[Bug tree-optimization/65930] Reduction with sign-change not handled

[tnfchris at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65930

--- Comment #12 from Tamar Christina <tnfchris at gcc dot gnu.org> ---
> If you have some clever ideas make sure to outline a patch
> before finalizing it so you won't be disappointed by negative feedback ;)

I'll be sure to do that with this and the other changes I intend to tackle! :)