/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2009 Marco Costalba
+ Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
#include "bitboard.h"
#include "bitcount.h"
-#include "direction.h"
#if defined(IS_64BIT)
#endif // defined(IS_64BIT)
-const Bitboard SquaresByColorBB[2] = { BlackSquaresBB, WhiteSquaresBB };
+const Bitboard LightSquaresBB = 0x55AA55AA55AA55AAULL;
+const Bitboard DarkSquaresBB = 0xAA55AA55AA55AA55ULL;
+
+const Bitboard SquaresByColorBB[2] = { DarkSquaresBB, LightSquaresBB };
const Bitboard FileBB[8] = {
FileABB, FileBBB, FileCBB, FileDBB, FileEBB, FileFBB, FileGBB, FileHBB
Bitboard ClearMaskBB[65];
Bitboard StepAttackBB[16][64];
-Bitboard RayBB[64][8];
Bitboard BetweenBB[64][64];
+Bitboard SquaresInFrontMask[2][64];
Bitboard PassedPawnMask[2][64];
-Bitboard OutpostMask[2][64];
+Bitboard AttackSpanMask[2][64];
Bitboard BishopPseudoAttacks[64];
Bitboard RookPseudoAttacks[64];
Bitboard QueenPseudoAttacks[64];
uint8_t BitCount8Bit[256];
+int8_t DirectionTable[64][64];
////
namespace {
+ SquareDelta get_direction(Square orig, Square dest);
+ void init_direction_table();
void init_masks();
- void init_ray_bitboards();
void init_attacks();
void init_between_bitboards();
+ void init_pseudo_attacks();
+ Bitboard index_to_bitboard(int index, Bitboard mask);
Bitboard sliding_attacks(int sq, Bitboard block, int dirs, int deltas[][2],
int fmin, int fmax, int rmin, int rmax);
- Bitboard index_to_bitboard(int index, Bitboard mask);
- void init_sliding_attacks(Bitboard attacks[],
- int attackIndex[], Bitboard mask[],
- const int shift[2], const Bitboard mult[],
- int deltas[][2]);
- void init_pseudo_attacks();
+ void init_sliding_attacks(Bitboard attacks[], int attackIndex[], Bitboard mask[],
+ const int shift[], const Bitboard mult[], int deltas[][2]);
}
/// standard output. This is sometimes useful for debugging.
void print_bitboard(Bitboard b) {
- for(Rank r = RANK_8; r >= RANK_1; r--) {
- std::cout << "+---+---+---+---+---+---+---+---+" << std::endl;
- for(File f = FILE_A; f <= FILE_H; f++)
- std::cout << "| " << (bit_is_set(b, make_square(f, r))? 'X' : ' ') << ' ';
- std::cout << "|" << std::endl;
+
+ for (Rank r = RANK_8; r >= RANK_1; r--)
+ {
+ std::cout << "+---+---+---+---+---+---+---+---+" << std::endl;
+ for (File f = FILE_A; f <= FILE_H; f++)
+ std::cout << "| " << (bit_is_set(b, make_square(f, r))? 'X' : ' ') << ' ';
+
+ std::cout << "|" << std::endl;
}
std::cout << "+---+---+---+---+---+---+---+---+" << std::endl;
}
/// program initialization.
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}};
+
+ init_direction_table();
init_masks();
- init_ray_bitboards();
init_attacks();
init_between_bitboards();
init_sliding_attacks(RAttacks, RAttackIndex, RMask, RShift, RMult, rookDeltas);
#if defined(IS_64BIT) && !defined(USE_BSFQ)
-CACHE_LINE_ALIGNMENT
-static const int BitTable[64] = {
+static CACHE_LINE_ALIGNMENT
+const int BitTable[64] = {
0, 1, 2, 7, 3, 13, 8, 19, 4, 25, 14, 28, 9, 34, 20, 40, 5, 17, 26, 38, 15,
46, 29, 48, 10, 31, 35, 54, 21, 50, 41, 57, 63, 6, 12, 18, 24, 27, 33, 39,
16, 37, 45, 47, 30, 53, 49, 56, 62, 11, 23, 32, 36, 44, 52, 55, 61, 22, 43,
#elif !defined(USE_BSFQ)
-CACHE_LINE_ALIGNMENT
-static const int BitTable[64] = {
+static CACHE_LINE_ALIGNMENT
+const int BitTable[64] = {
63, 30, 3, 32, 25, 41, 22, 33, 15, 50, 42, 13, 11, 53, 19, 34, 61, 29, 2,
51, 21, 43, 45, 10, 18, 47, 1, 54, 9, 57, 0, 35, 62, 31, 40, 4, 49, 5, 52,
26, 60, 6, 23, 44, 46, 27, 56, 16, 7, 39, 48, 24, 59, 14, 12, 55, 38, 28,
};
Square first_1(Bitboard b) {
+
b ^= (b - 1);
uint32_t fold = int(b) ^ int(b >> 32);
return Square(BitTable[(fold * 0x783a9b23) >> 26]);
Bitboard b;
struct {
+#if defined (BIGENDIAN)
+ uint32_t h;
+ uint32_t l;
+#else
uint32_t l;
uint32_t h;
+#endif
} dw;
};
-// WARNING: Needs -fno-strict-aliasing compiler option
Square pop_1st_bit(Bitboard* bb) {
- b_union u;
-
- u.b = *bb;
-
- if (u.dw.l)
- {
- *((uint32_t*)bb) = u.dw.l & (u.dw.l - 1);
- return Square(BitTable[((u.dw.l ^ (u.dw.l - 1)) * 0x783a9b23) >> 26]);
- }
-
- *((uint32_t*)bb+1) = u.dw.h & (u.dw.h - 1); // Little endian only?
- return Square(BitTable[((~(u.dw.h ^ (u.dw.h - 1))) * 0x783a9b23) >> 26]);
+ b_union u;
+ Square ret;
+
+ u.b = *bb;
+
+ if (u.dw.l)
+ {
+ ret = Square(BitTable[((u.dw.l ^ (u.dw.l - 1)) * 0x783a9b23) >> 26]);
+ u.dw.l &= (u.dw.l - 1);
+ *bb = u.b;
+ return ret;
+ }
+ ret = Square(BitTable[((~(u.dw.h ^ (u.dw.h - 1))) * 0x783a9b23) >> 26]);
+ u.dw.h &= (u.dw.h - 1);
+ *bb = u.b;
+ return ret;
}
#endif
+
namespace {
// All functions below are used to precompute various bitboards during
// understand, but they all seem to work correctly, and it should never
// be necessary to touch any of them.
- void init_masks() {
- SetMaskBB[SQ_NONE] = 0ULL;
- ClearMaskBB[SQ_NONE] = ~SetMaskBB[SQ_NONE];
- for(Square s = SQ_A1; s <= SQ_H8; s++) {
- SetMaskBB[s] = (1ULL << s);
- ClearMaskBB[s] = ~SetMaskBB[s];
+ SquareDelta get_direction(Square orig, Square dest) {
+
+ const SquareDelta directions[] = {
+ DELTA_E, DELTA_N, DELTA_NE, DELTA_NW, DELTA_W, DELTA_S, DELTA_SW, DELTA_SE
+ };
+
+ for (int idx = 0; idx < 8; idx++)
+ {
+ Square from = orig;
+ Square to = from + directions[idx];
+
+ while (to != dest && square_distance(to, from) == 1 && square_is_ok(to))
+ {
+ from = to;
+ to += directions[idx];
+ }
+
+ if (to == dest && square_distance(from, to) == 1)
+ return directions[idx];
}
- for(Color c = WHITE; c <= BLACK; c++)
- for(Square s = SQ_A1; s <= SQ_H8; s++) {
- PassedPawnMask[c][s] =
- in_front_bb(c, s) & this_and_neighboring_files_bb(s);
- OutpostMask[c][s] = in_front_bb(c, s) & neighboring_files_bb(s);
- }
+ return DELTA_NONE;
+ }
- for (Bitboard b = 0ULL; b < 256ULL; b++)
- BitCount8Bit[b] = (uint8_t)count_1s(b);
+ void init_direction_table() {
+
+ for (Square s1 = SQ_A1; s1 <= SQ_H8; s1++)
+ for (Square s2 = SQ_A1; s2 <= SQ_H8; s2++)
+ DirectionTable[s1][s2] = uint8_t(get_direction(s1, s2));
}
+ void init_masks() {
- void init_ray_bitboards() {
- int d[8] = {1, -1, 16, -16, 17, -17, 15, -15};
- for(int i = 0; i < 128; i = (i + 9) & ~8) {
- for(int j = 0; j < 8; j++) {
- RayBB[(i&7)|((i>>4)<<3)][j] = EmptyBoardBB;
- for(int k = i + d[j]; (k & 0x88) == 0; k += d[j])
- set_bit(&(RayBB[(i&7)|((i>>4)<<3)][j]), Square((k&7)|((k>>4)<<3)));
- }
+ SetMaskBB[SQ_NONE] = 0ULL;
+ ClearMaskBB[SQ_NONE] = ~SetMaskBB[SQ_NONE];
+
+ for (Square s = SQ_A1; s <= SQ_H8; s++)
+ {
+ SetMaskBB[s] = (1ULL << s);
+ ClearMaskBB[s] = ~SetMaskBB[s];
}
- }
+ 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);
+ }
void init_attacks() {
- int i, j, k, l;
- int step[16][8] = {
+
+ const int step[16][8] = {
{0},
{7,9,0}, {17,15,10,6,-6,-10,-15,-17}, {9,7,-7,-9,0}, {8,1,-1,-8,0},
{9,7,-7,-9,8,1,-1,-8}, {9,7,-7,-9,8,1,-1,-8}, {0}, {0},
{9,7,-7,-9,8,1,-1,-8}, {9,7,-7,-9,8,1,-1,-8}
};
- for(i = 0; i < 64; i++) {
- for(j = 0; j <= int(BK); j++) {
- StepAttackBB[j][i] = EmptyBoardBB;
- for(k = 0; k < 8 && step[j][k] != 0; k++) {
- l = i + step[j][k];
- if(l >= 0 && l < 64 && abs((i&7) - (l&7)) < 3)
- StepAttackBB[j][i] |= (1ULL << l);
+ for (int i = 0; i < 64; i++)
+ for (int j = 0; j <= int(BK); j++)
+ {
+ StepAttackBB[j][i] = EmptyBoardBB;
+ for (int k = 0; k < 8 && step[j][k] != 0; k++)
+ {
+ int l = i + step[j][k];
+ if (l >= 0 && l < 64 && abs((i & 7) - (l & 7)) < 3)
+ StepAttackBB[j][i] |= (1ULL << l);
+ }
}
- }
- }
}
-
Bitboard sliding_attacks(int sq, Bitboard block, int dirs, int deltas[][2],
int fmin=0, int fmax=7, int rmin=0, int rmax=7) {
Bitboard result = 0ULL;
- int rk = sq / 8, fl = sq % 8, r, f, i;
- for(i = 0; i < dirs; i++) {
- int dx = deltas[i][0], dy = deltas[i][1];
- for(f = fl+dx, r = rk+dy;
- (dx==0 || (f>=fmin && f<=fmax)) && (dy==0 || (r>=rmin && r<=rmax));
- f += dx, r += dy) {
- result |= (1ULL << (f + r*8));
- if(block & (1ULL << (f + r*8))) break;
- }
+ int rk = sq / 8;
+ int fl = sq % 8;
+
+ for (int i = 0; i < dirs; i++)
+ {
+ int dx = deltas[i][0];
+ int dy = deltas[i][1];
+ int f = fl + dx;
+ int r = rk + dy;
+
+ while ( (dx == 0 || (f >= fmin && f <= fmax))
+ && (dy == 0 || (r >= rmin && r <= rmax)))
+ {
+ result |= (1ULL << (f + r*8));
+ if (block & (1ULL << (f + r*8)))
+ break;
+
+ f += dx;
+ r += dy;
+ }
}
return result;
}
-
void init_between_bitboards() {
- SquareDelta step[8] = {
- DELTA_E, DELTA_W, DELTA_N, DELTA_S, DELTA_NE, DELTA_SW, DELTA_NW, DELTA_SE
- };
- SignedDirection d;
- for(Square s1 = SQ_A1; s1 <= SQ_H8; s1++)
- for(Square s2 = SQ_A1; s2 <= SQ_H8; s2++) {
- BetweenBB[s1][s2] = EmptyBoardBB;
- d = signed_direction_between_squares(s1, s2);
- if(d != SIGNED_DIR_NONE)
- for(Square s3 = s1 + step[d]; s3 != s2; s3 += step[d])
- set_bit(&(BetweenBB[s1][s2]), s3);
+
+ Square s1, s2, s3;
+ SquareDelta d;
+
+ for (s1 = SQ_A1; s1 <= SQ_H8; s1++)
+ for (s2 = SQ_A1; s2 <= SQ_H8; s2++)
+ {
+ BetweenBB[s1][s2] = EmptyBoardBB;
+ d = SquareDelta(DirectionTable[s1][s2]);
+
+ if (d == DELTA_NONE)
+ continue;
+
+ for (s3 = s1 + d; s3 != s2; s3 += d)
+ set_bit(&(BetweenBB[s1][s2]), s3);
}
}
-
Bitboard index_to_bitboard(int index, Bitboard mask) {
- int i, j, bits = count_1s(mask);
+
Bitboard result = 0ULL;
- for(i = 0; i < bits; i++) {
- j = pop_1st_bit(&mask);
- if(index & (1 << i)) result |= (1ULL << j);
+ int bits = count_1s<CNT32>(mask);
+
+ for (int i = 0; i < bits; i++)
+ {
+ int j = pop_1st_bit(&mask);
+ if (index & (1 << i))
+ result |= (1ULL << j);
}
return result;
}
+ void init_sliding_attacks(Bitboard attacks[], int attackIndex[], Bitboard mask[],
+ const int shift[], const Bitboard mult[], int deltas[][2]) {
- void init_sliding_attacks(Bitboard attacks[],
- int attackIndex[], Bitboard mask[],
- const int shift[2], const Bitboard mult[],
- int deltas[][2]) {
- int i, j, k, index = 0;
- Bitboard b;
- for(i = 0; i < 64; i++) {
- attackIndex[i] = index;
- mask[i] = sliding_attacks(i, 0ULL, 4, deltas, 1, 6, 1, 6);
+ for (int i = 0, index = 0; i < 64; i++)
+ {
+ attackIndex[i] = index;
+ mask[i] = sliding_attacks(i, 0, 4, deltas, 1, 6, 1, 6);
#if defined(IS_64BIT)
- j = (1 << (64 - shift[i]));
+ int j = (1 << (64 - shift[i]));
#else
- j = (1 << (32 - shift[i]));
+ int j = (1 << (32 - shift[i]));
#endif
- for(k = 0; k < j; k++) {
-
+ for (int k = 0; k < j; k++)
+ {
#if defined(IS_64BIT)
- b = index_to_bitboard(k, mask[i]);
- attacks[index + ((b * mult[i]) >> shift[i])] =
- sliding_attacks(i, b, 4, deltas);
+ Bitboard b = index_to_bitboard(k, mask[i]);
+ attacks[index + ((b * mult[i]) >> shift[i])] = sliding_attacks(i, b, 4, deltas);
#else
- b = index_to_bitboard(k, mask[i]);
- attacks[index +
- (unsigned(int(b) * int(mult[i]) ^
- int(b >> 32) * int(mult[i] >> 32))
- >> shift[i])] =
- sliding_attacks(i, b, 4, deltas);
+ Bitboard b = index_to_bitboard(k, mask[i]);
+ unsigned v = int(b) * int(mult[i]) ^ int(b >> 32) * int(mult[i] >> 32);
+ attacks[index + (v >> shift[i])] = sliding_attacks(i, b, 4, deltas);
#endif
- }
- index += j;
+ }
+ index += j;
}
}
-
void init_pseudo_attacks() {
- Square s;
- for(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);
+
+ 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);
}
}
projects / stockfish / blobdiff