CACHE_LINE_ALIGNMENT int BSFTable[64];
- void init_masks();
- void init_step_attacks();
- void init_pseudo_attacks();
- void init_between_bitboards();
- Bitboard index_to_bitboard(int index, Bitboard mask);
- Bitboard sliding_attacks(int sq, Bitboard occupied, int deltas[][2],
- int fmin, int fmax, int rmin, int rmax);
void init_sliding_attacks(Bitboard attacks[], int attackIndex[], Bitboard mask[],
const int shift[], const Bitboard mult[], int deltas[][2]);
}
void init_bitboards() {
- int rookDeltas[4][2] = {{0,1},{0,-1},{1,0},{-1,0}};
- int bishopDeltas[4][2] = {{1,1},{-1,1},{1,-1},{-1,-1}};
+ SquaresByColorBB[DARK] = 0xAA55AA55AA55AA55ULL;
+ SquaresByColorBB[LIGHT] = ~SquaresByColorBB[DARK];
- init_masks();
- init_step_attacks();
- init_sliding_attacks(RAttacks, RAttackIndex, RMask, RShift, RMult, rookDeltas);
- init_sliding_attacks(BAttacks, BAttackIndex, BMask, BShift, BMult, bishopDeltas);
- init_pseudo_attacks();
- init_between_bitboards();
-}
+ for (Square s = SQ_A1; s <= SQ_H8; s++)
+ {
+ SetMaskBB[s] = (1ULL << s);
+ ClearMaskBB[s] = ~SetMaskBB[s];
+ }
-namespace {
+ ClearMaskBB[SQ_NONE] = ~EmptyBoardBB;
- // All functions below are used to precompute various bitboards during
- // program initialization. Some of the functions may be difficult to
- // understand, but they all seem to work correctly, and it should never
- // be necessary to touch any of them.
+ FileBB[FILE_A] = FileABB;
+ RankBB[RANK_1] = Rank1BB;
- void init_masks() {
+ for (int f = FILE_B; f <= FILE_H; f++)
+ {
+ FileBB[f] = FileBB[f - 1] << 1;
+ RankBB[f] = RankBB[f - 1] << 8;
+ }
- SquaresByColorBB[DARK] = 0xAA55AA55AA55AA55ULL;
- SquaresByColorBB[LIGHT] = ~SquaresByColorBB[DARK];
+ for (int f = FILE_A; f <= FILE_H; f++)
+ {
+ NeighboringFilesBB[f] = (f > FILE_A ? FileBB[f - 1] : 0) | (f < FILE_H ? FileBB[f + 1] : 0);
+ ThisAndNeighboringFilesBB[f] = FileBB[f] | NeighboringFilesBB[f];
+ }
- FileBB[FILE_A] = FileABB;
- RankBB[RANK_1] = Rank1BB;
+ for (int rw = RANK_7, rb = RANK_2; rw >= RANK_1; rw--, rb++)
+ {
+ InFrontBB[WHITE][rw] = InFrontBB[WHITE][rw + 1] | RankBB[rw + 1];
+ InFrontBB[BLACK][rb] = InFrontBB[BLACK][rb - 1] | RankBB[rb - 1];
+ }
- for (int f = FILE_B; f <= FILE_H; f++)
- {
- FileBB[f] = FileBB[f - 1] << 1;
- RankBB[f] = RankBB[f - 1] << 8;
- }
+ for (Color c = WHITE; c <= BLACK; c++)
+ for (Square s = SQ_A1; s <= SQ_H8; s++)
+ {
+ SquaresInFrontMask[c][s] = in_front_bb(c, s) & file_bb(s);
+ PassedPawnMask[c][s] = in_front_bb(c, s) & this_and_neighboring_files_bb(s);
+ AttackSpanMask[c][s] = in_front_bb(c, s) & neighboring_files_bb(s);
+ }
+
+ for (Bitboard b = 0; b < 256; b++)
+ BitCount8Bit[b] = (uint8_t)count_1s<CNT32>(b);
+
+ for (int i = 1; i < 64; i++)
+ if (!CpuIs64Bit) // Matt Taylor's folding trick for 32 bit systems
+ {
+ Bitboard b = 1ULL << i;
+ b ^= b - 1;
+ b ^= b >> 32;
+ BSFTable[uint32_t(b * DeBruijnMagic) >> 26] = i;
+ }
+ else
+ BSFTable[((1ULL << i) * DeBruijnMagic) >> 58] = i;
+
+ int steps[][9] = {
+ {0}, {7,9,0}, {17,15,10,6,-6,-10,-15,-17,0}, {0}, {0}, {0}, {9,7,-7,-9,8,1,-1,-8,0}
+ };
+
+ for (Color c = WHITE; c <= BLACK; c++)
+ for (Square s = SQ_A1; s <= SQ_H8; s++)
+ for (PieceType pt = PAWN; pt <= KING; pt++)
+ for (int k = 0; steps[pt][k]; k++)
+ {
+ Square to = s + Square(c == WHITE ? steps[pt][k] : -steps[pt][k]);
+
+ if (square_is_ok(to) && square_distance(s, to) < 3)
+ set_bit(&StepAttacksBB[make_piece(c, pt)][s], to);
+ }
+
+ int rookDeltas[4][2] = { {0,1}, {0 ,-1}, {1, 0}, {-1, 0} };
+ int bishopDeltas[4][2] = { {1,1}, {-1, 1}, {1,-1}, {-1,-1} };
- for (int f = FILE_A; f <= FILE_H; f++)
- {
- NeighboringFilesBB[f] = (f > FILE_A ? FileBB[f - 1] : 0) | (f < FILE_H ? FileBB[f + 1] : 0);
- ThisAndNeighboringFilesBB[f] = FileBB[f] | NeighboringFilesBB[f];
- }
+ init_sliding_attacks(RAttacks, RAttackIndex, RMask, RShift, RMult, rookDeltas);
+ init_sliding_attacks(BAttacks, BAttackIndex, BMask, BShift, BMult, bishopDeltas);
- for (int rw = RANK_7, rb = RANK_2; rw >= RANK_1; rw--, rb++)
- {
- InFrontBB[WHITE][rw] = InFrontBB[WHITE][rw + 1] | RankBB[rw + 1];
- InFrontBB[BLACK][rb] = InFrontBB[BLACK][rb - 1] | RankBB[rb - 1];
- }
+ for (Square s = SQ_A1; s <= SQ_H8; s++)
+ {
+ BishopPseudoAttacks[s] = bishop_attacks_bb(s, EmptyBoardBB);
+ RookPseudoAttacks[s] = rook_attacks_bb(s, EmptyBoardBB);
+ QueenPseudoAttacks[s] = queen_attacks_bb(s, EmptyBoardBB);
+ }
- SetMaskBB[SQ_NONE] = EmptyBoardBB;
- ClearMaskBB[SQ_NONE] = ~SetMaskBB[SQ_NONE];
+ for (Square s1 = SQ_A1; s1 <= SQ_H8; s1++)
+ for (Square s2 = SQ_A1; s2 <= SQ_H8; s2++)
+ if (bit_is_set(QueenPseudoAttacks[s1], s2))
+ {
+ int f = file_distance(s1, s2);
+ int r = rank_distance(s1, s2);
- for (Square s = SQ_A1; s <= SQ_H8; s++)
- {
- SetMaskBB[s] = (1ULL << s);
- ClearMaskBB[s] = ~SetMaskBB[s];
- }
+ Square d = (s2 - s1) / Max(f, r);
- for (Color c = WHITE; c <= BLACK; c++)
- for (Square s = SQ_A1; s <= SQ_H8; s++)
- {
- SquaresInFrontMask[c][s] = in_front_bb(c, s) & file_bb(s);
- PassedPawnMask[c][s] = in_front_bb(c, s) & this_and_neighboring_files_bb(s);
- AttackSpanMask[c][s] = in_front_bb(c, s) & neighboring_files_bb(s);
- }
+ for (Square s3 = s1 + d; s3 != s2; s3 += d)
+ set_bit(&BetweenBB[s1][s2], s3);
+ }
+}
- for (Bitboard b = 0; b < 256; b++)
- BitCount8Bit[b] = (uint8_t)count_1s<CNT32>(b);
- for (int i = 1; i < 64; i++)
- if (!CpuIs64Bit) // Matt Taylor's folding trick for 32 bit systems
- {
- Bitboard b = 1ULL << i;
- b ^= b - 1;
- b ^= b >> 32;
- BSFTable[uint32_t(b * DeBruijnMagic) >> 26] = i;
- }
- else
- BSFTable[((1ULL << i) * DeBruijnMagic) >> 58] = i;
- }
+namespace {
+
+ Bitboard index_to_bitboard(int index, Bitboard mask) {
+
+ Bitboard result = 0;
+ int sq, cnt = 0;
+
+ while (mask)
+ {
+ sq = pop_1st_bit(&mask);
- void init_step_attacks() {
-
- const int step[][9] = {
- {0},
- {7,9,0}, {17,15,10,6,-6,-10,-15,-17,0}, {0}, {0}, {0},
- {9,7,-7,-9,8,1,-1,-8,0}, {0}, {0},
- {-7,-9,0}, {17,15,10,6,-6,-10,-15,-17,0}, {0}, {0}, {0},
- {9,7,-7,-9,8,1,-1,-8,0}
- };
-
- for (Square s = SQ_A1; s <= SQ_H8; s++)
- for (Piece pc = WP; pc <= BK; pc++)
- for (int k = 0; step[pc][k] != 0; k++)
- {
- Square to = s + Square(step[pc][k]);
-
- if (square_is_ok(to) && square_distance(s, to) < 3)
- set_bit(&StepAttacksBB[pc][s], to);
- }
+ if (index & (1 << cnt++))
+ result |= (1ULL << sq);
+ }
+ return result;
}
Bitboard sliding_attacks(int sq, Bitboard occupied, int deltas[][2],
int fmin, int fmax, int rmin, int rmax) {
+ Bitboard attacks = 0;
int dx, dy, f, r;
int rk = sq / 8;
int fl = sq % 8;
- Bitboard attacks = EmptyBoardBB;
for (int i = 0; i < 4; i++)
{
return attacks;
}
- Bitboard index_to_bitboard(int index, Bitboard mask) {
-
- Bitboard result = EmptyBoardBB;
- int sq, cnt = 0;
-
- while (mask)
- {
- sq = pop_1st_bit(&mask);
-
- if (index & (1 << cnt++))
- result |= (1ULL << sq);
- }
- return result;
- }
-
void init_sliding_attacks(Bitboard attacks[], int attackIndex[], Bitboard mask[],
const int shift[], const Bitboard mult[], int deltas[][2]) {
Bitboard b, v;
index += j;
}
}
-
- void init_pseudo_attacks() {
-
- for (Square s = SQ_A1; s <= SQ_H8; s++)
- {
- BishopPseudoAttacks[s] = bishop_attacks_bb(s, EmptyBoardBB);
- RookPseudoAttacks[s] = rook_attacks_bb(s, EmptyBoardBB);
- QueenPseudoAttacks[s] = queen_attacks_bb(s, EmptyBoardBB);
- }
- }
-
- void init_between_bitboards() {
-
- Square s1, s2, s3, d;
- int f, r;
-
- for (s1 = SQ_A1; s1 <= SQ_H8; s1++)
- for (s2 = SQ_A1; s2 <= SQ_H8; s2++)
- if (bit_is_set(QueenPseudoAttacks[s1], s2))
- {
- f = file_distance(s1, s2);
- r = rank_distance(s1, s2);
-
- d = (s2 - s1) / Max(f, r);
-
- for (s3 = s1 + d; s3 != s2; s3 += d)
- set_bit(&(BetweenBB[s1][s2]), s3);
- }
- }
-
}