https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53947 Bug 53947 depends on bug 115484, which changed state.
Bug 115484 Summary: [13/14/15 regression] if-to-switch prevents AVX vectorization https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115484 What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |RESOLVED Resolution|--- |FIXED