*/
#include <algorithm>
-#include <cstring> // For memset
+#include <cstring> // For std::memset
#include "bitboard.h"
#include "bitcount.h"
-#include "rkiss.h"
+#include "misc.h"
-CACHE_LINE_ALIGNMENT
+Bitboard RookMasks[SQUARE_NB];
+Bitboard RookMagics[SQUARE_NB];
+Bitboard* RookAttacks[SQUARE_NB];
+unsigned RookShifts[SQUARE_NB];
-Bitboard RMasks[SQUARE_NB];
-Bitboard RMagics[SQUARE_NB];
-Bitboard* RAttacks[SQUARE_NB];
-unsigned RShifts[SQUARE_NB];
-
-Bitboard BMasks[SQUARE_NB];
-Bitboard BMagics[SQUARE_NB];
-Bitboard* BAttacks[SQUARE_NB];
-unsigned BShifts[SQUARE_NB];
+Bitboard BishopMasks[SQUARE_NB];
+Bitboard BishopMagics[SQUARE_NB];
+Bitboard* BishopAttacks[SQUARE_NB];
+unsigned BishopShifts[SQUARE_NB];
Bitboard SquareBB[SQUARE_NB];
Bitboard FileBB[FILE_NB];
const uint64_t DeBruijn_64 = 0x3F79D71B4CB0A89ULL;
const uint32_t DeBruijn_32 = 0x783A9B23;
- CACHE_LINE_ALIGNMENT
-
int MS1BTable[256];
Square BSFTable[SQUARE_NB];
- Bitboard RTable[0x19000]; // Storage space for rook attacks
- Bitboard BTable[0x1480]; // Storage space for bishop attacks
+ Bitboard RookTable[0x19000]; // Storage space for rook attacks
+ Bitboard BishopTable[0x1480]; // Storage space for bishop attacks
typedef unsigned (Fn)(Square, Bitboard);
}
}
-
-/// Intel PEXT (parallel extraction) software implementation
-Bitboard pext(Bitboard b, Bitboard mask) {
-
- Bitboard res = 0;
-
- for (Bitboard bb = 1; mask; bb += bb)
- {
- if (b & mask & -mask)
- res |= bb;
-
- mask &= mask - 1;
- }
- return res;
-}
-
-
/// lsb()/msb() finds the least/most significant bit in a non-zero bitboard.
/// pop_lsb() finds and clears the least significant bit in a non-zero bitboard.
void Bitboards::init() {
for (Square s = SQ_A1; s <= SQ_H8; ++s)
- BSFTable[bsf_index(SquareBB[s] = 1ULL << s)] = s;
+ {
+ SquareBB[s] = 1ULL << s;
+ BSFTable[bsf_index(SquareBB[s])] = s;
+ }
for (Bitboard b = 1; b < 256; ++b)
MS1BTable[b] = more_than_one(b) ? MS1BTable[b - 1] : lsb(b);
for (Square s2 = SQ_A1; s2 <= SQ_H8; ++s2)
if (s1 != s2)
{
- SquareDistance[s1][s2] = std::max(file_distance(s1, s2), rank_distance(s1, s2));
+ SquareDistance[s1][s2] = std::max(distance<File>(s1, s2), distance<Rank>(s1, s2));
DistanceRingsBB[s1][SquareDistance[s1][s2] - 1] |= s2;
}
{
Square to = s + Square(c == WHITE ? steps[pt][i] : -steps[pt][i]);
- if (is_ok(to) && square_distance(s, to) < 3)
+ if (is_ok(to) && 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 };
+ Square RookDeltas[] = { DELTA_N, DELTA_E, DELTA_S, DELTA_W };
+ Square BishopDeltas[] = { DELTA_NE, DELTA_SE, DELTA_SW, DELTA_NW };
- init_magics(RTable, RAttacks, RMagics, RMasks, RShifts, RDeltas, magic_index<ROOK>);
- init_magics(BTable, BAttacks, BMagics, BMasks, BShifts, BDeltas, magic_index<BISHOP>);
+ init_magics(RookTable, RookAttacks, RookMagics, RookMasks, RookShifts, RookDeltas, magic_index<ROOK>);
+ init_magics(BishopTable, BishopAttacks, BishopMagics, BishopMasks, BishopShifts, BishopDeltas, magic_index<BISHOP>);
for (Square s1 = SQ_A1; s1 <= SQ_H8; ++s1)
{
for (int i = 0; i < 4; ++i)
for (Square s = sq + deltas[i];
- is_ok(s) && square_distance(s, s - deltas[i]) == 1;
+ is_ok(s) && distance(s, s - deltas[i]) == 1;
s += deltas[i])
{
attack |= s;
void init_magics(Bitboard table[], Bitboard* attacks[], Bitboard magics[],
Bitboard masks[], unsigned shifts[], Square deltas[], Fn index) {
- int MagicBoosters[][8] = { { 969, 1976, 2850, 542, 2069, 2852, 1708, 164 },
- { 3101, 552, 3555, 926, 834, 26, 2131, 1117 } };
+ int seeds[][RANK_NB] = { { 8977, 44560, 54343, 38998, 5731, 95205, 104912, 17020 },
+ { 728, 10316, 55013, 32803, 12281, 15100, 16645, 255 } };
- RKISS rk;
Bitboard occupancy[4096], reference[4096], edges, b;
- int i, size, booster;
+ int i, size;
// attacks[s] is a pointer to the beginning of the attacks table for square 's'
attacks[SQ_A1] = table;
reference[size] = sliding_attack(deltas, s, b);
if (HasPext)
- attacks[s][pext(occupancy[size], masks[s])] = reference[size];
+ attacks[s][_pext_u64(b, masks[s])] = reference[size];
size++;
b = (b - masks[s]) & masks[s];
if (HasPext)
continue;
- booster = MagicBoosters[Is64Bit][rank_of(s)];
+ PRNG rng(seeds[Is64Bit][rank_of(s)]);
// Find a magic for square 's' picking up an (almost) random number
// until we find the one that passes the verification test.
do {
- do magics[s] = rk.magic_rand<Bitboard>(booster);
+ do
+ magics[s] = rng.sparse_rand<Bitboard>();
while (popcount<Max15>((magics[s] * masks[s]) >> 56) < 6);
std::memset(attacks[s], 0, size * sizeof(Bitboard));