[Bug target/91796] Sub-optimal YMM register allocation.

[maxim.yegorushkin at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91796

--- Comment #8 from Maxim Egorushkin <maxim.yegorushkin at gmail dot com> ---
Another example
https://stackoverflow.com/questions/61975526/gcc-optimization-better-at-o0-than-o3