Index: include/clang/Driver/ToolChain.h
===================================================================
--- include/clang/Driver/ToolChain.h
+++ include/clang/Driver/ToolChain.h
@@ -299,6 +299,11 @@
   const char *getCompilerRTArgString(const llvm::opt::ArgList &Args,
                                      StringRef Component,
                                      bool Shared = false) const;
+
+  // Returns <ResourceDir>/lib/<OSName>/<arch>.  This is used by runtimes (such
+  // as OpenMP) to find arch-specific libraries.
+  const std::string getArchSpecificLibPath() const;
+
   /// needsProfileRT - returns true if instrumentation profile is on.
   static bool needsProfileRT(const llvm::opt::ArgList &Args);
 
Index: lib/Driver/ToolChain.cpp
===================================================================
--- lib/Driver/ToolChain.cpp
+++ lib/Driver/ToolChain.cpp
@@ -320,6 +320,14 @@
   return Args.MakeArgString(getCompilerRT(Args, Component, Shared));
 }
 
+const std::string ToolChain::getArchSpecificLibPath() const {
+  SmallString<128> Path(getDriver().ResourceDir);
+  StringRef OSLibName = getTriple().isOSFreeBSD() ? "freebsd" : getOS();
+  llvm::sys::path::append(Path, "lib", OSLibName,
+                          getArchName());
+  return Path.str();
+}
+
 bool ToolChain::needsProfileRT(const ArgList &Args) {
   if (Args.hasFlag(options::OPT_fprofile_arcs, options::OPT_fno_profile_arcs,
                    false) ||
Index: lib/Driver/Tools.cpp
===================================================================
--- lib/Driver/Tools.cpp
+++ lib/Driver/Tools.cpp
@@ -3260,6 +3260,12 @@
                     options::OPT_fno_openmp, false))
     return;
 
+  // Add <ResourceDir>/lib/<OSName>/<arch> to the linker search path if it
+  // exists.
+  std::string CandidateLibPath = TC.getArchSpecificLibPath();
+  if (llvm::sys::fs::is_directory(CandidateLibPath))
+    CmdArgs.push_back(Args.MakeArgString("-L" + CandidateLibPath));
+
   switch (TC.getDriver().getOpenMPRuntime(Args)) {
   case Driver::OMPRT_OMP:
     CmdArgs.push_back("-lomp");
@@ -10316,6 +10322,12 @@
         // FIXME: Does this really make sense for all GNU toolchains?
         WantPthread = true;
 
+        // Add <ResourceDir>/lib/<OSName>/<arch> to the linker search path if it
+        // exists.
+        std::string CandidateLibPath = ToolChain.getArchSpecificLibPath();
+        if (llvm::sys::fs::is_directory(CandidateLibPath))
+          CmdArgs.push_back(Args.MakeArgString("-L" + CandidateLibPath));
+
         // Also link the particular OpenMP runtimes.
         switch (ToolChain.getDriver().getOpenMPRuntime(Args)) {
         case Driver::OMPRT_OMP:
Index: test/Driver/openmp-arch-dir.c
===================================================================
--- /dev/null
+++ test/Driver/openmp-arch-dir.c
@@ -0,0 +1,57 @@
+// Test that the driver adds an arch-specific subdirectory in
+// {RESOURCE_DIR}/lib/linux to the search path.  This allows multilib toolchains
+// to package libomp.so for multiple architectures.
+
+// Directory resource_dir_with_arch_subdir is setup only for Linux
+// REQUIRES: linux
+//
+// RUN: %clang %s -### 2>&1 -fopenmp -target i686-unknown-linux \
+// RUN:     -resource-dir=%S/Inputs/resource_dir_with_arch_subdir \
+// RUN:   | FileCheck --check-prefix=CHECK-ARCHDIR \
+// RUN:       --check-prefix=CHECK-LOMP %s
+//
+// RUN: %clang %s -### 2>&1 -fopenmp -target i686-unknown-linux \
+// RUN:     -resource-dir=%S/Inputs/resource_dir \
+// RUN:   | FileCheck --check-prefix=CHECK-NO-ARCHDIR \
+// RUN:       --check-prefix=CHECK-LOMP %s
+//
+// RUN: %clang %s -### 2>&1 -fopenmp -target x86_64-unknown-linux \
+// RUN:     -resource-dir=%S/Inputs/resource_dir_with_arch_subdir \
+// RUN:   | FileCheck --check-prefix=CHECK-ARCHDIR \
+// RUN:       --check-prefix=CHECK-LOMP %s
+//
+// RUN: %clang %s -### 2>&1 -fopenmp -target x86_64-unknown-linux \
+// RUN:     -resource-dir=%S/Inputs/resource_dir \
+// RUN:   | FileCheck --check-prefix=CHECK-NO-ARCHDIR \
+// RUN:       --check-prefix=CHECK-LOMP %s
+//
+// RUN: %clang %s -### 2>&1 -fopenmp -target arm-unknown-linux \
+// RUN:     -resource-dir=%S/Inputs/resource_dir_with_arch_subdir \
+// RUN:   | FileCheck --check-prefix=CHECK-ARCHDIR \
+// RUN:       --check-prefix=CHECK-LOMP %s
+//
+// RUN: %clang %s -### 2>&1 -fopenmp -target arm-unknown-linux \
+// RUN:     -resource-dir=%S/Inputs/resource_dir \
+// RUN:   | FileCheck --check-prefix=CHECK-NO-ARCHDIR \
+// RUN:       --check-prefix=CHECK-LOMP %s
+//
+// RUN: %clang %s -### 2>&1 -fopenmp -target aarch64-unknown-linux \
+// RUN:     -resource-dir=%S/Inputs/resource_dir_with_arch_subdir \
+// RUN:   | FileCheck --check-prefix=CHECK-ARCHDIR \
+// RUN:       --check-prefix=CHECK-LOMP %s
+//
+// RUN: %clang %s -### 2>&1 -fopenmp -target aarch64-unknown-linux \
+// RUN:     -resource-dir=%S/Inputs/resource_dir \
+// RUN:   | FileCheck --check-prefix=CHECK-NO-ARCHDIR \
+// RUN:       --check-prefix=CHECK-LOMP %s
+//
+// Check correctness when -fopenmp is omitted
+// RUN: %clang %s -### 2>&1 -target arm-unknown-linux \
+// RUN:     -resource-dir=%S/Inputs/resource_dir_with_arch_subdir \
+// RUN:   | FileCheck --check-prefix=CHECK-NO-ARCHDIR \
+// RUN:       --check-prefix=CHECK-NO-LOMP %s
+//
+// CHECK-ARCHDIR: -L{{.*}}/Inputs/resource_dir_with_arch_subdir/lib/linux
+// CHECK-NO-ARCHDIR-NOT: -L{{.*}}Inputs/resource_dir
+// CHECK-LOMP: -lomp
+// CHECK-NO-LOMP-NOT: -lomp