Index: include/clang/Driver/Options.td
===================================================================
--- include/clang/Driver/Options.td
+++ include/clang/Driver/Options.td
@@ -452,6 +452,9 @@
 def fprofile_instr_use_EQ : Joined<["-"], "fprofile-instr-use=">,
     Group<f_Group>, Flags<[CC1Option]>,
     HelpText<"Use instrumentation data for profile-guided optimization">;
+def fprofile_ir_instr : Flag<["-"], "fprofile-ir-instr">, Group<f_Group>,
+    Flags<[CC1Option]>,
+    HelpText<"Use IR level instrumentation rather the FE implementation">;
 def fcoverage_mapping : Flag<["-"], "fcoverage-mapping">,
     Group<f_Group>, Flags<[CC1Option]>,
     HelpText<"Generate coverage mapping to enable code coverage analysis">;
Index: include/clang/Frontend/CodeGenOptions.def
===================================================================
--- include/clang/Frontend/CodeGenOptions.def
+++ include/clang/Frontend/CodeGenOptions.def
@@ -105,6 +105,7 @@
 
 CODEGENOPT(ProfileInstrGenerate , 1, 0) ///< Instrument code to generate
                                         ///< execution counts to use with PGO.
+CODEGENOPT(ProfileIRInstr, 1, 0) ///< IR level code PGO instrumentation and use.
 CODEGENOPT(CoverageMapping , 1, 0) ///< Generate coverage mapping regions to
                                    ///< enable code coverage analysis.
 CODEGENOPT(DumpCoverageMapping , 1, 0) ///< Dump the generated coverage mapping
Index: lib/CodeGen/BackendUtil.cpp
===================================================================
--- lib/CodeGen/BackendUtil.cpp
+++ lib/CodeGen/BackendUtil.cpp
@@ -431,6 +431,14 @@
     MPM->add(createInstrProfilingPass(Options));
   }
 
+  if (CodeGenOpts.ProfileIRInstr) {
+    assert (!CodeGenOpts.ProfileInstrGenerate);
+    if (!CodeGenOpts.InstrProfileOutput.empty())
+      PMBuilder.PGOInstrGen = CodeGenOpts.InstrProfileOutput;
+    if (!CodeGenOpts.InstrProfileInput.empty())
+      PMBuilder.PGOInstrUse = CodeGenOpts.InstrProfileInput;
+  }
+
   if (!CodeGenOpts.SampleProfileFile.empty())
     MPM->add(createSampleProfileLoaderPass(CodeGenOpts.SampleProfileFile));
 
Index: lib/CodeGen/CodeGenModule.cpp
===================================================================
--- lib/CodeGen/CodeGenModule.cpp
+++ lib/CodeGen/CodeGenModule.cpp
@@ -147,7 +147,7 @@
   if (C.getLangOpts().ObjC1)
     ObjCData = new ObjCEntrypoints();
 
-  if (!CodeGenOpts.InstrProfileInput.empty()) {
+  if (!CodeGenOpts.ProfileIRInstr && !CodeGenOpts.InstrProfileInput.empty()) {
     auto ReaderOrErr =
         llvm::IndexedInstrProfReader::create(CodeGenOpts.InstrProfileInput);
     if (std::error_code EC = ReaderOrErr.getError()) {
Index: lib/Driver/Tools.cpp
===================================================================
--- lib/Driver/Tools.cpp
+++ lib/Driver/Tools.cpp
@@ -3223,6 +3223,8 @@
       CmdArgs.push_back(Args.MakeArgString(CoverageFilename));
     }
   }
+
+  Args.AddAllArgs(CmdArgs, options::OPT_fprofile_ir_instr);
 }
 
 static void addPS4ProfileRTArgs(const ToolChain &TC, const ArgList &Args,
Index: lib/Frontend/CompilerInvocation.cpp
===================================================================
--- lib/Frontend/CompilerInvocation.cpp
+++ lib/Frontend/CompilerInvocation.cpp
@@ -449,8 +449,10 @@
   Opts.DisableIntegratedAS = Args.hasArg(OPT_fno_integrated_as);
   Opts.Autolink = !Args.hasArg(OPT_fno_autolink);
   Opts.SampleProfileFile = Args.getLastArgValue(OPT_fprofile_sample_use_EQ);
-  Opts.ProfileInstrGenerate = Args.hasArg(OPT_fprofile_instr_generate) ||
-      Args.hasArg(OPT_fprofile_instr_generate_EQ);
+  Opts.ProfileIRInstr = Args.hasArg(OPT_fprofile_ir_instr);
+  if (!Opts.ProfileIRInstr)
+    Opts.ProfileInstrGenerate = Args.hasArg(OPT_fprofile_instr_generate) ||
+        Args.hasArg(OPT_fprofile_instr_generate_EQ);
   Opts.InstrProfileOutput = Args.getLastArgValue(OPT_fprofile_instr_generate_EQ);
   Opts.InstrProfileInput = Args.getLastArgValue(OPT_fprofile_instr_use_EQ);
   Opts.CoverageMapping =