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| File: [Development] / linux-2.6-xfs / include / asm-generic / bitops / fls.h (download)
Revision 1.1, Mon May 29 16:35:25 2006 UTC (11 years, 5 months ago) by nathans.longdrop.melbourne.sgi.com
Merge up to 2.6.17-rc5. Merge of 2.6.x-xfs-melb:linux:26065a by kenmcd. |
#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 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_ */