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[Bug middle-end/31531] A microoptimization of isnegative of signed integer


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31531

--- Comment #9 from Andrew Pinski <pinskia at gcc dot gnu.org> 2012-02-12 22:58:41 UTC ---
(In reply to comment #8)
> forwprop already handles:
> int f(int a)
> {
>   int b = ~a;
>   return b<0;
> }
> 
> It just needs to handle:
> int f(unsigned a)
> {
>   int b = ~a;
>   return b<0;
> }

forward_propagate_into_comparison only handles combing of two SSA_NAMEs, it
could handle dealing with a conversion also.


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