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/*
X86-64 inline functions for MSB(), LSB() and PopCnt(). Note
that these are 64 bit functions and they use 64 bit (quad-word)
X86-64 instructions.
*/
/* *INDENT-OFF* */
static __inline__ int MSB(long word)
{
long dummy, dummy2;
asm(" bsrq %1, %0 " "\n\t"
" jnz 1f " "\n\t"
" movq $64, %0 " "\n\t"
"1: " "\n\t"
: "=&r"(dummy), "=&r" (dummy2)
: "1"((long) (word))
: "cc");
return (dummy);
}
static __inline__ int LSB(long word)
{
long dummy, dummy2;
asm(" bsfq %1, %0 " "\n\t"
" jnz 1f " "\n\t"
" movq $64, %0 " "\n\t"
"1: " "\n\t"
: "=&r"(dummy), "=&r" (dummy2)
: "1"((long) (word))
: "cc");
return (dummy);
}
#if defined(POPCNT)
static __inline__ int PopCnt(long word)
{
long dummy, dummy2;
asm(" popcnt %1, %0 " "\n\t"
: "=&r"(dummy), "=&r" (dummy2)
: "1"((long) (word))
: "cc");
return (dummy);
}
#else
static __inline__ int PopCnt(long word)
{
long dummy, dummy2, dummy3;
asm(" xorq %0, %0 " "\n\t"
" testq %1, %1 " "\n\t"
" jz 2f " "\n\t"
"1: leaq -1(%1),%2 " "\n\t"
" incq %0 " "\n\t"
" andq %2, %1 " "\n\t"
" jnz 1b " "\n\t"
"2: " "\n\t"
: "=&r"(dummy), "=&r"(dummy2), "=&r"(dummy3)
: "1"((long) (word))
: "cc");
return (dummy);
}
#endif
/* *INDENT-ON* */
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