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1 | #ifndef _ASM_X86_HWEIGHT_H |
2 | #define _ASM_X86_HWEIGHT_H | |
3 | ||
4 | #ifdef CONFIG_64BIT | |
c59bd568 PA |
5 | /* popcnt %edi, %eax -- redundant REX prefix for alignment */ |
6 | #define POPCNT32 ".byte 0xf3,0x40,0x0f,0xb8,0xc7" | |
d61931d8 | 7 | /* popcnt %rdi, %rax */ |
c59bd568 | 8 | #define POPCNT64 ".byte 0xf3,0x48,0x0f,0xb8,0xc7" |
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9 | #define REG_IN "D" |
10 | #define REG_OUT "a" | |
11 | #else | |
12 | /* popcnt %eax, %eax */ | |
c59bd568 | 13 | #define POPCNT32 ".byte 0xf3,0x0f,0xb8,0xc0" |
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14 | #define REG_IN "a" |
15 | #define REG_OUT "a" | |
16 | #endif | |
17 | ||
18 | /* | |
19 | * __sw_hweightXX are called from within the alternatives below | |
20 | * and callee-clobbered registers need to be taken care of. See | |
21 | * ARCH_HWEIGHT_CFLAGS in <arch/x86/Kconfig> for the respective | |
22 | * compiler switches. | |
23 | */ | |
24 | static inline unsigned int __arch_hweight32(unsigned int w) | |
25 | { | |
26 | unsigned int res = 0; | |
27 | ||
c59bd568 | 28 | asm (ALTERNATIVE("call __sw_hweight32", POPCNT32, X86_FEATURE_POPCNT) |
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29 | : "="REG_OUT (res) |
30 | : REG_IN (w)); | |
31 | ||
32 | return res; | |
33 | } | |
34 | ||
35 | static inline unsigned int __arch_hweight16(unsigned int w) | |
36 | { | |
37 | return __arch_hweight32(w & 0xffff); | |
38 | } | |
39 | ||
40 | static inline unsigned int __arch_hweight8(unsigned int w) | |
41 | { | |
42 | return __arch_hweight32(w & 0xff); | |
43 | } | |
44 | ||
45 | static inline unsigned long __arch_hweight64(__u64 w) | |
46 | { | |
47 | unsigned long res = 0; | |
48 | ||
49 | #ifdef CONFIG_X86_32 | |
50 | return __arch_hweight32((u32)w) + | |
51 | __arch_hweight32((u32)(w >> 32)); | |
52 | #else | |
c59bd568 | 53 | asm (ALTERNATIVE("call __sw_hweight64", POPCNT64, X86_FEATURE_POPCNT) |
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54 | : "="REG_OUT (res) |
55 | : REG_IN (w)); | |
56 | #endif /* CONFIG_X86_32 */ | |
57 | ||
58 | return res; | |
59 | } | |
60 | ||
61 | #endif |