[PATCH] D102246: [SampleFDO] New hierarchical discriminator for Flow Sensitive SampleFDO

[Hongtao Yu via Phabricator via llvm-commits]

hoy added inline comments.


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Comment at: llvm/lib/CodeGen/MIRFSDiscriminator.cpp:67
+  using BBSet = DenseSet<const MachineBasicBlock *>;
+  using LocationDiscriminatorBBMap = DenseMap<LocationDiscriminator, BBSet>;
+  using LocationDiscriminatorCurrPassMap =
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Nit: not sure if `std::unordered_multimap` can be a bit faster by not constructing a `BBSet` if most instructions are not duplicated.


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Comment at: llvm/lib/CodeGen/TargetPassConfig.cpp:1181
+  if (EnableFSDiscriminator && !FSNoFinalDiscrim)
+    addPass(createMIRAddFSDiscriminatorsPass(PASS_LAST_DIS_BIT_BEG,
+                                             PASS_LAST_DIS_BIT_END));
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Wondering why using `PASS_LAST_DIS_BIT_BEG` here. Will other bits be used in later patches?



CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D102246/new/

https://reviews.llvm.org/D102246