[PATCH] D115907: [misexpect] Re-implement MisExpect Diagnostics

[Paul Kirth via Phabricator via cfe-commits]

paulkirth created this revision.
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paulkirth updated this revision to Diff 394995.
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paulkirth updated this revision to Diff 394997.
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[misexpect] Fix Typo


paulkirth added a comment.

Fix bad diff in arctool


paulkirth added a comment.

Ready for review


Reimplements MisExpect diagnostics to reconstruct its original checking
methodology only using MD_prof branch_weights metadata.

New checks rely on 2 invariants:

1. for frontend instrumentation, MD_prof branch_weights will always be populated before llvm.expect intrinsics are lowered.

2. for IR and sample profiling, llvm.expect intrinsics will always be lowered before branch_weights are populated from the IR profiles.

These invariants allow the checking to assume how the existing branch
weights are populated depending on the profiling method used, and emit
the correct diagnostics. If these invariants are ever invalidated, the
MisExpect related checks would need to be updated, potentially by
re-introducing MD_misexpect metadata, and ensuring it always will be
transformed the same way as branch_weights in other optimization passes.

Frontend based profiling is now enabled without using LLVM Args, by
introducing a new CodeGen option, and checking if the -Wmisexpect flag
has been passed on the command line.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D115907

Files:
  clang/include/clang/Basic/CodeGenOptions.def
  clang/include/clang/Basic/DiagnosticFrontendKinds.td
  clang/include/clang/Basic/DiagnosticGroups.td
  clang/lib/CodeGen/BackendUtil.cpp
  clang/lib/CodeGen/CodeGenAction.cpp
  clang/lib/Frontend/CompilerInvocation.cpp
  clang/test/Profile/Inputs/misexpect-branch.proftext
  clang/test/Profile/misexpect-branch-cold.c
  clang/test/Profile/misexpect-branch-unpredictable.c
  clang/test/Profile/misexpect-branch.c
  llvm/docs/MisExpect.rst
  llvm/include/llvm/IR/DiagnosticInfo.h
  llvm/include/llvm/IR/LLVMContext.h
  llvm/include/llvm/Target/TargetOptions.h
  llvm/include/llvm/Transforms/Utils/MisExpect.h
  llvm/lib/IR/DiagnosticInfo.cpp
  llvm/lib/IR/LLVMContext.cpp
  llvm/lib/IR/LLVMContextImpl.h
  llvm/lib/Transforms/IPO/SampleProfile.cpp
  llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp
  llvm/lib/Transforms/Scalar/LowerExpectIntrinsic.cpp
  llvm/lib/Transforms/Utils/CMakeLists.txt
  llvm/lib/Transforms/Utils/MisExpect.cpp
  llvm/test/Transforms/PGOProfile/Inputs/misexpect-branch-correct.proftext
  llvm/test/Transforms/PGOProfile/Inputs/misexpect-branch.proftext
  llvm/test/Transforms/PGOProfile/Inputs/misexpect-switch-correct.proftext
  llvm/test/Transforms/PGOProfile/Inputs/misexpect-switch.proftext
  llvm/test/Transforms/PGOProfile/misexpect-branch-correct.ll
  llvm/test/Transforms/PGOProfile/misexpect-branch-stripped.ll
  llvm/test/Transforms/PGOProfile/misexpect-branch-unpredictable.ll
  llvm/test/Transforms/PGOProfile/misexpect-branch.ll
  llvm/test/Transforms/PGOProfile/misexpect-switch-default.ll
  llvm/test/Transforms/PGOProfile/misexpect-switch.ll

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