[Bug tree-optimization/105142] [12 Regression] Wrong code with -O2 since r12-2591

[rguenth at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105142

--- Comment #8 from Richard Biener <rguenth at gcc dot gnu.org> ---
Created attachment 52744
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=52744&action=edit
patch to rewrite undefined overflow stmts

Here's the initial patch, not solving the testcase.