[Pipeline] Remove early InstCombine in ThinLTO post link sample profile pipeline

With opaque pointers, all function pointer types are the same, meaning there should be no bitcasts.

Internal benchmarks with SampleFDO look neutral.

This was added in D36333.

Reviewed By: tejohnson, davidxl

Differential Revision: https://reviews.llvm.org/D146099

diff --git a/llvm/lib/Passes/PassBuilderPipelines.cpp b/llvm/lib/Passes/PassBuilderPipelines.cpp
index ff61fd9..c006488 100644 (file)
--- a/llvm/lib/Passes/PassBuilderPipelines.cpp
+++ b/llvm/lib/Passes/PassBuilderPipelines.cpp
@@ -968,14 +968,6 @@ PassBuilder::buildModuleSimplificationPipeline(OptimizationLevel Level,
   if (Level == OptimizationLevel::O3)
     EarlyFPM.addPass(CallSiteSplittingPass());
 
-  // In SamplePGO ThinLTO backend, we need instcombine before profile annotation
-  // to convert bitcast to direct calls so that they can be inlined during the
-  // profile annotation prepration step.
-  // More details about SamplePGO design can be found in:
-  // https://research.google.com/pubs/pub45290.html
-  // FIXME: revisit how SampleProfileLoad/Inliner/ICP is structured.
-  if (LoadSampleProfile)
-    EarlyFPM.addPass(InstCombinePass());
   MPM.addPass(createModuleToFunctionPassAdaptor(std::move(EarlyFPM),
                                                 PTO.EagerlyInvalidateAnalyses));
 

diff --git a/llvm/test/Other/new-pm-pgo.ll b/llvm/test/Other/new-pm-pgo.ll
index b5de48a..c4926f4 100644 (file)
--- a/llvm/test/Other/new-pm-pgo.ll
+++ b/llvm/test/Other/new-pm-pgo.ll
@@ -24,7 +24,6 @@
 ; SAMPLE_USE: Running pass: SimplifyCFGPass
 ; SAMPLE_USE: Running pass: SROAPass
 ; SAMPLE_USE: Running pass: EarlyCSEPass
-; SAMPLE_USE_POST_LINK: Running pass: InstCombinePass
 ; SAMPLE_USE: Running pass: SampleProfileLoaderPass
 ; SAMPLE_USE_O: Running pass: PGOIndirectCallPromotion
 ; SAMPLE_USE_POST_LINK-NOT: Running pass: GlobalOptPass

diff --git a/llvm/test/Other/new-pm-thinlto-postlink-samplepgo-defaults.ll b/llvm/test/Other/new-pm-thinlto-postlink-samplepgo-defaults.ll
index 8b0ea1a..5756203 100644 (file)
--- a/llvm/test/Other/new-pm-thinlto-postlink-samplepgo-defaults.ll
+++ b/llvm/test/Other/new-pm-thinlto-postlink-samplepgo-defaults.ll
@@ -44,18 +44,12 @@
 ; CHECK-O-NEXT: Running pass: EarlyCSEPass
 ; CHECK-O-NEXT: Running analysis: TargetLibraryAnalysis
 ; CHECK-O3-NEXT: Running pass: CallSiteSplittingPass
-; CHECK-O-NEXT: Running pass: InstCombinePass on foo
-; CHECK-O-NEXT: Running analysis: OptimizationRemarkEmitterAnalysis on foo
-; CHECK-O-NEXT: Running analysis: AAManager on foo
-; CHECK-O-NEXT: Running analysis: BasicAA
-; CHECK-O-NEXT: Running analysis: ScopedNoAliasAA
-; CHECK-O-NEXT: Running analysis: TypeBasedAA
-; CHECK-O-NEXT: Running analysis: OuterAnalysisManagerProxy
 ; CHECK-O-NEXT: Running pass: SampleProfileLoaderPass
 ; CHECK-O-NEXT: Running analysis: ProfileSummaryAnalysis
 ; CHECK-O-NEXT: Running analysis: CallGraphAnalysis
 ; CHECK-O-NEXT: Running pass: RequireAnalysisPass<{{.*}}ProfileSummaryAnalysis
 ; CHECK-O-NEXT: Running pass: PGOIndirectCallPromotion
+; CHECK-O-NEXT: Running analysis: OptimizationRemarkEmitterAnalysis
 ; CHECK-O-NEXT: Running pass: OpenMPOptPass
 ; CHECK-O-NEXT: Running pass: LowerTypeTestsPass
 ; CHECK-O-NEXT: Running pass: IPSCCPPass
@@ -64,6 +58,11 @@
 ; CHECK-O-NEXT: Running pass: GlobalOptPass
 ; CHECK-O-NEXT: Running pass: PromotePass
 ; CHECK-O-NEXT: Running pass: InstCombinePass
+; CHECK-O-NEXT: Running analysis: AAManager on foo
+; CHECK-O-NEXT: Running analysis: BasicAA
+; CHECK-O-NEXT: Running analysis: ScopedNoAliasAA
+; CHECK-O-NEXT: Running analysis: TypeBasedAA
+; CHECK-O-NEXT: Running analysis: OuterAnalysisManagerProxy
 ; CHECK-O-NEXT: Running analysis: BlockFrequencyAnalysis on foo
 ; These next two can appear in any order since they are accessed as parameters
 ; on the same call to BlockFrequencyInfo::calculate.

diff --git a/llvm/test/Other/new-pm-thinlto-prelink-samplepgo-defaults.ll b/llvm/test/Other/new-pm-thinlto-prelink-samplepgo-defaults.ll
index bf8826b..1bf48d8 100644 (file)
--- a/llvm/test/Other/new-pm-thinlto-prelink-samplepgo-defaults.ll
+++ b/llvm/test/Other/new-pm-thinlto-prelink-samplepgo-defaults.ll
@@ -42,13 +42,6 @@
 ; CHECK-O-NEXT: Running pass: EarlyCSEPass
 ; CHECK-O-NEXT: Running analysis: TargetLibraryAnalysis
 ; CHECK-O3-NEXT: Running pass: CallSiteSplittingPass
-; CHECK-O-NEXT: Running pass: InstCombinePass on foo
-; CHECK-O-NEXT: Running analysis: OptimizationRemarkEmitterAnalysis on foo
-; CHECK-O-NEXT: Running analysis: AAManager on foo
-; CHECK-O-NEXT: Running analysis: BasicAA
-; CHECK-O-NEXT: Running analysis: ScopedNoAliasAA
-; CHECK-O-NEXT: Running analysis: TypeBasedAA
-; CHECK-O-NEXT: Running analysis: OuterAnalysisManagerProxy
 ; CHECK-O-NEXT: Running pass: SampleProfileLoaderPass
 ; CHECK-O-NEXT: Running analysis: ProfileSummaryAnalysis
 ; CHECK-O-NEXT: Running analysis: CallGraphAnalysis
@@ -59,6 +52,12 @@
 ; CHECK-O-NEXT: Running pass: GlobalOptPass
 ; CHECK-O-NEXT: Running pass: PromotePass
 ; CHECK-O-NEXT: Running pass: InstCombinePass
+; CHECK-O-NEXT: Running analysis: OptimizationRemarkEmitterAnalysis on foo
+; CHECK-O-NEXT: Running analysis: AAManager on foo
+; CHECK-O-NEXT: Running analysis: BasicAA
+; CHECK-O-NEXT: Running analysis: ScopedNoAliasAA
+; CHECK-O-NEXT: Running analysis: TypeBasedAA
+; CHECK-O-NEXT: Running analysis: OuterAnalysisManagerProxy
 ; CHECK-O-NEXT: Running analysis: BlockFrequencyAnalysis on foo
 ; These next two can appear in any order since they are accessed as parameters
 ; on the same call to BlockFrequencyInfo::calculate.