diff options
| author | Chris Metcalf <cmetcalf@tilera.com> | 2012-05-25 12:32:09 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-06-01 15:18:27 +0800 |
| commit | c90791c7638d3c9a0de762d8b416d0e809b1dc31 (patch) | |
| tree | 41fdeb152f42222e38aa1200658c4a91bed88161 /arch/tile | |
| parent | e5bdf9b518d0ff03455dce3da9bce8ad95c25e6d (diff) | |
| download | lwn-c90791c7638d3c9a0de762d8b416d0e809b1dc31.tar.gz lwn-c90791c7638d3c9a0de762d8b416d0e809b1dc31.zip | |
tile: fix bug where fls(0) was not returning 0
commit 9f1d62bed7f015d11b9164078b7fea433b474114 upstream.
This is because __builtin_clz(0) returns 64 for the "undefined" case
of 0, since the builtin just does a right-shift 32 and "clz" instruction.
So, use the alpha approach of casting to u32 and using __builtin_clzll().
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/tile')
| -rw-r--r-- | arch/tile/include/asm/bitops.h | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/arch/tile/include/asm/bitops.h b/arch/tile/include/asm/bitops.h index 16f1fa51fea1..bd186c4eaa50 100644 --- a/arch/tile/include/asm/bitops.h +++ b/arch/tile/include/asm/bitops.h @@ -77,6 +77,11 @@ static inline int ffs(int x) return __builtin_ffs(x); } +static inline int fls64(__u64 w) +{ + return (sizeof(__u64) * 8) - __builtin_clzll(w); +} + /** * fls - find last set bit in word * @x: the word to search @@ -90,12 +95,7 @@ static inline int ffs(int x) */ static inline int fls(int x) { - return (sizeof(int) * 8) - __builtin_clz(x); -} - -static inline int fls64(__u64 w) -{ - return (sizeof(__u64) * 8) - __builtin_clzll(w); + return fls64((unsigned int) x); } static inline unsigned int __arch_hweight32(unsigned int w) |