cleanup

Makefile

@@ -205,7 +205,7 @@ cleanobjdir: cleanobj
 # "normal" ones, but do not imply to rebuild target.
 $(OBJDIR)/%.o: $(SRCDIR)/%.c | $(OBJDIR) $(DEPDIR)
 	@echo compiling brchess module: $< "->" $@.
-	$(CC) -c $(ALL_CFLAGS) $< -o $@
+	@$(CC) -c $(ALL_CFLAGS) $< -o $@
 
 ##################################### brlib libraries
 .PHONY: cleanbrlib cleanallbrlib brlib
@@ -231,7 +231,7 @@ cleanbindir:
 	$(call rmdir,$(BINDIR),binaries)
 
 $(TARGET): libs $(OBJ) | $(BINDIR)
-	@echo generating $@ executable.
+	@echo generating $@.
 	$(CC) $(LDFLAGS) $(OBJ) $(LIBS) -o $@
 
 ##################################### pre-processed (.i) and assembler (.s) output
@@ -241,11 +241,11 @@ 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 $@
+	@echo generating $@ (asm).
 	@$(CC) -S -fverbose-asm $(CPPFLAGS) $(CFLAGS) $< -o $@
 
 ##################################### LSP (ccls)

src/bitboard.c

@@ -25,6 +25,7 @@ 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];
 
@@ -139,6 +140,24 @@ void bitboard_init(void)
         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];
+
+                //if (bb_line[sq1][sq2]) {
+                //    printf("bb_line[%d][%d] = %16lx\n", sq1, sq2, bb_line[sq1][sq2]);
+                //}
+            }
+        }
+    }
 
     /* 3) knight and king moves */
     for (square_t sq = A1; sq <= H8; ++sq) {

src/bitboard.h

@@ -21,8 +21,6 @@
 #include "board.h"
 #include "piece.h"
 
-//typedef u64 bitboard_t;
-
 /* mapping square -> bitboard */
 extern bitboard_t bb_sq[64];
 /* squares between sq1 and sq2, exclusing both */
@@ -30,12 +28,17 @@ extern bitboard_t bb_between_excl[64][64];
 /* squares between sq1 and sq2, including sq2 */
 extern bitboard_t bb_between[64][64];
 
-/* bb_sqrank[64]: square to rank
+/**
+ * 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];
+
+/* line (rank, file, diagonal or anti-diagonal) between two squares */
+extern bitboard_t bb_line[64][64];
+
 /* knight and king moves */
 extern bitboard_t bb_knight[64], bb_king[64];
 
@@ -192,17 +195,24 @@ static __always_inline bitboard_t bb_file(int file)
 
 /**
  * bb_sq_aligned() - check if two squares are aligned (same file or rank).
- * @sq1:  square 1
- * @sq2:  square 2
+ * @sq1, @sq2:  the two squares.
  *
- * @sq2 is included in return value, to be non zero if the two squares
- * are neighbors.
- *
- * @return: bitboard of squares between @sq1 and @sq2, including @sq2.
+ * @return: true if @sq1 and @sq2 are on same line, false otherwise.
  */
-static __always_inline bitboard_t bb_sq_aligned(square_t sq1, square_t sq2)
+static __always_inline bool bb_sq_aligned(square_t sq1, square_t sq2)
 {
-    return bb_between[sq1][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] & mask(sq3);
 }
 
 /**

src/board.h

@@ -59,14 +59,28 @@ static __always_inline rank_t sq_rank(square_t square)
 #define sq_ok(sq)       ((sq) >= A1 && (sq) <= H8)
 #define sq_coord_ok(c)  ((c) >= 0 && (c) < 8)
 
-/* Chebyshev distance: max( |r2 - r1|, |f2 - f1| )
+/**
+ * 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 sq_dist(sq1, sq2) (max(abs(sq_file(sq2) - sq_file(sq1)),  \
                                abs(sq_rank(sq2) - sq_rank(sq1))))
-/* Manhattan distance: |r2 - r1| + |f2 - f1|
+
+/**
+ * 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 sq_manh(sq1, sq2) (abs(sq_file(sq2) - sq_file(sq1)) +     \
+#define sq_taxi(sq1, sq2) (abs(sq_file(sq2) - sq_file(sq1)) +     \
                            abs(sq_rank(sq2) - sq_rank(sq1)))
 
 extern const char *sq_to_string(const square_t sq);

src/hyperbola-quintessence.c

@@ -86,15 +86,16 @@ void hyperbola_init()
 }
 
 /**
- * hyperbola_rank_moves() - generate rank moves for a sliding piece.
+ * hyperbola_rank_moves() - get rank moves for a sliding piece.
  * @pieces: occupation bitboard
  * @sq: piece square
  *
- * Rank attacks are not handled by HQ, so we do it with a
+ * Rank attacks are not handled by HQ, so this function uses a pre-calculated
+ * rank attacks table (@bb_rank_attacks).
  *
- * @Return: The moves mask for piece
+ * @Return: bitboard of @piece available pseudo-moves.
  */
-static bitboard_t hyperbola_rank_moves(bitboard_t occ, square_t sq)
+bitboard_t hyperbola_rank_moves(bitboard_t occ, square_t sq)
 {
     u32 rank = sq & SQ_RANKMASK;
     u32 file = sq & SQ_FILEMASK;
@@ -109,16 +110,19 @@ static bitboard_t hyperbola_rank_moves(bitboard_t occ, square_t sq)
 }
 
 /**
- * hyperbola_moves() - generate hyperbola moves mask for a given sliding piece
+ * hyperbola_moves() - get hyperbola pseudo-moves for a sliding piece
  * @pieces: occupation bitboard
  * @sq: piece square
- * @mask: mask considered
+ * @mask: the appropriate mask (pre-calculated)
  *
- * See https://www.chessprogramming.org/Hyperbola_Quintessence
+ * 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: The moves mask for piece
+ * @Return: bitboard of piece available pseudo-moves.
  */
-static bitboard_t hyperbola_moves(const bitboard_t pieces, const square_t sq,
+bitboard_t hyperbola_moves(const bitboard_t pieces, const square_t sq,
                                    const bitboard_t mask)
 {
     bitboard_t o = pieces & mask;
@@ -130,32 +134,77 @@ static bitboard_t hyperbola_moves(const bitboard_t pieces, const square_t sq,
         & mask;
 }
 
-static bitboard_t hyperbola_file_moves(bitboard_t occ, square_t sq)
+/**
+ * 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]);
 }
 
-static bitboard_t hyperbola_diag_moves(bitboard_t occ, square_t 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]);
 }
 
-static bitboard_t hyperbola_anti_moves(bitboard_t occ, square_t 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]);
 }
 
-bitboard_t hyperbola_bishop_moves(bitboard_t occ, square_t 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);
 }
 
-bitboard_t hyperbola_rook_moves(bitboard_t occ, square_t 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);
 }
 
-bitboard_t hyperbola_queen_moves(bitboard_t occ, square_t 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

@@ -17,9 +17,17 @@
 #include "board.h"
 #include "bitboard.h"
 
-void hyperbola_init(void);
-extern bitboard_t hyperbola_bishop_moves(bitboard_t occ, square_t sq);
-extern bitboard_t hyperbola_rook_moves(bitboard_t occ, square_t sq);
-extern bitboard_t hyperbola_queen_moves(bitboard_t occ, square_t sq);
+extern void hyperbola_init(void);
+
+extern bitboard_t hyperbola_rank_moves(const bitboard_t occ, const square_t sq);
+extern bitboard_t hyperbola_moves(const bitboard_t pieces, const square_t sq,
+                                  const bitboard_t mask);
+extern bitboard_t hyperbola_file_moves(const bitboard_t occ, const square_t sq);
+extern bitboard_t hyperbola_diag_moves(const bitboard_t occ, const square_t sq);
+extern bitboard_t hyperbola_anti_moves(const bitboard_t occ, const square_t sq);
+
+extern bitboard_t hyperbola_bishop_moves(const bitboard_t occ, const square_t sq);
+extern bitboard_t hyperbola_rook_moves(const bitboard_t occ, const square_t sq);
+extern bitboard_t hyperbola_queen_moves(const bitboard_t occ, const square_t sq);
 
 #endif  /* _HYPERBOLA_QUINTESSENCE_H */

src/move-gen.c

@@ -27,18 +27,6 @@
 #include "move-gen.h"
 
 
-/**
- * gen_castle() - generate c
- * @pos: position
- *
- * Generate all pseudo pawn pushes.
- */
-//int gen_pawn_push(pos_t *pos, bitboard_t occ)
-//{
-
-
-//}
-
 /**
  * pseudo_is_legal() - check if a move is legal.
  * @pos:  position
@@ -47,10 +35,11 @@
  * We check all possible invalid moves:
  * (1) King:
  *  - K moves to a controlled square
- *  - Castling:
+ * (1) Castling:
  *  - K passes a controlled square   - already done in pseudomove gen
  *
- * (2) En-passant:
+ *
+ * (3) En-passant:
  *  - pinned taking pawn, done in (3)
  *  - taking and taken pawn on same rank than king, discovered check on rank
  *
@@ -103,10 +92,21 @@ bool pseudo_is_legal(pos_t *pos, move_t move)
  * gen_all_pseudomoves() - generate all pseudo moves
  * @pos: position
  *
- * Generate all moves, no check is done on validity due to castle rules,
- * or check (pinned pieces, etc...).
+ * Generate all @pos pseudo moves for player-to-move.
+ * The @pos->moves table is filled with the moves.
  *
- * @return: The number of 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}
+ *  - pawn capture (incl. en-passant): M_CAPTURE
+ *  - promotion: M_PROMOTION
+ *  - promotion and capture
+ *
+ * TODO: move code to specific functions (especially castling, pawn push/capture)
+ *
+ * @Return: The total number of moves.
  */
 int gen_all_pseudomoves(pos_t *pos)
 {
@@ -127,7 +127,7 @@ int gen_all_pseudomoves(pos_t *pos)
 
     int from, to;
 
-    /* king */
+    /* king - MUST BE FIRST ! */
     from = pos->king[us];
     movebits = bb_king_moves(not_my_pieces, from);
     bit_for_each64(to, tmp2, movebits) {
@@ -187,11 +187,28 @@ int gen_all_pseudomoves(pos_t *pos)
         //printf("push %d->%d %s->%s", from, to, sq_to_string(from), sq_to_string(to));
         moves[nmoves++] = move_make(from, to);
     }
+    /* possible second push */
     movebits = pawn_shift_up(movebits & rel_rank3, us) & empty;
     bit_for_each64(to, tmp1, movebits) {
         from = pawn_push_up(pawn_push_up(to, them), them);
         moves[nmoves++] = move_make(from, to);
     }
+
+    /* pawn: ranks 2-6 captures left, including en-passant */
+    from_pawns = pos->bb[us][PAWN] & ~rel_rank7; // & ~rel_filea;
+    movebits = pawn_shift_upleft(from_pawns, us) & enemy_avail;
+    bit_for_each64(to, tmp1, movebits) {
+        from = pawn_push_upleft(to, them);         /* reverse capture */
+        moves[nmoves++] = move_make_capture(from, to);
+    }
+    /* pawn: ranks 2-6 captures right, including en-passant */
+    from_pawns = pos->bb[us][PAWN] & ~rel_rank7; // & ~rel_fileh;
+    movebits = pawn_shift_upright(from_pawns, us) & enemy_avail;
+    bit_for_each64(to, tmp1, movebits) {
+        from = pawn_push_upright(to, them);
+        moves[nmoves++] = move_make_capture(from, to);
+    }
+
     /* pawn: rank 7 push */
     movebits = pawn_shift_up(pos->bb[us][PAWN] & rel_rank7, us) & empty;
     bit_for_each64(to, tmp1, movebits) {
@@ -201,44 +218,28 @@ int gen_all_pseudomoves(pos_t *pos)
         moves[nmoves++] = move_make_promote(from, to, BISHOP);
         moves[nmoves++] = move_make_promote(from, to, KNIGHT);
     }
-
-    /* pawn: ranks 2-6 captures left, including en-passant */
-    from_pawns = pos->bb[us][PAWN] & ~rel_rank7; // & ~rel_filea;
-    movebits = pawn_shift_upleft(from_pawns, us) & enemy_avail;
-    bit_for_each64(to, tmp1, movebits) {
-        from = pawn_push_upleft(to, them);         /* reverse capture */
-        moves[nmoves++] = move_make(from, to);
-    }
-    /* pawn: rank 7 captures left */
+    /* pawn promotion: rank 7 captures left */
     from_pawns = pos->bb[us][PAWN] & rel_rank7; // & ~rel_filea;
     movebits = pawn_shift_upleft(from_pawns, us) & enemy_avail;
     bit_for_each64(to, tmp1, movebits) {
         from = pawn_push_upleft(to, them);         /* reverse capture */
-        moves[nmoves++] = move_make_promote(from, to, QUEEN);
-        moves[nmoves++] = move_make_promote(from, to, ROOK);
-        moves[nmoves++] = move_make_promote(from, to, BISHOP);
-        moves[nmoves++] = move_make_promote(from, to, KNIGHT);
-    }
-
-    /* pawn: ranks 2-6 captures right, including en-passant */
-    from_pawns = pos->bb[us][PAWN] & ~rel_rank7; // & ~rel_fileh;
-    movebits = pawn_shift_upright(from_pawns, us) & enemy_avail;
-    bit_for_each64(to, tmp1, movebits) {
-        from = pawn_push_upright(to, them);
-        moves[nmoves++] = move_make(from, to);
+        moves[nmoves++] = move_make_promote_capture(from, to, QUEEN);
+        moves[nmoves++] = move_make_promote_capture(from, to, ROOK);
+        moves[nmoves++] = move_make_promote_capture(from, to, BISHOP);
+        moves[nmoves++] = move_make_promote_capture(from, to, KNIGHT);
     }
     /* pawn: rank 7 captures right */
     from_pawns = pos->bb[us][PAWN] & rel_rank7; // & ~rel_fileh;
     movebits = pawn_shift_upright(from_pawns, us) & enemy_pieces;
     bit_for_each64(to, tmp1, movebits) {
         from = pawn_push_upright(to, them);         /* reverse capture */
-        moves[nmoves++] = move_make_promote(from, to, QUEEN);
-        moves[nmoves++] = move_make_promote(from, to, ROOK);
-        moves[nmoves++] = move_make_promote(from, to, BISHOP);
-        moves[nmoves++] = move_make_promote(from, to, KNIGHT);
+        moves[nmoves++] = move_make_promote_capture(from, to, QUEEN);
+        moves[nmoves++] = move_make_promote_capture(from, to, ROOK);
+        moves[nmoves++] = move_make_promote_capture(from, to, BISHOP);
+        moves[nmoves++] = move_make_promote_capture(from, to, KNIGHT);
     }
 
-    /* castle - Attention ! We consider that castle flags are correct,
+    /* castle - Attention ! Castling flags are assumed correct
      */
     if (!pos->checkers) {
         bitboard_t rel_rank1 = BB_REL_RANK(RANK_1, us);

src/move.h

@@ -20,49 +20,51 @@
 
 /* move structure:
  * 3      2 2    1 1 1 1 1 1
- * 1     5 4     8 7 5 4 2 1    6 5    0
- * UUUUUUU FFFFFFF ppp ccc tttttt ffffff
+ * 1      5 3    8 7 5 4 2 1    6 5    0
+ * UUUUUUUU FFFFFF ppp ccc tttttt ffffff
  *
- * bits    range         type     mask        get   desc
- * ffffff    0-5     square_t       3f        &63   from
- * tttttt   6-11     square_t      fc0   (>>6)&63   to
- * ccc     12-14 piece_type_t     7000   (>>12)&7   captured
- * ppp     15-17 piece_type_t    38000   (>>15)&7   promoted
- * FFFFFFF 18-24          N/A  1fc0000        N/A   flags
- * UUUUUUU 25-31       unused fe000000        N/A   future usage ?
+ * bits    len  range           type       mask        get   desc
+ * ffffff    6    0-5       square_t         3f        &63   from
+ * tttttt    6   6-11       square_t        fc0   (>>6)&63   to
+ * ccc       3  12-14   piece_type_t       7000   (>>12)&7   captured
+ * ppp       3  15-17   piece_type_t      38000   (>>15)&7   promoted
+ * FFFFFF    6  18-23   move_flags_t     fc0000        N/A   flags
+ * UUUUUUUU  8  24-31         unused   fe000000        N/A   future usage ?
  */
-#define move_t u32
+typedef u32 move_t;
 
-/* move flags */
-#define M_FLAGS_BEG 18
-#define M_HAS_FLAGS mask(M_FLAGS_BEG + 0)         /* probably unused */
-#define M_CAPTURE   mask(M_FLAGS_BEG + 1)
-#define M_EPASSANT  mask(M_FLAGS_BEG + 2)
-#define M_PROMOTE   mask(M_FLAGS_BEG + 3)
-#define M_CASTLE_K  mask(M_FLAGS_BEG + 4)
-#define M_CASTLE_Q  mask(M_FLAGS_BEG + 5)
-#define M_CHECK     mask(M_FLAGS_BEG + 6)         /* probably unknown/useless */
-
-#define M_FLAGS     (M_CAPTURE | M_ENPASSANT | M_PROMOTION | \
-                     M_CASTLE_K | M_CASTLE_Q | M_CHECK)
-#define M_NORMAL    (~M_FLAGS)
+typedef enum {
+    M_START     = 18,
+    M_CAPTURE   = (1 << (M_START + 0)),
+    M_ENPASSANT = (1 << (M_START + 1)),
+    M_PROMOTION = (1 << (M_START + 2)),
+    M_CASTLE_K  = (1 << (M_START + 3)),           /* maybe only one ? */
+    M_CASTLE_Q  = (1 << (M_START + 4)),           /* maybe only one ? */
+    M_CHECK     = (1 << (M_START + 5))            /* maybe unknown/useless ? */
+} move_type_t;
 
 #define MOVES_MAX   256
 
-static inline move_t move_make(square_t from, square_t to)
-{
-    return (to << 6) | from;
-}
+typedef struct __movelist_s {
+    move_t move[MOVES_MAX];
+    int nmoves;                                   /* total moves (fill) */
+    int curmove;                                  /* current move (use) */
+} movelist_t;
 
-static inline move_t move_make_flags(square_t from, square_t to, int flags)
-{
-    return move_make(from, to) | flags;
-}
 
-static inline move_t move_make_promote(square_t from, square_t to, piece_type_t piece)
-{
-    return move_make(from, to) | M_PROMOTE | (piece << 15);
-}
+/* move flags */
+//#define M_FLAGS_BEG 18
+//#define M_HAS_FLAGS mask(M_FLAGS_BEG + 0)       /* probably useless */
+//#define M_CAPTURE     mask(M_FLAGS_BEG + 0)
+//#define M_EN_PASSANT  mask(M_FLAGS_BEG + 1)
+//#define M_PROMOTION   mask(M_FLAGS_BEG + 2)
+//#define M_CASTLE_K    mask(M_FLAGS_BEG + 3)       /* maybe only one ? */
+//#define M_CASTLE_Q    mask(M_FLAGS_BEG + 4)       /* maybe only one ? */
+//#define M_CHECK       mask(M_FLAGS_BEG + 5)       /* probably unknown/useless */
+
+//#define M_FLAGS     (M_CAPTURE | M_ENPASSANT | M_PROMOTION |
+//                     M_CASTLE_K | M_CASTLE_Q | M_CHECK)
+//#define M_NORMAL    (~M_FLAGS)
 
 static inline square_t move_from(move_t move)
 {
@@ -73,6 +75,43 @@ static inline square_t move_to(move_t move)
     return (move >> 6) & 077;
 }
 
+static inline piece_t move_promoted(move_t move)
+{
+    return (move >> 15) & 07;
+}
+
+static inline piece_t move_captured(move_t move)
+{
+    return (move >> 12) & 07;
+}
+
+static inline move_t move_make(square_t from, square_t to)
+{
+    return (to << 6) | from;
+}
+
+static inline move_t move_make_flags(square_t from, square_t to, move_type_t flags)
+{
+    return 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_promote(square_t from, square_t to,
+                                       piece_type_t promoted)
+{
+    return move_make_flags(from, to, M_PROMOTION) | (promoted << 15);
+}
+
+static inline move_t move_make_promote_capture(square_t from, square_t to,
+                                               piece_type_t promoted)
+{
+    return move_make_flags(from, to, M_CAPTURE | M_PROMOTION) | (promoted << 15);
+}
+
 /* moves_print flags
  */
 #define M_PR_CAPT      0x01
@@ -83,12 +122,6 @@ static inline square_t move_to(move_t move)
 #define M_PR_SEPARATE  0x40                       /* separate captures */
 #define M_PR_LONG      0x80
 
-typedef struct __movelist_s {
-    move_t move[MOVES_MAX];
-    int nmoves;                                   /* total moves (fill) */
-    int curmove;                                  /* current move (use) */
-} movelist_t;
-
 //pool_t *moves_pool_init();
 //void moves_pool_stats();
 

src/position.c

@@ -147,41 +147,41 @@ bitboard_t pos_pinners(const pos_t *pos, const color_t color)
 }
 
 /**
- * pos_check() - extensive position consistenci check.
+ * pos_check() - extensive position consistency check.
  * @pos:    &position
- * @strict: if not zero, call bug_on() on any error.
+ * @strict: if true, call bug_on() on any error.
  *
- * Check (hopefully) if position is valid:
- * - pawns on first or 8th rank
- * - number of pawns per color > 8
- * - total number of pieces per color > 16 or zero
- * - number of kings per color != 1
- * - discrepancy between bitboards per piece and ALL_PIECES per color
- * - discrepancy between bitboards and board
- * - side-to-move already checking opponent king.
- * - side to move in check more than twice
+ * 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 piece bitboards and ALL_PIECES bitboards (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
  *
- * In case of errors, and @abort is true, @bug_on() is called, and program will
+ * In case of errors, and @strict is true, @bug_on() is called, and program will
  * be terminated.
- * This function should be called with @abort == 0 during initialization phase
- * (eg after fen parsing), and with @abort != 0 otherwise (as we have some data
+ * 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).
  *
  * TODO: add more checks:
  * - kings attacking each other
  *
- * @Return: 0 if no error detected
- *          the number of detected error if @abort == 0.
- *          this function does not return if @abort != 0 and errors are found.
+ * @Return: Number of detected error (only if @strict is false).
  */
-int pos_check(const pos_t *pos, const int fatal)
+int pos_check(const pos_t *pos, const bool strict)
 {
     int n, count = 0, bbcount = 0, error = 0;
+    bitboard_t tmp;
 
     /* pawns on 1st ot 8th rank */
-    n = popcount64((pos->bb[WHITE][PAWN] | pos->bb[BLACK][PAWN]) &
-                   (RANK_1bb | RANK_8bb));
-    error += warn_on(n != 0);
+    tmp = (pos->bb[WHITE][PAWN] | pos->bb[BLACK][PAWN]) & (RANK_1bb | RANK_8bb);
+    error += warn_on(tmp);
 
     for (color_t color = WHITE; color <= BLACK; ++color) {
         /* pawn count */
@@ -190,6 +190,8 @@ int pos_check(const pos_t *pos, const int fatal)
         /* 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);
@@ -212,8 +214,10 @@ int pos_check(const pos_t *pos, const int fatal)
     error += warn_on(pos_checkers(pos, OPPONENT(pos->turn)));
     /* is color to play in check more than twice ? */
     error += warn_on(popcount64(pos_checkers(pos, OPPONENT(pos->turn))) > 2);
+    /* kings distance is less than 2 */
+    error += warn_on(sq_dist(pos->king[WHITE], pos->king[BLACK]) < 2);
 
-    bug_on(fatal && error);
+    bug_on(strict && error);
     return error;
 }
 

src/position.h

@@ -144,7 +144,7 @@ extern bitboard_t pos_pinners(const pos_t *pos, const color_t color);
 //extern char *pos_checkers2str(const pos_t *pos, char *str);
 //extern char *pos_pinners2str(const pos_t *pos, char *str);
 
-extern int pos_check(const pos_t *pos, const int strict);
+extern int pos_check(const pos_t *pos, const bool strict);
 
 extern void pos_print(const pos_t *pos);
 extern void pos_print_mask(const pos_t *pos, const bitboard_t mask);

test/attack-test.c

@@ -0,0 +1,50 @@
+/* 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();
+
+    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_print(pos);
+
+        pos_del(pos);
+        i++;
+    }
+    return 0;
+}

test/common-test.h

@@ -61,10 +61,6 @@ struct fentest {
       "checkers: g2 g7",
       "8/6R1/8/6k1/8/8/K5R1/8 b - - 1 1"
     },
-    { ATTACK,
-      "checkers: d5 e3, pinners: a1 h1 a4 h5",
-      "3k4/8/8/3r3b/b7/1N2n3/4B3/rN1K1R1r w - - 1 0"
-    },
     { ATTACK,
       "checkers: d5 e3, pinners: none (2 pieces between attacker & K)",
       "3k4/8/8/3r3b/b7/1N2nn2/2n1B3/rNBK1Rbr w - - 1 1"

test/movegen-test.c

@@ -207,7 +207,6 @@ int main(int __unused ac, __unused char**av)
             continue;
         }
         pos_print(pos);
-
         /* print movelists */
         send_stockfish_fen(outfd, fishpos, fen);
         gen_all_pseudomoves(pos);