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[PGO] Add flags to control IRPGO warnings.

Authored by JakeVanAdrighem on May 11 2016, 9:27 PM.



Currently there is no reasonable way to control the warnings in the 'use' phase of the IRPGO pass. This is problematic because the output can be somewhat spammy. This patch adds some flags which allow us to optionally disable these warnings. The current upstream behavior will remain the default.

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JakeVanAdrighem retitled this revision from to [PGO] Add flags to control IRPGO warnings..
JakeVanAdrighem updated this object.
JakeVanAdrighem added reviewers: xur, davidxl, silvas.
JakeVanAdrighem set the repository for this revision to rL LLVM.
JakeVanAdrighem added a subscriber: llvm-commits.
davidxl accepted this revision.May 11 2016, 9:37 PM
davidxl edited edge metadata.


Question : do you get warnings when there is no source change? This indicates some potential bugs in compiler. If you see them, can you help file bugs?

This revision is now accepted and ready to land.May 11 2016, 9:37 PM

Great, if possible Sean or David could you commit this for me? I don't have
commit access.

As for your question. Sean and I have actually experienced warnings
resulting from a difference in inlining choices in different TU's but we
will definitely be bringing this up very soon as a separate discussion.
These flags were mostly to deal with instrprof_error::unknown_function
which for our use case tends to be pretty spammy but not very helpful.

xur edited edge metadata.May 12 2016, 10:30 AM

It's good to add options to control the warning -- sometime there are just too many warnings.
But I would suggest to separate this from the stats collection. This patch disables it altogether with the message.

JakeVanAdrighem edited edge metadata.

The meaning/name of the flags have been changed so that we only pass them to disable the warnings. The flags also no longer interfere with the statistics.


xur accepted this revision.May 13 2016, 10:04 AM
xur edited edge metadata.

Looks good to me.
I will submit this patch for you.

Thanks for improving this.

This revision was automatically updated to reflect the committed changes.