[PM] Teach MemDep to invalidate its result object when its cached

analysis handles become invalid.

Add a test case for its invalidation logic.

llvm-svn: 290620

llvm/include/llvm/Analysis/MemoryDependenceAnalysis.h

@@ -350,6 +350,10 @@ public:
                           DominatorTree &DT)
       : AA(AA), AC(AC), TLI(TLI), DT(DT) {}
 
+  /// Handle invalidation in the new PM.
+  bool invalidate(Function &F, const PreservedAnalyses &PA,
+                  FunctionAnalysisManager::Invalidator &Inv);
+
   /// Some methods limit the number of instructions they will examine.
   /// The return value of this method is the default limit that will be
   /// used if no limit is explicitly passed in.

llvm/lib/Analysis/MemoryDependenceAnalysis.cpp

@@ -1683,6 +1683,24 @@ void MemoryDependenceWrapperPass::getAnalysisUsage(AnalysisUsage &AU) const {
   AU.addRequiredTransitive<TargetLibraryInfoWrapperPass>();
 }
 
+bool MemoryDependenceResults::invalidate(Function &F, const PreservedAnalyses &PA,
+                               FunctionAnalysisManager::Invalidator &Inv) {
+  // Check whether our analysis is preserved.
+  auto PAC = PA.getChecker<MemoryDependenceAnalysis>();
+  if (!PAC.preserved() && !PAC.preservedSet<AllAnalysesOn<Function>>())
+    // If not, give up now.
+    return true;
+
+  // Check whether the analyses we depend on became invalid for any reason.
+  if (Inv.invalidate<AAManager>(F, PA) ||
+      Inv.invalidate<AssumptionAnalysis>(F, PA) ||
+      Inv.invalidate<DominatorTreeAnalysis>(F, PA))
+    return true;
+
+  // Otherwise this analysis result remains valid.
+  return false;
+}
+
 unsigned MemoryDependenceResults::getDefaultBlockScanLimit() const {
   return BlockScanLimit;
 }

llvm/test/Analysis/MemoryDependenceAnalysis/invalidation.ll

@@ -0,0 +1,76 @@
+; Test that memdep gets invalidated when the analyses it depends on are
+; invalidated.
+;
+; Check AA specifically.
+; 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-AA-INVALIDATE: Running pass: GVN
+; CHECK-AA-INVALIDATE: Running analysis: MemoryDependenceAnalysis
+;
+; Check the assumptions analysis specifically.
+; FIXME: We don't have any test cases that actually fail if the assumption
+; cache becomes stale. This just tests what we believe to be correct.
+; RUN: opt -disable-output -debug-pass-manager %s 2>&1 \
+; RUN:     -passes='require<memdep>,invalidate<assumptions>,gvn' \
+; RUN:     | FileCheck %s --check-prefix=CHECK-ASSUMPTIONS-INVALIDATE
+; CHECK-ASSUMPTIONS-INVALIDATE: Running pass: RequireAnalysisPass
+; CHECK-ASSUMPTIONS-INVALIDATE: Running analysis: MemoryDependenceAnalysis
+; CHECK-ASSUMPTIONS-INVALIDATE: Running pass: InvalidateAnalysisPass
+; CHECK-ASSUMPTIONS-INVALIDATE: Invalidating analysis: AssumptionAnalysis
+; CHECK-ASSUMPTIONS-INVALIDATE: Invalidating analysis: MemoryDependenceAnalysis
+; CHECK-ASSUMPTIONS-INVALIDATE: Running pass: GVN
+; CHECK-ASSUMPTIONS-INVALIDATE: Running analysis: MemoryDependenceAnalysis
+;
+; Check domtree specifically.
+; RUN: opt -disable-output -debug-pass-manager %s 2>&1 \
+; RUN:     -passes='require<memdep>,invalidate<domtree>,gvn' \
+; RUN:     | FileCheck %s --check-prefix=CHECK-DT-INVALIDATE
+; CHECK-DT-INVALIDATE: Running pass: RequireAnalysisPass
+; CHECK-DT-INVALIDATE: Running analysis: MemoryDependenceAnalysis
+; CHECK-DT-INVALIDATE: Running pass: InvalidateAnalysisPass
+; CHECK-DT-INVALIDATE: Invalidating analysis: DominatorTreeAnalysis
+; CHECK-DT-INVALIDATE: Invalidating analysis: MemoryDependenceAnalysis
+; CHECK-DT-INVALIDATE: Running pass: GVN
+; CHECK-DT-INVALIDATE: Running analysis: MemoryDependenceAnalysis
+;
+
+define void @test_use_domtree(i32* nocapture %bufUInt, i32* nocapture %pattern) nounwind {
+entry:
+  br label %for.body
+
+for.exit:                                         ; preds = %for.body
+  ret void
+
+for.body:                                         ; preds = %for.body, %entry
+  %i.01 = phi i32 [ 0, %entry ], [ %tmp8.7, %for.body ]
+  %arrayidx = getelementptr i32, i32* %bufUInt, i32 %i.01
+  %arrayidx5 = getelementptr i32, i32* %pattern, i32 %i.01
+  %tmp6 = load i32, i32* %arrayidx5, align 4
+  store i32 %tmp6, i32* %arrayidx, align 4
+  %tmp8.7 = add i32 %i.01, 8
+  %cmp.7 = icmp ult i32 %tmp8.7, 1024
+  br i1 %cmp.7, label %for.body, label %for.exit
+}
+
+%t = type { i32 }
+declare void @foo(i8*)
+
+define void @test_use_aa(%t* noalias %stuff ) {
+entry:
+  %p = getelementptr inbounds %t, %t* %stuff, i32 0, i32 0
+  %before = load i32, i32* %p
+
+  call void @foo(i8* null)
+
+  %after = load i32, i32* %p
+  %sum = add i32 %before, %after
+
+  store i32 %sum, i32* %p
+  ret void
+}