[PATCH] D104579: [SampleFDO] Add Pass1 of MIRAddFSDiscriminatorsPass before Block-Placement

[Wenlei He via Phabricator via llvm-commits]

wenlei added a comment.

In D104579#2828504 <https://reviews.llvm.org/D104579#2828504>, @xur wrote:

> This might just be specific to our deployment. Our AFDO optimized build
> uses the profile generated in the previous release.
> If we hold this Pass1 discriminator change and commit together with the FS
> profile change. We won't see the FSAFDO performance in the release right
> after -- we need to wait for another release to get all the samples with
> Pass1 discriminations.
>
> -Rong

Thanks for clarification, makes sense.

Sounds like your production usage is going to have one FS-Disc pass before block layout. And if we add more FS-Disc pass, say before RA, or others, it's not worth it?


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