Index: lib/Driver/Tools.h
===================================================================
--- lib/Driver/Tools.h
+++ lib/Driver/Tools.h
@@ -108,7 +108,8 @@
     ClangAs(const ToolChain &TC) : Tool("clang::as",
                                         "clang integrated assembler", TC,
                                         RF_Full) {}
-
+    void AddMIPSTargetArgs(const llvm::opt::ArgList &Args,
+                           llvm::opt::ArgStringList &CmdArgs) const;
     bool hasGoodDiagnostics() const override { return true; }
     bool hasIntegratedAssembler() const override { return false; }
     bool hasIntegratedCPP() const override { return false; }
Index: lib/Driver/Tools.cpp
===================================================================
--- lib/Driver/Tools.cpp
+++ lib/Driver/Tools.cpp
@@ -1,4 +1,4 @@
-//===--- Tools.cpp - Tools Implementations --------------------------------===//
+//===--- Tools.cpp - Tools Implementations --------------------------------===//ddMIPSTargetArgs/
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -4810,6 +4810,17 @@
   return CLFallback.get();
 }
 
+void ClangAs::AddMIPSTargetArgs(const ArgList &Args,
+                              ArgStringList &CmdArgs) const {
+  StringRef CPUName;
+  StringRef ABIName;
+  const llvm::Triple &Triple = getToolChain().getTriple();
+  mips::getMipsCPUAndABI(Args, Triple, CPUName, ABIName);
+
+  CmdArgs.push_back("-target-abi");
+  CmdArgs.push_back(ABIName.data());
+}
+
 void ClangAs::ConstructJob(Compilation &C, const JobAction &JA,
                            const InputInfo &Output,
                            const InputInfoList &Inputs,
@@ -4915,6 +4926,19 @@
 
   // FIXME: Add -static support, once we have it.
 
+    // Add target specific flags.
+  switch(getToolChain().getArch()) {
+  default:
+    break;
+
+  case llvm::Triple::mips:
+  case llvm::Triple::mipsel:
+  case llvm::Triple::mips64:
+  case llvm::Triple::mips64el:
+    AddMIPSTargetArgs(Args, CmdArgs);
+    break;
+  }
+
   // Consume all the warning flags. Usually this would be handled more
   // gracefully by -cc1 (warning about unknown warning flags, etc) but -cc1as
   // doesn't handle that so rather than warning about unused flags that are
Index: test/Driver/mips-integrated-as.s
===================================================================
--- test/Driver/mips-integrated-as.s
+++ test/Driver/mips-integrated-as.s
@@ -7,6 +7,7 @@
 // ABI-O32: -cc1as
 // ABI-O32: "-target-feature" "-n64"
 // ABI-O32: "-target-feature" "+o32"
+// ABI-O32: "-target-abi" "o32"
 
 // RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -mabi=eabi 2>&1 | \
 // RUN:   FileCheck -check-prefix=ABI-EABI32 %s
@@ -14,6 +15,7 @@
 // ABI-EABI32: "-target-feature" "-o32"
 // ABI-EABI32: "-target-feature" "-n64"
 // ABI-EABI32: "-target-feature" "+eabi"
+// ABI-EABI32: "-target-abi" "eabi"
 
 // RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -mips64 -mabi=n32 2>&1 | \
 // RUN:   FileCheck -check-prefix=ABI-N32 %s
@@ -23,6 +25,7 @@
 // ABI-N32: "-target-feature" "-o32"
 // ABI-N32: "-target-feature" "-n64"
 // ABI-N32: "-target-feature" "+n32"
+// ABI-N32: "-target-abi" "n32"
 
 // FIXME: We should also test '-target mips-linux-gnu -mips64' defaults to the
 //        default 64-bit ABI (N64 but GCC uses N32). It currently selects O32
@@ -41,6 +44,7 @@
 // ABI-N64: -cc1as
 // ABI-N64: "-target-feature" "-o32"
 // ABI-N64: "-target-feature" "+n64"
+// ABI-N64: "-target-abi" "n64"
 
 // RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -msoft-float 2>&1 | \
 // RUN:   FileCheck -check-prefix=SOFTFLOAT %s