[Pipeline] Remove early InstCombine in ThinLTO post link sample profi…

…le 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
llvm · Mar 15, 2023 · 20ed9ce · 20ed9ce
1 parent ea9d404
commit 20ed9ce
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Showing 4 changed files with 12 additions and 23 deletions.
diff --git 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
@@ -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
@@ -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
@@ -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.