Re: [2.6.6-BK] x86_64 has buggy ffs() implementation

[H. Peter Anvin]

Gabriel Paubert wrote:
> Either I'm asleep or you are emulating bsrl, not bsfl. It
> should rather be:
>
> 	if ( y & 0x00000001) return 1;
> 	if ( y & 0x00000002) return 2;
> 	if ( y & 0x00000004) return 3;
> 	...
> 	if ( y & 0x80000000) return 32;
> 	return 0;
>
> No need for the else clauses either because of the return.
> But maybe even __builtin_ffs(y) would work in this case.

If __builtin_ffs() works *AND HAS THE RIGHT SEMANTICS* it's probably the 
best thing to use.

Otherwise, yes, generic_ffs() can clearly be used inside the 
__builtin_constant_p() clause.

	-hpa
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