diff options
Diffstat (limited to 'arch/x86/include/asm/bitops.h')
| -rw-r--r-- | arch/x86/include/asm/bitops.h | 20 |
1 files changed, 14 insertions, 6 deletions
diff --git a/arch/x86/include/asm/bitops.h b/arch/x86/include/asm/bitops.h index 2edf68475..990eb686c 100644 --- a/arch/x86/include/asm/bitops.h +++ b/arch/x86/include/asm/bitops.h @@ -94,18 +94,17 @@ arch___clear_bit(unsigned long nr, volatile unsigned long *addr) asm volatile(__ASM_SIZE(btr) " %1,%0" : : ADDR, "Ir" (nr) : "memory"); } -static __always_inline bool -arch_clear_bit_unlock_is_negative_byte(long nr, volatile unsigned long *addr) +static __always_inline bool arch_xor_unlock_is_negative_byte(unsigned long mask, + volatile unsigned long *addr) { bool negative; - asm volatile(LOCK_PREFIX "andb %2,%1" + asm volatile(LOCK_PREFIX "xorb %2,%1" CC_SET(s) : CC_OUT(s) (negative), WBYTE_ADDR(addr) - : "ir" ((char) ~(1 << nr)) : "memory"); + : "iq" ((char)mask) : "memory"); return negative; } -#define arch_clear_bit_unlock_is_negative_byte \ - arch_clear_bit_unlock_is_negative_byte +#define arch_xor_unlock_is_negative_byte arch_xor_unlock_is_negative_byte static __always_inline void arch___clear_bit_unlock(long nr, volatile unsigned long *addr) @@ -293,6 +292,9 @@ static __always_inline unsigned long variable_ffz(unsigned long word) */ static __always_inline unsigned long __fls(unsigned long word) { + if (__builtin_constant_p(word)) + return BITS_PER_LONG - 1 - __builtin_clzl(word); + asm("bsr %1,%0" : "=r" (word) : "rm" (word)); @@ -360,6 +362,9 @@ static __always_inline int fls(unsigned int x) { int r; + if (__builtin_constant_p(x)) + return x ? 32 - __builtin_clz(x) : 0; + #ifdef CONFIG_X86_64 /* * AMD64 says BSRL won't clobber the dest reg if x==0; Intel64 says the @@ -401,6 +406,9 @@ static __always_inline int fls(unsigned int x) static __always_inline int fls64(__u64 x) { int bitpos = -1; + + if (__builtin_constant_p(x)) + return x ? 64 - __builtin_clzll(x) : 0; /* * AMD64 says BSRQ won't clobber the dest reg if x==0; Intel64 says the * dest reg is undefined if x==0, but their CPU architect says its |