[Bug tree-optimization/128277] [13/14/15/16/17 Regression] Compile-time hog in ccp1 at -O1 on a loop header with many latch edges since r13-5102

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=128277

--- Comment #1 from Lvfan Yang <lyfanyang at smail dot nju.edu.cn> ---
Created attachment 66031
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=66031&action=edit
small testcase with single