3 files changed, 10 insertions, 4 deletions
diff --git a/lib/Transforms/Scalar/LowerAtomic.cpp b/lib/Transforms/Scalar/LowerAtomic.cpp
index 08e60b16bedf..6f77c5bd0d07 100644
--- a/lib/Transforms/Scalar/LowerAtomic.cpp
+++ b/lib/Transforms/Scalar/LowerAtomic.cpp
@@ -155,8 +155,7 @@ public:
   }
 
   bool runOnFunction(Function &F) override {
-    if (skipFunction(F))
-      return false;
+    // Don't skip optnone functions; atomics still need to be lowered.
     FunctionAnalysisManager DummyFAM;
     auto PA = Impl.run(F, DummyFAM);
     return !PA.areAllPreserved();
diff --git a/lib/Transforms/Scalar/Reassociate.cpp b/lib/Transforms/Scalar/Reassociate.cpp
index 29d1ba406ae4..e235e5eb1a06 100644
--- a/lib/Transforms/Scalar/Reassociate.cpp
+++ b/lib/Transforms/Scalar/Reassociate.cpp
@@ -1941,6 +1941,12 @@ Instruction *ReassociatePass::canonicalizeNegConstExpr(Instruction *I) {
   if (!User->isCommutative() && User->getOperand(1) != I)
     return nullptr;
 
+  // Don't canonicalize x + (-Constant * y) -> x - (Constant * y), if the
+  // resulting subtract will be broken up later.  This can get us into an
+  // infinite loop during reassociation.
+  if (UserOpcode == Instruction::FAdd && ShouldBreakUpSubtract(User))
+    return nullptr;
+
   // Change the sign of the constant.
   APFloat Val = CF->getValueAPF();
   Val.changeSign();
diff --git a/lib/Transforms/Utils/CloneFunction.cpp b/lib/Transforms/Utils/CloneFunction.cpp
index 7e75e8847785..9c4e13903ed7 100644
--- a/lib/Transforms/Utils/CloneFunction.cpp
+++ b/lib/Transforms/Utils/CloneFunction.cpp
@@ -341,8 +341,9 @@ void PruningFunctionCloner::CloneBlock(const BasicBlock *BB,
               SimplifyInstruction(NewInst, BB->getModule()->getDataLayout())) {
         // On the off-chance that this simplifies to an instruction in the old
         // function, map it back into the new function.
-        if (Value *MappedV = VMap.lookup(V))
-          V = MappedV;
+        if (NewFunc != OldFunc)
+          if (Value *MappedV = VMap.lookup(V))
+            V = MappedV;
 
         if (!NewInst->mayHaveSideEffects()) {
           VMap[&*II] = V;