[Bug tree-optimization/79828] missing div-by-zero warning

[glisse at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79828

--- Comment #5 from Marc Glisse <glisse at gcc dot gnu.org> ---
If we only warn when the trap is always executed as Arnd suggests (determined
in a similar way as uninitialized vs maybe-uninitialized), I guess there should
be fewer false positive (only cloning seems likely to produce them). On the
other hand, it would likely miss most interesting warnings (although it would
have helped the kernel this once, apparently).