[Bug middle-end/90796] [8/9/10 Regression] GCC: O2 vs O3 output differs on simple test

[glisse at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90796

--- Comment #2 from Marc Glisse <glisse at gcc dot gnu.org> ---
-fdisable-tree-unrolljam helps, which may (or may not) point at a potential
culprit.