xtensa: define __fls

Like fls, but can't be handed 0 and returns the bit number.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This commit is contained in:
Rusty Russell 2009-01-03 16:21:08 +10:30
parent 5c134dad43
commit 5ece5c5192
1 changed files with 11 additions and 0 deletions

View File

@ -82,6 +82,16 @@ static inline int fls (unsigned int x)
return 32 - __cntlz(x);
}
/**
* __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 inline unsigned long __fls(unsigned long word)
{
return 31 - __cntlz(word);
}
#else
/* Use the generic implementation if we don't have the nsa/nsau instructions. */
@ -90,6 +100,7 @@ static inline int fls (unsigned int x)
# include <asm-generic/bitops/__ffs.h>
# include <asm-generic/bitops/ffz.h>
# include <asm-generic/bitops/fls.h>
# include <asm-generic/bitops/__fls.h>
#endif