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frv: define __fls

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

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
hifive-unleashed-5.1
Rusty Russell 2009-01-03 16:14:05 +10:30
parent 0999769e6c
commit ee38e5140b
1 changed files with 13 additions and 0 deletions

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@ -339,6 +339,19 @@ int __ffs(unsigned long x)
return 31 - bit;
}
/**
* __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)
{
unsigned long bit;
asm("scan %1,gr0,%0" : "=r"(bit) : "r"(word));
return bit;
}
/*
* special slimline version of fls() for calculating ilog2_u32()
* - note: no protection against n == 0