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extern unsigned char first_ones[65536];
extern unsigned char last_ones[65536];
#if _MSC_VER >= 1200
#define FORCEINLINE __forceinline
#else
#define FORCEINLINE __inline
#endif
FORCEINLINE int PopCnt(BITBOARD a) {
/* Because Crafty bitboards are typically sparsely populated, we use a
streamlined version of the boolean.c algorithm instead of the one in x86.s */
__asm {
mov ecx, dword ptr a
xor eax, eax
test ecx, ecx
jz l1
l0: lea edx, [ecx-1]
inc eax
and ecx, edx
jnz l0
l1: mov ecx, dword ptr a+4
test ecx, ecx
jz l3
l2: lea edx, [ecx-1]
inc eax
and ecx, edx
jnz l2
l3:
}
}
FORCEINLINE int FirstOne(BITBOARD a) {
#if _M_IX86 <= 500 /* on plain Pentiums, use boolean.c algorithm */
__asm {
movzx edx, word ptr a+6
xor eax, eax
test edx, edx
jnz l1
mov dx, word ptr a+4
mov eax, 16
test edx, edx
jnz l1
mov dx, word ptr a+2
mov eax, 32
test edx, edx
jnz l1
mov dx, word ptr a
mov eax, 48
l1: add al, byte ptr first_ones[edx]
}
#else /* BSF and BSR are *fast* instructions on PPro/PII */
__asm {
bsr edx, dword ptr a+4
mov eax, 31
jnz l1
bsr edx, dword ptr a
mov eax, 63
jnz l1
mov edx, -1
l1: sub eax, edx
}
#endif /* _M_IX86 > 500 */
}
FORCEINLINE int LastOne(BITBOARD a) {
#if _M_IX86 <= 500 /* on plain Pentiums, use boolean.c algorithm */
__asm {
movzx edx, word ptr a
mov eax, 48
test edx, edx
jnz l1
mov dx, word ptr a+2
mov eax, 32
test edx, edx
jnz l1
mov dx, word ptr a+4
mov eax, 16
test edx, edx
jnz l1
mov dx, word ptr a+6
xor eax, eax
test edx, edx
jnz l1
mov eax, 48
l1: add al, byte ptr last_ones[edx]
}
#else /* BSF and BSR are *fast* instructions on PPro/PII */
__asm {
bsf edx, dword ptr a
mov eax, 63
jnz l1
bsf edx, dword ptr a+4
mov eax, 31
jnz l1
mov edx, -33
l1: sub eax, edx
}
#endif /* _M_IX386 > 500 */
}
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