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hbitmap: Use non-bitops ctzl 

Both uses of ctz have already eliminated zero, and thus the difference
in edge conditions between the two routines is irrelevant.

Signed-off-by: Richard Henderson <rth@twiddle.net>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
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 17:47:36 -08:00 committed by Blue Swirl
parent 72d81155d0
commit 18331e7c18
2 changed files with 4 additions and 2 deletions
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3
include/qemu/hbitmap.h
View File

@ -16,6 +16,7 @@
#include <stdint.h> #include <stdint.h>
#include <stdbool.h> #include <stdbool.h>
#include "bitops.h" #include "bitops.h"
#include "host-utils.h"
typedef struct HBitmap HBitmap; typedef struct HBitmap HBitmap;
typedef struct HBitmapIter HBitmapIter; typedef struct HBitmapIter HBitmapIter;
@ -170,7 +171,7 @@ static inline int64_t hbitmap_iter_next(HBitmapIter *hbi)
/* The next call will resume work from the next bit. */ /* The next call will resume work from the next bit. */
hbi->cur[HBITMAP_LEVELS - 1] = cur & (cur - 1); hbi->cur[HBITMAP_LEVELS - 1] = cur & (cur - 1);
item = ((uint64_t)hbi->pos << BITS_PER_LEVEL) + bitops_ctzl(cur); item = ((uint64_t)hbi->pos << BITS_PER_LEVEL) + ctzl(cur);
return item << hbi->granularity; return item << hbi->granularity;
} }

3
util/hbitmap.c
View File

@ -126,7 +126,8 @@ unsigned long hbitmap_iter_skip_words(HBitmapIter *hbi)
* The index of this word's least significant set bit provides * The index of this word's least significant set bit provides
* the low-order bits. * the low-order bits.
*/ */
pos = (pos << BITS_PER_LEVEL) + bitops_ctzl(cur); assert(cur);
pos = (pos << BITS_PER_LEVEL) + ctzl(cur);
hbi->cur[i] = cur & (cur - 1); hbi->cur[i] = cur & (cur - 1);
/* Set up next level for iteration. */ /* Set up next level for iteration. */