[Bug middle-end/100267] gcc -O2 for avx512 instrincts generates extra warnings and less optimizations

[crazylht at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100267

--- Comment #6 from Hongtao.liu <crazylht at gmail dot com> ---
a patch is posted at
https://gcc.gnu.org/pipermail/gcc-patches/2021-April/569248.html