Remove InstructionCombining and its related pass from sample pgo passes as we can handle "invoke" correctly.

[danielcdh]

Summary

We previously relies on InstructionCombining pass to remove invoke instructions. Now that we can inline invoke instructions correctly, we do not need these passes any more.

[dnovillo]

LGTM. Thanks.

lib/CodeGen/BackendUtil.cpp

if (Builder.OptLevel > 0)
     PM.add(createObjCARCOptPass());
 }
 
 static void addAddDiscriminatorsPass(const PassManagerBuilder &Builder,
                                      legacy::PassManagerBase &PM) {
   PM.add(createAddDiscriminatorsPass());
 }
 
-static void addCleanupPassesForSampleProfiler(
-    const PassManagerBuilder &Builder, legacy::PassManagerBase &PM) {
-  // instcombine is needed before sample profile annotation because it converts
-  // certain function calls to be inlinable. simplifycfg and sroa are needed
-  // before instcombine for necessary preparation. E.g. load store is eliminated
-  // properly so that instcombine will not introduce unecessary liverange.
-  PM.add(createCFGSimplificationPass());
-  PM.add(createSROAPass());
-  PM.add(createInstructionCombiningPass());
-}
-
 static void addBoundsCheckingPass(const PassManagerBuilder &Builder,
                                   legacy::PassManagerBase &PM) {
   PM.add(createBoundsCheckingPass());
 }
 
 static void addSanitizerCoveragePass(const PassManagerBuilder &Builder,
                                      legacy::PassManagerBase &PM) {
   const PassManagerBuilderWrapper &BuilderWrapper =
else
       PMBuilder.PGOInstrGen = "default_%m.profraw";
   }
   if (CodeGenOpts.hasProfileIRUse())
     PMBuilder.PGOInstrUse = CodeGenOpts.ProfileInstrumentUsePath;
 
   if (!CodeGenOpts.SampleProfileFile.empty()) {
     MPM.add(createPruneEHPass());
     MPM.add(createSampleProfileLoaderPass(CodeGenOpts.SampleProfileFile));
-    PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
-                           addCleanupPassesForSampleProfiler);
   }
 
   PMBuilder.populateFunctionPassManager(FPM);
   PMBuilder.populateModulePassManager(MPM);
 }
 
 void EmitAssemblyHelper::setCommandLineOpts() {
   SmallVector<const char *, 16> BackendArgs;

test/CodeGen/pgo-sample.c

 // Test if PGO sample use passes are invoked.
 //
 // Ensure Pass PGOInstrumentationGenPass is invoked.
 // RUN: %clang_cc1 -O2 -fprofile-sample-use=%S/Inputs/pgo-sample.prof %s -mllvm -debug-pass=Structure -emit-llvm -o - 2>&1 | FileCheck %s
-// CHECK: Simplify the CFG
-// CHECK: SROA
-// CHECK: Combine redundant instructions
 // CHECK: Remove unused exception handling info
 // CHECK: Sample profile pass