[Bug tree-optimization/67612] Unable to vectorize DOT_PROD_EXPR (PMADDWD?)

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67612

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |missed-optimization
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2015-09-18
             Blocks|                            |53947
     Ever confirmed|0                           |1

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
I think DOT_PROD_EXRP is only supported as reduction operation right now.  It
would need to be supported in vectorizable_conversion.  Disabling DOT_PROD
pattern detection makes the loop vectorized (but with awkward code...).


Referenced Bugs:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53947
[Bug 53947] [meta-bug] vectorizer missed-optimizations