X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fbitboard.cpp;h=40cdbb21ff956601238b0db0dc72176e5cb081cb;hp=41ce2955c147f27b2960130d0c2ec2ffa8c7d5f7;hb=797c960d2004eacbbd19c656f483f070130bb358;hpb=6e00aa6bae8a9634b3aea4b7b0bde652a588e9de diff --git a/src/bitboard.cpp b/src/bitboard.cpp index 41ce2955..40cdbb21 100644 --- a/src/bitboard.cpp +++ b/src/bitboard.cpp @@ -92,37 +92,18 @@ Square first_1(Bitboard b) { return Square(BSFTable[(fold * 0x783A9B23) >> 26]); } -// Use type-punning -union b_union { - - Bitboard dummy; - struct { -#if defined (BIGENDIAN) - uint32_t h; - uint32_t l; -#else - uint32_t l; - uint32_t h; -#endif - } b; -}; - Square pop_1st_bit(Bitboard* b) { - const b_union u = *((b_union*)b); - - if (u.b.l) - { - ((b_union*)b)->b.l = u.b.l & (u.b.l - 1); - return Square(BSFTable[((u.b.l ^ (u.b.l - 1)) * 0x783A9B23) >> 26]); - } - - ((b_union*)b)->b.h = u.b.h & (u.b.h - 1); - return Square(BSFTable[((~(u.b.h ^ (u.b.h - 1))) * 0x783A9B23) >> 26]); + Bitboard bb = *b; + *b = bb & (bb - 1); + bb ^= (bb - 1); + uint32_t fold = unsigned(bb) ^ unsigned(bb >> 32); + return Square(BSFTable[(fold * 0x783A9B23) >> 26]); } Square last_1(Bitboard b) { + unsigned b32; int result = 0; if (b > 0xFFFFFFFF) @@ -131,19 +112,21 @@ Square last_1(Bitboard b) { result = 32; } - if (b > 0xFFFF) + b32 = unsigned(b); + + if (b32 > 0xFFFF) { - b >>= 16; + b32 >>= 16; result += 16; } - if (b > 0xFF) + if (b32 > 0xFF) { - b >>= 8; + b32 >>= 8; result += 8; } - return Square(result + MS1BTable[b]); + return Square(result + MS1BTable[b32]); } #endif // !defined(USE_BSFQ)