[Bug tree-optimization/120268] Missed removing loop of setting zero when dereference pointer (memset) at -O3 -fallow-store-data-races

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120268

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
phiopt, where CSELIM is done might be the place to put this into.  We might
want to try simplifying the COND_EXPR ptr[i] != 0 ? 0 : ptr[i].