/*
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 <iostream>
+#include <cstring> // For memset
#include "bitboard.h"
#include "bitcount.h"
-#include "misc.h"
#include "rkiss.h"
CACHE_LINE_ALIGNMENT
Bitboard InFrontBB[COLOR_NB][RANK_NB];
Bitboard StepAttacksBB[PIECE_NB][SQUARE_NB];
Bitboard BetweenBB[SQUARE_NB][SQUARE_NB];
+Bitboard LineBB[SQUARE_NB][SQUARE_NB];
Bitboard DistanceRingsBB[SQUARE_NB][8];
Bitboard ForwardBB[COLOR_NB][SQUARE_NB];
Bitboard PassedPawnMask[COLOR_NB][SQUARE_NB];
}
}
-/// lsb()/msb() finds the least/most significant bit in a nonzero bitboard.
-/// pop_lsb() finds and clears the least significant bit in a nonzero bitboard.
+/// 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.
#ifndef USE_BSFQ
result += 8;
}
- return (Square)(result + MS1BTable[b32]);
+ return Square(result + MS1BTable[b32]);
}
#endif // ifndef USE_BSFQ
-/// Bitboards::print() prints a bitboard in an easily readable format to the
-/// standard output. This is sometimes useful for debugging.
+/// Bitboards::pretty() returns an ASCII representation of a bitboard to be
+/// printed to standard output. This is sometimes useful for debugging.
-void Bitboards::print(Bitboard b) {
+const std::string Bitboards::pretty(Bitboard b) {
- sync_cout;
+ std::string s = "+---+---+---+---+---+---+---+---+\n";
for (Rank rank = RANK_8; rank >= RANK_1; --rank)
{
- std::cout << "+---+---+---+---+---+---+---+---+" << '\n';
-
for (File file = FILE_A; file <= FILE_H; ++file)
- std::cout << "| " << (b & (file | rank) ? "X " : " ");
+ s.append(b & make_square(file, rank) ? "| X " : "| ");
- std::cout << "|\n";
+ s.append("|\n+---+---+---+---+---+---+---+---+\n");
}
- std::cout << "+---+---+---+---+---+---+---+---+" << sync_endl;
+
+ 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 (int i = 0; i < 64; i++)
- BSFTable[bsf_index(1ULL << i)] = Square(i);
-
for (Square s = SQ_A1; s <= SQ_H8; ++s)
- SquareBB[s] = 1ULL << s;
+ BSFTable[bsf_index(SquareBB[s] = 1ULL << s)] = s;
- FileBB[FILE_A] = FileABB;
- RankBB[RANK_1] = Rank1BB;
+ for (Bitboard b = 1; b < 256; ++b)
+ MS1BTable[b] = more_than_one(b) ? MS1BTable[b - 1] : lsb(b);
- for (int i = 1; i < 8; i++)
- {
- FileBB[i] = FileBB[i - 1] << 1;
- RankBB[i] = RankBB[i - 1] << 8;
- }
+ 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(file_distance(s1, s2), rank_distance(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 } };
for (Color c = WHITE; c <= BLACK; ++c)
for (PieceType pt = PAWN; pt <= KING; ++pt)
for (Square s = SQ_A1; s <= SQ_H8; ++s)
- for (int k = 0; steps[pt][k]; k++)
+ for (int i = 0; steps[pt][i]; ++i)
{
- Square to = s + Square(c == WHITE ? steps[pt][k] : -steps[pt][k]);
+ Square to = s + Square(c == WHITE ? steps[pt][i] : -steps[pt][i]);
if (is_ok(to) && square_distance(s, to) < 3)
StepAttacksBB[make_piece(c, pt)][s] |= to;
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)
+ for (Square s1 = SQ_A1; s1 <= SQ_H8; ++s1)
{
- PseudoAttacks[QUEEN][s] = PseudoAttacks[BISHOP][s] = attacks_bb<BISHOP>(s, 0);
- PseudoAttacks[QUEEN][s] |= PseudoAttacks[ ROOK][s] = attacks_bb< ROOK>(s, 0);
- }
+ PseudoAttacks[QUEEN][s1] = PseudoAttacks[BISHOP][s1] = attacks_bb<BISHOP>(s1, 0);
+ PseudoAttacks[QUEEN][s1] |= PseudoAttacks[ ROOK][s1] = attacks_bb< ROOK>(s1, 0);
- for (Square s1 = SQ_A1; s1 <= SQ_H8; ++s1)
for (Square s2 = SQ_A1; s2 <= SQ_H8; ++s2)
- if (PseudoAttacks[QUEEN][s1] & s2)
- {
- Square delta = (s2 - s1) / square_distance(s1, s2);
+ {
+ Piece pc = (PseudoAttacks[BISHOP][s1] & s2) ? W_BISHOP :
+ (PseudoAttacks[ROOK][s1] & s2) ? W_ROOK : NO_PIECE;
- for (Square s = s1 + delta; s != s2; s += delta)
- BetweenBB[s1][s2] |= s;
- }
+ if (pc == NO_PIECE)
+ continue;
+
+ LineBB[s1][s2] = (attacks_bb(pc, s1, 0) & attacks_bb(pc, s2, 0)) | s1 | s2;
+ BetweenBB[s1][s2] = attacks_bb(pc, s1, SquareBB[s2]) & attacks_bb(pc, s2, SquareBB[s1]);
+ }
+ }
}
Bitboard attack = 0;
- for (int i = 0; i < 4; i++)
+ for (int i = 0; i < 4; ++i)
for (Square s = sq + deltas[i];
is_ok(s) && square_distance(s, s - deltas[i]) == 1;
s += deltas[i])
}
- 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;
-
- 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[][8] = { { 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;
// 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));
// looks up the correct sliding attack in the attacks[s] database.
// Note that we build up the database for square 's' as a side
// effect of verifying the magic.
- for (i = 0; i < size; i++)
+ for (i = 0; i < size; ++i)
{
Bitboard& attack = attacks[s][index(s, occupancy[i])];
if (attack && attack != reference[i])
break;
- assert(reference[i] != 0);
+ assert(reference[i]);
attack = reference[i];
}
- } while (i != size);
+ } while (i < size);
}
}
}
projects / stockfish / blobdiff