[Bug tree-optimization/128082] Compile-time hog in fre1 at -O2 on a loop header with many latch edges (switch dispatch loop)

[lyfanyang at smail dot nju.edu.cn via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=128082

--- Comment #3 from Lvfan Yang <lyfanyang at smail dot nju.edu.cn> ---
Created attachment 65946
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=65946&action=edit
small testcase