[PM] The assumption cache is fundamentally designed to be self-updating,
mark it as never invalidated in the new PM.

The old PM already required this to work, and after a discussion with
Hal this seems to really be the only sensible answer. The cache
gracefully degrades as the IR is mutated, and most things which do this
should already be incrementally updating the cache.

This gets rid of a bunch of logic preserving and testing the
invalidation of this analysis.

llvm-svn: 292039
diff --git a/llvm/include/llvm/Analysis/AssumptionCache.h b/llvm/include/llvm/Analysis/AssumptionCache.h
index b50545a..c3b5428 100644
--- a/llvm/include/llvm/Analysis/AssumptionCache.h
+++ b/llvm/include/llvm/Analysis/AssumptionCache.h
@@ -84,6 +84,13 @@
   /// its instructions.
   AssumptionCache(Function &F) : F(F), Scanned(false) {}
 
+  /// This cache is designed to be self-updating and so it should never be
+  /// invalidated.
+  bool invalidate(Function &, const PreservedAnalyses &,
+                  FunctionAnalysisManager::Invalidator &) {
+    return false;
+  }
+
   /// \brief Add an @llvm.assume intrinsic to this function's cache.
   ///
   /// The call passed in must be an instruction within this function and must
diff --git a/llvm/include/llvm/Transforms/Scalar/LoopPassManager.h b/llvm/include/llvm/Transforms/Scalar/LoopPassManager.h
index b0e6dd6..e9973fe 100644
--- a/llvm/include/llvm/Transforms/Scalar/LoopPassManager.h
+++ b/llvm/include/llvm/Transforms/Scalar/LoopPassManager.h
@@ -321,7 +321,6 @@
     PA.preserveSet<AllAnalysesOn<Loop>>();
     PA.preserve<LoopAnalysisManagerFunctionProxy>();
     // We also preserve the set of standard analyses.
-    PA.preserve<AssumptionAnalysis>();
     PA.preserve<DominatorTreeAnalysis>();
     PA.preserve<LoopAnalysis>();
     PA.preserve<ScalarEvolutionAnalysis>();
diff --git a/llvm/lib/Analysis/LoopAnalysisManager.cpp b/llvm/lib/Analysis/LoopAnalysisManager.cpp
index 5be3ee3..2946bae 100644
--- a/llvm/lib/Analysis/LoopAnalysisManager.cpp
+++ b/llvm/lib/Analysis/LoopAnalysisManager.cpp
@@ -145,7 +145,6 @@
 
 PreservedAnalyses llvm::getLoopPassPreservedAnalyses() {
   PreservedAnalyses PA;
-  PA.preserve<AssumptionAnalysis>();
   PA.preserve<DominatorTreeAnalysis>();
   PA.preserve<LoopAnalysis>();
   PA.preserve<LoopAnalysisManagerFunctionProxy>();
diff --git a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
index b2c4baa..8ba19fd 100644
--- a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
@@ -3179,7 +3179,6 @@
   // FIXME: This should also 'preserve the CFG'.
   PreservedAnalyses PA;
   PA.preserve<AAManager>();
-  PA.preserve<AssumptionAnalysis>();
   PA.preserve<DominatorTreeAnalysis>();
   PA.preserve<GlobalsAA>();
   return PA;
diff --git a/llvm/test/Analysis/MemoryDependenceAnalysis/invalidation.ll b/llvm/test/Analysis/MemoryDependenceAnalysis/invalidation.ll
index 6e5d4a4..478ffc2 100644
--- a/llvm/test/Analysis/MemoryDependenceAnalysis/invalidation.ll
+++ b/llvm/test/Analysis/MemoryDependenceAnalysis/invalidation.ll
@@ -13,20 +13,6 @@
 ; 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' \
diff --git a/llvm/test/Analysis/ScalarEvolution/invalidation.ll b/llvm/test/Analysis/ScalarEvolution/invalidation.ll
index 1fcaddb..f750b3d 100644
--- a/llvm/test/Analysis/ScalarEvolution/invalidation.ll
+++ b/llvm/test/Analysis/ScalarEvolution/invalidation.ll
@@ -8,19 +8,6 @@
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-unknown-linux-gnu"
 
-; RUN: opt < %s -passes='require<scalar-evolution>,invalidate<assumptions>,print<scalar-evolution>' \
-; RUN:     -debug-pass-manager -disable-output 2>&1 \
-; RUN:     | FileCheck %s -check-prefixes=CHECK,CHECK-AC-INVALIDATE
-;
-; CHECK-AC-INVALIDATE: Running pass: RequireAnalysisPass
-; CHECK-AC-INVALIDATE: Running analysis: ScalarEvolutionAnalysis
-; CHECK-AC-INVALIDATE: Running analysis: AssumptionAnalysis
-; CHECK-AC-INVALIDATE: Running pass: InvalidateAnalysisPass
-; CHECK-AC-INVALIDATE: Invalidating analysis: AssumptionAnalysis
-; CHECK-AC-INVALIDATE: Running pass: ScalarEvolutionPrinterPass
-; CHECK-AC-INVALIDATE: Running analysis: ScalarEvolutionAnalysis
-; CHECK-AC-INVALIDATE: Running analysis: AssumptionAnalysis
-
 ; RUN: opt < %s -passes='require<scalar-evolution>,invalidate<domtree>,print<scalar-evolution>' \
 ; RUN:     -debug-pass-manager -disable-output 2>&1 \
 ; RUN:     | FileCheck %s -check-prefixes=CHECK,CHECK-DT-INVALIDATE
diff --git a/llvm/unittests/Transforms/Scalar/LoopPassManagerTest.cpp b/llvm/unittests/Transforms/Scalar/LoopPassManagerTest.cpp
index a099e35..8f5a0c9 100644
--- a/llvm/unittests/Transforms/Scalar/LoopPassManagerTest.cpp
+++ b/llvm/unittests/Transforms/Scalar/LoopPassManagerTest.cpp
@@ -551,7 +551,6 @@
   EXPECT_CALL(MFPHandle, run(HasName("f"), _)).WillOnce(InvokeWithoutArgs([] {
     auto PA = PreservedAnalyses::none();
     // Not preserving `AAManager`.
-    PA.preserve<AssumptionAnalysis>();
     PA.preserve<DominatorTreeAnalysis>();
     PA.preserve<LoopAnalysis>();
     PA.preserve<LoopAnalysisManagerFunctionProxy>();
@@ -568,24 +567,6 @@
   EXPECT_CALL(MFPHandle, run(HasName("f"), _)).WillOnce(InvokeWithoutArgs([] {
     auto PA = PreservedAnalyses::none();
     PA.preserve<AAManager>();
-    // Not preserving `AssumptionAnalysis`.
-    PA.preserve<DominatorTreeAnalysis>();
-    PA.preserve<LoopAnalysis>();
-    PA.preserve<LoopAnalysisManagerFunctionProxy>();
-    PA.preserve<ScalarEvolutionAnalysis>();
-    return PA;
-  }));
-  EXPECT_CALL(MLAHandle, run(HasName("loop.0.0"), _, _));
-  EXPECT_CALL(MLAHandle, run(HasName("loop.0.1"), _, _));
-  EXPECT_CALL(MLAHandle, run(HasName("loop.0"), _, _));
-  FPM.addPass(MFPHandle.getPass());
-  FPM.addPass(createFunctionToLoopPassAdaptor(
-      RequireAnalysisLoopPass<MockLoopAnalysisHandle::Analysis>()));
-
-  EXPECT_CALL(MFPHandle, run(HasName("f"), _)).WillOnce(InvokeWithoutArgs([] {
-    auto PA = PreservedAnalyses::none();
-    PA.preserve<AAManager>();
-    PA.preserve<AssumptionAnalysis>();
     // Not preserving `DominatorTreeAnalysis`.
     PA.preserve<LoopAnalysis>();
     PA.preserve<LoopAnalysisManagerFunctionProxy>();
@@ -602,7 +583,6 @@
   EXPECT_CALL(MFPHandle, run(HasName("f"), _)).WillOnce(InvokeWithoutArgs([] {
     auto PA = PreservedAnalyses::none();
     PA.preserve<AAManager>();
-    PA.preserve<AssumptionAnalysis>();
     PA.preserve<DominatorTreeAnalysis>();
     // Not preserving the `LoopAnalysis`.
     PA.preserve<LoopAnalysisManagerFunctionProxy>();
@@ -619,7 +599,6 @@
   EXPECT_CALL(MFPHandle, run(HasName("f"), _)).WillOnce(InvokeWithoutArgs([] {
     auto PA = PreservedAnalyses::none();
     PA.preserve<AAManager>();
-    PA.preserve<AssumptionAnalysis>();
     PA.preserve<DominatorTreeAnalysis>();
     PA.preserve<LoopAnalysis>();
     // Not preserving the `LoopAnalysisManagerFunctionProxy`.
@@ -636,7 +615,6 @@
   EXPECT_CALL(MFPHandle, run(HasName("f"), _)).WillOnce(InvokeWithoutArgs([] {
     auto PA = PreservedAnalyses::none();
     PA.preserve<AAManager>();
-    PA.preserve<AssumptionAnalysis>();
     PA.preserve<DominatorTreeAnalysis>();
     PA.preserve<LoopAnalysis>();
     PA.preserve<LoopAnalysisManagerFunctionProxy>();
@@ -654,7 +632,7 @@
   // 'g' once with a requires pass and then run our mock pass over g a bunch
   // but just get cached results each time.
   EXPECT_CALL(MLAHandle, run(HasName("loop.g.0"), _, _));
-  EXPECT_CALL(MFPHandle, run(HasName("g"), _)).Times(7);
+  EXPECT_CALL(MFPHandle, run(HasName("g"), _)).Times(6);
 
   MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
   MPM.run(*M, MAM);