/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2013 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2008-2014 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 <algorithm>
-#include <cstring>
-#include <sstream>
+#include <cstring> // For memset
#include "bitboard.h"
#include "bitcount.h"
#include "rkiss.h"
-CACHE_LINE_ALIGNMENT
-
Bitboard RMasks[SQUARE_NB];
Bitboard RMagics[SQUARE_NB];
Bitboard* RAttacks[SQUARE_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
result += 8;
}
- return (Square)(result + MS1BTable[b32]);
+ return Square(result + MS1BTable[b32]);
}
#endif // ifndef USE_BSFQ
const std::string Bitboards::pretty(Bitboard b) {
- std::ostringstream ss;
+ std::string s = "+---+---+---+---+---+---+---+---+\n";
- for (Rank rank = RANK_8; rank >= RANK_1; --rank)
+ for (Rank r = RANK_8; r >= RANK_1; --r)
{
- ss << "+---+---+---+---+---+---+---+---+" << '\n';
-
- for (File file = FILE_A; file <= FILE_H; ++file)
- ss << "| " << (b & (file | rank) ? "X " : " ");
+ for (File f = FILE_A; f <= FILE_H; ++f)
+ s.append(b & make_square(f, r) ? "| X " : "| ");
- ss << "|\n";
+ s.append("|\n+---+---+---+---+---+---+---+---+\n");
}
- ss << "+---+---+---+---+---+---+---+---+";
- return ss.str();
+
+ return s;
}
-/// Bitboards::init() initializes various bitboard arrays. It is called during
-/// program initialization.
+/// Bitboards::init() initializes various bitboard tables. It is called at
+/// startup and relies on global objects to be already zero-initialized.
void Bitboards::init() {
- for (int k = 0, i = 0; i < 8; ++i)
- while (k < (2 << i))
- MS1BTable[k++] = i;
-
for (Square s = SQ_A1; s <= SQ_H8; ++s)
- BSFTable[bsf_index(SquareBB[s] = 1ULL << s)] = s;
-
- FileBB[FILE_A] = FileABB;
- RankBB[RANK_1] = Rank1BB;
-
- for (int i = 1; i < 8; ++i)
{
- FileBB[i] = FileBB[i - 1] << 1;
- RankBB[i] = RankBB[i - 1] << 8;
+ 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 (File f = FILE_A; f <= FILE_H; ++f)
+ FileBB[f] = f > FILE_A ? FileBB[f - 1] << 1 : FileABB;
+
+ for (Rank r = RANK_1; r <= RANK_8; ++r)
+ RankBB[r] = r > RANK_1 ? RankBB[r - 1] << 8 : Rank1BB;
+
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);
for (Square s1 = SQ_A1; s1 <= SQ_H8; ++s1)
for (Square s2 = SQ_A1; s2 <= SQ_H8; ++s2)
- {
- SquareDistance[s1][s2] = std::max(file_distance(s1, s2), rank_distance(s1, s2));
if (s1 != s2)
- DistanceRingsBB[s1][SquareDistance[s1][s2] - 1] |= s2;
- }
+ {
+ SquareDistance[s1][s2] = std::max(distance<File>(s1, s2), distance<Rank>(s1, s2));
+ DistanceRingsBB[s1][SquareDistance[s1][s2] - 1] |= s2;
+ }
int steps[][9] = { {}, { 7, 9 }, { 17, 15, 10, 6, -6, -10, -15, -17 },
{}, {}, {}, { 9, 7, -7, -9, 8, 1, -1, -8 } };
{
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;
}
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;
}
- Bitboard pick_random(RKISS& rk, int booster) {
-
- // Values s1 and s2 are used to rotate the candidate magic of a
- // quantity known to be optimal to quickly find the magics.
- int s1 = booster & 63, s2 = (booster >> 6) & 63;
-
- 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>();
- }
-
-
// init_magics() computes all rook and bishop attacks at startup. Magic
// bitboards are used to look up attacks of sliding pieces. As a reference see
// chessprogramming.wikispaces.com/Magic+Bitboards. In particular, here we
void init_magics(Bitboard table[], Bitboard* attacks[], Bitboard magics[],
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 } };
+ int MagicBoosters[][RANK_NB] = { { 969, 1976, 2850, 542, 2069, 2852, 1708, 164 },
+ { 3101, 552, 3555, 926, 834, 26, 2131, 1117 } };
RKISS rk;
Bitboard occupancy[4096], reference[4096], edges, b;
int i, size, booster;
b = size = 0;
do {
occupancy[size] = b;
- reference[size++] = sliding_attack(deltas, s, b);
+ reference[size] = sliding_attack(deltas, s, b);
+
+ if (HasPext)
+ attacks[s][_pext_u64(b, masks[s])] = reference[size];
+
+ size++;
b = (b - masks[s]) & masks[s];
} while (b);
if (s < SQ_H8)
attacks[s + 1] = attacks[s] + size;
+ if (HasPext)
+ continue;
+
booster = MagicBoosters[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] = pick_random(rk, booster);
+ do
+ magics[s] = rk.magic_rand<Bitboard>(booster);
while (popcount<Max15>((magics[s] * masks[s]) >> 56) < 6);
std::memset(attacks[s], 0, size * sizeof(Bitboard));
if (attack && attack != reference[i])
break;
- assert(reference[i] != 0);
+ assert(reference[i]);
attack = reference[i];
}
- } while (i != size);
+ } while (i < size);
}
}
}