https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97223
--- Comment #4 from Eugene Rozenfeld <erozen at microsoft dot com> --- The commit that fixed this: https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=32ee472864ada44ef05b2a3b087b8ce413bee282
[Bug tree-optimization/97223] Failure to optimize comparison of char arithmetic to single comparison
erozen at microsoft dot com via Gcc-bugs Thu, 14 Jan 2021 13:13:28 -0800
