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Rev | Author | Line No. | Line |
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5270 | serge | 1 | #ifndef _ASM_X86_HWEIGHT_H |
2 | #define _ASM_X86_HWEIGHT_H |
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3 | |||
4 | #ifdef CONFIG_64BIT |
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5 | /* popcnt %edi, %eax -- redundant REX prefix for alignment */ |
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6 | #define POPCNT32 ".byte 0xf3,0x40,0x0f,0xb8,0xc7" |
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7 | /* popcnt %rdi, %rax */ |
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8 | #define POPCNT64 ".byte 0xf3,0x48,0x0f,0xb8,0xc7" |
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9 | #define REG_IN "D" |
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10 | #define REG_OUT "a" |
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11 | #else |
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12 | /* popcnt %eax, %eax */ |
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13 | #define POPCNT32 ".byte 0xf3,0x0f,0xb8,0xc0" |
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14 | #define REG_IN "a" |
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15 | #define REG_OUT "a" |
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16 | #endif |
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17 | |||
18 | /* |
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19 | * __sw_hweightXX are called from within the alternatives below |
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20 | * and callee-clobbered registers need to be taken care of. See |
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21 | * ARCH_HWEIGHT_CFLAGS in |
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22 | * compiler switches. |
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23 | */ |
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6082 | serge | 24 | static __always_inline unsigned int __arch_hweight32(unsigned int w) |
5270 | serge | 25 | { |
6082 | serge | 26 | unsigned int res = w - ((w >> 1) & 0x55555555); |
27 | res = (res & 0x33333333) + ((res >> 2) & 0x33333333); |
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28 | res = (res + (res >> 4)) & 0x0F0F0F0F; |
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29 | res = res + (res >> 8); |
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30 | return (res + (res >> 16)) & 0x000000FF; |
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5270 | serge | 31 | } |
32 | |||
33 | static inline unsigned int __arch_hweight16(unsigned int w) |
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34 | { |
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35 | return __arch_hweight32(w & 0xffff); |
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36 | } |
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37 | |||
38 | static inline unsigned int __arch_hweight8(unsigned int w) |
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39 | { |
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40 | return __arch_hweight32(w & 0xff); |
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41 | } |
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42 | |||
6082 | serge | 43 | #ifdef CONFIG_X86_32 |
5270 | serge | 44 | static inline unsigned long __arch_hweight64(__u64 w) |
45 | { |
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46 | return __arch_hweight32((u32)w) + |
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47 | __arch_hweight32((u32)(w >> 32)); |
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6082 | serge | 48 | } |
5270 | serge | 49 | #else |
6082 | serge | 50 | static __always_inline unsigned long __arch_hweight64(__u64 w) |
51 | { |
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52 | unsigned long res = 0; |
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53 | |||
5270 | serge | 54 | asm (ALTERNATIVE("call __sw_hweight64", POPCNT64, X86_FEATURE_POPCNT) |
55 | : "="REG_OUT (res) |
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56 | : REG_IN (w)); |
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57 | |||
58 | return res; |
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59 | } |
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6082 | serge | 60 | #endif /* CONFIG_X86_32 */ |
5270 | serge | 61 | |
62 | #endif |