Index: include/llvm/Analysis/ValueTracking.h
===================================================================
--- include/llvm/Analysis/ValueTracking.h
+++ include/llvm/Analysis/ValueTracking.h
@@ -170,11 +170,13 @@
   /// specified value does.  If the MaxLookup value is non-zero, it limits the
   /// number of instructions to be stripped off.
   Value *GetUnderlyingObject(Value *V, const DataLayout &DL,
-                             unsigned MaxLookup = 6);
-  static inline const Value *GetUnderlyingObject(const Value *V,
-                                                 const DataLayout &DL,
-                                                 unsigned MaxLookup = 6) {
-    return GetUnderlyingObject(const_cast<Value *>(V), DL, MaxLookup);
+                             unsigned MaxLookup = 6,
+                             SmallVectorImpl<Instruction *> *NoAlias = nullptr);
+  static inline
+  const Value *GetUnderlyingObject(const Value *V,
+                 const DataLayout &DL, unsigned MaxLookup = 6,
+                 SmallVectorImpl<Instruction *> *NoAlias = nullptr) {
+    return GetUnderlyingObject(const_cast<Value *>(V), DL, MaxLookup, NoAlias);
   }
 
   /// \brief This method is similar to GetUnderlyingObject except that it can
@@ -207,7 +209,8 @@
   /// it shouldn't look through the phi above.
   void GetUnderlyingObjects(Value *V, SmallVectorImpl<Value *> &Objects,
                             const DataLayout &DL, LoopInfo *LI = nullptr,
-                            unsigned MaxLookup = 6);
+                            unsigned MaxLookup = 6,
+                            SmallVectorImpl<Instruction *> *NoAlias = nullptr);
 
   /// onlyUsedByLifetimeMarkers - Return true if the only users of this pointer
   /// are lifetime markers.
Index: lib/Analysis/ValueTracking.cpp
===================================================================
--- lib/Analysis/ValueTracking.cpp
+++ lib/Analysis/ValueTracking.cpp
@@ -2769,7 +2769,8 @@
 }
 
 Value *llvm::GetUnderlyingObject(Value *V, const DataLayout &DL,
-                                 unsigned MaxLookup) {
+                                 unsigned MaxLookup,
+                                 SmallVectorImpl<Instruction *> *NoAlias) {
   if (!V->getType()->isPointerTy())
     return V;
   for (unsigned Count = 0; MaxLookup == 0 || Count < MaxLookup; ++Count) {
@@ -2785,6 +2786,9 @@
     } else {
       if (IntrinsicInst *I = dyn_cast<IntrinsicInst>(V))
         if (I->getIntrinsicID() == Intrinsic::noalias) {
+          if (NoAlias)
+            NoAlias->push_back(I);
+
           V = I->getOperand(0);
           continue;
         }
@@ -2806,13 +2810,14 @@
 
 void llvm::GetUnderlyingObjects(Value *V, SmallVectorImpl<Value *> &Objects,
                                 const DataLayout &DL, LoopInfo *LI,
-                                unsigned MaxLookup) {
+                                unsigned MaxLookup,
+                                SmallVectorImpl<Instruction *> *NoAlias) {
   SmallPtrSet<Value *, 4> Visited;
   SmallVector<Value *, 4> Worklist;
   Worklist.push_back(V);
   do {
     Value *P = Worklist.pop_back_val();
-    P = GetUnderlyingObject(P, DL, MaxLookup);
+    P = GetUnderlyingObject(P, DL, MaxLookup, NoAlias);
 
     if (!Visited.insert(P).second)
       continue;