Index: include/llvm/Transforms/Instrumentation.h
===================================================================
--- include/llvm/Transforms/Instrumentation.h
+++ include/llvm/Transforms/Instrumentation.h
@@ -74,6 +74,9 @@
 
   // Add the 'noredzone' attribute to added runtime library calls.
   bool NoRedZone;
+
+  // Name of the profile file to use as output
+  std::string InstrProfileOutput;
 };
 
 /// Insert frontend instrumentation based profiling.
Index: lib/Transforms/Instrumentation/InstrProfiling.cpp
===================================================================
--- lib/Transforms/Instrumentation/InstrProfiling.cpp
+++ lib/Transforms/Instrumentation/InstrProfiling.cpp
@@ -97,7 +97,8 @@
   /// Add uses of our data variables and runtime hook.
   void emitUses();
 
-  /// Create a static initializer for our data, on platforms that need it.
+  /// Create a static initializer for our data, on platforms that need it,
+  /// and for any profile output file that was specified.
   void emitInitialization();
 };
 
@@ -328,8 +329,10 @@
 }
 
 void InstrProfiling::emitInitialization() {
+  std::string InstrProfileOutput = Options.InstrProfileOutput;
+
   Constant *RegisterF = M->getFunction("__llvm_profile_register_functions");
-  if (!RegisterF)
+  if (!RegisterF && InstrProfileOutput.empty())
     return;
 
   // Create the initialization function.
@@ -344,7 +347,24 @@
 
   // Add the basic block and the necessary calls.
   IRBuilder<> IRB(BasicBlock::Create(M->getContext(), "", F));
-  IRB.CreateCall(RegisterF);
+  if (RegisterF)
+    IRB.CreateCall(RegisterF);
+  if (!InstrProfileOutput.empty()) {
+    auto *VoidTy = Type::getVoidTy(M->getContext());
+    auto *Int8PtrTy = Type::getInt8PtrTy(M->getContext());
+    auto *SetFnameFTy = FunctionType::get(VoidTy, Int8PtrTy, false);
+    auto *SetFnameF = Function::Create(SetFnameFTy, GlobalValue::ExternalLinkage,
+                                 "__llvm_profile_set_filename_env_override", M);
+
+    // Create variable for profile name
+    Constant *ProfileNameStrConst =
+        ConstantDataArray::getString(M->getContext(), InstrProfileOutput, true);
+    GlobalVariable *ProfileName =
+        new GlobalVariable(*M, ProfileNameStrConst->getType(), true,
+                           GlobalValue::PrivateLinkage, ProfileNameStrConst);
+
+    IRB.CreateCall(SetFnameF, IRB.CreatePointerCast(ProfileName, Int8PtrTy));
+  }
   IRB.CreateRetVoid();
 
   appendToGlobalCtors(*M, F, 0);