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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 | |||
7143 | serge | 4 | #include |
5 | |||
5270 | serge | 6 | #ifdef CONFIG_64BIT |
7 | /* popcnt %edi, %eax -- redundant REX prefix for alignment */ |
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8 | #define POPCNT32 ".byte 0xf3,0x40,0x0f,0xb8,0xc7" |
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9 | /* popcnt %rdi, %rax */ |
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10 | #define POPCNT64 ".byte 0xf3,0x48,0x0f,0xb8,0xc7" |
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11 | #define REG_IN "D" |
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12 | #define REG_OUT "a" |
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13 | #else |
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14 | /* popcnt %eax, %eax */ |
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15 | #define POPCNT32 ".byte 0xf3,0x0f,0xb8,0xc0" |
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16 | #define REG_IN "a" |
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17 | #define REG_OUT "a" |
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18 | #endif |
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19 | |||
20 | /* |
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21 | * __sw_hweightXX are called from within the alternatives below |
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22 | * and callee-clobbered registers need to be taken care of. See |
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23 | * ARCH_HWEIGHT_CFLAGS in |
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24 | * compiler switches. |
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25 | */ |
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6082 | serge | 26 | static __always_inline unsigned int __arch_hweight32(unsigned int w) |
5270 | serge | 27 | { |
6082 | serge | 28 | unsigned int res = w - ((w >> 1) & 0x55555555); |
29 | res = (res & 0x33333333) + ((res >> 2) & 0x33333333); |
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30 | res = (res + (res >> 4)) & 0x0F0F0F0F; |
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31 | res = res + (res >> 8); |
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32 | return (res + (res >> 16)) & 0x000000FF; |
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5270 | serge | 33 | } |
34 | |||
35 | static inline unsigned int __arch_hweight16(unsigned int w) |
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36 | { |
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37 | return __arch_hweight32(w & 0xffff); |
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38 | } |
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39 | |||
40 | static inline unsigned int __arch_hweight8(unsigned int w) |
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41 | { |
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42 | return __arch_hweight32(w & 0xff); |
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43 | } |
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44 | |||
6082 | serge | 45 | #ifdef CONFIG_X86_32 |
5270 | serge | 46 | static inline unsigned long __arch_hweight64(__u64 w) |
47 | { |
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48 | return __arch_hweight32((u32)w) + |
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49 | __arch_hweight32((u32)(w >> 32)); |
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6082 | serge | 50 | } |
5270 | serge | 51 | #else |
6082 | serge | 52 | static __always_inline unsigned long __arch_hweight64(__u64 w) |
53 | { |
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54 | unsigned long res = 0; |
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55 | |||
5270 | serge | 56 | asm (ALTERNATIVE("call __sw_hweight64", POPCNT64, X86_FEATURE_POPCNT) |
57 | : "="REG_OUT (res) |
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58 | : REG_IN (w)); |
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59 | |||
60 | return res; |
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61 | } |
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6082 | serge | 62 | #endif /* CONFIG_X86_32 */ |
5270 | serge | 63 | |
64 | #endif |