[Bug tree-optimization/125501] [14/15/16/17 Regression] wrong code at -O3 that crashes at runtime

[amacleod at redhat dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=125501

--- Comment #20 from Andrew Macleod <amacleod at redhat dot com> ---
Created attachment 64614
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=64614&action=edit
potential patch

I haven't run it through anything yet, but something like this should do the
trick...