[Bug libgomp/81386] [8 regression] libgomp.fortran/appendix-a/a.16.1.f90 fails starting with 249424

[wschmidt at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81386

Bill Schmidt <wschmidt at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |carll at gcc dot gnu.org

--- Comment #7 from Bill Schmidt <wschmidt at gcc dot gnu.org> ---
(In reply to Bill Schmidt from comment #5)
> The code is being vectorized in the "fails" dump and not being vectorized in
> the "works" dump.  This cannot be due to r249424, which does gimple folding
> on some Power-specific built-ins, for this is a generic test case that makes
> no use of such built-ins.
> 
> So either you have misidentified the revision responsible, or the code is
> somehow being compiled differently so that vectorization happens in one case
> and not the other.
> 
> Bill

Sorry, I got mixed up.  In introducing new multiply built-ins, Carl also
introduced some of the standard patterns that were previously not supported for
the POWER back ends, which allowed vectorization to occur that wouldn't have
before.  Very sorry for the mischaracterization.

Carl, we'll need you to investigate.  I assume that the semantics for the
standard patterns have been implemented incorrectly.  Let me know if you want
to discuss.

Bill