[PATCH] D92074: [llvm-profdata] Emit Error when Invalid MemOpSize Section is Created by llvm-profdata

Thu Jan 14 10:29:48 PST 2021

xur added a comment.

Sorry for the delay.

I replied to the comments on Dec 17 via email. But it did not come through. I don't know the reason. I put my comments here.

> I think it would be valuable to guard against this pattern within the transform, but I'm concerned that putting the error in the pass would make it harder to debug this issue. If we detect this in llvm-profdata, the user is more likely to have/provide the profraw files causing this behavior.

I don't think putting this into transformation will make it more difficult to debug. There are ready many legality heuristics there.
To me, the merge operation should be a straightforward translation from raw format to index format. We should not put filters there.
A warning is OK but not a filter of profile records.

>> Should we do something in profile runtime to prevent this.
>
> Do you think llvm-profdata could be causing this issue? I was thinking that profdata might be merging two profiles incorrectly. Either way, having the profraw files would be valuable for debugging...

There are chances of llvm-prodate bugs but more chances in the compiler-rt runtime.
Providing the raw profile and the index profile will be very helpful for the debuging.

Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D92074/new/

https://reviews.llvm.org/D92074