https://gcc.gnu.org/bugzilla/show_bug.cgi?id=19987 Bug 19987 depends on bug 94801, which changed state.
Bug 94801 Summary: Failure to optimize narrowed __builtin_clz https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94801 What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |RESOLVED Resolution|--- |FIXED