iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

tile: fix bug where fls(0) was not returning 0

Browse Source 
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().

Cc: stable@vger.kernel.org
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
This commit is contained in:
Chris Metcalf 2012-05-25 12:32:09 -04:00
parent acd1a19e00
commit 9f1d62bed7
1 changed files with 6 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
arch/tile/include/asm/bitops.h
View File

@ -77,6 +77,11 @@ static inline int ffs(int x)
return __builtin_ffs(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 * fls - find last set bit in word
* @x: the word to search * @x: the word to search
@ -90,12 +95,7 @@ static inline int ffs(int x)
*/ */
static inline int fls(int x) static inline int fls(int x)
{ {
return (sizeof(int) * 8) - __builtin_clz(x); return fls64((unsigned int) x);
}
static inline int fls64(__u64 w)
{
return (sizeof(__u64) * 8) - __builtin_clzll(w);
} }
static inline unsigned int __arch_hweight32(unsigned int w) static inline unsigned int __arch_hweight32(unsigned int w)