[Bug target/94123] [10 regression] r10-1734, SVN r273240, causes gcc.target/powerpc/pr87507.c to fail

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94123

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |missed-optimization

--- Comment #7 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Peter Bergner from comment #6)
> (In reply to Segher Boessenkool from comment #5)
> > Confirmed.
> > 
> > On p9 it is all fine.
> > 
> > On p7 it is worse, you get std's followed by an lxvd2x from the same stack
> > address (big LHS/SHL hazard there), and then two stxvd2x.
> > 
> > On p8 the TImode values aren't split at all, not until final output anyway.
> 
> My fix for PR87507 allowed them to be split early so they could be
> optimized, so this must have regressed without us seeing it.  I'll have a
> quick look at what is happening.
> 
> Richi, given this is a performance issue for TImode values, is there a
> reason you want this as a P1 bug?

Just default rules applied - the bug is new in GCC 10.  Since it's also a
testsuite regression it woudl be nice to at least make that clean.  If
we understand why the regression happens and can live with it we can demote
it to P2.