/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2015-2016 Marco Costalba, Joona Kiiski, Gary Linscott, 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
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
-
Stockfish is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
extern int SquareDistance[SQUARE_NB][SQUARE_NB];
-extern Bitboard RookMasks [SQUARE_NB];
-extern Bitboard RookMagics [SQUARE_NB];
-extern Bitboard* RookAttacks[SQUARE_NB];
-extern unsigned RookShifts [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];
extern Bitboard RankBB[RANK_NB];
}
-/// squares_of_color() returns a bitboard representing all the squares of the
-/// same color of the given one.
-
-inline Bitboard squares_of_color(Square s) {
- return DarkSquares & s ? DarkSquares : ~DarkSquares;
-}
-
-
/// aligned() returns true if the squares s1, s2 and s3 are aligned either on a
/// straight or on a diagonal line.
/// piece of type Pt (bishop or rook) placed on 's'. The helper magic_index()
/// looks up the index using the 'magic bitboards' approach.
template<PieceType Pt>
-FORCE_INLINE unsigned magic_index(Square s, Bitboard occupied) {
+inline unsigned magic_index(Square s, Bitboard occupied) {
+
+ extern Bitboard RookMasks[SQUARE_NB];
+ extern Bitboard RookMagics[SQUARE_NB];
+ extern unsigned RookShifts[SQUARE_NB];
+ extern Bitboard BishopMasks[SQUARE_NB];
+ extern Bitboard BishopMagics[SQUARE_NB];
+ extern unsigned BishopShifts[SQUARE_NB];
Bitboard* const Masks = Pt == ROOK ? RookMasks : BishopMasks;
Bitboard* const Magics = Pt == ROOK ? RookMagics : BishopMagics;
unsigned* const Shifts = Pt == ROOK ? RookShifts : BishopShifts;
if (HasPext)
- return unsigned(_pext_u64(occupied, Masks[s]));
+ return unsigned(pext(occupied, Masks[s]));
if (Is64Bit)
return unsigned(((occupied & Masks[s]) * Magics[s]) >> Shifts[s]);
template<PieceType Pt>
inline Bitboard attacks_bb(Square s, Bitboard occupied) {
+
+ extern Bitboard* RookAttacks[SQUARE_NB];
+ extern Bitboard* BishopAttacks[SQUARE_NB];
+
return (Pt == ROOK ? RookAttacks : BishopAttacks)[s][magic_index<Pt>(s, occupied)];
}
}
-/// lsb() and msb() return the least/most significant bit in a non-zero bitboard
+/// popcount() counts the number of non-zero bits in a bitboard
-#ifdef USE_BSFQ
+inline int popcount(Bitboard b) {
-# if defined(_MSC_VER) && !defined(__INTEL_COMPILER)
+#ifndef USE_POPCNT
-FORCE_INLINE Square lsb(Bitboard b) {
- unsigned long idx;
- _BitScanForward64(&idx, b);
- return (Square) idx;
-}
+ extern uint8_t PopCnt16[1 << 16];
+ union { Bitboard bb; uint16_t u[4]; } v = { b };
+ return PopCnt16[v.u[0]] + PopCnt16[v.u[1]] + PopCnt16[v.u[2]] + PopCnt16[v.u[3]];
-FORCE_INLINE Square msb(Bitboard b) {
- unsigned long idx;
- _BitScanReverse64(&idx, b);
- return (Square) idx;
-}
+#elif defined(_MSC_VER) || defined(__INTEL_COMPILER)
-# elif defined(__arm__)
+ return (int)_mm_popcnt_u64(b);
-FORCE_INLINE int lsb32(uint32_t v) {
- __asm__("rbit %0, %1" : "=r"(v) : "r"(v));
- return __builtin_clz(v);
+#else // Assumed gcc or compatible compiler
+
+ return __builtin_popcountll(b);
+
+#endif
}
-FORCE_INLINE Square msb(Bitboard b) {
- return (Square) (63 - __builtin_clzll(b));
+
+/// lsb() and msb() return the least/most significant bit in a non-zero bitboard
+
+#if defined(__GNUC__)
+
+inline Square lsb(Bitboard b) {
+ assert(b);
+ return Square(__builtin_ctzll(b));
}
-FORCE_INLINE Square lsb(Bitboard b) {
- return (Square) (uint32_t(b) ? lsb32(uint32_t(b)) : 32 + lsb32(uint32_t(b >> 32)));
+inline Square msb(Bitboard b) {
+ assert(b);
+ return Square(63 - __builtin_clzll(b));
}
-# else // Assumed gcc or compatible compiler
+#elif defined(_WIN64) && defined(_MSC_VER)
-FORCE_INLINE Square lsb(Bitboard b) { // Assembly code by Heinz van Saanen
- Bitboard idx;
- __asm__("bsfq %1, %0": "=r"(idx): "rm"(b) );
+inline Square lsb(Bitboard b) {
+ assert(b);
+ unsigned long idx;
+ _BitScanForward64(&idx, b);
return (Square) idx;
}
-FORCE_INLINE Square msb(Bitboard b) {
- Bitboard idx;
- __asm__("bsrq %1, %0": "=r"(idx): "rm"(b) );
+inline Square msb(Bitboard b) {
+ assert(b);
+ unsigned long idx;
+ _BitScanReverse64(&idx, b);
return (Square) idx;
}
-# endif
+#else
-#else // ifdef(USE_BSFQ)
+#define NO_BSF // Fallback on software implementation for other cases
Square lsb(Bitboard b);
Square msb(Bitboard b);
/// pop_lsb() finds and clears the least significant bit in a non-zero bitboard
-FORCE_INLINE Square pop_lsb(Bitboard* b) {
+inline Square pop_lsb(Bitboard* b) {
const Square s = lsb(*b);
*b &= *b - 1;
return s;