X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fbitboard.cpp;h=40cdbb21ff956601238b0db0dc72176e5cb081cb;hp=321055e826dba25609ab2ce00e0f5743080fcca7;hb=797c960d2004eacbbd19c656f483f070130bb358;hpb=673bc5526fa3d352f823ad144fb521b5dc98f45c diff --git a/src/bitboard.cpp b/src/bitboard.cpp index 321055e8..40cdbb21 100644 --- a/src/bitboard.cpp +++ b/src/bitboard.cpp @@ -92,33 +92,13 @@ 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) {