From 022daf0a89423cdcce3d47dc0bebfd2d8a7fbd45 Mon Sep 17 00:00:00 2001
From: Bruno Raoult <braoult@gmail.com>
Date: Wed, 15 May 2024 09:42:33 +0200
Subject: [PATCH] typedef key -> #define key_t - can't use typedef, due to
 <sys/types.h>

---
 Makefile       |  2 +-
 src/hash.c     |  4 ++--
 src/hash.h     | 17 +++++++++++++----
 src/move-do.c  | 14 ++++++++++++--
 src/position.h |  8 +++++---
 5 files changed, 33 insertions(+), 12 deletions(-)

diff --git a/Makefile b/Makefile
index bae6a13..0928bf6 100644
--- a/Makefile
+++ b/Makefile
@@ -346,7 +346,7 @@ FEN_OBJS      := $(PIECE_OBJS) fen.o position.o bitboard.o board.o \
 BB_OBJS       := $(FEN_OBJS)
 MOVEGEN_OBJS  := $(BB_OBJS) move.o move-gen.o
 ATTACK_OBJS   := $(MOVEGEN_OBJS)
-MOVEDO_OBJS   := $(ATTACK_OBJS) move-do.o
+MOVEDO_OBJS   := $(ATTACK_OBJS) move-do.o hash.o
 PERFT_OBJS    := $(MOVEDO_OBJS) search.o misc.o
 
 TEST          := $(addprefix $(BINDIR)/,$(TEST))
diff --git a/src/hash.c b/src/hash.c
index 6ca0e0b..befa61c 100644
--- a/src/hash.c
+++ b/src/hash.c
@@ -59,9 +59,9 @@ void zobrist_init(void)
  * - To verify incremental Zobrist calculation is correct
  *
  */
-key zobrist_calc(pos_t *pos)
+key_t zobrist_calc(pos_t *pos)
 {
-    key key = 0;
+    key_t key = 0;
 
     if (pos->turn == BLACK)
         key ^= zobrist_turn;
diff --git a/src/hash.h b/src/hash.h
index 9fc014f..76cc880 100644
--- a/src/hash.h
+++ b/src/hash.h
@@ -24,7 +24,7 @@
 #define HASH_SIZE_MIN        4
 #define HASH_SIZE_MAX    32768                    /* 32Gb */
 
-typedef u64 key;
+#define key_t u64                                 /* cannot use typedef for key_t */
 
 /**
  * hentry_t: hashtable bucket.
@@ -33,7 +33,7 @@ typedef u64 key;
  * 16 bytes in future, it should be updated to be exactly 32 bytes.
  */
 typedef struct {
-    key key;                                      /* zobrist */
+    key_t key;                                    /* zobrist */
     union {
         u64 data;
         struct {
@@ -81,9 +81,18 @@ typedef struct {
  */
 #define EP_ZOBRIST_IDX(ep) ( ( (ep) >> 3 ) | sq_file(ep) )
 
+extern key_t zobrist_pieces[16][64];
+extern key_t zobrist_castling[4 * 4 + 1];
+extern key_t zobrist_turn;                        /* for black, XOR each ply */
+extern key_t zobrist_ep[9];                       /* 0-7: ep file, 8: SQUARE_NONE */
+
+extern hasht_t hash_tt;                           /* main transposition table */
+
 void zobrist_init(void);
+key_t zobrist_calc(pos_t *pos);
+
 int hash_create(int Mb);
-void hash_clear();
-void hash_delete();
+void hash_clear(void);
+void hash_delete(void);
 
 #endif  /* HASH_H */
diff --git a/src/move-do.c b/src/move-do.c
index fe62ea2..6a27021 100644
--- a/src/move-do.c
+++ b/src/move-do.c
@@ -23,6 +23,7 @@
 #include "move.h"
 #include "position.h"
 #include "move-do.h"
+#include "hash.h"
 
 /**
  * move_do() - do move.
@@ -39,8 +40,12 @@
  *   - castling
  *   - en-passant
  * - captured piece (excl. en-passant)
+ * - tt hash values are updated for:
+ *   - side-to-move
+ *   - en-passant
+ *   - castling rights.
  *
- * @return: pos.
+ * @return: updated pos.
  */
 pos_t *move_do(pos_t *pos, const move_t move) //, state_t *state)
 {
@@ -57,6 +62,9 @@ pos_t *move_do(pos_t *pos, const move_t move) //, state_t *state)
     piece_t new_piece = piece;
     int up = sq_up(us);
 
+    /* update turn, reset castling and ep */
+    pos->key ^= zobrist_turn;
+
     ++pos->clock_50;
     ++pos->plycount;
     pos->en_passant = SQUARE_NONE;
@@ -119,7 +127,8 @@ pos_t *move_do(pos_t *pos, const move_t move) //, state_t *state)
         else if (from == rel_h1)
             pos->castle = clr_oo(pos->castle, us);
     }
-    if (can_castle(pos->castle, them)) {          /* do we save time with this test ? */
+
+    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)
@@ -128,6 +137,7 @@ pos_t *move_do(pos_t *pos, const move_t move) //, state_t *state)
             pos->castle = clr_oo(pos->castle, them);
     }
 
+
     return pos;
 }
 
diff --git a/src/position.h b/src/position.h
index c859188..3885710 100644
--- a/src/position.h
+++ b/src/position.h
@@ -16,11 +16,12 @@
 
 #include <stdint.h>
 
-#include "brlib.h"
-#include "bitops.h"
-#include "struct-group.h"
+#include <brlib.h>
+#include <bitops.h>
+#include <struct-group.h>
 
 #include "chessdefs.h"
+#include "hash.h"
 #include "bitboard.h"
 #include "piece.h"
 #include "move.h"
@@ -41,6 +42,7 @@ typedef struct __pos_s {
      * This allows a memcpy on this data (to save/restore position state).
      */
     struct_group_tagged(state_s, state,
+                        key_t key;
                         square_t en_passant;
                         castle_rights_t castle;
                         int clock_50;