https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79663
--- Comment #2 from amker at gcc dot gnu.org --- Unfortunately, 2) is not appropriate, in non-ZERO chain case, the root combined statement is used to setup next iterations combined result, it's not for CSE-use in this iteration. Manually insert root_stmt at an earlier place could result in def-after-use error. Though for some cases, there is no def-after-use issue because all insertion points are dominated by root_stmt. This is not always the case.
