mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-11-17 10:18:38 +00:00
42 lines
635 B
C
42 lines
635 B
C
|
#ifndef _ASM_GENERIC_BITOPS_FLS_H_
|
||
|
|
#define _ASM_GENERIC_BITOPS_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)
|
||
|
|
{
|
||
|
|
int r = 32;
|
||
|
|
|
||
|
|
if (!x)
|
||
|
|
return 0;
|
||
|
|
if (!(x & 0xffff0000u)) {
|
||
|
|
x <<= 16;
|
||
|
|
r -= 16;
|
||
|
|
}
|
||
|
|
if (!(x & 0xff000000u)) {
|
||
|
|
x <<= 8;
|
||
|
|
r -= 8;
|
||
|
|
}
|
||
|
|
if (!(x & 0xf0000000u)) {
|
||
|
|
x <<= 4;
|
||
|
|
r -= 4;
|
||
|
|
}
|
||
|
|
if (!(x & 0xc0000000u)) {
|
||
|
|
x <<= 2;
|
||
|
|
r -= 2;
|
||
|
|
}
|
||
|
|
if (!(x & 0x80000000u)) {
|
||
|
|
x <<= 1;
|
||
|
|
r -= 1;
|
||
|
|
}
|
||
|
|
return r;
|
||
|
|
}
|
||
|
|
|
||
|
|
#endif /* _ASM_GENERIC_BITOPS_FLS_H_ */
|