[PATCH] D104579: [SampleFDO] Add two passes of MIRAddFSDiscriminatorsPass

[Wenlei He via Phabricator via llvm-commits]

wenlei added a comment.

In D104579#2937770 <https://reviews.llvm.org/D104579#2937770>, @wmi wrote:

>> This extra pass turns to be positive in performance -- I'm seeing additional 0.6% - 0.8% improvement.
>
> That is a good improvement. I guess the improvement is because regalloc is profile sensitive and it is benefited from preciser fs profile information after you insert another pass of profile loading before regalloc?

Good to know, thanks for experimenting Rong! We've also seen RA being sensitive to profile in our profile inference work - sometimes small change in profile due to inference change can lead to significant cascading effect in RA.


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https://reviews.llvm.org/D104579