https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64130
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |missed-optimization
Status|UNCONFIRMED |NEW
Last reconfirmed| |2014-12-01
Ever confirmed|0 |1
--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Andi Kleen from comment #3)
> You're right. I actually meant
>
> x >= maxval(typeof(a)), x / a cannot be 0.
>
> Corrected test case (assuming 64bit target):
>
> #include <limits.h>
>
> int fsigned(int a)
> {
> return 0x1fffffffL / a == 0;
> }
0x1fffffffL / 0x20000000 == 0
Maybe you meant 0x1fffffffffffffffL / a == 0?
> int funsigned(unsigned a)
> {
> return 0x1fffffffL / a == 0;
> }
>
> >So this should be optimized to a > 100 instead.
>
> Yes this would make sense too.
Yes.
