[Bug tree-optimization/68294] gcc cannot deduce (a | b) != 0 from (a != 0 && b != 0)

[glisse at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68294

--- Comment #1 from Marc Glisse <glisse at gcc dot gnu.org> ---
Please always include a compilable testcase so everyone doesn't have to
reinvent one from your explanations.

Gcc knows that u|v is not 0 (from VRP), but does not take advantage of that
information in this case.