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1 #ifndef _ASM_GENERIC_BITOPS_FLS_H_ |
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2 #define _ASM_GENERIC_BITOPS_FLS_H_ |
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3 |
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4 /** |
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5 * fls - find last (most-significant) bit set |
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6 * @x: the word to search |
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7 * |
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8 * This is defined the same way as ffs. |
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9 * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32. |
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10 */ |
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11 |
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12 static inline int fls(int x) |
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13 { |
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14 int r = 32; |
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15 |
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16 if (!x) |
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17 return 0; |
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18 if (!(x & 0xffff0000u)) { |
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19 x <<= 16; |
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20 r -= 16; |
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21 } |
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22 if (!(x & 0xff000000u)) { |
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23 x <<= 8; |
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24 r -= 8; |
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25 } |
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26 if (!(x & 0xf0000000u)) { |
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27 x <<= 4; |
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28 r -= 4; |
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29 } |
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30 if (!(x & 0xc0000000u)) { |
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31 x <<= 2; |
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32 r -= 2; |
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33 } |
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34 if (!(x & 0x80000000u)) { |
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35 x <<= 1; |
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36 r -= 1; |
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37 } |
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38 return r; |
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39 } |
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40 |
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41 #endif /* _ASM_GENERIC_BITOPS_FLS_H_ */ |