mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-16 07:24:39 +08:00
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>
17 lines
364 B
C
17 lines
364 B
C
#ifndef _ASM_GENERIC_BITOPS_BUILTIN_FLS_H_
|
|
#define _ASM_GENERIC_BITOPS_BUILTIN_FLS_H_
|
|
|
|
/**
|
|
* fls - find last (most-significant) bit set
|
|
* @x: the word to search
|
|
*
|
|
* This is defined the same way as ffs.
|
|
* Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
|
|
*/
|
|
static __always_inline int fls(int x)
|
|
{
|
|
return x ? sizeof(x) * 8 - __builtin_clz(x) : 0;
|
|
}
|
|
|
|
#endif
|