[AliasAnalysis/NewPassManager] Invalidate AAManager less often.

Summary:
This is a redo of D60914.

The objective is to not invalidate AAManager, which is stateless, unless
there is an explicit invalidate in one of the AAResults.

To achieve this, this patch adds an API to PAC, to check precisely this:
is this analysis not invalidated explicitly == is this analysis not abandoned == is this analysis stateless, so preserved without explicitly being marked as preserved by everyone

Reviewers: chandlerc

Subscribers: mehdi_amini, jlebar, george.burgess.iv, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D61284

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@359622 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/Analysis/AliasAnalysis.h b/include/llvm/Analysis/AliasAnalysis.h
index dc850e9152cc95374d238b92853a167f82fe79ef..948341554f2334f0230b41d8be7bedecbc2a5fa7 100644 (file)
--- a/include/llvm/Analysis/AliasAnalysis.h
+++ b/include/llvm/Analysis/AliasAnalysis.h
@@ -1096,6 +1096,11 @@ bool isIdentifiedFunctionLocal(const Value *V);
 /// This manager effectively wraps the AnalysisManager for registering alias
 /// analyses. When you register your alias analysis with this manager, it will
 /// ensure the analysis itself is registered with its AnalysisManager.
+///
+/// The result of this analysis is only invalidated if one of the particular
+/// aggregated AA results end up being invalidated. This removes the need to
+/// explicitly preserve the results of `AAManager`. Note that analyses should no
+/// longer be registered once the `AAManager` is run.
 class AAManager : public AnalysisInfoMixin<AAManager> {
 public:
   using Result = AAResults;

diff --git a/include/llvm/IR/PassManager.h b/include/llvm/IR/PassManager.h
index 47bad5b2f1995bc91c17db4d5111d7c646d2bcb8..37fe2a5b01ada58ef84be6850fed2a4a7f86d772 100644 (file)
--- a/include/llvm/IR/PassManager.h
+++ b/include/llvm/IR/PassManager.h
@@ -286,6 +286,13 @@ public:
                               PA.PreservedIDs.count(ID));
     }
 
+    /// Return true if the checker's analysis was not abandoned, i.e. it was not
+    /// explicitly invalidated. Even if the analysis is not explicitly
+    /// preserved, if the analysis is known stateless, then it is preserved.
+    bool preservedWhenStateless() {
+      return !IsAbandoned;
+    }
+
     /// Returns true if the checker's analysis was not abandoned and either
     ///  - \p AnalysisSetT is explicitly preserved or
     ///  - all analyses are preserved.

diff --git a/lib/Analysis/AliasAnalysis.cpp b/lib/Analysis/AliasAnalysis.cpp
index 06a33f659c19301936cd7888b2208227237f5671..32241e355eb8057f8334d72e7def350edcb50fa6 100644 (file)
--- a/lib/Analysis/AliasAnalysis.cpp
+++ b/lib/Analysis/AliasAnalysis.cpp
@@ -79,12 +79,16 @@ AAResults::~AAResults() {
 
 bool AAResults::invalidate(Function &F, const PreservedAnalyses &PA,
                            FunctionAnalysisManager::Invalidator &Inv) {
-  // Check if the AA manager itself has been invalidated.
+  // AAResults preserves the AAManager by default, due to the stateless nature
+  // of AliasAnalysis. There is no need to check whether it has been preserved
+  // explicitly. Check if any module dependency was invalidated and caused the
+  // AAManager to be invalidated. Invalidate ourselves in that case.
   auto PAC = PA.getChecker<AAManager>();
-  if (!PAC.preserved() && !PAC.preservedSet<AllAnalysesOn<Function>>())
-    return true; // The manager needs to be blown away, clear everything.
+  if (!PAC.preservedWhenStateless())
+    return true;
 
-  // Check all of the dependencies registered.
+  // Check if any of the function dependencies were invalidated, and invalidate
+  // ourselves in that case.
   for (AnalysisKey *ID : AADeps)
     if (Inv.invalidate(ID, F, PA))
       return true;

diff --git a/test/Analysis/MemoryDependenceAnalysis/invalidation.ll b/test/Analysis/MemoryDependenceAnalysis/invalidation.ll
index 478ffc2914b7a7d075604ff704b7b34fca947278..16d17161ad219fa211a190f286bf85cb5eaa28d4 100644 (file)
--- a/test/Analysis/MemoryDependenceAnalysis/invalidation.ll
+++ b/test/Analysis/MemoryDependenceAnalysis/invalidation.ll
@@ -1,17 +1,16 @@
 ; Test that memdep gets invalidated when the analyses it depends on are
 ; invalidated.
 ;
-; Check AA specifically.
+; Check AA. AA is stateless, there's nothing to invalidate.
 ; RUN: opt -disable-output -debug-pass-manager -aa-pipeline='basic-aa' %s 2>&1 \
 ; RUN:     -passes='require<memdep>,invalidate<aa>,gvn' \
 ; RUN:     | FileCheck %s --check-prefix=CHECK-AA-INVALIDATE
 ; CHECK-AA-INVALIDATE: Running pass: RequireAnalysisPass
 ; CHECK-AA-INVALIDATE: Running analysis: MemoryDependenceAnalysis
 ; CHECK-AA-INVALIDATE: Running pass: InvalidateAnalysisPass
-; CHECK-AA-INVALIDATE: Invalidating analysis: AAManager
-; CHECK-AA-INVALIDATE: Invalidating analysis: MemoryDependenceAnalysis
+; CHECK-NOT-AA-INVALIDATE: Invalidating analysis: MemoryDependenceAnalysis
 ; CHECK-AA-INVALIDATE: Running pass: GVN
-; CHECK-AA-INVALIDATE: Running analysis: MemoryDependenceAnalysis
+; CHECK-NOT-AA-INVALIDATE: Running analysis: MemoryDependenceAnalysis
 ;
 ; Check domtree specifically.
 ; RUN: opt -disable-output -debug-pass-manager %s 2>&1 \

diff --git a/test/Other/new-pass-manager.ll b/test/Other/new-pass-manager.ll
index 9c914d4de4c31e4f199731e0c0fdb8599fb66467..e836b321007494a5fec3168528665a78e85e5dc1 100644 (file)
--- a/test/Other/new-pass-manager.ll
+++ b/test/Other/new-pass-manager.ll
@@ -355,13 +355,11 @@
 ; CHECK-AA-MODULE-INVALIDATE: Running analysis: AAManager
 ; CHECK-AA-MODULE-INVALIDATE: Finished llvm::Function pass manager run
 ; CHECK-AA-MODULE-INVALIDATE: Running pass: InvalidateAnalysisPass
-; CHECK-AA-MODULE-INVALIDATE: Invalidating analysis: AAManager
 ; CHECK-AA-MODULE-INVALIDATE: Invalidating analysis: GlobalsAA
 ; CHECK-AA-MODULE-INVALIDATE: Running pass: RequireAnalysisPass
 ; CHECK-AA-MODULE-INVALIDATE: Running analysis: GlobalsAA
 ; CHECK-AA-MODULE-INVALIDATE: Starting llvm::Function pass manager run
 ; CHECK-AA-MODULE-INVALIDATE: Running pass: AAEvaluator
-; CHECK-AA-MODULE-INVALIDATE: Running analysis: AAManager
 ; CHECK-AA-MODULE-INVALIDATE: Finished llvm::Function pass manager run
 ; CHECK-AA-MODULE-INVALIDATE: Finished llvm::Module pass manager run
 

diff --git a/unittests/Transforms/Scalar/LoopPassManagerTest.cpp b/unittests/Transforms/Scalar/LoopPassManagerTest.cpp
index 2615e19d44f5deef632ef957bed932cab75e8590..fc94b6e8c1abdb9cd3e4ee2f44ff9cd686b5fcaf 100644 (file)
--- a/unittests/Transforms/Scalar/LoopPassManagerTest.cpp
+++ b/unittests/Transforms/Scalar/LoopPassManagerTest.cpp
@@ -572,7 +572,6 @@ TEST_F(LoopPassManagerTest, InvalidationOfBundledAnalyses) {
   // invalidation and running.
   EXPECT_CALL(MFPHandle, run(HasName("f"), _))
       .WillOnce(Return(getLoopPassPreservedAnalyses()));
-  EXPECT_CALL(MLAHandle, invalidate(_, _, _)).Times(3);
   EXPECT_CALL(MLAHandle, run(HasName("loop.0.0"), _, _));
   EXPECT_CALL(MLAHandle, run(HasName("loop.0.1"), _, _));
   EXPECT_CALL(MLAHandle, run(HasName("loop.0"), _, _));