/*
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
#ifndef BITBOARD_H_INCLUDED
#define BITBOARD_H_INCLUDED
+#include <string>
+
#include "types.h"
namespace Bitboards {
const Bitboard Rank7BB = Rank1BB << (8 * 6);
const Bitboard Rank8BB = Rank1BB << (8 * 7);
-CACHE_LINE_ALIGNMENT
-
-extern Bitboard RMasks[SQUARE_NB];
-extern Bitboard RMagics[SQUARE_NB];
-extern Bitboard* RAttacks[SQUARE_NB];
-extern unsigned RShifts[SQUARE_NB];
+extern Bitboard RookMasks[SQUARE_NB];
+extern Bitboard RookMagics[SQUARE_NB];
+extern Bitboard* RookAttacks[SQUARE_NB];
+extern unsigned RookShifts[SQUARE_NB];
-extern Bitboard BMasks[SQUARE_NB];
-extern Bitboard BMagics[SQUARE_NB];
-extern Bitboard* BAttacks[SQUARE_NB];
-extern unsigned BShifts[SQUARE_NB];
+extern Bitboard BishopMasks[SQUARE_NB];
+extern Bitboard BishopMagics[SQUARE_NB];
+extern Bitboard* BishopAttacks[SQUARE_NB];
+extern unsigned BishopShifts[SQUARE_NB];
extern Bitboard SquareBB[SQUARE_NB];
extern Bitboard FileBB[FILE_NB];
return b & (b - 1);
}
-inline int square_distance(Square s1, Square s2) {
- return SquareDistance[s1][s2];
-}
+template<typename T> inline int distance(T x, T y) { return x < y ? y - x : x - y; }
+template<> inline int distance<Square>(Square x, Square y) { return SquareDistance[x][y]; }
-inline int file_distance(Square s1, Square s2) {
- return abs(file_of(s1) - file_of(s2));
-}
-
-inline int rank_distance(Square s1, Square s2) {
- return abs(rank_of(s1) - rank_of(s2));
-}
+template<typename T1, typename T2> inline int distance(T2 x, T2 y);
+template<> inline int distance<File>(Square x, Square y) { return distance(file_of(x), file_of(y)); }
+template<> inline int distance<Rank>(Square x, Square y) { return distance(rank_of(x), rank_of(y)); }
/// shift_bb() moves bitboard one step along direction Delta. Mainly for pawns.
/// between_bb() returns a bitboard representing all squares between two squares.
/// For instance, between_bb(SQ_C4, SQ_F7) returns a bitboard with the bits for
-/// square d5 and e6 set. If s1 and s2 are not on the same line, file or diagonal,
+/// square d5 and e6 set. If s1 and s2 are not on the same rank, file or diagonal,
/// 0 is returned.
inline Bitboard between_bb(Square s1, Square s2) {
/// a square and a bitboard of occupied squares as input, and returns a bitboard
/// representing all squares attacked by Pt (bishop or rook) on the given square.
template<PieceType Pt>
-FORCE_INLINE unsigned magic_index(Square s, Bitboard occ) {
+FORCE_INLINE unsigned magic_index(Square s, Bitboard occupied) {
+
+ Bitboard* const Masks = Pt == ROOK ? RookMasks : BishopMasks;
+ Bitboard* const Magics = Pt == ROOK ? RookMagics : BishopMagics;
+ unsigned* const Shifts = Pt == ROOK ? RookShifts : BishopShifts;
- Bitboard* const Masks = Pt == ROOK ? RMasks : BMasks;
- Bitboard* const Magics = Pt == ROOK ? RMagics : BMagics;
- unsigned* const Shifts = Pt == ROOK ? RShifts : BShifts;
+ if (HasPext)
+ return unsigned(_pext_u64(occupied, Masks[s]));
if (Is64Bit)
- return unsigned(((occ & Masks[s]) * Magics[s]) >> Shifts[s]);
+ return unsigned(((occupied & Masks[s]) * Magics[s]) >> Shifts[s]);
- unsigned lo = unsigned(occ) & unsigned(Masks[s]);
- unsigned hi = unsigned(occ >> 32) & unsigned(Masks[s] >> 32);
+ unsigned lo = unsigned(occupied) & unsigned(Masks[s]);
+ unsigned hi = unsigned(occupied >> 32) & unsigned(Masks[s] >> 32);
return (lo * unsigned(Magics[s]) ^ hi * unsigned(Magics[s] >> 32)) >> Shifts[s];
}
template<PieceType Pt>
-inline Bitboard attacks_bb(Square s, Bitboard occ) {
- return (Pt == ROOK ? RAttacks : BAttacks)[s][magic_index<Pt>(s, occ)];
+inline Bitboard attacks_bb(Square s, Bitboard occupied) {
+ return (Pt == ROOK ? RookAttacks : BishopAttacks)[s][magic_index<Pt>(s, occupied)];
}
-inline Bitboard attacks_bb(Piece p, Square s, Bitboard occ) {
+inline Bitboard attacks_bb(Piece pc, Square s, Bitboard occupied) {
- switch (type_of(p))
+ switch (type_of(pc))
{
- case BISHOP: return attacks_bb<BISHOP>(s, occ);
- case ROOK : return attacks_bb<ROOK>(s, occ);
- case QUEEN : return attacks_bb<BISHOP>(s, occ) | attacks_bb<ROOK>(s, occ);
- default : return StepAttacksBB[p][s];
+ case BISHOP: return attacks_bb<BISHOP>(s, occupied);
+ case ROOK : return attacks_bb<ROOK>(s, occupied);
+ case QUEEN : return attacks_bb<BISHOP>(s, occupied) | attacks_bb<ROOK>(s, occupied);
+ default : return StepAttacksBB[pc][s];
}
}
-/// 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.
#ifdef USE_BSFQ
# if defined(_MSC_VER) && !defined(__INTEL_COMPILER)
FORCE_INLINE Square lsb(Bitboard b) {
- unsigned long index;
- _BitScanForward64(&index, b);
- return (Square) index;
+ unsigned long idx;
+ _BitScanForward64(&idx, b);
+ return (Square) idx;
}
FORCE_INLINE Square msb(Bitboard b) {
- unsigned long index;
- _BitScanReverse64(&index, b);
- return (Square) index;
+ unsigned long idx;
+ _BitScanReverse64(&idx, b);
+ return (Square) idx;
}
# elif defined(__arm__)
# else
FORCE_INLINE Square lsb(Bitboard b) { // Assembly code by Heinz van Saanen
- Bitboard index;
- __asm__("bsfq %1, %0": "=r"(index): "rm"(b) );
- return (Square) index;
+ Bitboard idx;
+ __asm__("bsfq %1, %0": "=r"(idx): "rm"(b) );
+ return (Square) idx;
}
FORCE_INLINE Square msb(Bitboard b) {
- Bitboard index;
- __asm__("bsrq %1, %0": "=r"(index): "rm"(b) );
- return (Square) index;
+ Bitboard idx;
+ __asm__("bsrq %1, %0": "=r"(idx): "rm"(b) );
+ return (Square) idx;
}
# endif