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[NewPM][LVI] Abandon LVI after CVP
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As mentioned on D70376, LVI can currently cause performance issues
when running under NewPM. The problem is that, unlike the legacy
pass manager, NewPM will not immediately discard the LVI analysis
if the following pass does not need it. This is a problem, because
LVI has a high memory requirement, and mass invalidation of LVI
values is very inefficient. LVI should only be alive during passes
that actively interact with it.

This patch addresses the issue by explicitly abandoning LVI after CVP,
which gets us back to the LegacyPM behavior.

Differential Revision: https://reviews.llvm.org/D84959
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@nikic
nikic committed Aug 1, 2020
1 parent e297d92 commit 25af353
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Showing 8 changed files with 48 additions and 6 deletions.
2 changes: 1 addition & 1 deletion clang/test/CodeGen/thinlto-distributed-newpm.ll
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Expand Up @@ -97,6 +97,7 @@
; CHECK-O: Running pass: JumpThreadingPass on main
; CHECK-O: Running analysis: LazyValueAnalysis on main
; CHECK-O: Running pass: CorrelatedValuePropagationPass on main
; CHECK-O: Invalidating analysis: LazyValueAnalysis on main
; CHECK-O: Running pass: SimplifyCFGPass on main
; CHECK-O3: Running pass: AggressiveInstCombinePass on main
; CHECK-O: Running pass: InstCombinePass on main
Expand Down Expand Up @@ -144,7 +145,6 @@
; CHECK-O: Invalidating analysis: BasicAA on main
; CHECK-O: Invalidating analysis: AAManager on main
; CHECK-O: Invalidating analysis: MemorySSAAnalysis on main
; CHECK-O: Invalidating analysis: LazyValueAnalysis on main
; CHECK-O: Invalidating analysis: LoopAnalysis on main
; CHECK-O: Invalidating analysis: PhiValuesAnalysis on main
; CHECK-O: Invalidating analysis: MemoryDependenceAnalysis on main
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18 changes: 13 additions & 5 deletions llvm/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp
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Expand Up @@ -973,11 +973,19 @@ CorrelatedValuePropagationPass::run(Function &F, FunctionAnalysisManager &AM) {

bool Changed = runImpl(F, LVI, DT, getBestSimplifyQuery(AM, F));

if (!Changed)
return PreservedAnalyses::all();
PreservedAnalyses PA;
PA.preserve<GlobalsAA>();
PA.preserve<DominatorTreeAnalysis>();
PA.preserve<LazyValueAnalysis>();
if (!Changed) {
PA = PreservedAnalyses::all();
} else {
PA.preserve<GlobalsAA>();
PA.preserve<DominatorTreeAnalysis>();
PA.preserve<LazyValueAnalysis>();
}

// Keeping LVI alive is expensive, both because it uses a lot of memory, and
// because invalidating values in LVI is expensive. While CVP does preserve
// LVI, we know that passes after JumpThreading+CVP will not need the result
// of this analysis, so we forcefully discard it early.
PA.abandon<LazyValueAnalysis>();
return PA;
}
3 changes: 3 additions & 0 deletions llvm/test/Other/new-pm-defaults.ll
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Expand Up @@ -147,6 +147,7 @@
; CHECK-O23SZ-NEXT: Running pass: JumpThreadingPass
; CHECK-O23SZ-NEXT: Running analysis: LazyValueAnalysis
; CHECK-O23SZ-NEXT: Running pass: CorrelatedValuePropagationPass
; CHECK-O23SZ-NEXT: Invalidating analysis: LazyValueAnalysis
; CHECK-O-NEXT: Running pass: SimplifyCFGPass
; CHECK-O3-NEXT: AggressiveInstCombinePass
; CHECK-O-NEXT: Running pass: InstCombinePass
Expand Down Expand Up @@ -200,7 +201,9 @@
; CHECK-O-NEXT: Running pass: InstCombinePass
; CHECK-EP-PEEPHOLE-NEXT: Running pass: NoOpFunctionPass
; CHECK-O23SZ-NEXT: Running pass: JumpThreadingPass
; CHECK-O23SZ-NEXT: Running analysis: LazyValueAnalysis
; CHECK-O23SZ-NEXT: Running pass: CorrelatedValuePropagationPass
; CHECK-O23SZ-NEXT: Invalidating analysis: LazyValueAnalysis
; CHECK-O23SZ-NEXT: Running pass: DSEPass
; CHECK-O23SZ-NEXT: Starting llvm::Function pass manager run.
; CHECK-O23SZ-NEXT: Running pass: LoopSimplifyPass
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3 changes: 3 additions & 0 deletions llvm/test/Other/new-pm-thinlto-defaults.ll
View file
Expand Up @@ -112,6 +112,7 @@
; CHECK-O23SZ-NEXT: Running pass: JumpThreadingPass
; CHECK-O23SZ-NEXT: Running analysis: LazyValueAnalysis
; CHECK-O23SZ-NEXT: Running pass: CorrelatedValuePropagationPass
; CHECK-O23SZ-NEXT: Invalidating analysis: LazyValueAnalysis
; CHECK-O-NEXT: Running pass: SimplifyCFGPass
; CHECK-O3-NEXT: Running pass: AggressiveInstCombinePass
; CHECK-O-NEXT: Running pass: InstCombinePass
Expand Down Expand Up @@ -173,7 +174,9 @@
; CHECK-O-NEXT: Running analysis: DemandedBitsAnalysis
; CHECK-O-NEXT: Running pass: InstCombinePass
; CHECK-O23SZ-NEXT: Running pass: JumpThreadingPass
; CHECK-O23SZ-NEXT: Running analysis: LazyValueAnalysis
; CHECK-O23SZ-NEXT: Running pass: CorrelatedValuePropagationPass
; CHECK-O23SZ-NEXT: Invalidating analysis: LazyValueAnalysis
; CHECK-O23SZ-NEXT: Running pass: DSEPass
; CHECK-O23SZ-NEXT: Starting llvm::Function pass manager run
; CHECK-O23SZ-NEXT: Running pass: LoopSimplifyPass
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3 changes: 3 additions & 0 deletions llvm/test/Other/new-pm-thinlto-postlink-pgo-defaults.ll
View file
Expand Up @@ -86,6 +86,7 @@
; CHECK-O23SZ-NEXT: Running pass: JumpThreadingPass
; CHECK-O23SZ-NEXT: Running analysis: LazyValueAnalysis
; CHECK-O23SZ-NEXT: Running pass: CorrelatedValuePropagationPass
; CHECK-O23SZ-NEXT: Invalidating analysis: LazyValueAnalysis
; CHECK-O-NEXT: Running pass: SimplifyCFGPass
; CHECK-O3-NEXT: Running pass: AggressiveInstCombinePass
; CHECK-O-NEXT: Running pass: InstCombinePass
Expand Down Expand Up @@ -146,7 +147,9 @@
; CHECK-O-NEXT: Running analysis: DemandedBitsAnalysis
; CHECK-O-NEXT: Running pass: InstCombinePass
; CHECK-O23SZ-NEXT: Running pass: JumpThreadingPass
; CHECK-O23SZ-NEXT: Running analysis: LazyValueAnalysis
; CHECK-O23SZ-NEXT: Running pass: CorrelatedValuePropagationPass
; CHECK-O23SZ-NEXT: Invalidating analysis: LazyValueAnalysis
; CHECK-O23SZ-NEXT: Running pass: DSEPass
; CHECK-O23SZ-NEXT: Starting {{.*}}Function pass manager run
; CHECK-O23SZ-NEXT: Running pass: LoopSimplifyPass
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3 changes: 3 additions & 0 deletions llvm/test/Other/new-pm-thinlto-postlink-samplepgo-defaults.ll
View file
Expand Up @@ -94,6 +94,7 @@
; CHECK-O23SZ-NEXT: Running pass: JumpThreadingPass
; CHECK-O23SZ-NEXT: Running analysis: LazyValueAnalysis
; CHECK-O23SZ-NEXT: Running pass: CorrelatedValuePropagationPass
; CHECK-O23SZ-NEXT: Invalidating analysis: LazyValueAnalysis
; CHECK-O-NEXT: Running pass: SimplifyCFGPass
; CHECK-O3-NEXT: Running pass: AggressiveInstCombinePass
; CHECK-O-NEXT: Running pass: InstCombinePass
Expand Down Expand Up @@ -154,7 +155,9 @@
; CHECK-O-NEXT: Running analysis: DemandedBitsAnalysis
; CHECK-O-NEXT: Running pass: InstCombinePass
; CHECK-O23SZ-NEXT: Running pass: JumpThreadingPass
; CHECK-O23SZ-NEXT: Running analysis: LazyValueAnalysis
; CHECK-O23SZ-NEXT: Running pass: CorrelatedValuePropagationPass
; CHECK-O23SZ-NEXT: Invalidating analysis: LazyValueAnalysis
; CHECK-O23SZ-NEXT: Running pass: DSEPass
; CHECK-O23SZ-NEXT: Starting {{.*}}Function pass manager run
; CHECK-O23SZ-NEXT: Running pass: LoopSimplifyPass
Expand Down
19 changes: 19 additions & 0 deletions llvm/test/Other/new-pm-thinlto-prelink-pgo-defaults.ll
View file
Expand Up @@ -127,6 +127,7 @@
; CHECK-O23SZ-NEXT: Running pass: JumpThreadingPass
; CHECK-O23SZ-NEXT: Running analysis: LazyValueAnalysis
; CHECK-O23SZ-NEXT: Running pass: CorrelatedValuePropagationPass
; CHECK-O23SZ-NEXT: Invalidating analysis: LazyValueAnalysis
; CHECK-O-NEXT: Running pass: SimplifyCFGPass
; CHECK-O3-NEXT: Running pass: AggressiveInstCombinePass
; CHECK-O-NEXT: Running pass: InstCombinePass
Expand Down Expand Up @@ -196,7 +197,9 @@
; CHECK-O-NEXT: Running analysis: DemandedBitsAnalysis
; CHECK-O-NEXT: Running pass: InstCombinePass
; CHECK-O23SZ-NEXT: Running pass: JumpThreadingPass
; CHECK-O23SZ-NEXT: Running analysis: LazyValueAnalysis
; CHECK-O23SZ-NEXT: Running pass: CorrelatedValuePropagationPass
; CHECK-O23SZ-NEXT: Invalidating analysis: LazyValueAnalysis
; CHECK-O23SZ-NEXT: Running pass: DSEPass
; CHECK-O23SZ-NEXT: Starting {{.*}}Function pass manager run
; CHECK-O23SZ-NEXT: Running pass: LoopSimplifyPass
Expand All @@ -213,10 +216,26 @@
; CHECK-O-NEXT: Finished CGSCC pass manager run.
; CHECK-O-NEXT: Finished {{.*}}Module pass manager run.
; CHECK-O-NEXT: Finished {{.*}}Module pass manager run.
; CHECK-O23SZ-NEXT: Clearing all analysis results for: <possibly invalidated loop>
; CHECK-O23SZ-NEXT: Invalidating analysis: DominatorTreeAnalysis
; CHECK-O23SZ-NEXT: Invalidating analysis: MemorySSAAnalysis
; CHECK-O23SZ-NEXT: Invalidating analysis: LoopAnalysis
; CHECK-O23SZ-NEXT: Invalidating analysis: PostDominatorTreeAnalysis
; CHECK-O23SZ-NEXT: Invalidating analysis: BranchProbabilityAnalysis
; CHECK-O23SZ-NEXT: Invalidating analysis: BlockFrequencyAnalysis
; CHECK-O23SZ-NEXT: Invalidating analysis: ScalarEvolutionAnalysis
; CHECK-O23SZ-NEXT: Invalidating analysis: InnerAnalysisManagerProxy
; CHECK-O23SZ-NEXT: Invalidating analysis: PhiValuesAnalysis
; CHECK-O23SZ-NEXT: Invalidating analysis: MemoryDependenceAnalysis
; CHECK-O23SZ-NEXT: Invalidating analysis: DemandedBitsAnalysis
; CHECK-O3-NEXT: Invalidating analysis: DominanceFrontierAnalysis
; CHECK-O3-NEXT: Invalidating analysis: RegionInfoAnalysis
; CHECK-O23SZ-NEXT: Clearing all analysis results for: foo
; CHECK-O-NEXT: Running pass: GlobalOptPass
; CHECK-O-NEXT: Running analysis: TargetLibraryAnalysis on bar
; CHECK-EXT: Running pass: {{.*}}::Bye
; CHECK-O-NEXT: Finished {{.*}}Module pass manager run.
; CHECK-O23SZ-NEXT: Clearing all analysis results for: foo
; CHECK-O-NEXT: Running pass: NameAnonGlobalPass
; CHECK-O-NEXT: Running pass: PrintModulePass

Expand Down
3 changes: 3 additions & 0 deletions llvm/test/Other/new-pm-thinlto-prelink-samplepgo-defaults.ll
View file
Expand Up @@ -93,6 +93,7 @@
; CHECK-O23SZ-NEXT: Running pass: JumpThreadingPass
; CHECK-O23SZ-NEXT: Running analysis: LazyValueAnalysis
; CHECK-O23SZ-NEXT: Running pass: CorrelatedValuePropagationPass
; CHECK-O23SZ-NEXT: Invalidating analysis: LazyValueAnalysis
; CHECK-O-NEXT: Running pass: SimplifyCFGPass
; CHECK-O3-NEXT: Running pass: AggressiveInstCombinePass
; CHECK-O-NEXT: Running pass: InstCombinePass
Expand Down Expand Up @@ -152,7 +153,9 @@
; CHECK-O-NEXT: Running analysis: DemandedBitsAnalysis
; CHECK-O-NEXT: Running pass: InstCombinePass
; CHECK-O23SZ-NEXT: Running pass: JumpThreadingPass
; CHECK-O23SZ-NEXT: Running analysis: LazyValueAnalysis
; CHECK-O23SZ-NEXT: Running pass: CorrelatedValuePropagationPass
; CHECK-O23SZ-NEXT: Invalidating analysis: LazyValueAnalysis
; CHECK-O23SZ-NEXT: Running pass: DSEPass
; CHECK-O23SZ-NEXT: Starting {{.*}}Function pass manager run
; CHECK-O23SZ-NEXT: Running pass: LoopSimplifyPass
Expand Down

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