Index: lib/Driver/Tools.cpp
===================================================================
--- lib/Driver/Tools.cpp
+++ lib/Driver/Tools.cpp
@@ -3808,6 +3808,10 @@
   Args.AddLastArg(CmdArgs, options::OPT_fdiagnostics_show_template_tree);
   Args.AddLastArg(CmdArgs, options::OPT_fno_elide_type);
 
+  // Forward flags for OpenMP
+  Args.AddLastArg(CmdArgs, options::OPT_fopenmp);
+  Args.AddLastArg(CmdArgs, options::OPT_fopenmp_EQ);
+
   const SanitizerArgs &Sanitize = getToolChain().getSanitizerArgs();
   Sanitize.addArgs(Args, CmdArgs);
 
@@ -6267,9 +6271,7 @@
   Args.AddAllArgs(CmdArgs, options::OPT_L);
 
   LibOpenMP UsedOpenMPLib = LibUnknown;
-  if (Args.hasArg(options::OPT_fopenmp)) {
-    UsedOpenMPLib = LibGOMP;
-  } else if (const Arg *A = Args.getLastArg(options::OPT_fopenmp_EQ)) {
+  if (const Arg *A = Args.getLastArg(options::OPT_fopenmp_EQ)) {
     UsedOpenMPLib = llvm::StringSwitch<LibOpenMP>(A->getValue())
         .Case("libgomp",  LibGOMP)
         .Case("libiomp5", LibIOMP5)
@@ -6277,6 +6279,8 @@
     if (UsedOpenMPLib == LibUnknown)
       getToolChain().getDriver().Diag(diag::err_drv_unsupported_option_argument)
         << A->getOption().getName() << A->getValue();
+  } else if (Args.hasArg(options::OPT_fopenmp)) {
+    UsedOpenMPLib = LibIOMP5;
   }
   switch (UsedOpenMPLib) {
   case LibGOMP:
@@ -7992,16 +7996,16 @@
         linkSanitizerRuntimeDeps(ToolChain, CmdArgs);
 
       LibOpenMP UsedOpenMPLib = LibUnknown;
-      if (Args.hasArg(options::OPT_fopenmp)) {
-        UsedOpenMPLib = LibGOMP;
-      } else if (const Arg *A = Args.getLastArg(options::OPT_fopenmp_EQ)) {
+      if (const Arg *A = Args.getLastArg(options::OPT_fopenmp_EQ)) {
         UsedOpenMPLib = llvm::StringSwitch<LibOpenMP>(A->getValue())
-            .Case("libgomp",  LibGOMP)
-            .Case("libiomp5", LibIOMP5)
-            .Default(LibUnknown);
+                            .Case("libgomp", LibGOMP)
+                            .Case("libiomp5", LibIOMP5)
+                            .Default(LibUnknown);
         if (UsedOpenMPLib == LibUnknown)
           D.Diag(diag::err_drv_unsupported_option_argument)
-            << A->getOption().getName() << A->getValue();
+              << A->getOption().getName() << A->getValue();
+      } else if (Args.hasArg(options::OPT_fopenmp)) {
+        UsedOpenMPLib = LibIOMP5;
       }
       switch (UsedOpenMPLib) {
       case LibGOMP:
Index: lib/Frontend/CompilerInvocation.cpp
===================================================================
--- lib/Frontend/CompilerInvocation.cpp
+++ lib/Frontend/CompilerInvocation.cpp
@@ -1632,11 +1632,12 @@
     Opts.setMSPointerToMemberRepresentationMethod(InheritanceModel);
   }
 
-  // Check if -fopenmp= is specified.
+  // Check if -fopenmp or -fopenmp= is specified.
+  Opts.OpenMP = Args.hasArg(options::OPT_fopenmp);
   if (const Arg *A = Args.getLastArg(options::OPT_fopenmp_EQ)) {
     Opts.OpenMP = llvm::StringSwitch<bool>(A->getValue())
-        .Case("libiomp5", true)
-        .Default(false);
+                      .Case("libiomp5", true)
+                      .Default(false);
   }
 
   // Record whether the __DEPRECATED define was requested.
Index: test/OpenMP/linking.c
===================================================================
--- test/OpenMP/linking.c
+++ test/OpenMP/linking.c
@@ -5,14 +5,14 @@
 // RUN:     -fopenmp -target i386-unknown-linux \
 // RUN:   | FileCheck --check-prefix=CHECK-LD-32 %s
 // CHECK-LD-32: "{{.*}}ld{{(.exe)?}}"
-// CHECK-LD-32: "-lgomp" "-lrt" "-lgcc"
+// CHECK-LD-32: "-liomp5" "-lgcc"
 // CHECK-LD-32: "-lpthread" "-lc"
 //
 // RUN: %clang -no-canonical-prefixes %s -### -o %t.o 2>&1 \
 // RUN:     -fopenmp -target x86_64-unknown-linux \
 // RUN:   | FileCheck --check-prefix=CHECK-LD-64 %s
 // CHECK-LD-64: "{{.*}}ld{{(.exe)?}}"
-// CHECK-LD-64: "-lgomp" "-lrt" "-lgcc"
+// CHECK-LD-64: "-liomp5" "-lgcc"
 // CHECK-LD-64: "-lpthread" "-lc"
 //
 // RUN: %clang -no-canonical-prefixes %s -### -o %t.o 2>&1 \
@@ -54,18 +54,16 @@
 // CHECK-LIB-LD-64: error: unsupported argument 'lib' to option 'fopenmp='
 //
 // RUN: %clang -no-canonical-prefixes %s -### -o %t.o 2>&1 \
-// RUN:     -fopenmp -fopenmp=libiomp5 -target i386-unknown-linux \
-// RUN:   | FileCheck --check-prefix=CHECK-LD-WARN-32 %s
-// CHECK-LD-WARN-32: warning: argument unused during compilation: '-fopenmp=libiomp5'
-// CHECK-LD-WARN-32: "{{.*}}ld{{(.exe)?}}"
-// CHECK-LD-WARN-32: "-lgomp" "-lrt" "-lgcc"
-// CHECK-LD-WARN-32: "-lpthread" "-lc"
+// RUN:     -fopenmp -fopenmp=libgomp -target i386-unknown-linux \
+// RUN:   | FileCheck --check-prefix=CHECK-LD-OVERRIDE-32 %s
+// CHECK-LD-OVERRIDE-32: "{{.*}}ld{{(.exe)?}}"
+// CHECK-LD-OVERRIDE-32: "-lgomp" "-lrt" "-lgcc"
+// CHECK-LD-OVERRIDE-32: "-lpthread" "-lc"
 //
 // RUN: %clang -no-canonical-prefixes %s -### -o %t.o 2>&1 \
-// RUN:     -fopenmp -fopenmp=libiomp5 -target x86_64-unknown-linux \
-// RUN:   | FileCheck --check-prefix=CHECK-LD-WARN-64 %s
-// CHECK-LD-WARN-64: warning: argument unused during compilation: '-fopenmp=libiomp5'
-// CHECK-LD-WARN-64: "{{.*}}ld{{(.exe)?}}"
-// CHECK-LD-WARN-64: "-lgomp" "-lrt" "-lgcc"
-// CHECK-LD-WARN-64: "-lpthread" "-lc"
+// RUN:     -fopenmp -fopenmp=libgomp -target x86_64-unknown-linux \
+// RUN:   | FileCheck --check-prefix=CHECK-LD-OVERRIDE-64 %s
+// CHECK-LD-OVERRIDE-64: "{{.*}}ld{{(.exe)?}}"
+// CHECK-LD-OVERRIDE-64: "-lgomp" "-lrt" "-lgcc"
+// CHECK-LD-OVERRIDE-64: "-lpthread" "-lc"
 //
Index: test/OpenMP/openmp_common.c
===================================================================
--- test/OpenMP/openmp_common.c
+++ test/OpenMP/openmp_common.c
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -verify -fopenmp=libiomp5 -ferror-limit 100 -o - %s
+// RUN: %clang_cc1 -verify -fopenmp -ferror-limit 100 -o - %s
 
 #pragma omp // expected-error {{expected an OpenMP directive}}
 #pragma omp unknown_directive // expected-error {{expected an OpenMP directive}}
Index: test/OpenMP/predefined_macro.c
===================================================================
--- test/OpenMP/predefined_macro.c
+++ test/OpenMP/predefined_macro.c
@@ -1,33 +1,19 @@
 // RUN: %clang_cc1 -fopenmp=libiomp5 -verify -DFOPENMP -o - %s
+// RUN: %clang_cc1 -fopenmp -verify -DFOPENMP -o - %s
 // RUN: %clang_cc1 -verify -o - %s
+// RUN: %clang_cc1 -verify -fopenmp -fopenmp=libgomp -o - %s
 // expected-no-diagnostics
 #ifdef FOPENMP
-// -fopenmp=libiomp5 option is specified
+// -fopenmp=libiomp5 or -fopenmp option is specified
 #ifndef _OPENMP
 #error "No _OPENMP macro is defined with -fopenmp option"
 #elsif _OPENMP != 201307
 #error "_OPENMP has incorrect value"
 #endif //_OPENMP
 #else
-// No -fopenmp=libiomp5 option is specified
+// No -fopenmp=libiomp5 or -fopenmp option is specified
 #ifdef _OPENMP
 #error "_OPENMP macro is defined without -fopenmp option"
 #endif // _OPENMP
 #endif // FOPENMP
 
-// RUN: %clang_cc1 -fopenmp=libiomp5 -verify -DFOPENMP -o - %s
-// RUN: %clang_cc1 -verify -o - %s
-// expected-no-diagnostics
-#ifdef FOPENMP
-// -fopenmp=libiomp5 option is specified
-#ifndef _OPENMP
-#error "No _OPENMP macro is defined with -fopenmp option"
-#elsif _OPENMP != 201307
-#error "_OPENMP has incorrect value"
-#endif // _OPENMP
-#else
-// No -fopenmp=libiomp5 option is specified
-#ifdef _OPENMP
-#error "_OPENMP macro is defined without -fopenmp option"
-#endif // _OPENMP
-#endif // FOPENMP