[PATCH] D92998: [CSSPGO][llvm-profgen] Pseudo probe based CS profile generation

[Hongtao Yu via Phabricator via llvm-commits]

hoy added inline comments.


================
Comment at: llvm/tools/llvm-profgen/ProfileGenerator.cpp:42
   if (SampleType == PERF_LBR_STACK) {
+    // Enable context-sensitive functionalities in SampleProf
+    FunctionSamples::ProfileIsCS = true;
----------------
wlei wrote:
> hoy wrote:
> > The setting of the two flags should not be necessary on the profile generation side. They are used on the loader side. Do you see any issue without setting them?
> Yeah, if not explicitly setting here, the value will be false.
> 
> you see in llvm/lib/Transforms/IPO/SampleProfile.cpp:
> 
> ```
>   // Apply tweaks if context-sensitive profile is available.
>   if (Reader->profileIsCS()) {
>     ProfileIsCS = true;
>     FunctionSamples::ProfileIsCS = true;
> 
>     // Tracker for profiles under different context
>     ContextTracker =
>         std::make_unique<SampleContextTracker>(Reader->getProfiles());
>   }
> ```
> It's set when the reader know it's a CS profile. But for llvm-profgen side, it doesn't set this.
> 
I see. So `ContextTracker` used in profile generation?


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https://reviews.llvm.org/D92998