https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68654
--- Comment #10 from Jeffrey A. Law <law at redhat dot com> --- I've just scanned the provided dumps. This is almost certainly a difference in the SSA_NAME_VERSIONs causing different coalescing. The tell-tale sign is seeing identical code in the .optimized dump, except that the SSA_NAME versions are different, then seeing different code being generated in the .expand dump. This can be confirmed by providing the same dumps, but with the "details" modifier. ie, -fdump-tree-optimized-details
