[llvm] f9d6f37 - [LegacyPM] Remove ControlHeightReductionLegacyPass

[Fangrui Song via llvm-commits]

Author: Fangrui Song
Date: 2022-07-16T01:35:56-07:00
New Revision: f9d6f37201eb45a831a99204281f963f2748b786

URL: https://github.com/llvm/llvm-project/commit/f9d6f37201eb45a831a99204281f963f2748b786
DIFF: https://github.com/llvm/llvm-project/commit/f9d6f37201eb45a831a99204281f963f2748b786.diff

LOG: [LegacyPM] Remove ControlHeightReductionLegacyPass

This pass tries to reduce the number of conditional branches in the hot path
based on profile. It's mostly a no-op after legacy PGO passes are moved.

Added: 
    

Modified: 
    llvm/include/llvm/InitializePasses.h
    llvm/include/llvm/LinkAllPasses.h
    llvm/include/llvm/Transforms/Utils.h
    llvm/lib/Transforms/IPO/PassManagerBuilder.cpp
    llvm/lib/Transforms/Instrumentation/ControlHeightReduction.cpp
    llvm/lib/Transforms/Instrumentation/Instrumentation.cpp
    llvm/test/Transforms/PGOProfile/chr.ll

Removed: 
    


################################################################################
diff  --git a/llvm/include/llvm/InitializePasses.h b/llvm/include/llvm/InitializePasses.h
index 34f9e4dfdb1a..7cbc4015f9d6 100644
--- a/llvm/include/llvm/InitializePasses.h
+++ b/llvm/include/llvm/InitializePasses.h
@@ -112,7 +112,6 @@ void initializeCodeGenPreparePass(PassRegistry&);
 void initializeConstantHoistingLegacyPassPass(PassRegistry&);
 void initializeConstantMergeLegacyPassPass(PassRegistry&);
 void initializeConstraintEliminationPass(PassRegistry &);
-void initializeControlHeightReductionLegacyPassPass(PassRegistry&);
 void initializeCorrelatedValuePropagationPass(PassRegistry&);
 void initializeCostModelAnalysisPass(PassRegistry&);
 void initializeCrossDSOCFIPass(PassRegistry&);

diff  --git a/llvm/include/llvm/LinkAllPasses.h b/llvm/include/llvm/LinkAllPasses.h
index 46f5c9959924..dc5f784de6e0 100644
--- a/llvm/include/llvm/LinkAllPasses.h
+++ b/llvm/include/llvm/LinkAllPasses.h
@@ -91,7 +91,6 @@ namespace {
       (void) llvm::createLibCallsShrinkWrapPass();
       (void) llvm::createCalledValuePropagationPass();
       (void) llvm::createConstantMergePass();
-      (void) llvm::createControlHeightReductionLegacyPass();
       (void) llvm::createCostModelAnalysisPass();
       (void) llvm::createDeadArgEliminationPass();
       (void) llvm::createDeadCodeEliminationPass();

diff  --git a/llvm/include/llvm/Transforms/Utils.h b/llvm/include/llvm/Transforms/Utils.h
index ebd4bd318573..ac4838bd69a5 100644
--- a/llvm/include/llvm/Transforms/Utils.h
+++ b/llvm/include/llvm/Transforms/Utils.h
@@ -113,13 +113,6 @@ extern char &LoopSimplifyID;
 /// module to line tables only.
 ModulePass *createStripNonLineTableDebugLegacyPass();
 
-//===----------------------------------------------------------------------===//
-//
-// ControlHeightReudction - Merges conditional blocks of code and reduces the
-// number of conditional branches in the hot paths based on profiles.
-//
-FunctionPass *createControlHeightReductionLegacyPass();
-
 //===----------------------------------------------------------------------===//
 //
 // InjectTLIMappingsLegacy - populates the VFABI attribute with the

diff  --git a/llvm/lib/Transforms/IPO/PassManagerBuilder.cpp b/llvm/lib/Transforms/IPO/PassManagerBuilder.cpp
index 2a2d141cee28..63ba5c122acb 100644
--- a/llvm/lib/Transforms/IPO/PassManagerBuilder.cpp
+++ b/llvm/lib/Transforms/IPO/PassManagerBuilder.cpp
@@ -470,10 +470,6 @@ void PassManagerBuilder::addFunctionSimplificationPasses(
   // Clean up after everything.
   MPM.add(createInstructionCombiningPass());
   addExtensionsToPM(EP_Peephole, MPM);
-
-  if (EnableCHR && OptLevel >= 3 &&
-      (!PGOInstrUse.empty() || !PGOSampleUse.empty() || EnablePGOCSInstrGen))
-    MPM.add(createControlHeightReductionLegacyPass());
 }
 
 /// FIXME: Should LTO cause any 
diff erences to this set of passes?

diff  --git a/llvm/lib/Transforms/Instrumentation/ControlHeightReduction.cpp b/llvm/lib/Transforms/Instrumentation/ControlHeightReduction.cpp
index e5c0705b916e..adc007dacae4 100644
--- a/llvm/lib/Transforms/Instrumentation/ControlHeightReduction.cpp
+++ b/llvm/lib/Transforms/Instrumentation/ControlHeightReduction.cpp
@@ -102,47 +102,6 @@ static void parseCHRFilterFiles() {
   }
 }
 
-namespace {
-class ControlHeightReductionLegacyPass : public FunctionPass {
-public:
-  static char ID;
-
-  ControlHeightReductionLegacyPass() : FunctionPass(ID) {
-    initializeControlHeightReductionLegacyPassPass(
-        *PassRegistry::getPassRegistry());
-    parseCHRFilterFiles();
-  }
-
-  bool runOnFunction(Function &F) override;
-  void getAnalysisUsage(AnalysisUsage &AU) const override {
-    AU.addRequired<BlockFrequencyInfoWrapperPass>();
-    AU.addRequired<DominatorTreeWrapperPass>();
-    AU.addRequired<ProfileSummaryInfoWrapperPass>();
-    AU.addRequired<RegionInfoPass>();
-    AU.addPreserved<GlobalsAAWrapperPass>();
-  }
-};
-} // end anonymous namespace
-
-char ControlHeightReductionLegacyPass::ID = 0;
-
-INITIALIZE_PASS_BEGIN(ControlHeightReductionLegacyPass,
-                      "chr",
-                      "Reduce control height in the hot paths",
-                      false, false)
-INITIALIZE_PASS_DEPENDENCY(BlockFrequencyInfoWrapperPass)
-INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
-INITIALIZE_PASS_DEPENDENCY(ProfileSummaryInfoWrapperPass)
-INITIALIZE_PASS_DEPENDENCY(RegionInfoPass)
-INITIALIZE_PASS_END(ControlHeightReductionLegacyPass,
-                    "chr",
-                    "Reduce control height in the hot paths",
-                    false, false)
-
-FunctionPass *llvm::createControlHeightReductionLegacyPass() {
-  return new ControlHeightReductionLegacyPass();
-}
-
 namespace {
 
 struct CHRStats {
@@ -2083,18 +2042,6 @@ bool CHR::run() {
   return Changed;
 }
 
-bool ControlHeightReductionLegacyPass::runOnFunction(Function &F) {
-  BlockFrequencyInfo &BFI =
-      getAnalysis<BlockFrequencyInfoWrapperPass>().getBFI();
-  DominatorTree &DT = getAnalysis<DominatorTreeWrapperPass>().getDomTree();
-  ProfileSummaryInfo &PSI =
-      getAnalysis<ProfileSummaryInfoWrapperPass>().getPSI();
-  RegionInfo &RI = getAnalysis<RegionInfoPass>().getRegionInfo();
-  std::unique_ptr<OptimizationRemarkEmitter> OwnedORE =
-      std::make_unique<OptimizationRemarkEmitter>(&F);
-  return CHR(F, BFI, DT, PSI, RI, *OwnedORE).run();
-}
-
 namespace llvm {
 
 ControlHeightReductionPass::ControlHeightReductionPass() {

diff  --git a/llvm/lib/Transforms/Instrumentation/Instrumentation.cpp b/llvm/lib/Transforms/Instrumentation/Instrumentation.cpp
index 28895af4d02c..22ba2f58d2c0 100644
--- a/llvm/lib/Transforms/Instrumentation/Instrumentation.cpp
+++ b/llvm/lib/Transforms/Instrumentation/Instrumentation.cpp
@@ -94,7 +94,6 @@ void llvm::initializeInstrumentation(PassRegistry &Registry) {
   initializeMemProfilerLegacyPassPass(Registry);
   initializeModuleMemProfilerLegacyPassPass(Registry);
   initializeBoundsCheckingLegacyPassPass(Registry);
-  initializeControlHeightReductionLegacyPassPass(Registry);
   initializeInstrOrderFileLegacyPassPass(Registry);
   initializeDataFlowSanitizerLegacyPassPass(Registry);
 }

diff  --git a/llvm/test/Transforms/PGOProfile/chr.ll b/llvm/test/Transforms/PGOProfile/chr.ll
index e412ec5f8805..280ecc4124d0 100644
--- a/llvm/test/Transforms/PGOProfile/chr.ll
+++ b/llvm/test/Transforms/PGOProfile/chr.ll
@@ -1,5 +1,4 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt < %s -chr -instcombine -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -S -enable-new-pm=0 | FileCheck %s
 ; RUN: opt < %s -passes='require<profile-summary>,function(chr,instcombine,simplifycfg)' -S | FileCheck %s
 
 declare void @foo()