1 files changed, 18 insertions, 46 deletions

diff --git a/llvm/lib/Transforms/Utils/AssumeBundleBuilder.cpp b/llvm/lib/Transforms/Utils/AssumeBundleBuilder.cpp
index d17c399ba798..45cf98e65a5a 100644
--- a/llvm/lib/Transforms/Utils/AssumeBundleBuilder.cpp
+++ b/llvm/lib/Transforms/Utils/AssumeBundleBuilder.cpp
@@ -290,17 +290,20 @@ AssumeInst *llvm::buildAssumeFromInst(Instruction *I) {
   return Builder.build();
 }
 
-void llvm::salvageKnowledge(Instruction *I, AssumptionCache *AC,
+bool llvm::salvageKnowledge(Instruction *I, AssumptionCache *AC,
                             DominatorTree *DT) {
   if (!EnableKnowledgeRetention || I->isTerminator())
-    return;
+    return false;
+  bool Changed = false;
   AssumeBuilderState Builder(I->getModule(), I, AC, DT);
   Builder.addInstruction(I);
   if (auto *Intr = Builder.build()) {
     Intr->insertBefore(I);
+    Changed = true;
     if (AC)
       AC->registerAssumption(Intr);
   }
+  return Changed;
 }
 
 AssumeInst *
@@ -563,57 +566,26 @@ PreservedAnalyses AssumeSimplifyPass::run(Function &F,
                                           FunctionAnalysisManager &AM) {
   if (!EnableKnowledgeRetention)
     return PreservedAnalyses::all();
-  simplifyAssumes(F, &AM.getResult<AssumptionAnalysis>(F),
-                  AM.getCachedResult<DominatorTreeAnalysis>(F));
-  return PreservedAnalyses::all();
-}
-
-namespace {
-class AssumeSimplifyPassLegacyPass : public FunctionPass {
-public:
-  static char ID;
-
-  AssumeSimplifyPassLegacyPass() : FunctionPass(ID) {
-    initializeAssumeSimplifyPassLegacyPassPass(
-        *PassRegistry::getPassRegistry());
-  }
-  bool runOnFunction(Function &F) override {
-    if (skipFunction(F) || !EnableKnowledgeRetention)
-      return false;
-    AssumptionCache &AC =
-        getAnalysis<AssumptionCacheTracker>().getAssumptionCache(F);
-    DominatorTreeWrapperPass *DTWP =
-        getAnalysisIfAvailable<DominatorTreeWrapperPass>();
-    return simplifyAssumes(F, &AC, DTWP ? &DTWP->getDomTree() : nullptr);
-  }
-
-  void getAnalysisUsage(AnalysisUsage &AU) const override {
-    AU.addRequired<AssumptionCacheTracker>();
-
-    AU.setPreservesAll();
-  }
-};
-} // namespace
-
-char AssumeSimplifyPassLegacyPass::ID = 0;
-
-INITIALIZE_PASS_BEGIN(AssumeSimplifyPassLegacyPass, "assume-simplify",
-                      "Assume Simplify", false, false)
-INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)
-INITIALIZE_PASS_END(AssumeSimplifyPassLegacyPass, "assume-simplify",
-                    "Assume Simplify", false, false)
-
-FunctionPass *llvm::createAssumeSimplifyPass() {
-  return new AssumeSimplifyPassLegacyPass();
+  if (!simplifyAssumes(F, &AM.getResult<AssumptionAnalysis>(F),
+                       AM.getCachedResult<DominatorTreeAnalysis>(F)))
+    return PreservedAnalyses::all();
+  PreservedAnalyses PA;
+  PA.preserveSet<CFGAnalyses>();
+  return PA;
 }
 
 PreservedAnalyses AssumeBuilderPass::run(Function &F,
                                          FunctionAnalysisManager &AM) {
   AssumptionCache *AC = &AM.getResult<AssumptionAnalysis>(F);
   DominatorTree* DT = AM.getCachedResult<DominatorTreeAnalysis>(F);
+  bool Changed = false;
   for (Instruction &I : instructions(F))
-    salvageKnowledge(&I, AC, DT);
-  return PreservedAnalyses::all();
+    Changed |= salvageKnowledge(&I, AC, DT);
+  if (!Changed)
+    PreservedAnalyses::all();
+  PreservedAnalyses PA;
+  PA.preserveSet<CFGAnalyses>();
+  return PA;
 }
 
 namespace {