https://gcc.gnu.org/bugzilla/show_bug.cgi?id=19987 Bug 19987 depends on bug 94916, which changed state.
Bug 94916 Summary: Failure to optimize pattern into difference or zero selector https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94916 What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |RESOLVED Resolution|--- |FIXED