[Bug middle-end/66313] Unsafe factorization of a*b+a*c

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66313

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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                URL|                            |https://gcc.gnu.org/ml/gcc-
                   |                            |patches/2015-10/msg02907.ht
                   |                            |ml

--- Comment #12 from Richard Biener <rguenth at gcc dot gnu.org> ---
See patch at https://gcc.gnu.org/ml/gcc-patches/2015-10/msg02907.html, yes I
think
even the latest variant regressed at least the tail-recursion testcase and I
didn't have time to review Josephs last comment and change the exceptions
accordingly.

That said, I believe the transform would be best done in the reassoc pass
but that has to be enhanced to handle types with non-wrapping overflow
characteristics first.