[Bug rtl-optimization/78116] [7 regression] Performance drop after r241173 on avx512 target

[ysrumyan at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78116

--- Comment #1 from Yuri Rumyantsev <ysrumyan at gmail dot com> ---
Created attachment 39892
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=39892&action=edit
test-case to reproduce

Must be compiled with "-Ofast -funroll-loops -march=knl" options.