[Bug tree-optimization/128102] [14/15/16/17 Regression] GCC 12+ keeps a small state-machine loop rolled, 1.85x slower than GCC 11 on x86-64

[yansendao at 126 dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=128102

--- Comment #3 from 颜森道 <yansendao at 126 dot com> ---
Created attachment 65952
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=65952&action=edit
propose patch