Index: include/clang/Driver/Options.td
===================================================================
--- include/clang/Driver/Options.td
+++ include/clang/Driver/Options.td
@@ -416,7 +416,10 @@
     Alias<fprofile_sample_use_EQ>;
 def fprofile_instr_generate : Flag<["-"], "fprofile-instr-generate">,
     Group<f_Group>, Flags<[CC1Option]>,
-    HelpText<"Generate instrumented code to collect execution counts">;
+    HelpText<"Generate instrumented code to collect execution counts into default.profraw file (overriden by '=' form of option or LLVM_PROFILE_FILE env var)">;
+def fprofile_instr_generate_EQ : Joined<["-"], "fprofile-instr-generate=">,
+    Group<f_Group>, Flags<[CC1Option]>, MetaVarName<"<file>">,
+    HelpText<"Generate instrumented code to collect execution counts into <file> (overridden by LLVM_PROFILE_FILE env var)">;
 def fprofile_instr_use : Flag<["-"], "fprofile-instr-use">, Group<f_Group>;
 def fprofile_instr_use_EQ : Joined<["-"], "fprofile-instr-use=">,
     Group<f_Group>, Flags<[CC1Option]>,
Index: include/clang/Frontend/CodeGenOptions.h
===================================================================
--- include/clang/Frontend/CodeGenOptions.h
+++ include/clang/Frontend/CodeGenOptions.h
@@ -154,6 +154,9 @@
   /// A list of dependent libraries.
   std::vector<std::string> DependentLibraries;
 
+  /// Name of the profile file to use as output for -fprofile-instr-generate
+  std::string InstrProfileOutput;
+
   /// Name of the profile file to use with -fprofile-sample-use.
   std::string SampleProfileFile;
 
Index: lib/CodeGen/BackendUtil.cpp
===================================================================
--- lib/CodeGen/BackendUtil.cpp
+++ lib/CodeGen/BackendUtil.cpp
@@ -395,6 +395,7 @@
   if (CodeGenOpts.ProfileInstrGenerate) {
     InstrProfOptions Options;
     Options.NoRedZone = CodeGenOpts.DisableRedZone;
+    Options.InstrProfileOutput = CodeGenOpts.InstrProfileOutput;
     MPM->add(createInstrProfilingPass(Options));
   }
 
Index: lib/Driver/ToolChains.cpp
===================================================================
--- lib/Driver/ToolChains.cpp
+++ lib/Driver/ToolChains.cpp
@@ -376,6 +376,7 @@
                    false) ||
       Args.hasArg(options::OPT_fprofile_generate) ||
       Args.hasArg(options::OPT_fprofile_instr_generate) ||
+      Args.hasArg(options::OPT_fprofile_instr_generate_EQ) ||
       Args.hasArg(options::OPT_fcreate_profile) ||
       Args.hasArg(options::OPT_coverage)) {
     // Select the appropriate runtime library for the target.
Index: lib/Driver/Tools.cpp
===================================================================
--- lib/Driver/Tools.cpp
+++ lib/Driver/Tools.cpp
@@ -2227,6 +2227,7 @@
                      false) ||
         Args.hasArg(options::OPT_fprofile_generate) ||
         Args.hasArg(options::OPT_fprofile_instr_generate) ||
+        Args.hasArg(options::OPT_fprofile_instr_generate_EQ) ||
         Args.hasArg(options::OPT_fcreate_profile) ||
         Args.hasArg(options::OPT_coverage)))
     return;
@@ -3357,13 +3358,17 @@
 
   Args.AddAllArgs(CmdArgs, options::OPT_finstrument_functions);
 
-  if (Args.hasArg(options::OPT_fprofile_instr_generate) &&
+  if ((Args.hasArg(options::OPT_fprofile_instr_generate) ||
+       Args.hasArg(options::OPT_fprofile_instr_generate_EQ)) &&
       (Args.hasArg(options::OPT_fprofile_instr_use) ||
        Args.hasArg(options::OPT_fprofile_instr_use_EQ)))
     D.Diag(diag::err_drv_argument_not_allowed_with)
       << "-fprofile-instr-generate" << "-fprofile-instr-use";
 
-  Args.AddAllArgs(CmdArgs, options::OPT_fprofile_instr_generate);
+  if (Arg *A = Args.getLastArg(options::OPT_fprofile_instr_generate_EQ))
+    A->render(Args, CmdArgs);
+  else
+    Args.AddAllArgs(CmdArgs, options::OPT_fprofile_instr_generate);
 
   if (Arg *A = Args.getLastArg(options::OPT_fprofile_instr_use_EQ))
     A->render(Args, CmdArgs);
@@ -3379,7 +3384,8 @@
     CmdArgs.push_back("-femit-coverage-data");
 
   if (Args.hasArg(options::OPT_fcoverage_mapping) &&
-      !Args.hasArg(options::OPT_fprofile_instr_generate))
+      !(Args.hasArg(options::OPT_fprofile_instr_generate) ||
+        Args.hasArg(options::OPT_fprofile_instr_generate_EQ)))
     D.Diag(diag::err_drv_argument_only_allowed_with)
       << "-fcoverage-mapping" << "-fprofile-instr-generate";
 
Index: lib/Frontend/CompilerInvocation.cpp
===================================================================
--- lib/Frontend/CompilerInvocation.cpp
+++ lib/Frontend/CompilerInvocation.cpp
@@ -427,7 +427,9 @@
   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);
+  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 = Args.hasArg(OPT_fcoverage_mapping);
   Opts.DumpCoverageMapping = Args.hasArg(OPT_dump_coverage_mapping);
Index: test/Profile/c-generate.c
===================================================================
--- /dev/null
+++ test/Profile/c-generate.c
@@ -0,0 +1,10 @@
+// Check that the -fprofile-instr-generate= form works.
+// RUN: %clang_cc1 -main-file-name c-generate.c %s -o - -emit-llvm -fprofile-instr-generate=c-generate-test.profraw | FileCheck %s
+
+// CHECK: private constant [24 x i8] c"c-generate-test.profraw\00"
+// CHECK: call void @__llvm_profile_set_filename_env_override(i8* getelementptr inbounds ([24 x i8], [24 x i8]* @0, i32 0, i32 0))
+// CHECK: declare void @__llvm_profile_set_filename_env_override(i8*)
+
+int main(void) {
+  return 0;
+}