[Bug middle-end/57073] __builtin_powif (-1.0, k) should be optimized to "1.0 - 2.0 * (K%2)"

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57073

--- Comment #5 from Tobias Burnus <burnus at gcc dot gnu.org> 2013-04-29 08:40:59 UTC ---
(In reply to comment #4)
> patch that fails

The Fortran patch of the attachments looks fine, except for:

+      one = gfc_copy_expr (op1);
+      gfc_free_expr (op1);
+      gfc_free_expr (op2);
+      *e = *one;

I would simply use "op1" directly instead of copying it and then freeing the
original expression. Otherwise, I am okay with that patch (with a test case).

 * * *

For the middle-end patch: Richard things that the problem is probably in the
COND_EXPR re-gimplification - which means the problem is elsewhere.