diff --git a/llvm/lib/ExecutionEngine/MCJIT/MCJIT.cpp b/llvm/lib/ExecutionEngine/MCJIT/MCJIT.cpp
index 4cf3e2044dff..efd30ba7580a 100644
--- a/llvm/lib/ExecutionEngine/MCJIT/MCJIT.cpp
+++ b/llvm/lib/ExecutionEngine/MCJIT/MCJIT.cpp
@@ -351,9 +351,13 @@ uint64_t MCJIT::getFunctionAddress(const std::string &Name) {
 void *MCJIT::getPointerToFunction(Function *F) {
   MutexGuard locked(lock);
 
+  Mangler Mang(TM->getSubtargetImpl()->getDataLayout());
+  SmallString<128> Name;
+  TM->getNameWithPrefix(Name, F, Mang);
+
   if (F->isDeclaration() || F->hasAvailableExternallyLinkage()) {
     bool AbortOnFailure = !F->hasExternalWeakLinkage();
-    void *Addr = getPointerToNamedFunction(F->getName(), AbortOnFailure);
+    void *Addr = getPointerToNamedFunction(Name, AbortOnFailure);
     addGlobalMapping(F, Addr);
     return Addr;
   }
@@ -364,17 +368,18 @@ void *MCJIT::getPointerToFunction(Function *F) {
   // Make sure the relevant module has been compiled and loaded.
   if (HasBeenAddedButNotLoaded)
     generateCodeForModule(M);
-  else if (!OwnedModules.hasModuleBeenLoaded(M))
+  else if (!OwnedModules.hasModuleBeenLoaded(M)) {
     // If this function doesn't belong to one of our modules, we're done.
+    // FIXME: Asking for the pointer to a function that hasn't been registered,
+    //        and isn't a declaration (which is handled above) should probably
+    //        be an assertion.
     return nullptr;
+  }
 
   // FIXME: Should the Dyld be retaining module information? Probably not.
   //
   // This is the accessor for the target address, so make sure to check the
   // load address of the symbol, not the local address.
-  Mangler Mang(TM->getSubtargetImpl()->getDataLayout());
-  SmallString<128> Name;
-  TM->getNameWithPrefix(Name, F, Mang);
   return (void*)Dyld.getSymbolLoadAddress(Name);
 }
 
diff --git a/llvm/lib/ExecutionEngine/RTDyldMemoryManager.cpp b/llvm/lib/ExecutionEngine/RTDyldMemoryManager.cpp
index 1646937e816c..9cbcd2fa8142 100644
--- a/llvm/lib/ExecutionEngine/RTDyldMemoryManager.cpp
+++ b/llvm/lib/ExecutionEngine/RTDyldMemoryManager.cpp
@@ -253,19 +253,20 @@ uint64_t RTDyldMemoryManager::getSymbolAddress(const std::string &Name) {
   // is called before ExecutionEngine::runFunctionAsMain() is called.
   if (Name == "__main") return (uint64_t)&jit_noop;
 
-  const char *NameStr = Name.c_str();
-  void *Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(NameStr);
-  if (Ptr)
-    return (uint64_t)Ptr;
+  // Try to demangle Name before looking it up in the process, otherwise symbol
+  // '_<Name>' (if present) will shadow '<Name>', and there will be no way to
+  // refer to the latter.
 
-  // If it wasn't found and if it starts with an underscore ('_') character,
-  // try again without the underscore.
-  if (NameStr[0] == '_') {
-    Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(NameStr+1);
-    if (Ptr)
+  const char *NameStr = Name.c_str();
+
+  if (NameStr[0] == '_')
+    if (void *Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(NameStr + 1))
       return (uint64_t)Ptr;
-  }
-  return 0;
+
+  // If we Name did not require demangling, or we failed to find the demangled
+  // name, try again without demangling.
+  if (void *Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(NameStr))
+    return (uint64_t)Ptr;
 }
 
 void *RTDyldMemoryManager::getPointerToNamedFunction(const std::string &Name,