[Bug tree-optimization/84737] [8 Regression] 20% degradation in CPU2000 172.mgrid starting with r256888

[pthaugen at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84737

--- Comment #10 from Pat Haugen <pthaugen at gcc dot gnu.org> ---
(In reply to Pat Haugen from comment #9)
> (pr83497, which I'm still digging on). Ignoring output miscompare and just
> timing the two versions built with -fno-tree-vectorize, I see that the 
> performance is similar. So possibly a powerpc vector cost issue.
> 

And then again, maybe not. Running with -fno-tree-vectorize and removing
-ffast-math (which eliminates the output miscompare), I still see the
degradation.