forked from Minki/linux
048fa2df92
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>
16 lines
397 B
C
16 lines
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
|