[Bug gcov-profile/90364] 521.wrf_r is 9.5 % slower with PGO on Zen CPUs at -Ofast and native march/mtune

rguenth at gcc dot gnu.org gcc-bugzilla@gcc.gnu.org
Tue May 7 13:01:00 GMT 2019


https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90364

--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Martin Liška from comment #3)
> So the problem is that without a profile tree-vectorizer does a
> vectorization in 1162 functions, while with PGO only 49 functions are
> vectorized.
> Can you please Richi take a look? I can provide vectorizer dump files.

optimize_loop_nest_for_speed_p returning false?

Does the train profile match the ref profile or is there a clear mismatch
so we guess a ref hot loop as cold?


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