[PATCH] D81981: [PGO] Supplement PGO profile with Sample profile

[Wei Mi via Phabricator via llvm-commits]

wmi updated this revision to Diff 280621.
wmi added a comment.

Address David's comments.

The major change is to remove the dependence on always having entry counter in the profile. For function with all zero instr profile or most of zero instr profile, its counters will be set to all -1. All -1 counters indicates the internal profile for the function is unaccountable and also indicates the function is hot. PGO profile-use will drop all the internal counters while set the function entry count to be several times above hot threshold.

I choose to set all counters to all -1 instead of dropping the profile to express the indications above because I am afraid in rare case, PGO profile may be accidently used when building an unrelated target. If we set the functions to be hot when their profiles cannot be found, we may treat all the functions to be hot and that may bloat up the code and trigger compile-time issue.


Repository:
  rL LLVM

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D81981/new/

https://reviews.llvm.org/D81981

Files:
  llvm/docs/CommandGuide/llvm-profdata.rst
  llvm/include/llvm/ProfileData/InstrProf.h
  llvm/include/llvm/ProfileData/InstrProfWriter.h
  llvm/lib/ProfileData/InstrProf.cpp
  llvm/lib/ProfileData/InstrProfWriter.cpp
  llvm/lib/ProfileData/ProfileSummaryBuilder.cpp
  llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp
  llvm/test/Transforms/PGOProfile/Inputs/sample-profile.proftext
  llvm/test/Transforms/PGOProfile/Inputs/suppl-profile.proftext
  llvm/test/Transforms/PGOProfile/suppl-profile.ll
  llvm/test/tools/llvm-profdata/Inputs/mix_instr.proftext
  llvm/test/tools/llvm-profdata/Inputs/mix_sample.proftext
  llvm/test/tools/llvm-profdata/suppl-instr-with-sample.test
  llvm/tools/llvm-profdata/llvm-profdata.cpp

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