[PATCH] D127026: [CSSPGO][llvm-profgen] Reimplement computeSummaryAndThreshold using context trie

[Hongtao Yu via Phabricator via llvm-commits]

hoy added inline comments.


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Comment at: llvm/tools/llvm-profgen/ProfileGenerator.cpp:435
-  } else {
-    // This is for the case the input is a llvm sample profile.
-    for (const auto &FS : ProfileMap) {
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wlei wrote:
> hoy wrote:
> > why delete this?
> It's not completely deleted, it's moved to the ctor(see:  ProfileGenerator.h: 180), this is because we don't ever save the llvm-sample-profile into ProfileMap, I made the llvm-sample-profile  a temporary variable, it's converted to trie right in the ctor and dropped. So I also moved this part of code there.
I see. Profiled functions are also used to on-demand decode pseudo probes and it's needed for non-CS profile generator too.


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Comment at: llvm/tools/llvm-profgen/ProfileGenerator.cpp:1010
+  ContextTracker.createContextLessProfileMap(ContextLessProfiles);
+  ProfileGeneratorBase::computeSummaryAndThreshold(ContextLessProfiles, false);
+}
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wlei wrote:
> hoy wrote:
> > Is `false` needed here? We are passing in contextless profiles so merging them again inside `computeSummaryAndThreshold` should be fine?
> Yeah, we can merge the contextless profiles twice, but is there any concern to save one?
I guess my questions should be why this the extra parameter needed. Is the original implementation that checks `FunctionSamples::ProfileIsCS` inside `SampleProfileSummaryBuilder::computeSummaryForProfiles` not working?


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  https://reviews.llvm.org/D127026/new/

https://reviews.llvm.org/D127026