[Bug target/101456] Unnecessary vzeroupper when upper bits of YMM registers already zero

[hjl.tools at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101456

--- Comment #2 from H.J. Lu <hjl.tools at gmail dot com> ---
Created attachment 51153
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=51153&action=edit
A patch