mirror of
https://github.com/sockspls/badfish
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d4876dc963
Get rid of macros and use templates instead, this is safer and allows us fix the warning: ISO C++ forbids braced-groups within expressions That broke compilation with -pedantic flag under gcc and POPCNT enabled. No functional and no performance change. Signed-off-by: Marco Costalba <mcostalba@gmail.com>
125 lines
3.7 KiB
C++
125 lines
3.7 KiB
C++
/*
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Stockfish, a UCI chess playing engine derived from Glaurung 2.1
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Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
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Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
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Stockfish is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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Stockfish is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#if !defined(BITCOUNT_H_INCLUDED)
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#define BITCOUNT_H_INCLUDED
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#include "types.h"
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enum BitCountType {
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CNT64,
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CNT64_MAX15,
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CNT32,
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CNT32_MAX15,
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CNT_POPCNT
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};
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/// count_1s() counts the number of nonzero bits in a bitboard.
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/// We have different optimized versions according if platform
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/// is 32 or 64 bits, and to the maximum number of nonzero bits.
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/// We also support hardware popcnt instruction. See Readme.txt
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/// on how to pgo compile with popcnt support.
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template<BitCountType> inline int count_1s(Bitboard);
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template<>
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inline int count_1s<CNT64>(Bitboard b) {
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b -= ((b>>1) & 0x5555555555555555ULL);
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b = ((b>>2) & 0x3333333333333333ULL) + (b & 0x3333333333333333ULL);
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b = ((b>>4) + b) & 0x0F0F0F0F0F0F0F0FULL;
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b *= 0x0101010101010101ULL;
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return int(b >> 56);
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}
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template<>
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inline int count_1s<CNT64_MAX15>(Bitboard b) {
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b -= (b>>1) & 0x5555555555555555ULL;
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b = ((b>>2) & 0x3333333333333333ULL) + (b & 0x3333333333333333ULL);
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b *= 0x1111111111111111ULL;
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return int(b >> 60);
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}
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template<>
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inline int count_1s<CNT32>(Bitboard b) {
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unsigned w = unsigned(b >> 32), v = unsigned(b);
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v -= (v >> 1) & 0x55555555; // 0-2 in 2 bits
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w -= (w >> 1) & 0x55555555;
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v = ((v >> 2) & 0x33333333) + (v & 0x33333333); // 0-4 in 4 bits
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w = ((w >> 2) & 0x33333333) + (w & 0x33333333);
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v = ((v >> 4) + v) & 0x0F0F0F0F; // 0-8 in 8 bits
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v += (((w >> 4) + w) & 0x0F0F0F0F); // 0-16 in 8 bits
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v *= 0x01010101; // mul is fast on amd procs
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return int(v >> 24);
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}
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template<>
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inline int count_1s<CNT32_MAX15>(Bitboard b) {
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unsigned w = unsigned(b >> 32), v = unsigned(b);
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v -= (v >> 1) & 0x55555555; // 0-2 in 2 bits
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w -= (w >> 1) & 0x55555555;
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v = ((v >> 2) & 0x33333333) + (v & 0x33333333); // 0-4 in 4 bits
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w = ((w >> 2) & 0x33333333) + (w & 0x33333333);
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v += w; // 0-8 in 4 bits
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v *= 0x11111111;
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return int(v >> 28);
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}
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template<>
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inline int count_1s<CNT_POPCNT>(Bitboard b) {
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#if !defined(USE_POPCNT)
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return int(b != 0); // Avoid 'b not used' warning
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#elif defined(_MSC_VER)
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return __popcnt64(b);
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#elif defined(__GNUC__)
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unsigned long ret;
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__asm__("popcnt %1, %0" : "=r" (ret) : "r" (b));
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return ret;
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#endif
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}
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/// cpu_has_popcnt() detects support for popcnt instruction at runtime
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inline bool cpu_has_popcnt() {
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int CPUInfo[4] = {-1};
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__cpuid(CPUInfo, 0x00000001);
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return (CPUInfo[2] >> 23) & 1;
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}
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/// CpuHasPOPCNT is a global constant initialized at startup that
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/// is set to true if CPU on which application runs supports popcnt
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/// hardware instruction. Unless USE_POPCNT is not defined.
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#if defined(USE_POPCNT)
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const bool CpuHasPOPCNT = cpu_has_popcnt();
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#else
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const bool CpuHasPOPCNT = false;
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#endif
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/// CpuIs64Bit is a global constant initialized at compile time that
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/// is set to true if CPU on which application runs is a 64 bits.
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#if defined(IS_64BIT)
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const bool CpuIs64Bit = true;
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#else
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const bool CpuIs64Bit = false;
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#endif
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#endif // !defined(BITCOUNT_H_INCLUDED)
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