[Bug middle-end/66313] Unsafe factorization of a*b+a*c

[babokin at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66313

--- Comment #15 from Dmitry Babokin <babokin at gmail dot com> ---
The bug is almost 2 years old. I consider it's quite important, as false
positives make UBSAN not usable on any large codebases.