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bitops: Write bitops_flsl in terms of clzl 

Signed-off-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
This commit is contained in:
Richard Henderson 2013-02-13 17:47:39 -08:00 committed by Blue Swirl
parent 5bbf90be97
commit 0cfa6adc7f
1 changed files with 1 additions and 28 deletions
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29
include/qemu/bitops.h
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@ -57,34 +57,7 @@ static unsigned long bitops_ctzl(unsigned long word)
*/ */
static inline unsigned long bitops_flsl(unsigned long word) static inline unsigned long bitops_flsl(unsigned long word)
{ {
int num = BITS_PER_LONG - 1; return BITS_PER_LONG - 1 - clzl(word);
#if LONG_MAX > 0x7FFFFFFF
if (!(word & (~0ul << 32))) {
num -= 32;
word <<= 32;
}
#endif
if (!(word & (~0ul << (BITS_PER_LONG-16)))) {
num -= 16;
word <<= 16;
}
if (!(word & (~0ul << (BITS_PER_LONG-8)))) {
num -= 8;
word <<= 8;
}
if (!(word & (~0ul << (BITS_PER_LONG-4)))) {
num -= 4;
word <<= 4;
}
if (!(word & (~0ul << (BITS_PER_LONG-2)))) {
num -= 2;
word <<= 2;
}
if (!(word & (~0ul << (BITS_PER_LONG-1))))
num -= 1;
return num;
} }
/** /**