[Bug tree-optimization/81503] [8 Regression] Wrong code at -O2

[wschmidt at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81503

--- Comment #15 from Bill Schmidt <wschmidt at gcc dot gnu.org> ---
Proposed patch awaiting approval: 
https://gcc.gnu.org/ml/gcc-patches/2017-08/msg00347.html