Index: include/clang/Driver/CC1Options.td
===================================================================
--- include/clang/Driver/CC1Options.td
+++ include/clang/Driver/CC1Options.td
@@ -274,8 +274,8 @@
     : Flag<["-"], "fsanitize-coverage-trace-pc">,
       HelpText<"Enable PC tracing in sanitizer coverage">;
 def fprofile_instrument_EQ : Joined<["-"], "fprofile-instrument=">,
-    HelpText<"Enable PGO instrumentation. The accepted values is clang or "
-             "none">;
+    HelpText<"Enable PGO instrumentation. The accepted value is clang, llvm, "
+             "or none">;
 def fprofile_instrument_path_EQ : Joined<["-"], "fprofile-instrument-path=">,
     HelpText<"Generate instrumented code to collect execution counts into "
              "<file> (overridden by LLVM_PROFILE_FILE env var)">;
Index: include/clang/Frontend/CodeGenOptions.h
===================================================================
--- include/clang/Frontend/CodeGenOptions.h
+++ include/clang/Frontend/CodeGenOptions.h
@@ -80,9 +80,10 @@
   };
 
   enum ProfileInstrKind {
-    ProfileNoInstr,    // No instrumentation.
-    ProfileClangInstr  // Clang instrumentation to generate execution counts
+    ProfileNone,       // Profile instrumentation is turned off.
+    ProfileClangInstr, // Clang instrumentation to generate execution counts
                        // to use with PGO.
+    ProfileIRInstr,    // IR level PGO instrumentation in LLVM.
   };
 
   /// The code model to use (-mcmodel).
@@ -226,6 +227,11 @@
   bool hasProfileClangInstr() const {
     return getProfileInstr() == ProfileClangInstr;
   }
+
+  /// \brief Check if IR level profile instrumentation is on.
+  bool hasProfileIRInstr() const {
+    return getProfileInstr() == ProfileIRInstr;
+  }
 };
 
 }  // end namespace clang
Index: include/clang/Frontend/CodeGenOptions.def
===================================================================
--- include/clang/Frontend/CodeGenOptions.def
+++ include/clang/Frontend/CodeGenOptions.def
@@ -104,7 +104,7 @@
 VALUE_CODEGENOPT(OptimizeSize, 2, 0) ///< If -Os (==1) or -Oz (==2) is specified.
 
 /// \brief Choose profile instrumenation kind or no instrumentation.
-ENUM_CODEGENOPT(ProfileInstr, ProfileInstrKind, 2, ProfileNoInstr)
+ENUM_CODEGENOPT(ProfileInstr, ProfileInstrKind, 2, ProfileNone)
 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
@@ -437,6 +437,12 @@
     Options.InstrProfileOutput = CodeGenOpts.InstrProfileOutput;
     MPM->add(createInstrProfilingPass(Options));
   }
+  if (CodeGenOpts.hasProfileIRInstr()) {
+    if (!CodeGenOpts.InstrProfileOutput.empty())
+      PMBuilder.PGOInstrGen = CodeGenOpts.InstrProfileOutput;
+    else
+      PMBuilder.PGOInstrGen = "default.profraw";
+  }
 
   if (!CodeGenOpts.SampleProfileFile.empty())
     MPM->add(createSampleProfileLoaderPass(CodeGenOpts.SampleProfileFile));
Index: lib/Frontend/CompilerInvocation.cpp
===================================================================
--- lib/Frontend/CompilerInvocation.cpp
+++ lib/Frontend/CompilerInvocation.cpp
@@ -481,18 +481,23 @@
   Opts.Autolink = !Args.hasArg(OPT_fno_autolink);
   Opts.SampleProfileFile = Args.getLastArgValue(OPT_fprofile_sample_use_EQ);
 
-  enum PGOInstrumentor { Unknown, None, Clang };
+  enum PGOInstrumentor { Unknown, None, Clang, LLVM };
   if (Arg *A = Args.getLastArg(OPT_fprofile_instrument_EQ)) {
     StringRef Value = A->getValue();
     PGOInstrumentor Method = llvm::StringSwitch<PGOInstrumentor>(Value)
-                                 .Case("clang", Clang)
                                  .Case("none", None)
+                                 .Case("clang", Clang)
+                                 .Case("llvm", LLVM)
                                  .Default(Unknown);
     switch (Method) {
+    case LLVM:
+      Opts.setProfileInstr(CodeGenOptions::ProfileIRInstr);
+      break;
     case Clang:
       Opts.setProfileInstr(CodeGenOptions::ProfileClangInstr);
       break;
     case None:
+      // Null operation -- The default is ProfileNone.
       break;
     case Unknown:
       Diags.Report(diag::err_drv_invalid_pgo_instrumentor)
Index: test/CodeGen/pgo-instrumentation.c
===================================================================
--- test/CodeGen/pgo-instrumentation.c
+++ test/CodeGen/pgo-instrumentation.c
@@ -0,0 +1,9 @@
+// Test if PGO instrumentation and use pass are invoked.
+//
+// Ensure Pass PGOInstrumentationGenPass is invoked.
+// RUN: %clang_cc1 -O2 -fprofile-instrument=llvm %s -mllvm -debug-pass=Structure -emit-llvm -o - 2>&1 | FileCheck %s -check-prefix=CHECK-PGOGENPASS-INVOKED-INSTR-GEN
+// CHECK-PGOGENPASS-INVOKED-INSTR-GEN: PGOInstrumentationGenPass
+//
+// Ensure Pass PGOInstrumentationGenPass is not invoked.
+// RUN: %clang_cc1 -O2 -fprofile-instrument=clang %s -mllvm -debug-pass=Structure -emit-llvm -o - 2>&1 | FileCheck %s -check-prefix=CHECK-PGOGENPASS-INVOKED-INSTR-GEN-CLANG
+// CHECK-PGOGENPASS-INVOKED-INSTR-GEN-CLANG-NOT: PGOInstrumentationGenPass