- unsigned long index;\r
- uint32_t *l, *h;\r
-\r
- if (*(l = (uint32_t*)b) != 0)\r
- {\r
- _BitScanForward(&index, *l);\r
- *l &= ~(1 << index);\r
- } \r
- else if (*(h = (uint32_t*)b + 1) != 0)\r
- {\r
- _BitScanForward(&index, *h);\r
- *h &= ~(1 << index);\r
- index += 32;\r
- } else\r
- return SQ_NONE;\r
-\r
- return Square(index);
+// WARNING: Needs -fno-strict-aliasing compiler option
+Square pop_1st_bit(Bitboard *bb) {
+
+ b_union u;
+ uint32_t b;
+
+ u.b = *bb;
+
+ if (u.l)
+ {
+ b = u.l;
+ *((uint32_t*)bb) = b & (b - 1);
+ b ^= (b - 1);
+ }
+ else
+ {
+ b = u.h;
+ *((uint32_t*)bb+1) = b & (b - 1); // Little endian only?
+ b = ~(b ^ (b - 1));
+ }
+ return Square(BitTable[(b * 0x783a9b23) >> 26]);