| 1 |
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| 2 | #ifndef _ASM_GENERIC_BITOPS___FFS_H_
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| 3 | #define _ASM_GENERIC_BITOPS___FFS_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___ffs - find first bit in word.
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| 9 | * @word: The word to search
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| 10 | *
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| 11 | * Undefined if no 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___ffs(unsigned long word)
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| 14 | {
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| 15 | unsigned int num = 0;
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| 16 |
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| 17 | #if BITS_PER_LONG == 64
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| 18 | if ((word & 0xffffffff) == 0) {
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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 & 0xffff) == 0) {
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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 & 0xff) == 0) {
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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 & 0xf) == 0) {
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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 & 0x3) == 0) {
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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 & 0x1) == 0)
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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___FFS
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| 45 | #define __ffs(word) generic___ffs(word)
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| 46 | #endif
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| 47 |
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| 48 | #endif
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