diff options
| -rw-r--r-- | arch/x86/include/asm/bitops.h | 28 |
1 files changed, 19 insertions, 9 deletions
diff --git a/arch/x86/include/asm/bitops.h b/arch/x86/include/asm/bitops.h index 879238e5a6a0..2edf68475fec 100644 --- a/arch/x86/include/asm/bitops.h +++ b/arch/x86/include/asm/bitops.h @@ -247,17 +247,30 @@ arch_test_bit_acquire(unsigned long nr, const volatile unsigned long *addr) variable_test_bit(nr, addr); } +static __always_inline unsigned long variable__ffs(unsigned long word) +{ + asm("rep; bsf %1,%0" + : "=r" (word) + : "rm" (word)); + return word; +} + /** * __ffs - find first set bit in word * @word: The word to search * * Undefined if no bit exists, so code should check against 0 first. */ -static __always_inline unsigned long __ffs(unsigned long word) +#define __ffs(word) \ + (__builtin_constant_p(word) ? \ + (unsigned long)__builtin_ctzl(word) : \ + variable__ffs(word)) + +static __always_inline unsigned long variable_ffz(unsigned long word) { asm("rep; bsf %1,%0" : "=r" (word) - : "rm" (word)); + : "r" (~word)); return word; } @@ -267,13 +280,10 @@ static __always_inline unsigned long __ffs(unsigned long word) * * Undefined if no zero exists, so code should check against ~0UL first. */ -static __always_inline unsigned long ffz(unsigned long word) -{ - asm("rep; bsf %1,%0" - : "=r" (word) - : "r" (~word)); - return word; -} +#define ffz(word) \ + (__builtin_constant_p(word) ? \ + (unsigned long)__builtin_ctzl(~word) : \ + variable_ffz(word)) /* * __fls: find last set bit in word |