[Bug target/91735] [9/10 Regression] Runtime regression for SPEC2000 177.mesa on Haswell around the end of August 2018

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91735

--- Comment #11 from Richard Biener <rguenth at gcc dot gnu.org> ---
Created attachment 46880
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=46880&action=edit
prototype

This improves code-gen to use pextrw where possible but that doesn't make any
measurable difference on runtime.  Maybe the example loop isn't representative
or the improvement isn't big enough.