| 1 |
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| 2 | #ifndef _ASM_GENERIC_BITOPS___FLS_H_
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| 3 | #define _ASM_GENERIC_BITOPS___FLS_H_
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| 4 |
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| 5 | #include <asm/types.h>
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| 6 |
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| 7 | |
| 8 | * generic___fls - find last (most-significant) set bit in a long word
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| 9 | * @word: the word to search
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| 10 | *
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| 11 | * Undefined if no set bit exists, so code should check against 0 first.
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| 12 |
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| 13 | static __always_inline __attribute_const__ unsigned int generic___fls(unsigned long word)
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| 14 | {
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| 15 | unsigned int num = BITS_PER_LONG - 1;
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| 16 |
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| 17 | #if BITS_PER_LONG == 64
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| 18 | if (!(word & (~0ul << 32))) {
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| 19 | num -= 32;
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| 20 | word <<= 32;
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| 21 | }
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| 22 | #endif
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| 23 | if (!(word & (~0ul << (BITS_PER_LONG-16)))) {
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| 24 | num -= 16;
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| 25 | word <<= 16;
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| 26 | }
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| 27 | if (!(word & (~0ul << (BITS_PER_LONG-8)))) {
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| 28 | num -= 8;
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| 29 | word <<= 8;
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| 30 | }
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| 31 | if (!(word & (~0ul << (BITS_PER_LONG-4)))) {
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| 32 | num -= 4;
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| 33 | word <<= 4;
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| 34 | }
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| 35 | if (!(word & (~0ul << (BITS_PER_LONG-2)))) {
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| 36 | num -= 2;
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| 37 | word <<= 2;
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| 38 | }
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| 39 | if (!(word & (~0ul << (BITS_PER_LONG-1))))
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| 40 | num -= 1;
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| 41 | return num;
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| 42 | }
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| 43 |
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| 44 | #ifndef __HAVE_ARCH___FLS
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| 45 | #define __fls(word) generic___fls(word)
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| 46 | #endif
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| 47 |
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| 48 | #endif
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