X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fbitcount.h;h=9feed19f9755a94be0022f3e9cf5c891972589d0;hp=ad8df94ab078522066fdfa44da80c931fa732c88;hb=c014444f09ace05e908909d9c5c60127e998b538;hpb=002062ae934c1fae3e56157e8e7e6451b552ada5 diff --git a/src/bitcount.h b/src/bitcount.h index ad8df94a..9feed19f 100644 --- a/src/bitcount.h +++ b/src/bitcount.h @@ -1,7 +1,7 @@ /* 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 @@ -32,14 +32,14 @@ enum BitCountType { CNT_HW_POPCNT }; -/// Determine at compile time the best popcount<> specialization according if -/// platform is 32 or 64 bits, to the maximum number of nonzero bits to count -/// and if hardware popcnt instruction is available. +/// Determine at compile time the best popcount<> specialization according to +/// whether the platform is 32 or 64 bit, the maximum number of non-zero +/// bits to count and if the hardware popcnt instruction is available. const BitCountType Full = HasPopCnt ? CNT_HW_POPCNT : Is64Bit ? CNT_64 : CNT_32; const BitCountType Max15 = HasPopCnt ? CNT_HW_POPCNT : Is64Bit ? CNT_64_MAX15 : CNT_32_MAX15; -/// popcount() counts the number of nonzero bits in a bitboard +/// popcount() counts the number of non-zero bits in a bitboard template inline int popcount(Bitboard); template<> @@ -96,8 +96,7 @@ inline int popcount(Bitboard b) { #else - __asm__("popcnt %1, %0" : "=r" (b) : "r" (b)); - return b; + return __builtin_popcountll(b); #endif }