3/2P1Q3/5N2/PP1P1PPP/R1B1KB1R b KQkq - 0 1"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "",
+      "r1b2rk1/pp2nppp/1b2p3/3p4/3N1P2/2P2NP1/PP3PBP/R3R1K1 b - - 0 1"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "",
+      "n1q1r1k1/3b3n/p2p1bp1/P1pPp2p/2P1P3/2NBB2P/3Q1PK1/1R4N1 b - - 0 1"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "",
+      "r1bq1r1k/b1p1npp1/p2p3p/1p6/3PP3/1B2NN2/PP3PPP/R2Q1RK1 w - - 1 16"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "",
+      "3r1rk1/p5pp/bpp1pp2/8/q1PP1P2/b3P3/P2NQRPP/1R2B1K1 b - - 6 22"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "",
+      "r1q2rk1/2p1bppp/2Pp4/p6b/Q1PNp3/4B3/PP1R1PPP/2K4R w - - 2 18"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "",
+      "4k2r/1pb2ppp/1p2p3/1R1p4/3P4/2r1PN2/P4PPP/1R4K1 b - - 3 22"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "",
+      "3q2k1/pb3p1p/4pbp1/2r5/PpN2N2/1P2P2P/5PP1/Q2R2K1 b - - 4 26"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "",
+      "2r5/8/1n6/1P1p1pkp/p2P4/R1P1PKP1/8/1R6 w - - 0 1"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "",
+      "r2q1rk1/1b1nbppp/4p3/3pP3/p1pP4/PpP2N1P/1P3PP1/R1BQRNK1 b - - 0 1"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "",
+      "6k1/5pp1/7p/p1p2n1P/P4N2/6P1/1P3P1K/8 w - - 0 35"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "",
+      "r4rk1/1pp1q1pp/p2p4/3Pn3/1PP1Pp2/P7/3QB1PP/2R2RK1 b - - 0 1"
+    },
+
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "",
+      "r3k2r/Pppp1ppp/1b3nbN/nP6/BBP1P3/q4N2/Pp1P2PP/R2Q1RK1 w kq - 0 1"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "",
+      "1k6/1b6/8/8/7R/8/8/4K2R b K - 0 1"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "Illegal ep move #1",
+      "3k4/3p4/8/K1P4r/8/8/8/8 b - - 0 1"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "Illegal ep move #2",
+      "8/8/4k3/8/2p5/8/B2P2K1/8 w - - 0 1"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "EP Capture Checks Opponent",
+      "8/8/1k6/2b5/2pP4/8/5K2/8 b - d3 0 1"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "Short Castling Gives Check",
+      "5k2/8/8/8/8/8/8/4K2R w K - 0 1"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "Long Castling Gives Check",
+      "3k4/8/8/8/8/8/8/R3K3 w Q - 0 1"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "Castle Rights",
+      "r3k2r/1b4bq/8/8/8/8/7B/R3K2R w KQkq - 0 1"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "Castling Prevented",
+      "r3k2r/8/3Q4/8/8/5q2/8/R3K2R b KQkq - 0 1"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "Promote out of Check",
+      "2K2r2/4P3/8/8/8/8/8/3k4 w - - 0 1"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "Discovered Check",
+      "8/8/1P2K3/8/2n5/1q6/8/5k2 b - - 0 1"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "Promote to give check",
+      "4k3/1P6/8/8/8/8/K7/8 w - - 0 1"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "Under Promote to give check",
+      "8/P1k5/K7/8/8/8/8/8 w - - 0 1"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "Self Stalemate",
+      "K1k5/8/P7/8/8/8/8/8 w - - 0 1"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "Stalemate & Checkmate",
+      "8/k1P5/8/1K6/8/8/8/8 w - - 0 1"
+    },
+    { __LINE__, FEN | MOVEGEN | MOVEDO | PERFT,
+      "Stalemate & Checkmate",
+      "8/8/2k5/5q2/5n2/8/5K2/8 b - - 0 1"
+    },
+    { __LINE__, MOVEDO | PERFT,
+      "simple movedo/undo: only 2 W knights",
+      "8/1k6/8/8/8/8/6K1/1NN5 w - - 0 1"
+    },
+    { __LINE__, MOVEDO | PERFT,
+      "simple movedo/undo: only 2 W knights",
+      "5n2/1k6/8/8/5K2/8/P7/1N6 w - - 0 1"
+    },
+    { __LINE__, FEN,
+      "legal EP",
+      "4k3/8/8/3pP3/8/8/8/4K3 w - d6 0 1"
+    },
+    { __LINE__, FEN,
+      "illegal EP, fix-able by fen parser",
+      "4k3/8/8/3p1P2/8/8/8/4K3 w - d6 0 1"
+    },
+    { __LINE__, FEN,
+      "illegal EP and castle flags, fix-able by fen parser, SF crash",
+      "4k3/8/8/8/7B/8/8/4K3 w KQkq e6 0 1"
+    },
+    { __LINE__, FEN,
+      "illegal, SF crash",
+      "4k3/8/8/8/7b/8/8/4K3 b - - 0 1"
+    },
+    { __LINE__, FEN,
+      "illegal, SF crash",
+      "2r1k3/3B4/8/8/8/8/8/4K3 w - - 0 1"
+    },
+    { __LINE__, FEN,
+      "illegal, SF crash",
+      "2r1k3/3P4/8/8/8/8/8/4K3 w - - 0 1"
+    },
+    { __LINE__, 0, NULL, NULL }
+};
+
+static int fentest_cur = -1;
+
+static char *next_fen(uint module)
+{
+    fentest_cur++;
+
+    /* skip first entry if NULL - for special testing, see  */
+    if (fentest_cur == 0 && fentest[fentest_cur].fen == NULL)
+        fentest_cur++;
+    while (fentest[fentest_cur].fen && !(fentest[fentest_cur].modules & module))
+        fentest_cur++;
+    return fentest[fentest_cur].fen;
+}
+
+static __unused char* cur_comment()
+{
+    return fentest[fentest_cur].comment;
+}
+
+static __unused int cur_line()
+{
+    return fentest[fentest_cur].line;
+}

test/fen-test.c

@@ -0,0 +1,50 @@
+/* fen-test.c - basic fen tests.
+ *
+ * Copyright (C) 2024 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#include <stdio.h>
+
+#include "chessdefs.h"
+#include "bitboard.h"
+#include "position.h"
+#include "fen.h"
+
+#include "common-test.h"
+
+int main(__unused int ac, __unused char**av)
+{
+    pos_t *pos;
+    const char *fen;
+    char revfen[128];
+
+    setlinebuf(stdout);                           /* line-buffered stdout */
+
+    bitboard_init();
+
+    while ((fen = next_fen(FEN))) {
+        printf("line %3d: [%s] ", cur_line(), fen);
+        if (!(pos = fen2pos(NULL, fen))) {
+            printf("**INVALID\n");
+        } else {
+            //pos_print(pos);
+            pos2fen(pos, revfen);
+            if (!strcmp(fen, revfen)) {
+                printf("OK\n");
+            } else {
+                //printf("fen = [%s]\nrev = [%s]", fen, revfen);
+                printf("-> [%s] **FIXED\n",revfen);
+                pos_print_raw(pos, 1);
+            }
+            pos_del(pos);
+        }
+    }
+}

test/fen.c

@@ -1,20 +0,0 @@
-#include "debug.h"
-#include "pool.h"
-#include "../src/position.h"
-#include "../src/fen.h"
-
-int main(int ac, char**av)
-{
-    pos_t *pos;
-
-    debug_init(5, stderr, true);
-    piece_pool_init();
-    pos_pool_init();
-    pos = pos_get();
-    if (ac == 1) {
-        pos_startpos(pos);
-    } else {
-        fen2pos(pos, av[1]);
-    }
-    pos_print(pos);
-}

test/move.c

@@ -1,31 +0,0 @@
-#include <stdio.h>
-#include "debug.h"
-
-#include "../src/fen.h"
-#include "../src/move.h"
-
-int main(int ac, char**av)
-{
-    pos_t *pos;
-
-    debug_init(5, stderr, true);
-    piece_pool_init();
-    moves_pool_init();
-    pos_pool_init();
-    pos = pos_get();
-
-    if (ac == 1) {
-        fen2pos(pos, "rnbqkbnr/pppp1ppp/8/4p3/4P3/8/PPPP1PPP/RNBQKBNR w KQkq - 0 2");
-        //pos_startpos(pos);
-    } else {
-        fen2pos(pos, av[1]);
-    }
-    //printf("turn = %d opponent = %d\n", pos->turn, OPPONENT(pos->turn));
-    moves_gen_all(pos);
-    pos_print(pos);
-    pos_pieces_print(pos);
-    moves_print(pos, M_PR_SEPARATE);
-
-    //bitboard_print2(castle_squares[0].controlled, castle_squares[1].controlled);
-    //bitboard_print2(castle_squares[0].occupied, castle_squares[1].occupied);
-}

test/movedo-test.c

@@ -0,0 +1,90 @@
+/* movedo-test.c - basic movedo/undo tests.
+ *
+ * Copyright (C) 2024 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include "chessdefs.h"
+#include "fen.h"
+#include "position.h"
+#include "move.h"
+#include "move-do.h"
+#include "move-gen.h"
+
+#include "common-test.h"
+
+int main(int __unused ac, __unused char**av)
+{
+    int i = 0, test_line;
+    char *fen, movebuf[8];;
+    pos_t *pos, *savepos;
+    movelist_t movelist;
+    move_t *move, *last;
+
+    init_all();
+
+    while ((fen = next_fen(MOVEDO))) {
+        test_line = cur_line();
+        if (!(pos = fen2pos(NULL, fen))) {
+            printf("wrong fen %d: [%s]\n", i, fen);
+            continue;
+        }
+
+        movelist.nmoves = 0;
+        pos_set_checkers_pinners_blockers(pos);
+        pos_legal(pos, pos_gen_pseudo(pos, &movelist));
+        last = movelist.move + movelist.nmoves;
+        savepos = pos_dup(pos);
+
+        state_t state = pos->state;
+        int j = 0;
+        for (move = movelist.move; move < last; ++move) {
+            //pos_print(pos);
+            //printf("i=%d j=%d  turn=%d move=[%s]\n", i, j, pos->turn,
+            //       move_str(movebuf, move, 0));
+            //move_p
+            move_do(pos, *move, &state);
+            //pos_print(pos);
+            //fflush(stdout);
+            if (!pos_ok(pos, false)) {
+                printf("*** fen %d [%s] move %d [%s] invalid position after move_do\n",
+                       test_line, fen, j, move_to_str(movebuf, *move, 0));
+                exit(0);
+            }
+
+            //printf("%d/%d move_do check ok\n", i, j);
+            move_undo(pos, *move, &state);
+            pos->state = state;
+            if (!pos_ok(pos, false)) {
+                printf("*** fen %d [%s] move %d [%s] invalid position after move_undo\n",
+                       test_line, fen, j, movebuf);
+                exit(0);
+            }
+            if (pos_cmp(pos, savepos) != true) {
+                printf("*** fen %d [%s] move %d [%s] position differ after move_{do,undo}\n",
+                       test_line, fen, j, movebuf);
+                exit(0);
+            }
+            //fflush(stdout);
+            //pos_check(pos, true);
+            //printf("%d/%d move_undo check ok\n", i, j);
+            j++;
+        }
+        printf("fen %d line=%d [%s] %d move_{do,undo} OK\n", i, test_line, fen, j);
+        pos_del(savepos);
+        pos_del(pos);
+        i++;
+    }
+    return 0;
+}

test/movegen-test.c

@@ -0,0 +1,288 @@
+/* movegen-test.c - basic movegen tests.
+ *
+ * Copyright (C) 2024 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include "chessdefs.h"
+#include "fen.h"
+#include "move-gen.h"
+#include "position.h"
+
+#include "common-test.h"
+
+#define RD 0
+#define WR 1
+
+/**
+ * return write pipd fd
+ */
+static FILE *open_stockfish()
+{
+    int rpipe[2], wpipe[2];
+    FILE *out_desc;
+    pid_t pid;
+
+    if ((pipe(rpipe) < 0) || (pipe(wpipe) < 0)) {
+        perror("pipe");
+        return NULL;
+    }
+    if ((pid = fork()) < 0) {
+        perror("fork");
+        return NULL;
+    }
+
+    if (!pid) {                                   /* stockfish */
+        setvbuf(stdin,  NULL, _IOLBF, 0);
+        setvbuf(stdout, NULL, _IOLBF, 0);
+        setvbuf(stderr, NULL, _IOLBF, 0);
+
+        dup2(wpipe[RD], STDIN_FILENO);
+        dup2(rpipe[WR], STDOUT_FILENO);
+        dup2(rpipe[WR], STDERR_FILENO);
+
+        close(wpipe[RD]);
+        close(wpipe[WR]);
+        close(rpipe[RD]);
+        close(rpipe[WR]);
+        if (execlp("stockfish", "stockfish", NULL) == -1) {
+            perror("execlp");
+            return NULL;
+        }
+        return 0;                                 /* not reached */
+    }
+    /* us */
+    dup2(rpipe[RD], STDIN_FILENO);
+    setvbuf(stdin, NULL, _IOLBF, 0);
+
+    close(wpipe[RD]);
+    close(rpipe[RD]);
+    close(rpipe[WR]);
+
+    out_desc = fdopen(wpipe[WR], "w");
+    setvbuf(out_desc, NULL, _IOLBF, 0);
+
+    return out_desc;
+}
+
+static void send_stockfish_fen(FILE *desc, pos_t *pos, movelist_t *movelist, char *fen)
+{
+    char *buf = NULL;
+    int count, __unused mycount = 0, fishcount;
+    size_t alloc = 0;
+    ssize_t buflen;
+
+    pos_clear(pos);
+
+    move_t *moves = movelist->move;
+    int *nmoves = &movelist->nmoves;
+    *nmoves = 0;
+    //char nodescount[] = "Nodes searched";
+    //printf("nmoves = %d\n", nmoves);
+    fflush(stdout);
+    //sprintf(str, "stockfish \"position fen %s\ngo perft depth\n\"", fen);
+    fprintf(desc, "position fen %s\ngo perft 1\n", fen);
+    //fflush(desc);
+    while ((buflen = getline(&buf, &alloc, stdin)) > 0) {
+        buf[--buflen] = 0;
+        if (buflen == 0)
+            continue;
+        if (sscanf(buf, "Nodes searched: %d", &fishcount) == 1) {
+            break;
+        }
+        //printf("%d: %s\n", line++, buf);
+        if (sscanf(buf, "%*4s: %d", &count) == 1) {
+            square_t from = sq_from_string(buf);
+            square_t to   = sq_from_string(buf + 2);
+            mycount += count;
+            //printf("move found: %c%c->%c%c %s->%s count=%d\n",
+            //       buf[0], buf[1], buf[2], buf[3],
+            //       sq_to_string(from), sq_to_string(to),
+            //       count);
+            moves[(*nmoves)++] = move_make(from, to);
+
+        } else if (sscanf(buf, "%*5s: %d", &count) == 1) {
+            square_t from = sq_from_string(buf);
+            square_t to   = sq_from_string(buf + 2);
+            piece_type_t promoted = piece_t_from_char(*(buf + 4));
+            mycount += count;
+            //printf("move found: %c%c->%c%c %s->%s count=%d\n",
+            //       buf[0], buf[1], buf[2], buf[3],
+            //       sq_to_string(from), sq_to_string(to),
+            //       count);
+            moves[(*nmoves)++] = move_make_promote(from, to, promoted);
+        }
+    }
+    //pos->moves.nmoves = nmoves;
+    // printf("fishcount=%d mycount=%d\n", fishcount, mycount);
+    free(buf);
+}
+
+static __unused bool movelists_equal(movelist_t *fish, movelist_t *me)
+{
+    move_t *m1 = fish->move, *m2 = me->move;
+    int n1 = fish->nmoves, n2 = me->nmoves;
+    int mask = 077777;
+
+    if (n1 != n2)
+        return false;
+    for (int cur = 0; cur < n1; ++cur) {
+        if ((m1[cur] & mask) != (m2[cur] & mask))
+            return false;
+    }
+    return true;
+}
+
+static __unused void compare_moves(movelist_t *fish, movelist_t *me)
+{
+    char str1[1024] = {0}, str2[1024] = {0}, tmpstr[1024];
+    char *skip = "      ";
+    move_t *m1 = fish->move;
+    move_t *m2 = me->move;
+    int n1 = fish->nmoves;
+    int n2 = me->nmoves;
+
+#define f(c) move_from(c)
+#define t(c) move_to(c)
+
+    for (move_t *c1 = m1, *c2 = m2; (c1 - m1 < n1) || (c2 - m2 < n2);) {
+        // square_t f1 = move_from(*c1); square_t t1 = move_to(*c1);
+        // square_t f2 = move_from(*c2); square_t t2 = move_to(*c2);
+
+        /* no more move in c2 */
+        if (c2 - m2 >= n2) {
+            while (c1 - m1 < n1) {
+                sprintf(tmpstr, " %s-%s", sq_to_string(f(*c1)), sq_to_string(t(*c1)));
+                strcat (str1, tmpstr);
+                c1++;
+            }
+            break;
+        }
+        if (c1 - m1 >= n1) {
+            while (c2 - m2 < n2) {
+                sprintf(tmpstr, " %s-%s", sq_to_string(f(*c2)), sq_to_string(t(*c2)));
+                strcat (str2, tmpstr);
+                c2++;
+            }
+            break;
+        }
+
+        /* missing move in c2 */
+        if (f(*c1) < f(*c2) ||
+            (f(*c1) == f(*c2) && t(*c1) < t(*c2))) {
+            strcat(str2, skip);
+            sprintf(tmpstr, " %s-%s", sq_to_string(f(*c1)), sq_to_string(t(*c1)));
+            strcat (str1, tmpstr);
+            while ((c1 - m1 < n1) && (f(*c1) < f(*c2) ||
+                                      (f(*c1) == f(*c2) && t(*c1) < t(*c2)))) {
+                c1++;
+            }
+            continue;
+        }
+        /* missing move in c1 */
+        if (f(*c1) > f(*c2) ||
+            (f(*c1) == f(*c2) && t(*c1) > t(*c2))) {
+            strcat(str1, skip);
+            sprintf(tmpstr, " %s-%s", sq_to_string(f(*c2)), sq_to_string(t(*c2)));
+            strcat (str2, tmpstr);
+            while ((c2 - m2 < n2) && (f(*c1) > f(*c2) ||
+                                      (f(*c1) == f(*c2) && t(*c1) > t(*c2)))) {
+                c2++;
+            }
+            continue;
+        }
+        sprintf(tmpstr, " %s-%s", sq_to_string(f(*c1)), sq_to_string(t(*c1)));
+        strcat(str1, tmpstr);
+        strcat(str2, tmpstr);
+        c1++, c2++;
+    }
+    printf("F(%2d): %s\nM(%2d): %s\n", n1, str1, n2, str2);
+}
+
+int main(int __unused ac, __unused char**av)
+{
+    int i = 0;
+    FILE *outfd;
+    char *fen;
+    pos_t *pos, *fishpos = pos_new();
+    movelist_t pseudo, fishmoves;
+    //bitboard_t wrong = 0x5088000040, tmp, loop;
+    //bit_for_each64(loop, tmp, )
+    //printf("fishpos 1=%p\n", fishpos);
+
+    setlinebuf(stdout);                           /* line-buffered stdout */
+
+    bitboard_init();
+    hyperbola_init();
+    outfd = open_stockfish();
+
+    while ((fen = next_fen(MOVEGEN))) {
+        //printf(">>>>> %s\n", test[i]);
+        //printf("fishpos 2=%p\n", fishpos);
+        //printf("original fen %d: [%p][%s]\n", i, fen, fen);
+        if (!(pos = fen2pos(NULL, fen))) {
+            printf("wrong fen %d: [%s]\n", i, fen);
+            continue;
+        }
+        /* print movelists */
+        send_stockfish_fen(outfd, fishpos, &fishmoves, fen);
+
+        pos_set_checkers_pinners_blockers(pos);
+        pos_gen_pseudo(pos, &pseudo);
+        //moves_print(&pseudo, 0);
+        pos_legal(pos, &pseudo);
+
+        //moves_print(&legal, 0);
+        //printf("Fu ");
+        //moves_print(fishpos, 0);
+        //fflush(stdout);
+        //printf("Mu ");
+        //moves_print(pos, 0);
+        //fflush(stdout);
+
+        /* sort and print movelists */
+        move_sort_by_sq(&fishmoves);
+        move_sort_by_sq(&pseudo);
+        // printf("\nFs ");
+        // moves_print(fishpos, 0);
+        // fflush(stdout);
+        // printf("Ms ");
+        // moves_print(pos, 0);
+        // fflush(stdout);
+
+        /* compare movelists */
+        if (!movelists_equal(&fishmoves, &pseudo)) {
+            pos_print(pos);
+            printf("F: ");
+            moves_print(&fishmoves, 0);
+            printf("M: ");
+            moves_print(&pseudo, 0);
+        } else {
+            printf("[%s]: OK (%d Moves)\n", fen, pseudo.nmoves);
+            //moves_print(&fishpos->moves, 0);
+        }
+        //compare_moves(&fishpos->moves, &legal);
+            //} else {
+            //printf("fen %d: [%s] - OK (%d moves)\n", i, fen, legal.nmoves);
+            //}
+        //pos_print_board_raw(pos, 1);
+        //printf("%s\n", pos2fen(pos, str));
+        //get_stockfish_moves(test[i]);
+        //exit(0);
+        pos_del(pos);
+        i++;
+    }
+    fclose(outfd);
+    return 0;
+}

test/perft-test.c

@@ -0,0 +1,469 @@
+/* perft-test.c - perft test.
+ *
+ * Copyright (C) 2024 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <time.h>
+#include <locale.h>
+#include <limits.h>
+
+#include "chessdefs.h"
+#include "fen.h"
+#include "position.h"
+#include "move.h"
+#include "move-do.h"
+#include "move-gen.h"
+#include "search.h"
+
+#include "common-test.h"
+
+#define RD 0
+#define WR 1
+
+typedef struct {
+    move_t move;
+    int count;
+} ddperft;
+
+/**
+ * return write pipd fd
+ */
+static FILE *open_stockfish()
+{
+    int rpipe[2], wpipe[2];
+    FILE *out_desc;
+    pid_t pid;
+    char *buf = NULL;
+    size_t alloc = 0;
+    ssize_t buflen;
+
+    if ((pipe(rpipe) < 0) || (pipe(wpipe) < 0)) {
+        perror("pipe");
+        return NULL;
+    }
+    if ((pid = fork()) < 0) {
+        perror("fork");
+        return NULL;
+    }
+
+    if (!pid) {                                   /* stockfish */
+        setvbuf(stdin,  NULL, _IOLBF, 0);
+        setvbuf(stdout, NULL, _IOLBF, 0);
+        setvbuf(stderr, NULL, _IOLBF, 0);
+
+        dup2(wpipe[RD], STDIN_FILENO);
+        dup2(rpipe[WR], STDOUT_FILENO);
+        dup2(rpipe[WR], STDERR_FILENO);
+
+        close(wpipe[RD]);
+        close(wpipe[WR]);
+        close(rpipe[RD]);
+        close(rpipe[WR]);
+        if (execlp("stockfish", "stockfish", NULL) == -1) {
+            perror("execlp");
+            return NULL;
+        }
+        return 0;                                 /* not reached */
+    }
+    /* us */
+    dup2(rpipe[RD], STDIN_FILENO);
+    setvbuf(stdin, NULL, _IOLBF, 0);
+
+    close(wpipe[RD]);
+    close(rpipe[RD]);
+    close(rpipe[WR]);
+
+    out_desc = fdopen(wpipe[WR], "w");
+    setvbuf(out_desc, NULL, _IOLBF, 0);
+
+    fprintf(out_desc, "uci\n");
+    while (true) {
+        if ((buflen = getline(&buf, &alloc, stdin)) < 0) {
+            perror("getline");
+            exit(1);
+        }
+        if (!strncmp(buf, "uciok", 5))
+            break;
+    }
+    free(buf);
+    return out_desc;
+}
+
+static void stockfish_fen(FILE *desc, char *fen)
+{
+    char *buf = NULL;
+    size_t alloc = 0;
+    ssize_t buflen;
+
+    fprintf(desc, "ucinewgame\nisready\n");
+    while ((buflen = getline(&buf, &alloc, stdin)) > 0) {
+        if (!strncmp(buf, "readyok", 7))
+            break;
+    }
+    fprintf(desc, "position fen %s\n", fen);
+    free(buf);
+}
+
+static u64 stockfish_perft(FILE *desc, pos_t *pos, movelist_t *movelist,
+                               int depth)
+{
+    char *buf = NULL;
+    u64 count, mycount = 0, fishcount;
+    size_t alloc = 0;
+    ssize_t buflen;
+
+    pos_clear(pos);
+
+    move_t *moves = movelist->move;
+    int *nmoves = &movelist->nmoves;
+    *nmoves = 0;
+    //char nodescount[] = "Nodes searched";
+    //printf("nmoves = %d\n", nmoves);
+    //fflush(stdout);
+    //sprintf(str, "stockfish \"position fen %s\ngo perft depth\n\"", fen);
+    //fprintf(desc, "position fen %s\ngo perft %d\n", fen, depth);
+    //fflush(desc);
+    fprintf(desc, "go perft %d\n", depth);
+
+    while ((buflen = getline(&buf, &alloc, stdin)) > 0) {
+        buf[--buflen] = 0;
+        if (buflen == 0)
+            continue;
+        if (sscanf(buf, "Nodes searched: %lu", &fishcount) == 1) {
+            break;
+        }
+        //printf("%d: %s\n", line++, buf);
+        if (sscanf(buf, "%*4s: %lu", &count) == 1) {
+            square_t from = sq_from_string(buf);
+            square_t to   = sq_from_string(buf + 2);
+            mycount += count;
+            //printf("move found: %c%c->%c%c %s->%s count=%d\n",
+            //       buf[0], buf[1], buf[2], buf[3],
+            //       sq_to_string(from), sq_to_string(to),
+            //       count);
+            moves[(*nmoves)++] = move_make(from, to);
+
+        } else if (sscanf(buf, "%*5s: %lu", &count) == 1) {
+            square_t from = sq_from_string(buf);
+            square_t to   = sq_from_string(buf + 2);
+            piece_type_t promoted = piece_t_from_char(*(buf + 4));
+            mycount += count;
+            //printf("move found: %c%c->%c%c %s->%s count=%d\n",
+            //       buf[0], buf[1], buf[2], buf[3],
+            //       sq_to_string(from), sq_to_string(to),
+            //       count);
+            moves[(*nmoves)++] = move_make_promote(from, to, promoted);
+        }
+    }
+    //pos->moves.nmoves = nmoves;
+    // printf("fishcount=%d mycount=%d\n", fishcount, mycount);
+    free(buf);
+    return mycount;
+}
+
+static __unused bool movelists_equal(movelist_t *fish, movelist_t *me)
+{
+    move_t *m1 = fish->move, *m2 = me->move;
+    int n1 = fish->nmoves, n2 = me->nmoves;
+    int mask = 077777;
+
+    if (n1 != n2)
+        return false;
+    for (int cur = 0; cur < n1; ++cur) {
+        if ((m1[cur] & mask) != (m2[cur] & mask))
+            return false;
+    }
+    return true;
+}
+
+static __unused void compare_moves(movelist_t *fish, movelist_t *me)
+{
+    char str1[1024] = {0}, str2[1024] = {0}, tmpstr[1024];
+    char *skip = "      ";
+    move_t *m1 = fish->move;
+    move_t *m2 = me->move;
+    int n1 = fish->nmoves;
+    int n2 = me->nmoves;
+
+#define f(c) move_from(c)
+#define t(c) move_to(c)
+
+    for (move_t *c1 = m1, *c2 = m2; (c1 - m1 < n1) || (c2 - m2 < n2);) {
+        // square_t f1 = move_from(*c1); square_t t1 = move_to(*c1);
+        // square_t f2 = move_from(*c2); square_t t2 = move_to(*c2);
+
+        /* no more move in c2 */
+        if (c2 - m2 >= n2) {
+            while (c1 - m1 < n1) {
+                sprintf(tmpstr, " %s-%s", sq_to_string(f(*c1)), sq_to_string(t(*c1)));
+                strcat (str1, tmpstr);
+                c1++;
+            }
+            break;
+        }
+        if (c1 - m1 >= n1) {
+            while (c2 - m2 < n2) {
+                sprintf(tmpstr, " %s-%s", sq_to_string(f(*c2)), sq_to_string(t(*c2)));
+                strcat (str2, tmpstr);
+                c2++;
+            }
+            break;
+        }
+
+        /* missing move in c2 */
+        if (f(*c1) < f(*c2) ||
+            (f(*c1) == f(*c2) && t(*c1) < t(*c2))) {
+            strcat(str2, skip);
+            sprintf(tmpstr, " %s-%s", sq_to_string(f(*c1)), sq_to_string(t(*c1)));
+            strcat (str1, tmpstr);
+            while ((c1 - m1 < n1) && (f(*c1) < f(*c2) ||
+                                      (f(*c1) == f(*c2) && t(*c1) < t(*c2)))) {
+                c1++;
+            }
+            continue;
+        }
+        /* missing move in c1 */
+        if (f(*c1) > f(*c2) ||
+            (f(*c1) == f(*c2) && t(*c1) > t(*c2))) {
+            strcat(str1, skip);
+            sprintf(tmpstr, " %s-%s", sq_to_string(f(*c2)), sq_to_string(t(*c2)));
+            strcat (str2, tmpstr);
+            while ((c2 - m2 < n2) && (f(*c1) > f(*c2) ||
+                                      (f(*c1) == f(*c2) && t(*c1) > t(*c2)))) {
+                c2++;
+            }
+            continue;
+        }
+        sprintf(tmpstr, " %s-%s", sq_to_string(f(*c1)), sq_to_string(t(*c1)));
+        strcat(str1, tmpstr);
+        strcat(str2, tmpstr);
+        c1++, c2++;
+    }
+    printf("F(%2d): %s\nM(%2d): %s\n", n1, str1, n2, str2);
+}
+
+static int usage(char *prg)
+{
+    fprintf(stderr, "Usage: %s [-cms][-d depth] [-p version] [-t size:\n", prg);
+    fprintf(stderr, "\t-c:         do *not* print FEN comments\n");
+    fprintf(stderr, "\t-d depth:   perft depth (default: 6)");
+    fprintf(stderr, "\t-m:         print moves details\n");
+    fprintf(stderr, "\t-s:         use Stockfish to validate perft result\n");
+    fprintf(stderr, "\t-t size:    Transposition Table size (Mb). Default: 32\n");
+    fprintf(stderr,
+            "\t-p flavor:  perft flavor, 1:perft, 2:perft_alt 3:both, default:1\n");
+    return 1;
+}
+
+int main(int ac, char**av)
+{
+    int curtest = 0;
+    u64 sf_count = 0, my_count;
+    bool comment = true, sf_run = false, moves_output = false;
+    char *fen;
+    pos_t *pos = NULL, *fenpos;
+    pos_t *fishpos = pos_new();
+    movelist_t fishmoves;
+    FILE *outfd = NULL;
+    s64 ms, lps;
+    int opt, depth = 6, run = 3, tt, newtt = HASH_SIZE_DEFAULT;
+    struct {
+        s64 count, countskipped, ms;
+        s64 minlps, maxlps;
+        int skipped;
+        int err;
+    } res[3] = {
+        { .minlps = LONG_MAX },
+        { .minlps = LONG_MAX },
+        { .minlps = LONG_MAX },
+    };
+
+    while ((opt = getopt(ac, av, "cd:mp:st:")) != -1) {
+        switch (opt) {
+            case 'c':
+                comment = false;
+                break;
+            case 'd':
+                depth = atoi(optarg);
+                if (depth <= 0)
+                    depth = 6;
+                break;
+            case 'm':
+                moves_output = false;
+                break;
+            case 'p':
+                run = atoi(optarg);
+                break;
+            case 's':
+                sf_run = true;
+                break;
+            case 't':
+                newtt = atoi(optarg);
+                break;
+            default:
+                    return usage(*av);
+        }
+    }
+
+    if (!run) {
+        printf("Nothing to do, exiting\n");
+        exit(0);
+    }
+
+    init_all();
+    tt = hash_tt.mb;
+
+    if (run & 1 && newtt != tt) {
+        tt_create(newtt);
+
+        printf("changing TT size from %d to %d\n", tt, newtt);
+        tt = newtt;
+    }
+    printf("%s: depth:%d tt_size:%d run:%x SF:%s\n",
+           *av,
+           depth, newtt, run,
+           sf_run? "yes": "no");
+
+    tt_info();
+    printf("\n");
+
+    if (sf_run)
+        outfd = open_stockfish();
+
+    CLOCK_DEFINE(clock, CLOCK_MONOTONIC);
+    while ((fen = next_fen(PERFT | MOVEDO))) {
+        if (!(fenpos = fen2pos(pos, fen))) {
+            printf("wrong fen line:%d fen:%s\n\n", cur_line(), fen);
+            continue;
+        }
+        curtest++;
+        printf("test:%d line:%d fen:%s\n", curtest, cur_line(), fen);
+        if (comment)
+            printf("\t\"%s\"\n",
+                   *cur_comment()? cur_comment(): "no test desc");
+
+        tt_clear();
+
+        pos = fenpos;
+        if (sf_run) {
+            stockfish_fen(outfd, fen);
+            clock_start(&clock);
+            sf_count = stockfish_perft(outfd, fishpos, &fishmoves, depth);
+            ms = clock_elapsed_ms(&clock);
+            if (!ms) {
+                res[2].skipped++;
+                res[2].countskipped += sf_count;
+                lps = 0;
+            } else {
+                lps = sf_count * 1000l / ms;
+                res[2].ms += ms;
+                res[2].count += sf_count;
+                if (lps > res[2].maxlps)
+                    res[2].maxlps = lps;
+                if (lps < res[2].minlps)
+                    res[2].minlps = lps;
+            }
+            printf("Stockfish : perft:%'lu ms:%'ld lps:%'lu\n",
+                   sf_count, ms, lps);
+        }
+
+        if (run & 1) {
+            clock_start(&clock);
+            my_count = perft(pos, depth, 1, moves_output);
+            ms = clock_elapsed_ms(&clock);
+            if (!ms) {
+                res[0].skipped++;
+                res[0].countskipped += my_count;
+                lps = 0;
+            } else {
+                lps = my_count * 1000l / ms;
+                res[0].ms += ms;
+                res[0].count += my_count;
+                if (lps > res[0].maxlps)
+                    res[0].maxlps = lps;
+                if (lps < res[0].minlps)
+                    res[0].minlps = lps;
+            }
+
+            if (!sf_run || sf_count == my_count) {
+                printf("perft     : perft:%'lu ms:%'ld lps:%'lu ",
+                       my_count, ms, lps);
+                tt_stats();
+            } else  {
+                printf("perft     : perft:%'lu ***ERROR***\n", my_count);
+                res[0].err++;
+            }
+        }
+
+        if (run & 2) {
+            clock_start(&clock);
+            my_count = perft_alt(pos, depth, 1, moves_output);
+            ms = clock_elapsed_ms(&clock);
+            if (!ms) {
+                res[1].skipped++;
+                res[1].countskipped += my_count;
+                lps = 0;
+            } else {
+                lps = my_count * 1000l / ms;
+                res[1].ms += ms;
+                res[1].count += my_count;
+                if (lps > res[1].maxlps)
+                    res[1].maxlps = lps;
+                if (lps < res[1].minlps)
+                    res[1].minlps = lps;
+            }
+
+            if (!sf_run || sf_count == my_count) {
+                printf("perft_alt : perft:%'lu ms:%'ld lps:%'lu\n",
+                       my_count, ms, lps);
+            } else  {
+                printf("perft_alt : perft:%'lu ***ERROR***\n", my_count);
+                res[1].err++;
+            }
+        }
+        printf("\n");
+    }
+    pos_del(pos);
+    if (sf_run) {
+        if (!res[2].ms)
+            res[2].ms = 1;
+        printf("total Stockfish : perft:%'lu ms:%'lu lps:%'lu min:%'lu max:%'lu "
+               "(skipped %d/%d)\n",
+               res[2].count + res[2].countskipped, res[2].ms,
+               res[2].count * 1000l / res[2].ms,
+               res[2].minlps, res[2].maxlps,
+               res[2].skipped, curtest);
+    }
+    if (run & 1) {
+        if (!res[0].ms)
+            res[0].ms = 1;
+        printf("total perft     : perft:%'lu ms:%'lu lps:%'lu min:%'lu max:%'lu "
+               "(pos:%d skipped:%d err:%d)\n",
+               res[0].count + res[0].countskipped, res[0].ms,
+               res[0].count * 1000l / res[0].ms,
+               res[0].minlps, res[0].maxlps,
+               curtest, res[0].skipped, res[0].err);
+    }
+    if (run & 2) {
+        if (!res[1].ms)
+            res[1].ms = 1;
+        printf("total perft_alt : perft:%'lu ms:%'lu lps:%'lu min:%'lu max:%'lu "
+               "(pos:%d skipped:%d err:%d)\n",
+               res[1].count + res[1].countskipped, res[1].ms,
+               res[1].count * 1000l / res[1].ms,
+               res[1].minlps, res[1].maxlps,
+               curtest, res[1].skipped, res[1].err);
+    }
+    return 0;
+}

test/piece-test.c

@@ -0,0 +1,20 @@
+#include <stdio.h>
+
+#include "brlib.h"
+
+#include "piece.h"
+
+int main(__unused int ac, __unused char**av)
+{
+
+    piece_t p;
+    char *test="PNBRQKpnbrqk";
+
+    for (u64 i = 0; i < sizeof(test); ++i) {
+        char c1 = test[i], *c2;
+        p = piece_from_fen(c1);
+        c2 = piece_to_fen(p);
+        printf("c1=%c c2=%c\n", c1, *c2);
+    }
+    return 0;
+}

test/piece.c

@@ -1,55 +0,0 @@
-#include <stdio.h>
-
-#include "debug.h"
-
-#include "../src/fen.h"
-#include "../src/position.h"
-#include "../src/bitboard.h"
-
-int main(int ac, char**av)
-{
-    pos_t *pos;
-    printf("zobi\n");fflush(stdout);
-    debug_init(6, stderr, true);
-    log_f(5, "kfsjdhg\n");
-    pos_pool_init();
-    pos = pos_get();
-    piece_pool_init();
-
-    if (ac == 1) {
-    printf("zoba\n");fflush(stdout);
-        pos_startpos(pos);
-    } else {
-        fen2pos(pos, av[1]);
-    }
-    pos_print(pos);
-    pos_pieces_print(pos);
-
-    printf("0x1c = 11100 = C1-E1:\n");
-    bitboard_print(0x1c);
-
-    printf("0x70 = 111 = A1-C1\n");
-    bitboard_print(0x70);
-
-    printf("0x0e = 1110 = B1-D1\n");
-    bitboard_print(0x0e);
-
-    printf("0x60 = 1100000 = F1-G1\n");
-    bitboard_print(0x60);
-
-    printf("A1:\n");
-    bitboard_print(A1);
-
-    printf("1:\n");
-    bitboard_print(1L);
-    printf("H1:\n");
-    bitboard_print(H1);
-    printf("C1:\n");
-    bitboard_print(C1);
-    printf("D1:\n");
-    bitboard_print(D1);
-    printf("C1|D1:\n");
-    bitboard_print(C1|D1);
-    printf("H8:\n");
-    bitboard_print(H8);
-}

test/tt-test.c

@@ -0,0 +1,118 @@
+/* tt-test.c - transposition table test.
+ *
+ * Copyright (C) 2024 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <unistd.h>
+#include <time.h>
+#include <locale.h>
+#include <limits.h>
+
+#include <brlib.h>
+
+#include "chessdefs.h"
+#include "fen.h"
+#include "position.h"
+#include "move.h"
+#include "move-do.h"
+#include "move-gen.h"
+#include "search.h"
+
+static void pr_entry(hentry_t *entry)
+{
+    if (!entry)
+        printf("entry: NULL\n");
+    else {
+        printf("entry: key=%lx depth=%d n=%lu\n",
+               entry->key, HASH_PERFT_DEPTH(entry->data),
+               HASH_PERFT_VAL(entry->data));
+    }
+}
+
+int main()
+{
+    pos_t *pos = NULL;
+    char *token, *str, buf[128];
+    hentry_t *entry;
+    move_t move;
+    state_t state;
+    movelist_t movelist;
+
+    const char *moves_array[] = {
+        "e2e4 e7e5 g1f3 b8c6",
+        "e2e4 b8c6 g1f3 e7e5"
+    };
+
+    init_all();
+
+    for (uint i = 0; i < ARRAY_SIZE(moves_array); ++i) {
+        int depth = 0;
+        str = strdup(moves_array[i]);
+        printf("%2d: ", i + 1);
+
+        pos = startpos(pos);
+        entry = tt_store_perft(pos->key, 0, 123 + depth);
+        pr_entry(entry);
+        token = strtok(str, " \t");
+        while (token) {
+            depth++;
+            printf("%s ", token);
+
+            move = move_from_str(token);
+            pos_set_checkers_pinners_blockers(pos);
+            pos_legal(pos, pos_gen_pseudo(pos, &movelist));
+            printf("move: %s\n", move_to_str(buf, move, 0));
+            move =  move_find_in_movelist(move, &movelist);
+            if (move != MOVE_NONE) {
+                move_do(pos, move, &state);
+                if ((entry = tt_probe_perft(pos->key, depth))) {
+                    printf("tt hit: depth=%d val=%lu",
+                           HASH_PERFT_DEPTH(entry->data),
+                           HASH_PERFT_VAL(entry->data));
+                } else {
+                    tt_store_perft(pos->key, i + 1, depth);
+                    printf("tt store: depth=%d val=%lu", depth, (u64)i * 123);
+                };
+            }
+
+            token = strtok(NULL, " \t");
+        }
+        printf("\n");
+        free(str);
+    }
+    return 0;
+}
+
+/* ccls bug report: https://github.com/emacs-lsp/emacs-ccls/issues/126
+ */
+/*
+ * int called(int), caller();
+ *
+ * /\**
+ *  * called() - test ccls.
+ *  * @x: int, the test value
+ *  *
+ *  * @called() description.
+ *  *
+ *  * @return: int, a very interesting value.
+ *  *\/
+ * int called(int x) { return x; }
+ *
+ * int caller()
+ * {
+ *     int i = 0;
+ *     called(int x)
+ *     return i;
+ * }
+ */