diff options
author | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2016-10-20 00:10:27 -0300 |
---|---|---|
committer | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2016-10-20 00:10:27 -0300 |
commit | d0b2f91bede3bd5e3d24dd6803e56eee959c1797 (patch) | |
tree | 7fee4ab0509879c373c4f2cbd5b8a5be5b4041ee /tools/include/asm-generic/bitops/__fls.h | |
parent | e914f8eb445e8f74b00303c19c2ffceaedd16a05 (diff) |
Linux-libre 4.8.2-gnupck-4.8.2-gnu
Diffstat (limited to 'tools/include/asm-generic/bitops/__fls.h')
-rw-r--r-- | tools/include/asm-generic/bitops/__fls.h | 44 |
1 files changed, 43 insertions, 1 deletions
diff --git a/tools/include/asm-generic/bitops/__fls.h b/tools/include/asm-generic/bitops/__fls.h index 494c9c615..a60a7ccb6 100644 --- a/tools/include/asm-generic/bitops/__fls.h +++ b/tools/include/asm-generic/bitops/__fls.h @@ -1 +1,43 @@ -#include "../../../../include/asm-generic/bitops/__fls.h" +#ifndef _ASM_GENERIC_BITOPS___FLS_H_ +#define _ASM_GENERIC_BITOPS___FLS_H_ + +#include <asm/types.h> + +/** + * __fls - find last (most-significant) set bit in a long word + * @word: the word to search + * + * Undefined if no set bit exists, so code should check against 0 first. + */ +static __always_inline unsigned long __fls(unsigned long word) +{ + int num = BITS_PER_LONG - 1; + +#if BITS_PER_LONG == 64 + if (!(word & (~0ul << 32))) { + num -= 32; + word <<= 32; + } +#endif + if (!(word & (~0ul << (BITS_PER_LONG-16)))) { + num -= 16; + word <<= 16; + } + if (!(word & (~0ul << (BITS_PER_LONG-8)))) { + num -= 8; + word <<= 8; + } + if (!(word & (~0ul << (BITS_PER_LONG-4)))) { + num -= 4; + word <<= 4; + } + if (!(word & (~0ul << (BITS_PER_LONG-2)))) { + num -= 2; + word <<= 2; + } + if (!(word & (~0ul << (BITS_PER_LONG-1)))) + num -= 1; + return num; +} + +#endif /* _ASM_GENERIC_BITOPS___FLS_H_ */ |