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1 | #ifndef _ASM_X86_HWEIGHT_H |
2 | #define _ASM_X86_HWEIGHT_H | |
3 | ||
4 | #ifdef CONFIG_64BIT | |
5 | /* popcnt %rdi, %rax */ | |
6 | #define POPCNT ".byte 0xf3,0x48,0x0f,0xb8,0xc7" | |
7 | #define REG_IN "D" | |
8 | #define REG_OUT "a" | |
9 | #else | |
10 | /* popcnt %eax, %eax */ | |
11 | #define POPCNT ".byte 0xf3,0x0f,0xb8,0xc0" | |
12 | #define REG_IN "a" | |
13 | #define REG_OUT "a" | |
14 | #endif | |
15 | ||
16 | /* | |
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 | |
20 | * compiler switches. | |
21 | */ | |
22 | static inline unsigned int __arch_hweight32(unsigned int w) | |
23 | { | |
24 | unsigned int res = 0; | |
25 | ||
26 | asm (ALTERNATIVE("call __sw_hweight32", POPCNT, X86_FEATURE_POPCNT) | |
27 | : "="REG_OUT (res) | |
28 | : REG_IN (w)); | |
29 | ||
30 | return res; | |
31 | } | |
32 | ||
33 | static inline unsigned int __arch_hweight16(unsigned int w) | |
34 | { | |
35 | return __arch_hweight32(w & 0xffff); | |
36 | } | |
37 | ||
38 | static inline unsigned int __arch_hweight8(unsigned int w) | |
39 | { | |
40 | return __arch_hweight32(w & 0xff); | |
41 | } | |
42 | ||
43 | static inline unsigned long __arch_hweight64(__u64 w) | |
44 | { | |
45 | unsigned long res = 0; | |
46 | ||
47 | #ifdef CONFIG_X86_32 | |
48 | return __arch_hweight32((u32)w) + | |
49 | __arch_hweight32((u32)(w >> 32)); | |
50 | #else | |
51 | asm (ALTERNATIVE("call __sw_hweight64", POPCNT, X86_FEATURE_POPCNT) | |
52 | : "="REG_OUT (res) | |
53 | : REG_IN (w)); | |
54 | #endif /* CONFIG_X86_32 */ | |
55 | ||
56 | return res; | |
57 | } | |
58 | ||
59 | #endif |