[Bug rtl-optimization/115565] [4.0/4.1/4.2/4.3/4.4/4.5/4.6/4.7/4.8/4.9/5/6/7/8/9/10/11/12/13/14/15 Regression] CSE: Comparison incorrectly evaluated as constant causing optimization to produce wrong code

[macro at orcam dot me.uk via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115565

--- Comment #2 from Maciej W. Rozycki <macro at orcam dot me.uk> ---
Created attachment 58475
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=58475&action=edit
Reduced reproducer and incorrect code + RTL dumps produced with commit
08a692679fb8