[PATCH] D67561: [SampleFDO] minimize performance impact when profile-sample-accurate is enabled

[David Li via Phabricator via llvm-commits]

davidxl added inline comments.


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Comment at: lib/Transforms/IPO/SampleProfile.cpp:1792
+    // actually not be cold after current build.
+    StringRef CanonName = FunctionSamples::getCanonicalFnName(F);
+    if (NamesInProfile.count(CanonName))
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wmi wrote:
> davidxl wrote:
> > If this is no symbol list, then it should not use this heuristic to be consistent with old behavior? 
> I think it is beneficial to have the change when profile-sample-accurate is true no matter symbol list is there or not. symbol list is used to prevent new hot functions from being treated as cold.  NamesInProfile is used to prevent functions are mistakenly treated as cold because inlining difference between sampled binary and the IR after early inlining in current build. These two changes are orthogonal to each other and are both beneficial individually. 
Keeping the old behavior without Symbol list may be able to fix Chrome's size regression.


Repository:
  rL LLVM

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D67561/new/

https://reviews.llvm.org/D67561