https://gcc.gnu.org/bugzilla/show_bug.cgi?id=26731
Joost VandeVondele <Joost.VandeVondele at mat dot ethz.ch> changed:
What |Removed |Added
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CC| |Joost.VandeVondele at mat dot
ethz
| |.ch
--- Comment #3 from Joost VandeVondele <Joost.VandeVondele at mat dot ethz.ch>
---
(In reply to Andrew Pinski from comment #0)
> Jump threading causes bad interactions with loops:
> int f(int t, int a, int x)
> {
> int n, g;
> if (t)
> n = a;
> else
> n = 4;
> for (g=0; g<n; g++)
> x++;
> return x;
> }
>
> This should be optimized to:
> int f(int t, int a, int x)
> {
> int n, g;
> if (t)
> n = a;
> else
> n = 4;
> x+=n;
> return x;
> }
> But is not because of jump threading getting in the way to dect that the
> loop is finite.
actually, it should not, for a<0 and t=1.
