#include "bitboard.h"
#include "bitcount.h"
-#include "direction.h"
#if defined(IS_64BIT)
}
};
+// Global bitboards definitions with static storage duration are
+// automatically set to zero before enter main().
Bitboard RMask[64];
int RAttackIndex[64];
Bitboard RAttacks[0x19000];
Bitboard SetMaskBB[65];
Bitboard ClearMaskBB[65];
-Bitboard StepAttackBB[16][64];
-Bitboard RayBB[64][8];
+Bitboard NonSlidingAttacksBB[16][64];
Bitboard BetweenBB[64][64];
Bitboard SquaresInFrontMask[2][64];
uint8_t BitCount8Bit[256];
-////
-//// Local definitions
-////
-
namespace {
void init_masks();
- void init_ray_bitboards();
- void init_attacks();
- void init_between_bitboards();
+ void init_non_sliding_attacks();
void init_pseudo_attacks();
+ void init_between_bitboards();
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);
}
-////
-//// Functions
-////
-
/// print_bitboard() prints a bitboard in an easily readable format to the
-/// standard output. This is sometimes useful for debugging.
+/// 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;
+ std::cout << "+---+---+---+---+---+---+---+---+" << '\n';
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 << "|\n";
}
std::cout << "+---+---+---+---+---+---+---+---+" << std::endl;
}
-/// init_bitboards() initializes various bitboard arrays. It is called during
-/// 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_masks();
- init_ray_bitboards();
- init_attacks();
- init_between_bitboards();
- init_sliding_attacks(RAttacks, RAttackIndex, RMask, RShift, RMult, rookDeltas);
- init_sliding_attacks(BAttacks, BAttackIndex, BMask, BShift, BMult, bishopDeltas);
- init_pseudo_attacks();
-}
-
-
/// 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.
#endif
+/// init_bitboards() initializes various bitboard arrays. It is called during
+/// 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_masks();
+ init_non_sliding_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();
+}
+
namespace {
// All functions below are used to precompute various bitboards during
void init_masks() {
- SetMaskBB[SQ_NONE] = 0ULL;
+ SetMaskBB[SQ_NONE] = EmptyBoardBB;
ClearMaskBB[SQ_NONE] = ~SetMaskBB[SQ_NONE];
for (Square s = SQ_A1; s <= SQ_H8; s++)
AttackSpanMask[c][s] = in_front_bb(c, s) & neighboring_files_bb(s);
}
- for (Bitboard b = 0ULL; b < 256ULL; b++)
+ for (Bitboard b = 0; b < 256; b++)
BitCount8Bit[b] = (uint8_t)count_1s<CNT32>(b);
}
- int remove_bit_8(int i) { return ((i & ~15) >> 1) | (i & 7); }
-
- 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[remove_bit_8(i)][j] = EmptyBoardBB;
- for (int k = i + d[j]; (k & 0x88) == 0; k += d[j])
- set_bit(&(RayBB[remove_bit_8(i)][j]), Square(remove_bit_8(k)));
- }
- }
-
- void init_attacks() {
+ void init_non_sliding_attacks() {
- const int step[16][8] = {
+ const int step[][9] = {
{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},
- {-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}
+ {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 (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++)
+ 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++)
{
- int l = i + step[j][k];
- if (l >= 0 && l < 64 && abs((i & 7) - (l & 7)) < 3)
- StepAttackBB[j][i] |= (1ULL << l);
+ Square to = s + Square(step[pc][k]);
+
+ if (square_is_ok(to) && square_distance(s, to) < 3)
+ set_bit(&NonSlidingAttacksBB[pc][s], to);
}
- }
}
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;
+ Bitboard result = 0;
int rk = sq / 8;
int fl = sq % 8;
return result;
}
- void init_between_bitboards() {
-
- const SquareDelta step[8] = { DELTA_E, DELTA_W, DELTA_N, DELTA_S,
- DELTA_NE, DELTA_SW, DELTA_NW, DELTA_SE };
-
- for (Square s1 = SQ_A1; s1 <= SQ_H8; s1++)
- for (Square s2 = SQ_A1; s2 <= SQ_H8; s2++)
- {
- BetweenBB[s1][s2] = EmptyBoardBB;
- SignedDirection 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);
- }
- }
- }
-
Bitboard index_to_bitboard(int index, Bitboard mask) {
- Bitboard result = 0ULL;
- int bits = count_1s<CNT32>(mask);
+ Bitboard result = EmptyBoardBB;
+ int sq, cnt = 0;
- for (int i = 0; i < bits; i++)
+ while (mask)
{
- int j = pop_1st_bit(&mask);
- if (index & (1 << i))
- result |= (1ULL << j);
+ sq = pop_1st_bit(&mask);
+
+ if (index & (1 << cnt++))
+ result |= (1ULL << sq);
}
return result;
}
for (int i = 0, index = 0; i < 64; i++)
{
attackIndex[i] = index;
- mask[i] = sliding_attacks(i, 0ULL, 4, deltas, 1, 6, 1, 6);
+ mask[i] = sliding_attacks(i, 0, 4, deltas, 1, 6, 1, 6);
#if defined(IS_64BIT)
int j = (1 << (64 - shift[i]));
}
}
+ void init_between_bitboards() {
+
+ Square s1, s2, s3;
+ SquareDelta 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 = SquareDelta(s2 - s1) / Max(f, r);
+
+ for (s3 = s1 + d; s3 != s2; s3 += d)
+ set_bit(&(BetweenBB[s1][s2]), s3);
+ }
+ }
+
}