1 #ifndef _ASM_X86_HWEIGHT_H
2 #define _ASM_X86_HWEIGHT_H
5 /* popcnt %rdi, %rax */
6 #define POPCNT ".byte 0xf3,0x48,0x0f,0xb8,0xc7"
10 /* popcnt %eax, %eax */
11 #define POPCNT ".byte 0xf3,0x0f,0xb8,0xc0"
17 * __sw_hweightXX are called from within the alternatives below
18 * and callee-clobbered registers need to be taken care of. See
19 * ARCH_HWEIGHT_CFLAGS in <arch/x86/Kconfig> for the respective
22 static inline unsigned int __arch_hweight32(unsigned int w
)
26 asm (ALTERNATIVE("call __sw_hweight32", POPCNT
, X86_FEATURE_POPCNT
)
33 static inline unsigned int __arch_hweight16(unsigned int w
)
35 return __arch_hweight32(w
& 0xffff);
38 static inline unsigned int __arch_hweight8(unsigned int w
)
40 return __arch_hweight32(w
& 0xff);
43 static inline unsigned long __arch_hweight64(__u64 w
)
45 unsigned long res
= 0;
48 return __arch_hweight32((u32
)w
) +
49 __arch_hweight32((u32
)(w
>> 32));
51 asm (ALTERNATIVE("call __sw_hweight64", POPCNT
, X86_FEATURE_POPCNT
)
54 #endif /* CONFIG_X86_32 */