[Bug rtl-optimization/64294] invalid code, zero check gets optimized away

[gcc at breakpoint dot cc]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64294

--- Comment #8 from Sebastian Andrzej Siewior <gcc at breakpoint dot cc> ---
Created attachment 34305
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=34305&action=edit
self-contained complete TC