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Restore correct 64 bit version of pop_1st_bit()

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Was erroneusly changed with the 32bit in recent
patch "Retire USE_COMPACT_ROOK_ATTACKS...".

Also another clean up of define magics. Move compiler
specific definitions in types.h and remove redundant cruft.

Now this macro ugly mess seems more reasonable.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
This commit is contained in:
Marco Costalba
2009-07-03 08:40:41 +01:00
parent a87ea9846d
commit 5d79af9e0d
4 changed files with 65 additions and 91 deletions
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30
src/bitboard.cpp
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@@ -242,20 +242,44 @@ void init_bitboards() {
}
/// first_1() finds the least significant nonzero bit in a nonzero bitboard.
/// pop_1st_bit() finds and clears the least significant nonzero bit in a
/// nonzero bitboard.
#if defined(IS_64BIT) && !defined(USE_BSFQ)
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,
16, 37, 45, 47, 30, 53, 49, 56, 62, 11, 23, 32, 36, 44, 52, 55, 61, 22, 43,
51, 60, 42, 59, 58
};
Square first_1(Bitboard b) {
return Square(BitTable[((b & -b) * 0x218a392cd3d5dbfULL) >> 58]);
}
Square pop_1st_bit(Bitboard* b) {
Bitboard bb = *b ^ (*b - 1);
uint32_t fold = int(bb) ^ int(bb >> 32);
Bitboard bb = *b;
*b &= (*b - 1);
return Square(BitTable[(fold * 0x783a9b23) >> 26]);
return Square(BitTable[((bb & -bb) * 0x218a392cd3d5dbfULL) >> 58]);
}
#elif !defined(USE_BSFQ)
static 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,
58, 20, 37, 17, 36, 8
};
Square first_1(Bitboard b) {
b ^= (b - 1);
uint32_t fold = int(b) ^ int(b >> 32);
return Square(BitTable[(fold * 0x783a9b23) >> 26]);
}
// Use type-punning
union b_union {