Bitboard RMasks[64];
Bitboard RMagics[64];
Bitboard* RAttacks[64];
-int RShifts[64];
+unsigned RShifts[64];
Bitboard BMasks[64];
Bitboard BMagics[64];
Bitboard* BAttacks[64];
-int BShifts[64];
+unsigned BShifts[64];
Bitboard SquareBB[64];
Bitboard FileBB[8];
Bitboard InFrontBB[2][8];
Bitboard StepAttacksBB[16][64];
Bitboard BetweenBB[64][64];
-Bitboard SquaresInFrontMask[2][64];
+Bitboard ForwardBB[2][64];
Bitboard PassedPawnMask[2][64];
Bitboard AttackSpanMask[2][64];
Bitboard PseudoAttacks[6][64];
-uint8_t BitCount8Bit[256];
int SquareDistance[64][64];
namespace {
CACHE_LINE_ALIGNMENT
int BSFTable[64];
+ int MS1BTable[256];
Bitboard RTable[0x19000]; // Storage space for rook attacks
Bitboard BTable[0x1480]; // Storage space for bishop attacks
+ uint8_t BitCount8Bit[256];
typedef unsigned (Fn)(Square, Bitboard);
void init_magics(Bitboard table[], Bitboard* attacks[], Bitboard magics[],
- Bitboard masks[], int shifts[], Square deltas[], Fn get_index);
+ Bitboard masks[], unsigned shifts[], Square deltas[], Fn index);
}
-
-/// print_bitboard() prints a bitboard in an easily readable format to the
-/// standard output. This is sometimes useful for debugging.
-
-void print_bitboard(Bitboard b) {
-
- for (Rank r = RANK_8; r >= RANK_1; r--)
- {
- std::cout << "+---+---+---+---+---+---+---+---+" << '\n';
- for (File f = FILE_A; f <= FILE_H; f++)
- std::cout << "| " << ((b & make_square(f, r)) ? "X " : " ");
-
- std::cout << "|\n";
- }
- std::cout << "+---+---+---+---+---+---+---+---+" << std::endl;
-}
-
-
/// first_1() finds the least significant nonzero bit in a nonzero bitboard.
/// pop_1st_bit() finds and clears the least significant nonzero bit in a
/// nonzero bitboard.
return Square(BSFTable[(fold * 0x783A9B23) >> 26]);
}
-// Use type-punning
-union b_union {
-
- Bitboard b;
- struct {
-#if defined (BIGENDIAN)
- uint32_t h;
- uint32_t l;
-#else
- uint32_t l;
- uint32_t h;
-#endif
- } dw;
-};
-
-Square pop_1st_bit(Bitboard* bb) {
-
- b_union u;
- Square ret;
-
- u.b = *bb;
-
- if (u.dw.l)
- {
- ret = Square(BSFTable[((u.dw.l ^ (u.dw.l - 1)) * 0x783A9B23) >> 26]);
- u.dw.l &= (u.dw.l - 1);
- *bb = u.b;
- return ret;
- }
- ret = Square(BSFTable[((~(u.dw.h ^ (u.dw.h - 1))) * 0x783A9B23) >> 26]);
- u.dw.h &= (u.dw.h - 1);
- *bb = u.b;
- return ret;
+Square pop_1st_bit(Bitboard* b) {
+
+ Bitboard bb = *b;
+ *b = bb & (bb - 1);
+ bb ^= (bb - 1);
+ uint32_t fold = unsigned(bb) ^ unsigned(bb >> 32);
+ return Square(BSFTable[(fold * 0x783A9B23) >> 26]);
+}
+
+Square last_1(Bitboard b) {
+
+ unsigned b32;
+ int result = 0;
+
+ if (b > 0xFFFFFFFF)
+ {
+ b >>= 32;
+ result = 32;
+ }
+
+ b32 = unsigned(b);
+
+ if (b32 > 0xFFFF)
+ {
+ b32 >>= 16;
+ result += 16;
+ }
+
+ if (b32 > 0xFF)
+ {
+ b32 >>= 8;
+ result += 8;
+ }
+
+ return Square(result + MS1BTable[b32]);
}
#endif // !defined(USE_BSFQ)
-/// bitboards_init() initializes various bitboard arrays. It is called during
+/// Bitboards::print() prints a bitboard in an easily readable format to the
+/// standard output. This is sometimes useful for debugging.
+
+void Bitboards::print(Bitboard b) {
+
+ for (Rank rank = RANK_8; rank >= RANK_1; rank--)
+ {
+ std::cout << "+---+---+---+---+---+---+---+---+" << '\n';
+
+ for (File file = FILE_A; file <= FILE_H; file++)
+ std::cout << "| " << (b & make_square(file, rank) ? "X " : " ");
+
+ std::cout << "|\n";
+ }
+ std::cout << "+---+---+---+---+---+---+---+---+" << std::endl;
+}
+
+
+/// Bitboards::init() initializes various bitboard arrays. It is called during
/// program initialization.
-void bitboards_init() {
+void Bitboards::init() {
+
+ for (int k = 0, i = 0; i < 8; i++)
+ while (k < (2 << i))
+ MS1BTable[k++] = i;
for (Bitboard b = 0; b < 256; b++)
BitCount8Bit[b] = (uint8_t)popcount<Max15>(b);
FileBB[FILE_A] = FileABB;
RankBB[RANK_1] = Rank1BB;
- for (int f = FILE_B; f <= FILE_H; f++)
+ for (int i = 1; i < 8; i++)
{
- FileBB[f] = FileBB[f - 1] << 1;
- RankBB[f] = RankBB[f - 1] << 8;
+ FileBB[i] = FileBB[i - 1] << 1;
+ RankBB[i] = RankBB[i - 1] << 8;
}
- for (int f = FILE_A; f <= FILE_H; f++)
+ for (File f = FILE_A; f <= FILE_H; f++)
{
AdjacentFilesBB[f] = (f > FILE_A ? FileBB[f - 1] : 0) | (f < FILE_H ? FileBB[f + 1] : 0);
ThisAndAdjacentFilesBB[f] = FileBB[f] | AdjacentFilesBB[f];
}
- 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 (Rank r = RANK_1; r < RANK_8; r++)
+ InFrontBB[WHITE][r] = ~(InFrontBB[BLACK][r + 1] = InFrontBB[BLACK][r] | RankBB[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_adjacent_files_bb(file_of(s));
- AttackSpanMask[c][s] = in_front_bb(c, s) & adjacent_files_bb(file_of(s));
+ ForwardBB[c][s] = InFrontBB[c][rank_of(s)] & FileBB[file_of(s)];
+ PassedPawnMask[c][s] = InFrontBB[c][rank_of(s)] & ThisAndAdjacentFilesBB[file_of(s)];
+ AttackSpanMask[c][s] = InFrontBB[c][rank_of(s)] & AdjacentFilesBB[file_of(s)];
}
for (Square s1 = SQ_A1; s1 <= SQ_H8; s1++)
{
Square to = s + Square(c == WHITE ? steps[pt][k] : -steps[pt][k]);
- if (square_is_ok(to) && square_distance(s, to) < 3)
+ if (is_ok(to) && square_distance(s, to) < 3)
StepAttacksBB[make_piece(c, pt)][s] |= to;
}
Square RDeltas[] = { DELTA_N, DELTA_E, DELTA_S, DELTA_W };
Square BDeltas[] = { DELTA_NE, DELTA_SE, DELTA_SW, DELTA_NW };
- init_magics(RTable, RAttacks, RMagics, RMasks, RShifts, RDeltas, r_index);
- init_magics(BTable, BAttacks, BMagics, BMasks, BShifts, BDeltas, b_index);
+ init_magics(RTable, RAttacks, RMagics, RMasks, RShifts, RDeltas, magic_index<ROOK>);
+ init_magics(BTable, BAttacks, BMagics, BMasks, BShifts, BDeltas, magic_index<BISHOP>);
for (Square s = SQ_A1; s <= SQ_H8; s++)
{
- PseudoAttacks[BISHOP][s] = bishop_attacks_bb(s, 0);
- PseudoAttacks[ROOK][s] = rook_attacks_bb(s, 0);
- PseudoAttacks[QUEEN][s] = PseudoAttacks[BISHOP][s] | PseudoAttacks[ROOK][s];
+ PseudoAttacks[QUEEN][s] = PseudoAttacks[BISHOP][s] = attacks_bb<BISHOP>(s, 0);
+ PseudoAttacks[QUEEN][s] |= PseudoAttacks[ ROOK][s] = attacks_bb< ROOK>(s, 0);
}
for (Square s1 = SQ_A1; s1 <= SQ_H8; s1++)
for (int i = 0; i < 4; i++)
for (Square s = sq + deltas[i];
- square_is_ok(s) && square_distance(s, s - deltas[i]) == 1;
+ is_ok(s) && square_distance(s, s - deltas[i]) == 1;
s += deltas[i])
{
attack |= s;
}
- Bitboard pick_random(Bitboard mask, RKISS& rk, int booster) {
-
- Bitboard magic;
+ Bitboard pick_random(RKISS& rk, int booster) {
// Values s1 and s2 are used to rotate the candidate magic of a
// quantity known to be the optimal to quickly find the magics.
int s1 = booster & 63, s2 = (booster >> 6) & 63;
- while (true)
- {
- magic = rk.rand<Bitboard>();
- magic = (magic >> s1) | (magic << (64 - s1));
- magic &= rk.rand<Bitboard>();
- magic = (magic >> s2) | (magic << (64 - s2));
- magic &= rk.rand<Bitboard>();
-
- if (BitCount8Bit[(mask * magic) >> 56] >= 6)
- return magic;
- }
+ Bitboard m = rk.rand<Bitboard>();
+ m = (m >> s1) | (m << (64 - s1));
+ m &= rk.rand<Bitboard>();
+ m = (m >> s2) | (m << (64 - s2));
+ return m & rk.rand<Bitboard>();
}
// use the so called "fancy" approach.
void init_magics(Bitboard table[], Bitboard* attacks[], Bitboard magics[],
- Bitboard masks[], int shifts[], Square deltas[], Fn get_index) {
+ Bitboard masks[], unsigned shifts[], Square deltas[], Fn index) {
int MagicBoosters[][8] = { { 3191, 2184, 1310, 3618, 2091, 1308, 2452, 3996 },
{ 1059, 3608, 605, 3234, 3326, 38, 2029, 3043 } };
// Find a magic for square 's' picking up an (almost) random number
// until we find the one that passes the verification test.
do {
- magics[s] = pick_random(masks[s], rk, booster);
+ do magics[s] = pick_random(rk, booster);
+ while (BitCount8Bit[(magics[s] * masks[s]) >> 56] < 6);
+
memset(attacks[s], 0, size * sizeof(Bitboard));
// A good magic must map every possible occupancy to an index that
// effect of verifying the magic.
for (i = 0; i < size; i++)
{
- Bitboard& attack = attacks[s][get_index(s, occupancy[i])];
+ Bitboard& attack = attacks[s][index(s, occupancy[i])];
if (attack && attack != reference[i])
break;
+ assert(reference[i] != 0);
+
attack = reference[i];
}
} while (i != size);
projects / stockfish / blobdiff