From cc21d1909aa06c9f84233d9fecfad81ddfed1e3b Mon Sep 17 00:00:00 2001 From: Hari Limaye Date: Tue, 24 Sep 2024 16:12:29 +0000 Subject: [PATCH 1/2] [LTO] Run Argument Promotion before IPSCCP Run ArgumentPromotion before IPSCCP in the LTO pipeline, to expose more constants to be propagated. We also run PostOrderFunctionAttrs to improve the information available to ArgumentPromotion's alias analysis, and SROA to clean up allocas. --- llvm/lib/Passes/PassBuilderPipelines.cpp | 9 +++++++++ llvm/test/Other/new-pm-lto-defaults.ll | 9 ++++++--- 2 files changed, 15 insertions(+), 3 deletions(-) diff --git a/llvm/lib/Passes/PassBuilderPipelines.cpp b/llvm/lib/Passes/PassBuilderPipelines.cpp index 8f151a99b1170..cdb9431c755bc 100644 --- a/llvm/lib/Passes/PassBuilderPipelines.cpp +++ b/llvm/lib/Passes/PassBuilderPipelines.cpp @@ -1831,6 +1831,15 @@ PassBuilder::buildLTODefaultPipeline(OptimizationLevel Level, MPM.addPass(PGOIndirectCallPromotion( true /* InLTO */, PGOOpt && PGOOpt->Action == PGOOptions::SampleUse)); + // Promoting by-reference arguments to by-value exposes more constants to + // IPSCCP. + MPM.addPass(createModuleToPostOrderCGSCCPassAdaptor( + PostOrderFunctionAttrsPass(/*SkipNonRecursive*/ true))); + MPM.addPass( + createModuleToPostOrderCGSCCPassAdaptor(ArgumentPromotionPass())); + MPM.addPass( + createModuleToFunctionPassAdaptor(SROAPass(SROAOptions::ModifyCFG))); + // Propagate constants at call sites into the functions they call. This // opens opportunities for globalopt (and inlining) by substituting function // pointers passed as arguments to direct uses of functions. diff --git a/llvm/test/Other/new-pm-lto-defaults.ll b/llvm/test/Other/new-pm-lto-defaults.ll index 5543472df685b..2dd754ecef4d7 100644 --- a/llvm/test/Other/new-pm-lto-defaults.ll +++ b/llvm/test/Other/new-pm-lto-defaults.ll @@ -41,14 +41,17 @@ ; CHECK-O23SZ-NEXT: PGOIndirectCallPromotion ; CHECK-O23SZ-NEXT: Running analysis: ProfileSummaryAnalysis ; CHECK-O23SZ-NEXT: Running analysis: OptimizationRemarkEmitterAnalysis -; CHECK-O23SZ-NEXT: Running pass: IPSCCPPass -; CHECK-O23SZ-NEXT: Running analysis: AssumptionAnalysis on foo -; CHECK-O23SZ-NEXT: Running pass: CalledValuePropagationPass ; CHECK-O-NEXT: Running analysis: InnerAnalysisManagerProxy<{{.*}}SCC ; CHECK-O-NEXT: Running analysis: LazyCallGraphAnalysis ; CHECK-O1-NEXT: Running analysis: TargetLibraryAnalysis ; CHECK-O-NEXT: Running analysis: FunctionAnalysisManagerCGSCCProxy ; CHECK-O-NEXT: Running analysis: OuterAnalysisManagerProxy<{{.*}}LazyCallGraph{{.*}}> +; CHECK-O23SZ-NEXT: Running pass: PostOrderFunctionAttrsPass +; CHECK-O23SZ-NEXT: Running pass: ArgumentPromotionPass +; CHECK-O23SZ-NEXT: Running pass: SROAPass +; CHECK-O23SZ-NEXT: Running analysis: AssumptionAnalysis on foo +; CHECK-O23SZ-NEXT: Running pass: IPSCCPPass +; CHECK-O23SZ-NEXT: Running pass: CalledValuePropagationPass ; CHECK-O-NEXT: Running pass: PostOrderFunctionAttrsPass ; CHECK-O-NEXT: Running analysis: AAManager ; CHECK-O-NEXT: Running analysis: BasicAA From 8b6aed2653dc2d70c5dc01f220bc25036d3626f1 Mon Sep 17 00:00:00 2001 From: Hari Limaye Date: Wed, 9 Oct 2024 13:03:19 +0000 Subject: [PATCH 2/2] [Pipelines] Run ArgProm before IPSCCP in non-LTO (WIP) Run Argument Promotion before IPSCCP in the Module Simplification pipeline, provided we are not LTO pre-link. Compile-time impact, measured by instruction count, for the CTMark suite at O3 (non-LTO): Benchmark | Change | -----------------+---------+ 7zip | +0.11% | Bullet | +0.21% | ClamAV | +0.08% | SPASS | +0.25% | consumer-typeset | +0.14% | kimwitu++ | +0.35% | lencod | +0.01% | mafft | +0.01% | sqlite3 | +0.11% | tramp3d-v4 | +0.28% | -----------------+---------+ GEOMEAN | 0.15% | --- llvm/lib/Passes/PassBuilderPipelines.cpp | 11 +++++++++++ llvm/test/Other/new-pm-defaults.ll | 11 +++++++---- 2 files changed, 18 insertions(+), 4 deletions(-) diff --git a/llvm/lib/Passes/PassBuilderPipelines.cpp b/llvm/lib/Passes/PassBuilderPipelines.cpp index cdb9431c755bc..26fcc51c3c7a2 100644 --- a/llvm/lib/Passes/PassBuilderPipelines.cpp +++ b/llvm/lib/Passes/PassBuilderPipelines.cpp @@ -1136,6 +1136,17 @@ PassBuilder::buildModuleSimplificationPipeline(OptimizationLevel Level, invokePipelineEarlySimplificationEPCallbacks(MPM, Level); + // Promoting by-reference arguments to by-value exposes more constants to + // IPSCCP. + if (!isLTOPreLink(Phase)) { + MPM.addPass(createModuleToPostOrderCGSCCPassAdaptor( + PostOrderFunctionAttrsPass(/*SkipNonRecursive*/ true))); + MPM.addPass( + createModuleToPostOrderCGSCCPassAdaptor(ArgumentPromotionPass())); + MPM.addPass( + createModuleToFunctionPassAdaptor(SROAPass(SROAOptions::ModifyCFG))); + } + // Interprocedural constant propagation now that basic cleanup has occurred // and prior to optimizing globals. // FIXME: This position in the pipeline hasn't been carefully considered in diff --git a/llvm/test/Other/new-pm-defaults.ll b/llvm/test/Other/new-pm-defaults.ll index 55dbdb1b8366d..5bf1872dc2404 100644 --- a/llvm/test/Other/new-pm-defaults.ll +++ b/llvm/test/Other/new-pm-defaults.ll @@ -113,6 +113,13 @@ ; CHECK-O3-NEXT: Running pass: CallSiteSplittingPass ; CHECK-O-NEXT: Running pass: OpenMPOptPass ; CHECK-EP-PIPELINE-EARLY-SIMPLIFICATION-NEXT: Running pass: NoOpModulePass +; CHECK-O-NEXT: Running analysis: InnerAnalysisManagerProxy +; CHECK-O-NEXT: Running analysis: LazyCallGraphAnalysis +; CHECK-O-NEXT: Running analysis: FunctionAnalysisManagerCGSCCProxy +; CHECK-O-NEXT: Running analysis: OuterAnalysisManagerProxy<{{.*}}LazyCallGraph::SCC{{.*}}> +; CHECK-O-NEXT: Running pass: PostOrderFunctionAttrsPass +; CHECK-O-NEXT: Running pass: ArgumentPromotionPass +; CHECK-O-NEXT: Running pass: SROAPass ; CHECK-O-NEXT: Running pass: IPSCCPPass ; CHECK-O-NEXT: Running pass: CalledValuePropagationPass ; CHECK-O-NEXT: Running pass: GlobalOptPass @@ -136,10 +143,6 @@ ; CHECK-O-NEXT: Running pass: InvalidateAnalysisPass<{{.*}}AAManager ; CHECK-O-NEXT: Invalidating analysis: AAManager ; CHECK-O-NEXT: Running pass: RequireAnalysisPass<{{.*}}ProfileSummaryAnalysis -; CHECK-O-NEXT: Running analysis: InnerAnalysisManagerProxy -; CHECK-O-NEXT: Running analysis: LazyCallGraphAnalysis -; CHECK-O-NEXT: Running analysis: FunctionAnalysisManagerCGSCCProxy -; CHECK-O-NEXT: Running analysis: OuterAnalysisManagerProxy<{{.*}}LazyCallGraph::SCC{{.*}}> ; CHECK-O-NEXT: Running pass: DevirtSCCRepeatedPass ; CHECK-O-NEXT: Running pass: InlinerPass ; CHECK-O-NEXT: Running pass: PostOrderFunctionAttrsPass