#if defined(IS_64BIT) && !defined(USE_BSFQ)
+CACHE_LINE_ALIGNMENT
static const int BitTable[64] = {
0, 1, 2, 7, 3, 13, 8, 19, 4, 25, 14, 28, 9, 34, 20, 40, 5, 17, 26, 38, 15,
46, 29, 48, 10, 31, 35, 54, 21, 50, 41, 57, 63, 6, 12, 18, 24, 27, 33, 39,
#elif !defined(USE_BSFQ)
-static const int BitTable[64] = {
+static CACHE_LINE_ALIGNMENT
+const int BitTable[64] = {
63, 30, 3, 32, 25, 41, 22, 33, 15, 50, 42, 13, 11, 53, 19, 34, 61, 29, 2,
51, 21, 43, 45, 10, 18, 47, 1, 54, 9, 57, 0, 35, 62, 31, 40, 4, 49, 5, 52,
26, 60, 6, 23, 44, 46, 27, 56, 16, 7, 39, 48, 24, 59, 14, 12, 55, 38, 28,
Bitboard b;
struct {
+#if defined (BIGENDIAN)
+ uint32_t h;
+ uint32_t l;
+#else
uint32_t l;
uint32_t h;
+#endif
} dw;
};
-// WARNING: Needs -fno-strict-aliasing compiler option
Square pop_1st_bit(Bitboard* bb) {
- b_union u;
- uint32_t b;
-
- u.b = *bb;
-
- if (u.dw.l)
- {
- b = u.dw.l;
- *((uint32_t*)bb) = b & (b - 1);
- b ^= (b - 1);
- }
- else
- {
- b = u.dw.h;
- *((uint32_t*)bb+1) = b & (b - 1); // Little endian only?
- b = ~(b ^ (b - 1));
- }
- return Square(BitTable[(b * 0x783a9b23) >> 26]);
+ b_union u;
+ Square ret;
+
+ u.b = *bb;
+
+ if (u.dw.l)
+ {
+ ret = Square(BitTable[((u.dw.l ^ (u.dw.l - 1)) * 0x783a9b23) >> 26]);
+ u.dw.l &= (u.dw.l - 1);
+ *bb = u.b;
+ return ret;
+ }
+ ret = Square(BitTable[((~(u.dw.h ^ (u.dw.h - 1))) * 0x783a9b23) >> 26]);
+ u.dw.h &= (u.dw.h - 1);
+ *bb = u.b;
+ return ret;
}
#endif