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linux-next/include/asm-generic/bitops/builtin-__fls.h
Catalin Marinas 048fa2df92 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>
2012-09-14 17:15:41 +01:00

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397 B
C

#ifndef _ASM_GENERIC_BITOPS_BUILTIN___FLS_H_
#define _ASM_GENERIC_BITOPS_BUILTIN___FLS_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)
{
return (sizeof(word) * 8) - 1 - __builtin_clzl(word);
}
#endif