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];
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
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 dummy;
- struct {
-#if defined (BIGENDIAN)
- uint32_t h;
- uint32_t l;
-#else
- uint32_t l;
- uint32_t h;
-#endif
- } b;
-};
-
Square pop_1st_bit(Bitboard* b) {
- const b_union u = *((b_union*)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 (u.b.l)
- {
- ((b_union*)b)->b.l = u.b.l & (u.b.l - 1);
- return Square(BSFTable[((u.b.l ^ (u.b.l - 1)) * 0x783A9B23) >> 26]);
- }
+ if (b32 > 0xFFFF)
+ {
+ b32 >>= 16;
+ result += 16;
+ }
- ((b_union*)b)->b.h = u.b.h & (u.b.h - 1);
- return Square(BSFTable[((~(u.b.h ^ (u.b.h - 1))) * 0x783A9B23) >> 26]);
+ 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);
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] = 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));
}
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;
}
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;