https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80570
Richard Biener <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Last reconfirmed| |2017-05-02 Blocks| |53947 Ever confirmed|0 |1 --- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> --- Confirmed. The vectorizer doesn't have the ability to avoid unpacking / packing by using half-width vectors when it feeds packing/unpacking conversions. Referenced Bugs: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53947 [Bug 53947] [meta-bug] vectorizer missed-optimizations