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| author | Catalin Marinas <catalin.marinas@arm.com> | 2012-09-13 01:00:53 +0400 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2012-09-14 20:15:41 +0400 |
| commit | 048fa2df92c325cb4425dccd66c8922c8342b507 (patch) | |
| tree | a76ddbd3f05752f27e0867906a34e102cb76b4e4 /include/asm-generic/bitops/builtin-__ffs.h | |
| parent | 0753f70f07fbbd23a48d61ffea37028bd0bd6c7d (diff) | |
| download | linux-048fa2df92c325cb4425dccd66c8922c8342b507.tar.xz | |
generic: Implement generic ffs/fls using __builtin_* functions
This patch implements ffs, __ffs, fls, __fls using __builtin_* gcc
functions. These header files can be used by other architectures that
rely on the gcc builtins.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'include/asm-generic/bitops/builtin-__ffs.h')
| -rw-r--r-- | include/asm-generic/bitops/builtin-__ffs.h | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/include/asm-generic/bitops/builtin-__ffs.h b/include/asm-generic/bitops/builtin-__ffs.h new file mode 100644 index 000000000000..90041e3a41f0 --- /dev/null +++ b/include/asm-generic/bitops/builtin-__ffs.h @@ -0,0 +1,15 @@ +#ifndef _ASM_GENERIC_BITOPS_BUILTIN___FFS_H_ +#define _ASM_GENERIC_BITOPS_BUILTIN___FFS_H_ + +/** + * __ffs - find first bit in word. + * @word: The word to search + * + * Undefined if no bit exists, so code should check against 0 first. + */ +static __always_inline unsigned long __ffs(unsigned long word) +{ + return __builtin_ctzl(word); +} + +#endif |