[Bug tree-optimization/77980] Regression in GCC-7.0.0's optimizer.

[glisse at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77980

--- Comment #3 from Marc Glisse <glisse at gcc dot gnu.org> ---
Note that "regression in gcc-7.0.0" would mean that gcc-6 was doing better,
which is not the case.