[Bug tree-optimization/70005] [6 Regression] wrong code at -O2 and -O3 on x86_64-linux-gnu

[law at redhat dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70005

--- Comment #2 from Jeffrey A. Law <law at redhat dot com> ---
Thanks.  Something unexpected slipped through the IL confusing uncprop.  So
there's really two issues here.  Why did an always-true/always-false test
manage to survive until uncprop, a missed optimization, but probably not a
regression.   And uncprop should be tolerant of that IL state.  I fixed the
same thing in DOM a while back, but clearly forgot to update uncprop with the
same fix.

Testing the obvious fix to uncprop right now.