[Bug tree-optimization/67975] Failure to optimise equality between two call sequences

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67975

--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
https://gcc.gnu.org/ml/gcc-patches/2015-10/msg01580.html

Hope that fixes all cases you ran into.