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1 | #ifndef _ASM_X86_HWEIGHT_H |
2 | #define _ASM_X86_HWEIGHT_H | |
3 | ||
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4 | #include <asm/cpufeatures.h> |
5 | ||
d61931d8 | 6 | #ifdef CONFIG_64BIT |
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7 | /* popcnt %edi, %eax -- redundant REX prefix for alignment */ |
8 | #define POPCNT32 ".byte 0xf3,0x40,0x0f,0xb8,0xc7" | |
d61931d8 | 9 | /* popcnt %rdi, %rax */ |
c59bd568 | 10 | #define POPCNT64 ".byte 0xf3,0x48,0x0f,0xb8,0xc7" |
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11 | #define REG_IN "D" |
12 | #define REG_OUT "a" | |
13 | #else | |
14 | /* popcnt %eax, %eax */ | |
c59bd568 | 15 | #define POPCNT32 ".byte 0xf3,0x0f,0xb8,0xc0" |
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16 | #define REG_IN "a" |
17 | #define REG_OUT "a" | |
18 | #endif | |
19 | ||
20 | /* | |
21 | * __sw_hweightXX are called from within the alternatives below | |
22 | * and callee-clobbered registers need to be taken care of. See | |
23 | * ARCH_HWEIGHT_CFLAGS in <arch/x86/Kconfig> for the respective | |
24 | * compiler switches. | |
25 | */ | |
d14edb16 | 26 | static __always_inline unsigned int __arch_hweight32(unsigned int w) |
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27 | { |
28 | unsigned int res = 0; | |
29 | ||
c59bd568 | 30 | asm (ALTERNATIVE("call __sw_hweight32", POPCNT32, X86_FEATURE_POPCNT) |
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31 | : "="REG_OUT (res) |
32 | : REG_IN (w)); | |
33 | ||
34 | return res; | |
35 | } | |
36 | ||
37 | static inline unsigned int __arch_hweight16(unsigned int w) | |
38 | { | |
39 | return __arch_hweight32(w & 0xffff); | |
40 | } | |
41 | ||
42 | static inline unsigned int __arch_hweight8(unsigned int w) | |
43 | { | |
44 | return __arch_hweight32(w & 0xff); | |
45 | } | |
46 | ||
d14edb16 | 47 | #ifdef CONFIG_X86_32 |
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48 | static inline unsigned long __arch_hweight64(__u64 w) |
49 | { | |
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50 | return __arch_hweight32((u32)w) + |
51 | __arch_hweight32((u32)(w >> 32)); | |
d14edb16 | 52 | } |
d61931d8 | 53 | #else |
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54 | static __always_inline unsigned long __arch_hweight64(__u64 w) |
55 | { | |
56 | unsigned long res = 0; | |
57 | ||
c59bd568 | 58 | asm (ALTERNATIVE("call __sw_hweight64", POPCNT64, X86_FEATURE_POPCNT) |
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59 | : "="REG_OUT (res) |
60 | : REG_IN (w)); | |
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61 | |
62 | return res; | |
63 | } | |
d14edb16 | 64 | #endif /* CONFIG_X86_32 */ |
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65 | |
66 | #endif |