[Bug tree-optimization/89176] Vectorizer fails to consider narrower vector width for res[i] = v1[i] < v2[i] ? v2[i] : v1[i]

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89176

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2019-02-04
             Blocks|                            |53947
     Ever confirmed|0                           |1

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
Oddly enough with --param vect-epilogues-nomask=1 we vectorize the epilogue but
immediately throw it away afterwards.

The reason it works with multiplication is that basic-block vectorization
works there but in the condition case is presented with non-ifconverted
form in multiple BBs which it doesn't handle.

I think this one is then a duplicate of a bug that mentions that phiopt
doesn't use .FMIN/MAX internal functions if available.

The epilogue vectorization issue also needs investigation.


Referenced Bugs:

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