diff options
Diffstat (limited to 'arch/x86/include/asm/arch_hweight.h')
| -rw-r--r-- | arch/x86/include/asm/arch_hweight.h | 24 |
1 files changed, 10 insertions, 14 deletions
diff --git a/arch/x86/include/asm/arch_hweight.h b/arch/x86/include/asm/arch_hweight.h index 02e799fa43d1..e7cd63175de4 100644 --- a/arch/x86/include/asm/arch_hweight.h +++ b/arch/x86/include/asm/arch_hweight.h @@ -4,8 +4,8 @@ #include <asm/cpufeatures.h> #ifdef CONFIG_64BIT -/* popcnt %edi, %eax -- redundant REX prefix for alignment */ -#define POPCNT32 ".byte 0xf3,0x40,0x0f,0xb8,0xc7" +/* popcnt %edi, %eax */ +#define POPCNT32 ".byte 0xf3,0x0f,0xb8,0xc7" /* popcnt %rdi, %rax */ #define POPCNT64 ".byte 0xf3,0x48,0x0f,0xb8,0xc7" #define REG_IN "D" @@ -17,19 +17,15 @@ #define REG_OUT "a" #endif -/* - * __sw_hweightXX are called from within the alternatives below - * and callee-clobbered registers need to be taken care of. See - * ARCH_HWEIGHT_CFLAGS in <arch/x86/Kconfig> for the respective - * compiler switches. - */ +#define __HAVE_ARCH_SW_HWEIGHT + static __always_inline unsigned int __arch_hweight32(unsigned int w) { - unsigned int res = 0; + unsigned int res; asm (ALTERNATIVE("call __sw_hweight32", POPCNT32, X86_FEATURE_POPCNT) - : "="REG_OUT (res) - : REG_IN (w)); + : "="REG_OUT (res) + : REG_IN (w)); return res; } @@ -53,11 +49,11 @@ static inline unsigned long __arch_hweight64(__u64 w) #else static __always_inline unsigned long __arch_hweight64(__u64 w) { - unsigned long res = 0; + unsigned long res; asm (ALTERNATIVE("call __sw_hweight64", POPCNT64, X86_FEATURE_POPCNT) - : "="REG_OUT (res) - : REG_IN (w)); + : "="REG_OUT (res) + : REG_IN (w)); return res; } |