X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fbitboard.h;h=2280f66c808e4b67722bf81e834e17c723589d3d;hp=1140664838b47bfb875a4a4841b7c07f90c1e7e3;hb=3e6e57231ecb1c23e43e02109efa3bcaf7ebe7c3;hpb=14c1fd4d27fa3bf9b4b68ffe3b088160ba6cbee4 diff --git a/src/bitboard.h b/src/bitboard.h index 11406648..2280f66c 100644 --- a/src/bitboard.h +++ b/src/bitboard.h @@ -395,23 +395,23 @@ inline int count_1s_max_15(Bitboard b) { inline int count_1s(Bitboard b) { unsigned w = unsigned(b >> 32), v = unsigned(b); - v = v - ((v >> 1) & 0x55555555); - w = w - ((w >> 1) & 0x55555555); + v -= (v >> 1) & 0x55555555; + w -= (w >> 1) & 0x55555555; v += w; - v = (v & 0x33333333) + ((v >> 2) & 0x33333333); - v = (v + (v >> 4)) & 0x0F0F0F0F; - v = (v * 0x01010101) >> 24; // mul is fast on amd procs - return int(v); + v = ((v >> 2) & 0x33333333) + (v & 0x33333333); + v = ((v >> 4) + v) & 0x0F0F0F0F; + v *= 0x01010101; // mul is fast on amd procs + return int(v >> 24); } inline int count_1s_max_15(Bitboard b) { unsigned w = unsigned(b >> 32), v = unsigned(b); - v = v - ((v >> 1) & 0x55555555); - w = w - ((w >> 1) & 0x55555555); + v -= (v >> 1) & 0x55555555; + w -= (w >> 1) & 0x55555555; v += w; - v = (v & 0x33333333) + ((v >> 2) & 0x33333333); - v = (v * 0x11111111) >> 28; - return int(v); + v = ((v >> 2) & 0x33333333) + (v & 0x33333333); + v *= 0x11111111; + return int(v >> 28); } #elif defined(BITCOUNT_SWAR_64)