https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102032
--- Comment #4 from Vincent Lefèvre <vincent-gcc at vinc17 dot net> --- Note that as said in PR111560 comment 6, re-association may break CSE, e.g. if there are also a + b + d and a + c + e with my example. So, re-association for global optimal CSE, in addition to being difficult, will not allow the optimization in all cases of equivalent expressions.
