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Ole Morud
2025-12-09 02:34:33 +01:00
parent fe2e026f1e
commit 25705d6cd6
4 changed files with 701 additions and 395 deletions
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748
base.h
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@@ -51,7 +51,6 @@ ULL
#define BITBOARD_FMT PRIu64
#define BITBOARD_FMT_X PRIx64
typedef uint64_t index;
#define INDEX(n) n##ULL
#define INDEX_FMT PRIu64
@@ -65,9 +64,9 @@ typedef uint64_t index;
#define RANK_MASK(n) RANK_SHIFT_UP((index)0x00000000000000FFULL, n)
#define INDEX_FROM_RF(rank, file) ((index)(8ULL*(index)(rank) + (index)(file)))
#define SQUARE_MASK_FROM_RF(rank, file) ((index)1ULL << INDEX_FROM_RF(rank,file))
#define SQ_MASK_FROM_RF(rank, file) ((index)1ULL << INDEX_FROM_RF(rank,file))
#define SQUARE_MASK_FROM_INDEX(idx) (1ULL<<(idx))
#define SQ_MASK_FROM_INDEX(idx) (1ULL<<(idx))
enum file_index : index {
FILE_INDEX_BEGIN,
@@ -95,48 +94,9 @@ enum rank_index : index {
RANK_INDEX_COUNT,
};
enum : bitboard {
FILEMASK_A = FILE_MASK(FILE_INDEX_A),
FILEMASK_B = FILE_MASK(FILE_INDEX_B),
FILEMASK_C = FILE_MASK(FILE_INDEX_C),
FILEMASK_D = FILE_MASK(FILE_INDEX_D),
FILEMASK_E = FILE_MASK(FILE_INDEX_E),
FILEMASK_F = FILE_MASK(FILE_INDEX_F),
FILEMASK_G = FILE_MASK(FILE_INDEX_G),
FILEMASK_H = FILE_MASK(FILE_INDEX_H),
RANKMASK_1 = RANK_MASK(RANK_INDEX_1),
RANKMASK_2 = RANK_MASK(RANK_INDEX_2),
RANKMASK_3 = RANK_MASK(RANK_INDEX_3),
RANKMASK_4 = RANK_MASK(RANK_INDEX_4),
RANKMASK_5 = RANK_MASK(RANK_INDEX_5),
RANKMASK_6 = RANK_MASK(RANK_INDEX_6),
RANKMASK_7 = RANK_MASK(RANK_INDEX_7),
RANKMASK_8 = RANK_MASK(RANK_INDEX_8),
FILE_SHIFT_RIGHT_GUARD_0 = ~0ULL,
FILE_SHIFT_RIGHT_GUARD_1 = ~FILEMASK_H,
FILE_SHIFT_RIGHT_GUARD_2 = ~(FILEMASK_G | FILEMASK_H),
FILE_SHIFT_RIGHT_GUARD_3 = ~(FILEMASK_F | FILEMASK_G | FILEMASK_H),
FILE_SHIFT_RIGHT_GUARD_4 = ~(FILEMASK_E | FILEMASK_F | FILEMASK_G | FILEMASK_H),
FILE_SHIFT_RIGHT_GUARD_5 = ~(FILEMASK_D | FILEMASK_E | FILEMASK_F | FILEMASK_G | FILEMASK_H),
FILE_SHIFT_RIGHT_GUARD_6 = ~(FILEMASK_C | FILEMASK_D | FILEMASK_E | FILEMASK_F | FILEMASK_G | FILEMASK_H),
FILE_SHIFT_RIGHT_GUARD_7 = ~(FILEMASK_B | FILEMASK_C | FILEMASK_D | FILEMASK_E | FILEMASK_F | FILEMASK_G | FILEMASK_H),
FILE_SHIFT_LEFT_GUARD_0 = ~0ULL,
FILE_SHIFT_LEFT_GUARD_1 = ~FILEMASK_A,
FILE_SHIFT_LEFT_GUARD_2 = ~(FILEMASK_A | FILEMASK_B),
FILE_SHIFT_LEFT_GUARD_3 = ~(FILEMASK_A | FILEMASK_B | FILEMASK_C),
FILE_SHIFT_LEFT_GUARD_4 = ~(FILEMASK_A | FILEMASK_B | FILEMASK_C | FILEMASK_D),
FILE_SHIFT_LEFT_GUARD_5 = ~(FILEMASK_A | FILEMASK_B | FILEMASK_C | FILEMASK_D | FILEMASK_E),
FILE_SHIFT_LEFT_GUARD_6 = ~(FILEMASK_A | FILEMASK_B | FILEMASK_C | FILEMASK_D | FILEMASK_E | FILEMASK_F),
FILE_SHIFT_LEFT_GUARD_7 = ~(FILEMASK_A | FILEMASK_B | FILEMASK_C | FILEMASK_D | FILEMASK_E | FILEMASK_F | FILEMASK_G),
};
#define STR(x) #x
#define SQUARE_MASK_PREFIX SQUARE_MASK_
#define SQ_MASK_PREFIX SQ_MASK_
#define SQUARES_LIST_BEGIN \
X(A, 1)
#define SQUARES_LIST \
@@ -203,45 +163,85 @@ enum : bitboard {
X(H, 5) \
X(H, 6) \
X(H, 7) \
X(H, 8) \
X(H, 8)
/* define mask constants: SQUARE_MASK_A1, SQUARE_MASK_A2, ..., SQUARE_MASK_H8 */
/* define mask constants: SQ_MASK_A1, SQ_MASK_A2, ..., SQ_MASK_H8 */
enum : bitboard {
#define X(file, rank) SQUARE_MASK_##file##rank = SQUARE_MASK_FROM_RF(RANK_INDEX_##rank, FILE_INDEX_##file),
#define X(file, rank) SQ_MASK_##file##rank = SQ_MASK_FROM_RF(RANK_INDEX_##rank, FILE_INDEX_##file),
SQUARES_LIST
#undef X
};
enum square_index : bitboard {
#define X(file, rank) SQUARE_INDEX_##file##rank = INDEX_FROM_RF(RANK_INDEX_##rank, FILE_INDEX_##file),
#define X(file, rank) SQ_INDEX_##file##rank = INDEX_FROM_RF(RANK_INDEX_##rank, FILE_INDEX_##file),
SQUARES_LIST
SQUARE_INDEX_COUNT,
SQ_INDEX_COUNT,
#undef X
/* define iterator begin enum */
#define X(file, rank) SQUARE_INDEX_BEGIN = SQUARE_INDEX_##file##rank,
#define X(file, rank) SQ_INDEX_BEGIN = SQ_INDEX_##file##rank,
SQUARES_LIST_BEGIN
#undef X
};
const char* square_index_display[SQUARE_INDEX_COUNT] = {
const char* square_index_display[SQ_INDEX_COUNT] = {
#define X(file, rank) \
[SQUARE_INDEX_##file##rank] = STR(file##rank),
[SQ_INDEX_##file##rank] = STR(file##rank),
SQUARES_LIST
#undef X
};
const char* square_index_str[SQUARE_INDEX_COUNT] = {
const char* square_index_str[SQ_INDEX_COUNT] = {
#define X(file, rank) \
[SQUARE_INDEX_##file##rank] = STR(SQUARE_INDEX_##file##rank),
[SQ_INDEX_##file##rank] = STR(SQ_INDEX_##file##rank),
SQUARES_LIST
#undef X
};
enum : bitboard {
FILE_MASK_A = FILE_MASK(FILE_INDEX_A),
FILE_MASK_B = FILE_MASK(FILE_INDEX_B),
FILE_MASK_C = FILE_MASK(FILE_INDEX_C),
FILE_MASK_D = FILE_MASK(FILE_INDEX_D),
FILE_MASK_E = FILE_MASK(FILE_INDEX_E),
FILE_MASK_F = FILE_MASK(FILE_INDEX_F),
FILE_MASK_G = FILE_MASK(FILE_INDEX_G),
FILE_MASK_H = FILE_MASK(FILE_INDEX_H),
RANK_MASK_1 = RANK_MASK(RANK_INDEX_1),
RANK_MASK_2 = RANK_MASK(RANK_INDEX_2),
RANK_MASK_3 = RANK_MASK(RANK_INDEX_3),
RANK_MASK_4 = RANK_MASK(RANK_INDEX_4),
RANK_MASK_5 = RANK_MASK(RANK_INDEX_5),
RANK_MASK_6 = RANK_MASK(RANK_INDEX_6),
RANK_MASK_7 = RANK_MASK(RANK_INDEX_7),
RANK_MASK_8 = RANK_MASK(RANK_INDEX_8),
FILE_SHIFT_RIGHT_GUARD_0 = ~0ULL,
FILE_SHIFT_RIGHT_GUARD_1 = ~FILE_MASK_H,
FILE_SHIFT_RIGHT_GUARD_2 = ~(FILE_MASK_G | FILE_MASK_H),
FILE_SHIFT_RIGHT_GUARD_3 = ~(FILE_MASK_F | FILE_MASK_G | FILE_MASK_H),
FILE_SHIFT_RIGHT_GUARD_4 = ~(FILE_MASK_E | FILE_MASK_F | FILE_MASK_G | FILE_MASK_H),
FILE_SHIFT_RIGHT_GUARD_5 = ~(FILE_MASK_D | FILE_MASK_E | FILE_MASK_F | FILE_MASK_G | FILE_MASK_H),
FILE_SHIFT_RIGHT_GUARD_6 = ~(FILE_MASK_C | FILE_MASK_D | FILE_MASK_E | FILE_MASK_F | FILE_MASK_G | FILE_MASK_H),
FILE_SHIFT_RIGHT_GUARD_7 = ~(FILE_MASK_B | FILE_MASK_C | FILE_MASK_D | FILE_MASK_E | FILE_MASK_F | FILE_MASK_G | FILE_MASK_H),
FILE_SHIFT_LEFT_GUARD_0 = ~0ULL,
FILE_SHIFT_LEFT_GUARD_1 = ~FILE_MASK_A,
FILE_SHIFT_LEFT_GUARD_2 = ~(FILE_MASK_A | FILE_MASK_B),
FILE_SHIFT_LEFT_GUARD_3 = ~(FILE_MASK_A | FILE_MASK_B | FILE_MASK_C),
FILE_SHIFT_LEFT_GUARD_4 = ~(FILE_MASK_A | FILE_MASK_B | FILE_MASK_C | FILE_MASK_D),
FILE_SHIFT_LEFT_GUARD_5 = ~(FILE_MASK_A | FILE_MASK_B | FILE_MASK_C | FILE_MASK_D | FILE_MASK_E),
FILE_SHIFT_LEFT_GUARD_6 = ~(FILE_MASK_A | FILE_MASK_B | FILE_MASK_C | FILE_MASK_D | FILE_MASK_E | FILE_MASK_F),
FILE_SHIFT_LEFT_GUARD_7 = ~(FILE_MASK_A | FILE_MASK_B | FILE_MASK_C | FILE_MASK_D | FILE_MASK_E | FILE_MASK_F | FILE_MASK_G),
};
#define _FILE_SHIFT_RIGHT_GUARDED(b, n) \
((((bitboard)(b)) & FILE_SHIFT_RIGHT_GUARD_##n) << ((index)(n) * 1ULL))
(((bitboard)(b) & FILE_SHIFT_RIGHT_GUARD_##n) << (index)(n))
#define _FILE_SHIFT_LEFT_GUARDED(b, n) \
((((bitboard)(b)) & FILE_SHIFT_LEFT_GUARD_##n) >> ((index)(n) * 1ULL))
(((bitboard)(b) & FILE_SHIFT_LEFT_GUARD_##n) >> (index)(n))
/* FILE_SHIFT_RIGHT_n shifts the bitboard right by n ranks without wrapping */
#define FILE_SHIFT_RIGHT_1(b) _FILE_SHIFT_RIGHT_GUARDED(b, 1)
@@ -299,7 +299,14 @@ struct magic {
static index bitboard_lsb(bitboard p)
{
return __builtin_ffsll(p);
return __builtin_ffsll(p) - 1;
}
static index bitboard_pop_lsb(bitboard* p)
{
const index lsb = bitboard_lsb(*p);
*p &= ~(1ULL<<(lsb));
return lsb;
}
static uint64_t bitboard_popcount(bitboard b)
@@ -321,7 +328,7 @@ static bitboard cardinals_from_index(enum square_index p)
{
/* might benefit from a lookup table */
return (FILE_MASK(index_to_file(p)) | RANK_MASK(index_to_rank(p)))
& ~SQUARE_MASK_FROM_INDEX(p);
& ~SQ_MASK_FROM_INDEX(p);
}
static bitboard diagonals_from_index(enum square_index sq)
@@ -341,7 +348,7 @@ static bitboard diagonals_from_index(enum square_index sq)
r <= RANK_INDEX_8 && f <= FILE_INDEX_H;
++r, ++f)
{
mask |= SQUARE_MASK_FROM_RF(r, f);
mask |= SQ_MASK_FROM_RF(r, f);
}
/* NW (rank+1, file-1) */
@@ -349,7 +356,7 @@ static bitboard diagonals_from_index(enum square_index sq)
r <= RANK_INDEX_8 && f <= FILE_INDEX_H;
++r, --f)
{
mask |= SQUARE_MASK_FROM_RF(r, f);
mask |= SQ_MASK_FROM_RF(r, f);
}
/* SE (rank-1, file+1) */
@@ -357,7 +364,7 @@ static bitboard diagonals_from_index(enum square_index sq)
r <= RANK_INDEX_8 && f <= FILE_INDEX_H;
--r, ++f)
{
mask |= SQUARE_MASK_FROM_RF(r, f);
mask |= SQ_MASK_FROM_RF(r, f);
}
/* SW (rank-1, file-1) */
@@ -365,7 +372,7 @@ static bitboard diagonals_from_index(enum square_index sq)
r <= RANK_INDEX_8 && f <= FILE_INDEX_H;
--r, --f)
{
mask |= SQUARE_MASK_FROM_RF(r, f);
mask |= SQ_MASK_FROM_RF(r, f);
}
return mask;
@@ -374,14 +381,18 @@ static bitboard diagonals_from_index(enum square_index sq)
/* PIECE ATTACKS
* ================== */
* ==================
*
* All piece attack functions rely on the caller masking their own pieces.
* e.g. `knight_attacks(knights) & ~own_occupied`
* */
static bitboard knight_attacks(bitboard p)
{
const bitboard l1 = FILE_SHIFT_RIGHT_1(p & ~FILEMASK_H);
const bitboard l2 = FILE_SHIFT_RIGHT_2(p & ~(FILEMASK_G | FILEMASK_H));
const bitboard r1 = FILE_SHIFT_LEFT_1 (p & ~FILEMASK_A);
const bitboard r2 = FILE_SHIFT_LEFT_2 (p & ~(FILEMASK_A | FILEMASK_B));
const bitboard l1 = FILE_SHIFT_RIGHT_1(p & ~FILE_MASK_H);
const bitboard l2 = FILE_SHIFT_RIGHT_2(p & ~(FILE_MASK_G | FILE_MASK_H));
const bitboard r1 = FILE_SHIFT_LEFT_1 (p & ~FILE_MASK_A);
const bitboard r2 = FILE_SHIFT_LEFT_2 (p & ~(FILE_MASK_A | FILE_MASK_B));
const bitboard h1 = l1 | r1;
const bitboard h2 = l2 | r2;
return RANK_SHIFT_UP_2(h1)
@@ -390,57 +401,6 @@ static bitboard knight_attacks(bitboard p)
| RANK_SHIFT_DOWN_1(h2);
}
/* rook_attacks_from_index computes rook attack sets from an index, and its
* purpose is code generation (the magic bitboard).
*
* It does not discriminate between friendly and opponent pieces, the caller
* should therefore do something like:
* ```
* rook_attacks_from_index(p, friendly_occ | opponent_occ) & ~friendly_occ
* ```
* */
static bitboard rook_attacks_from_index_slow(enum square_index sq, bitboard occ)
{
const enum rank_index rank = index_to_rank(sq);
const enum file_index file = index_to_file(sq);
bitboard atk = 0ULL;
/* following loops assume rank and file types are unsigned, which relies on C23 enums */
_Static_assert(((enum rank_index)0) - ((enum rank_index)1) > ((enum rank_index)0));
_Static_assert(((enum file_index)0) - ((enum file_index)1) > ((enum file_index)0));
for (enum rank_index walk_rank = rank+1; walk_rank <= RANK_INDEX_8; ++walk_rank) {
const bitboard sq = SQUARE_MASK_FROM_RF(walk_rank, file);
atk |= sq;
if (occ & sq) {
break;
}
}
for (enum rank_index walk_rank = rank-1; walk_rank <= RANK_INDEX_8; --walk_rank) {
const bitboard sq = SQUARE_MASK_FROM_RF(walk_rank, file);
atk |= sq;
if (occ & sq) {
break;
}
}
for (enum file_index walk_file = file+1; walk_file <= FILE_INDEX_H; ++walk_file) {
const bitboard sq = SQUARE_MASK_FROM_RF(rank, walk_file);
atk |= sq;
if (occ & sq) {
break;
}
}
for (enum file_index walk_file = file-1; walk_file <= FILE_INDEX_H; --walk_file) {
const bitboard sq = SQUARE_MASK_FROM_RF(rank, walk_file);
atk |= sq;
if (occ & sq) {
break;
}
}
return atk;
}
static bitboard rook_attacks_from_index(enum square_index sq, bitboard occ)
{
@@ -452,8 +412,8 @@ static bitboard rook_attacks_from_index(enum square_index sq, bitboard occ)
#else
/* defines
- `mbb_rook[SQUARE_INDEX_COUNT]`
- `bitboard rook_attacks[SQUARE_INDEX_COUNT][1<<12ULL] */
- `mbb_rook[SQ_INDEX_COUNT]`
- `bitboard rook_attacks[SQ_INDEX_COUNT][1<<12ULL] */
#include "mbb_rook.h"
const struct magic m = mbb_rook[sq];
@@ -470,75 +430,12 @@ static bitboard rook_attacks(bitboard p, bitboard occ)
{
bitboard b = 0ULL;
while (p) {
const index lsb = bitboard_lsb(p) - 1;
p &= ~(1ULL<<(lsb));
const index lsb = bitboard_pop_lsb(&p);
b |= rook_attacks_from_index(lsb, occ);
}
return b;
}
/* bishop_attacks_from_index computes bishop attack sets from an index, and its
* purpose is code generation (the magic bitboard).
*
* It does not discriminate between friendly and opponent pieces, the caller
* should therefore do something like:
* ```
* bishop_attacks_from_index(p, occ) & ~friendly_occ
* ```
* */
static bitboard bishop_attacks_from_index_slow(enum square_index sq, bitboard occ)
{
const enum rank_index rank = index_to_rank(sq);
const enum file_index file = index_to_file(sq);
bitboard atk = 0ULL;
/* following loops assume rank and file types are unsigned, which relies on C23 enums */
_Static_assert(((enum rank_index)0) - ((enum rank_index)1) > ((enum rank_index)0));
_Static_assert(((enum file_index)0) - ((enum file_index)1) > ((enum file_index)0));
enum rank_index walk_rank;
enum file_index walk_file;
for (walk_rank = rank+1, walk_file = file+1;
walk_rank <= RANK_INDEX_8 && walk_file <= FILE_INDEX_H;
++walk_rank, ++walk_file) {
const bitboard sq = SQUARE_MASK_FROM_RF(walk_rank, walk_file);
atk |= sq;
if (occ & sq) {
break;
}
}
for (walk_rank = rank+1, walk_file = file-1;
walk_rank <= RANK_INDEX_8 && walk_file <= FILE_INDEX_H;
++walk_rank, --walk_file) {
const bitboard sq = SQUARE_MASK_FROM_RF(walk_rank, walk_file);
atk |= sq;
if (occ & sq) {
break;
}
}
for (walk_rank = rank-1, walk_file = file+1;
walk_rank <= RANK_INDEX_8 && walk_file <= FILE_INDEX_H;
--walk_rank, ++walk_file) {
const bitboard sq = SQUARE_MASK_FROM_RF(walk_rank, walk_file);
atk |= sq;
if (occ & sq) {
break;
}
}
for (walk_rank = rank-1, walk_file = file-1;
walk_rank <= RANK_INDEX_8 && walk_file <= FILE_INDEX_H;
--walk_rank, --walk_file) {
const bitboard sq = SQUARE_MASK_FROM_RF(walk_rank, walk_file);
atk |= sq;
if (occ & sq) {
break;
}
}
return atk;
}
static bitboard bishop_attacks_from_index(enum square_index sq, bitboard occ)
{
#ifdef CODEGEN
@@ -549,8 +446,8 @@ static bitboard bishop_attacks_from_index(enum square_index sq, bitboard occ)
#else
/* defines
- `mbb_bishop[SQUARE_INDEX_COUNT]`
- `bitboard bishop_attacks[SQUARE_INDEX_COUNT][1<<9ULL] */
- `mbb_bishop[SQ_INDEX_COUNT]`
- `bitboard bishop_attacks[SQ_INDEX_COUNT][1<<9ULL] */
#include "mbb_bishop.h"
const struct magic m = mbb_bishop[sq];
occ &= m.mask;
@@ -565,76 +462,89 @@ static bitboard bishop_attacks(bitboard p, bitboard occ)
{
bitboard b = 0ULL;
while (p) {
const index lsb = bitboard_lsb(p) - 1;
p &= ~(1ULL<<(lsb));
const index lsb = bitboard_pop_lsb(&p);
b |= bishop_attacks_from_index(lsb, occ);
}
return b;
}
static inline bitboard pawn_white_moves(bitboard p, bitboard empty)
static bitboard queen_attacks_from_index(enum square_index sq, bitboard occ)
{
return bishop_attacks_from_index(sq, occ) | rook_attacks_from_index(sq, occ);
}
static bitboard queen_attacks(bitboard p, bitboard occ)
{
bitboard b = 0ULL;
while (p) {
const index lsb = bitboard_pop_lsb(&p);
b |= queen_attacks_from_index(lsb, occ);
}
return b;
}
static inline bitboard pawn_moves_white(bitboard p, bitboard empty)
{
/* Assumptions:
- empty = ~(black_occupied | white_occupied);
*/
const bitboard single_push = RANK_SHIFT_UP(p, 1) & empty;
const bitboard single_push = RANK_SHIFT_UP_1(p) & empty;
const bitboard double_push =
RANK_SHIFT_UP(single_push & RANKMASK_3, 1) & empty;
RANK_SHIFT_UP_1(single_push & RANK_MASK_3) & empty;
return single_push | double_push;
return (single_push | double_push);
}
static inline bitboard pawn_white_attacks(bitboard p, bitboard ep_targets, bitboard black_occupied)
static inline bitboard pawn_attacks_white(bitboard p)
{
const bitboard up = RANK_SHIFT_UP(p, 1);
const bitboard captures_right = FILE_SHIFT_RIGHT(up, 1) & ~FILEMASK_H;
const bitboard captures_left = FILE_SHIFT_LEFT(up, 1) & ~FILEMASK_A;
const bitboard up = RANK_SHIFT_UP_1(p);
const bitboard captures_right = FILE_SHIFT_RIGHT_1(up);
const bitboard captures_left = FILE_SHIFT_LEFT_1(up);
return (captures_right | captures_left) & (black_occupied | ep_targets);
return (captures_right | captures_left);
}
static inline bitboard pawn_black_moves(bitboard p, bitboard empty)
static inline bitboard pawn_moves_black(bitboard p, bitboard empty)
{
/* Assumptions:
- empty = ~(black_occupied | white_occupied);
*/
const bitboard single_push = RANK_SHIFT_DOWN(p, 1) & empty;
const bitboard single_push = RANK_SHIFT_DOWN_1(p) & empty;
const bitboard double_push =
RANK_SHIFT_DOWN(single_push & RANKMASK_6, 1) & empty;
RANK_SHIFT_DOWN_1(single_push & RANK_MASK_6) & empty;
return single_push | double_push;
return (single_push | double_push);
}
static inline bitboard pawn_black_attacks(bitboard p, bitboard ep_targets, bitboard white_occupied)
static inline bitboard pawn_attacks_black(bitboard p)
{
const bitboard down = RANK_SHIFT_UP(p, 1);
const bitboard captures_right = FILE_SHIFT_RIGHT(down, 1) & ~FILEMASK_H;
const bitboard captures_left = FILE_SHIFT_LEFT(down, 1) & ~FILEMASK_A;
const bitboard down = RANK_SHIFT_DOWN_1(p);
const bitboard captures_right = FILE_SHIFT_RIGHT_1(down);
const bitboard captures_left = FILE_SHIFT_LEFT_1(down);
return (captures_right | captures_left) & (white_occupied | ep_targets);
return (captures_right | captures_left);
}
static bitboard king_attacks(enum square_index sq)
{
/* candidate for improvement */
const bitboard n = RANK_SHIFT_UP(sq, 1);
const bitboard s = RANK_SHIFT_DOWN(sq, 1);
const bitboard w = FILE_SHIFT_LEFT(sq, 1);
const bitboard e = FILE_SHIFT_RIGHT(sq, 1);
const bitboard n = RANK_SHIFT_UP_1(sq);
const bitboard s = RANK_SHIFT_DOWN_1(sq);
const bitboard w = FILE_SHIFT_LEFT_1(sq);
const bitboard e = FILE_SHIFT_RIGHT_1(sq);
const bitboard nw = FILE_SHIFT_LEFT(n, 1);
const bitboard ne = FILE_SHIFT_RIGHT(n, 1);
const bitboard sw = FILE_SHIFT_RIGHT(s, 1);
const bitboard se = FILE_SHIFT_LEFT(s, 1);
const bitboard nw = FILE_SHIFT_LEFT_1(n);
const bitboard ne = FILE_SHIFT_RIGHT_1(n);
const bitboard sw = FILE_SHIFT_RIGHT_1(s);
const bitboard se = FILE_SHIFT_LEFT_1(s);
return n | s | w | e | nw | ne | sw | se;
return (n | s | w | e | nw | ne | sw | se);
}
/* BOARD
* ================= */
enum player : index {
@@ -644,80 +554,308 @@ enum player : index {
PLAYER_COUNT,
};
enum piece : index {
PIECE_BEGIN,
PIECE_PAWN = PIECE_BEGIN,
PIECE_KING,
PIECE_QUEEN,
PIECE_BISHOP,
PIECE_ROOK,
PIECE_KNIGHT,
static inline enum player opposite_player(enum player p)
{
return (p == PLAYER_WHITE ? PLAYER_BLACK : PLAYER_WHITE);
}
const char* player_str[PLAYER_COUNT] = {
[PLAYER_WHITE] = "PLAYER_WHITE",
[PLAYER_BLACK] = "PLAYER_BLACK",
};
#define PIECE_BEGIN PIECE_PAWN
/* enum value white char white unicode black char black unicode */
#define PIECES \
X(PIECE_PAWN, 1.0, 'P', 0x2659, 'p', 0x265F) \
X(PIECE_KING, 5.0, 'K', 0x2654, 'k', 0x265A) \
X(PIECE_QUEEN, 9.0, 'Q', 0x2655, 'q', 0x265B) \
X(PIECE_BISHOP, 3.0, 'Q', 0x2657, 'q', 0x265D) \
X(PIECE_ROOK, 5.0, 'R', 0x2656, 'q', 0x265C) \
X(PIECE_KNIGHT, 3.0, 'N', 0x2658, 'n', 0x265E)
enum piece : size_t {
#define X(e, v, wc, wu, bc, bu) e,
PIECES
PIECE_COUNT,
#undef X
};
double piece_value[PIECE_COUNT] = {
#define X(e, v, wc, wu, bc, bu) [e] = v,
PIECES
#undef X
};
const char* piece_str[PIECE_COUNT] = {
#define X(e, v, wc, wu, bc, bu) [e] = STR(e),
PIECES
#undef X
};
const char piece_char[PLAYER_COUNT][PIECE_COUNT] = {
[PLAYER_WHITE] = {
[PIECE_PAWN] = 'P',
[PIECE_KING] = 'K',
[PIECE_QUEEN] = 'Q',
[PIECE_BISHOP] = 'B',
[PIECE_ROOK] = 'R',
[PIECE_KNIGHT] = 'N',
#define X(e, v, wc, wu, bc, bu) [e] = wc,
PIECES
#undef X
},
[PLAYER_BLACK] = {
[PIECE_PAWN] = 'p',
[PIECE_KING] = 'k',
[PIECE_QUEEN] = 'q',
[PIECE_BISHOP] = 'b',
[PIECE_ROOK] = 'r',
[PIECE_KNIGHT] = 'n',
#define X(e, v, wc, wu, bc, bu) [e] = bc,
PIECES
#undef X
}
};
const int piece_unicode[PLAYER_COUNT][PIECE_COUNT] = {
[PLAYER_WHITE] = {
[PIECE_PAWN] = 0x2659,
[PIECE_KING] = 0x2654,
[PIECE_QUEEN] = 0x2655,
[PIECE_BISHOP] = 0x2657,
[PIECE_ROOK] = 0x2656,
[PIECE_KNIGHT] = 0x2658,
#define X(e, v, wc, wu, bc, bu) [e] = wu,
PIECES
#undef X
},
[PLAYER_BLACK] = {
[PIECE_PAWN] = 0x265F,
[PIECE_KING] = 0x265A,
[PIECE_QUEEN] = 0x265B,
[PIECE_BISHOP] = 0x265D,
[PIECE_ROOK] = 0x265C,
[PIECE_KNIGHT] = 0x265E,
#define X(e, v, wc, wu, bc, bu) [e] = bu,
PIECES
#undef X
}
};
struct board {
bitboard pieces[PLAYER_COUNT][PIECE_COUNT];
bitboard enpassent_targets[PLAYER_COUNT];
bitboard ep_targets;
bitboard occupied[PLAYER_COUNT];
/* Used only for square->piece lookups, not central to logic.
* Does not store which player owns the square piece */
enum piece mailbox[SQ_INDEX_COUNT];
};
#define BOARD_INITIAL (struct board) { \
.pieces = { \
[PLAYER_WHITE] = { \
[PIECE_PAWN] = RANKMASK_2, \
[PIECE_ROOK] = SQUARE_MASK_A1 | SQUARE_MASK_H1, \
[PIECE_KNIGHT] = SQUARE_MASK_B1 | SQUARE_MASK_G1, \
[PIECE_BISHOP] = SQUARE_MASK_C1 | SQUARE_MASK_F1, \
[PIECE_QUEEN] = SQUARE_MASK_D1, \
[PIECE_KING] = SQUARE_MASK_E1, \
}, \
[PLAYER_BLACK] = { \
[PIECE_PAWN] = RANKMASK_7, \
[PIECE_ROOK] = SQUARE_MASK_A8 | SQUARE_MASK_H8, \
[PIECE_KNIGHT] = SQUARE_MASK_B8 | SQUARE_MASK_G8, \
[PIECE_BISHOP] = SQUARE_MASK_C8 | SQUARE_MASK_F8, \
[PIECE_QUEEN] = SQUARE_MASK_D8, \
[PIECE_KING] = SQUARE_MASK_E8, \
} \
} \
#define BOARD_INITIAL (struct board) { \
.pieces = { \
[PLAYER_WHITE] = { \
[PIECE_PAWN] = RANK_MASK_2, \
[PIECE_ROOK] = SQ_MASK_A1 | SQ_MASK_H1, \
[PIECE_KNIGHT] = SQ_MASK_B1 | SQ_MASK_G1, \
[PIECE_BISHOP] = SQ_MASK_C1 | SQ_MASK_F1, \
[PIECE_QUEEN] = SQ_MASK_D1, \
[PIECE_KING] = SQ_MASK_E1, \
}, \
[PLAYER_BLACK] = { \
[PIECE_PAWN] = RANK_MASK_7, \
[PIECE_ROOK] = SQ_MASK_A8 | SQ_MASK_H8, \
[PIECE_KNIGHT] = SQ_MASK_B8 | SQ_MASK_G8, \
[PIECE_BISHOP] = SQ_MASK_C8 | SQ_MASK_F8, \
[PIECE_QUEEN] = SQ_MASK_D8, \
[PIECE_KING] = SQ_MASK_E8, \
} \
}, \
.ep_targets = 0ULL, \
.occupied = { \
[PLAYER_WHITE] = \
RANK_MASK_2 | SQ_MASK_A1 | SQ_MASK_H1 | \
SQ_MASK_B1 | SQ_MASK_G1 | SQ_MASK_C1 | \
SQ_MASK_F1 | SQ_MASK_D1 | SQ_MASK_E1, \
[PLAYER_BLACK] = \
RANK_MASK_7 | SQ_MASK_A8 | SQ_MASK_H8 | \
SQ_MASK_B8 | SQ_MASK_G8| SQ_MASK_C8 | \
SQ_MASK_F8| SQ_MASK_D8| SQ_MASK_E8, \
}, \
.mailbox = { \
[SQ_INDEX_A1] = PIECE_ROOK, \
[SQ_INDEX_B1] = PIECE_KNIGHT, \
[SQ_INDEX_C1] = PIECE_BISHOP, \
[SQ_INDEX_D1] = PIECE_QUEEN, \
[SQ_INDEX_E1] = PIECE_KING, \
[SQ_INDEX_F1] = PIECE_BISHOP, \
[SQ_INDEX_G1] = PIECE_KNIGHT, \
[SQ_INDEX_H1] = PIECE_ROOK, \
[SQ_INDEX_A2] = PIECE_PAWN, \
[SQ_INDEX_B2] = PIECE_PAWN, \
[SQ_INDEX_C2] = PIECE_PAWN, \
[SQ_INDEX_D2] = PIECE_PAWN, \
[SQ_INDEX_E2] = PIECE_PAWN, \
[SQ_INDEX_F2] = PIECE_PAWN, \
[SQ_INDEX_G2] = PIECE_PAWN, \
[SQ_INDEX_H2] = PIECE_PAWN, \
[SQ_INDEX_A7] = PIECE_PAWN, \
[SQ_INDEX_B7] = PIECE_PAWN, \
[SQ_INDEX_C7] = PIECE_PAWN, \
[SQ_INDEX_D7] = PIECE_PAWN, \
[SQ_INDEX_E7] = PIECE_PAWN, \
[SQ_INDEX_F7] = PIECE_PAWN, \
[SQ_INDEX_G7] = PIECE_PAWN, \
[SQ_INDEX_H7] = PIECE_PAWN, \
[SQ_INDEX_A8] = PIECE_ROOK, \
[SQ_INDEX_B8] = PIECE_KNIGHT, \
[SQ_INDEX_C8] = PIECE_BISHOP, \
[SQ_INDEX_D8] = PIECE_QUEEN, \
[SQ_INDEX_E8] = PIECE_KING, \
[SQ_INDEX_F8] = PIECE_BISHOP, \
[SQ_INDEX_G8] = PIECE_KNIGHT, \
[SQ_INDEX_H8] = PIECE_ROOK, \
}, \
}
double board_score_heuristic(const struct board* board, enum player player)
{
double score = 0.0;
enum player opp = opposite_player(player);
for (enum piece piece = PIECE_BEGIN; piece < PIECE_COUNT; ++piece) {
score += (double)bitboard_popcount(board->pieces[player][piece]) * piece_value[piece];
}
for (enum piece piece = PIECE_BEGIN; piece < PIECE_COUNT; ++piece) {
score -= (double)bitboard_popcount(board->pieces[opp][piece]) * piece_value[piece];
}
return score;
}
struct move {
index from;
index to;
};
struct move move(index from, index to)
{
return (struct move){
.from = from,
.to = to
};
}
#define MOVE_MAX 32
static size_t all_moves_from(const struct board* board,
enum player player,
enum square_index from,
struct move moves[static MOVE_MAX])
{
const enum piece piece = board->mailbox[from];
const enum player opp = opposite_player(player);
const bitboard own_occ = board->occupied[player];
const bitboard opp_occ = board->occupied[opp];
const bitboard occ = own_occ | opp_occ;
const bitboard sqmask = SQ_MASK_FROM_INDEX(from);
bitboard x = 0ULL;
switch (piece) {
case PIECE_PAWN: {
if (player == PLAYER_WHITE) {
x |= pawn_moves_white(sqmask, ~occ);
x |= pawn_attacks_white(sqmask) & (board->ep_targets | opp_occ);
} else {
x |= pawn_moves_black(sqmask, ~occ);
x |= pawn_attacks_black(sqmask) & (board->ep_targets | opp_occ);
}
} break;
case PIECE_KNIGHT: {
x |= knight_attacks(sqmask);
} break;
case PIECE_BISHOP: {
x |= bishop_attacks_from_index(from, occ);
} break;
case PIECE_ROOK: {
x |= rook_attacks_from_index(from, occ);
} break;
case PIECE_QUEEN: {
x |= queen_attacks_from_index(from, occ);
} break;
case PIECE_KING: {
x |= king_attacks(sqmask);
} break;
}
x &= ~board->occupied[player];
size_t move_count = 0;
while (x) {
const index to = bitboard_pop_lsb(&x);
moves[move_count++] = (struct move){.from = from, .to = to};
}
return move_count;
}
static size_t all_player_pieces(struct board* board,
enum player player,
enum square_index out[static SQ_INDEX_COUNT])
{
size_t count = 0;
fprintf(stderr, "%s\n", player_str[player]);
for (enum piece piece = PIECE_BEGIN; piece < PIECE_COUNT; ++piece) {
bitboard x = board->pieces[player][piece];
fprintf(stderr, "%s:\t%016"BITBOARD_FMT_X"\n", piece_str[piece], x);
while (x) {
out[count++] = (enum square_index)bitboard_pop_lsb(&x);
}
}
return count;
}
/* caller is resposible for checking validity */
static void board_move_piece(struct board* board,
enum player player,
struct move move)
{
const bitboard from_mask = SQ_MASK_FROM_INDEX(move.from);
const bitboard to_mask = SQ_MASK_FROM_INDEX(move.to);
const enum player opp = opposite_player(player);
const enum piece from_piece = board->mailbox[move.from];
const enum piece to_piece = board->mailbox[move.to];
board->pieces[player][from_piece] &= ~from_mask;
board->pieces[player][from_piece] |= to_mask;
board->pieces[opp][to_piece] &= ~to_mask;
board->occupied[player] &= ~from_mask;
board->occupied[player] |= to_mask;
board->occupied[opp] &= ~to_mask;
/* mailboxes are solely used for fast lookups of pieces in already valid
* moves, it's safe to ignore the from index */
board->mailbox[move.to] = from_piece;
}
static bool board_is_check(struct board* b, enum player player)
{
const bitboard kb = b->pieces[player][PIECE_KING];
const enum player opp = opposite_player(player);
const bitboard player_occ = bitboard->occupied[player];
const bitboard opp_occ = bitboard->occupied[opp];
const bitboard occ = player_occ | opp_occ;
const bitboard* p = b->pieces[opp];
bitboard threats = 0ULL;
if (player == PLAYER_WHITE) {
threats |= pawn_attacks_white(p[PIECE_PAWN]);
} else {
threats |= pawn_attacks_black(p[PIECE_PAWN]);
}
threats |= bishop_attacks(p[PIECE_BISHOP], occ);
threats |= rook_attacks(p[PIECE_ROOK], occ);
threats |= king_attacks(p[PIECE_KING]);
threats |= queen_attacks(p[PIECE_QUEEN], occ);
threats |= knight_attacks(p[PIECE_KNIGHT]);
threats &= ~player_occ;
if (threats & kb) {
return true;
}
return false;
}
void board_print(struct board* b, FILE* out)
@@ -765,9 +903,6 @@ void board_print(struct board* b, FILE* out)
fprintf(out, " A B C D E F G H \n");
}
/* debug functions
* =============== */
void bitboard_print(bitboard b, FILE* out)
{
setlocale(LC_ALL, "");
@@ -794,3 +929,76 @@ void bitboard_print(bitboard b, FILE* out)
fprintf(out, " A B C D E F G H \n");
}
void board_print_threats(struct board* b, FILE* out, enum player player)
{
int buf[8][8] = {0};
for (size_t i = 0; i < 8; i++) {
for (size_t i = 0; i < 8; i++) {
buf[i][i] = 0;
}
}
enum player opp = opposite_player(player);
bitboard opp_occ = 0ULL,
own_occ = 0ULL;
for (enum piece piece = PIECE_BEGIN; piece < PIECE_COUNT; ++piece) {
opp_occ |= b->pieces[opp][piece];
own_occ |= b->pieces[player][piece];
}
const bitboard occ = opp_occ | own_occ;
bitboard threats = 0ULL;
const bitboard* p = b->pieces[player];
if (player == PLAYER_WHITE) {
threats |= pawn_attacks_white(p[PIECE_PAWN]);
} else {
threats |= pawn_attacks_black(p[PIECE_PAWN]);
}
threats |= bishop_attacks(p[PIECE_BISHOP], occ);
threats |= rook_attacks(p[PIECE_ROOK], occ);
threats |= king_attacks(p[PIECE_KING]);
threats |= queen_attacks(p[PIECE_QUEEN], occ);
threats |= knight_attacks(p[PIECE_KNIGHT]);
threats &= ~own_occ;
for (enum player player = PLAYER_BEGIN; player < PLAYER_COUNT; player++) {
for (enum piece piece = PIECE_BEGIN; piece < PIECE_COUNT; piece++) {
bitboard x = b->pieces[player][piece];
for (index i = 7; i < 8; i--) {
for (index j = 0; j < 8; j++) {
if (x & (1ULL<<(i*8+j))) {
buf[i][j] = piece_unicode[player][piece];
}
}
}
}
}
/* see: https://en.wikipedia.org/wiki/ANSI_escape_code#Colors */
setlocale(LC_ALL, "");
for (index i = 7; i < 8; i--) {
fprintf(out, "\033[0m"); /* reset background color */
fprintf(out, "%"INDEX_FMT" ", i+1);
for (index j = 0; j < 8; j++) {
const index n = i*8+j;
if ((threats >> n) & 1) {
fprintf(out, "\033[%d;%dm", 30, 41);
} else {
/* 45: magenta, 47: white */
fprintf(out, "\033[%d;%dm", 30, (i+j) % 2 ? 45 : 47);
}
if (buf[i][j]) {
fprintf(out, "%lc ", buf[i][j]);
} else {
fprintf(out, " "); /* idk why this hack is needed but "%lc "
is not working when buf[i][j] = ' ' */
}
}
fprintf(out, "\033[0m"); /* reset background color */
fprintf(out, "\n");
}
fprintf(out, " A B C D E F G H \n");
}