Index: lib/Basic/Targets.cpp
===================================================================
--- lib/Basic/Targets.cpp	(revision 153508)
+++ lib/Basic/Targets.cpp	(working copy)
@@ -3474,6 +3474,10 @@
       Builder.defineMacro("__mips_hard_float", Twine(1));
     else
       llvm_unreachable("Invalid float ABI for Mips.");
+
+    Builder.defineMacro("_MIPS_SZPTR", Twine(getPointerWidth(0)));
+    Builder.defineMacro("_MIPS_SZINT", Twine(getIntWidth()));
+    Builder.defineMacro("_MIPS_SZLONG", Twine(getLongWidth()));
   }
 
   virtual void getTargetDefines(const LangOptions &Opts,
@@ -3577,10 +3581,6 @@
                               MacroBuilder &Builder) const {
     MipsTargetInfoBase::getArchDefines(Opts, Builder);
 
-    Builder.defineMacro("_MIPS_SZPTR", Twine(getPointerWidth(0)));
-    Builder.defineMacro("_MIPS_SZINT", Twine(getIntWidth()));
-    Builder.defineMacro("_MIPS_SZLONG", Twine(getLongWidth()));
-
     if (ABI == "o32") {
       Builder.defineMacro("__mips_o32");
       Builder.defineMacro("_ABIO32", "1");
Index: lib/Driver/Tools.cpp
===================================================================
--- lib/Driver/Tools.cpp	(revision 153508)
+++ lib/Driver/Tools.cpp	(working copy)
@@ -5016,6 +5016,18 @@
       CmdArgs.push_back("-march");
       CmdArgs.push_back(CPUName);
     }
+
+    if (getToolChain().getArch() == llvm::Triple::mips ||
+        getToolChain().getArch() == llvm::Triple::mips64)
+      CmdArgs.push_back("-EB");
+    else
+      CmdArgs.push_back("-EL");
+
+    if (getToolChain().getArch() == llvm::Triple::mips ||
+        getToolChain().getArch() == llvm::Triple::mipsel)
+      CmdArgs.push_back("-32");
+    else
+      CmdArgs.push_back("-64");
   }
 
   Args.AddAllArgValues(CmdArgs, options::OPT_Wa_COMMA,
@@ -5142,6 +5154,9 @@
     else if (ToolChain.getArch() == llvm::Triple::mips ||
              ToolChain.getArch() == llvm::Triple::mipsel)
       CmdArgs.push_back("/lib/ld.so.1");
+    else if (ToolChain.getArch() == llvm::Triple::mips64 ||
+             ToolChain.getArch() == llvm::Triple::mips64el)
+      CmdArgs.push_back("/lib64/ld.so.1");
     else if (ToolChain.getArch() == llvm::Triple::ppc)
       CmdArgs.push_back("/lib/ld.so.1");
     else if (ToolChain.getArch() == llvm::Triple::ppc64)
Index: lib/Driver/ToolChains.cpp
===================================================================
--- lib/Driver/ToolChains.cpp	(revision 153508)
+++ lib/Driver/ToolChains.cpp	(working copy)
@@ -1212,11 +1212,16 @@
     "i486-slackware-linux"
   };
 
-  static const char *const MIPSLibDirs[] = { "/lib" };
+  static const char *const MIPSLibDirs[] = { "/lib32", "/lib" };
   static const char *const MIPSTriples[] = { "mips-linux-gnu" };
-  static const char *const MIPSELLibDirs[] = { "/lib" };
+  static const char *const MIPSELLibDirs[] = { "/lib32", "/lib" };
   static const char *const MIPSELTriples[] = { "mipsel-linux-gnu" };
 
+  static const char *const MIPS64LibDirs[] = { "/lib64", "/lib" };
+  static const char *const MIPS64Triples[] = { "mips64-linux-gnu" };
+  static const char *const MIPS64ELLibDirs[] = { "/lib64", "/lib" };
+  static const char *const MIPS64ELTriples[] = { "mips64el-linux-gnu" };
+
   static const char *const PPCLibDirs[] = { "/lib32", "/lib" };
   static const char *const PPCTriples[] = {
     "powerpc-linux-gnu",
@@ -1262,13 +1267,41 @@
       MIPSLibDirs, MIPSLibDirs + llvm::array_lengthof(MIPSLibDirs));
     TripleAliases.append(
       MIPSTriples, MIPSTriples + llvm::array_lengthof(MIPSTriples));
+    MultiarchLibDirs.append(
+      MIPS64LibDirs, MIPS64LibDirs + llvm::array_lengthof(MIPS64LibDirs));
+    MultiarchTripleAliases.append(
+      MIPS64Triples, MIPS64Triples + llvm::array_lengthof(MIPS64Triples));
     break;
   case llvm::Triple::mipsel:
     LibDirs.append(
       MIPSELLibDirs, MIPSELLibDirs + llvm::array_lengthof(MIPSELLibDirs));
     TripleAliases.append(
       MIPSELTriples, MIPSELTriples + llvm::array_lengthof(MIPSELTriples));
+    MultiarchLibDirs.append(
+      MIPS64ELLibDirs, MIPS64ELLibDirs + llvm::array_lengthof(MIPS64ELLibDirs));
+    MultiarchTripleAliases.append(
+      MIPS64ELTriples, MIPS64ELTriples + llvm::array_lengthof(MIPS64ELTriples));
     break;
+  case llvm::Triple::mips64:
+    LibDirs.append(
+      MIPS64LibDirs, MIPS64LibDirs + llvm::array_lengthof(MIPS64LibDirs));
+    TripleAliases.append(
+      MIPS64Triples, MIPS64Triples + llvm::array_lengthof(MIPS64Triples));
+    MultiarchLibDirs.append(
+      MIPSLibDirs, MIPSLibDirs + llvm::array_lengthof(MIPSLibDirs));
+    MultiarchTripleAliases.append(
+      MIPSTriples, MIPSTriples + llvm::array_lengthof(MIPSTriples));
+    break;
+  case llvm::Triple::mips64el:
+    LibDirs.append(
+      MIPS64ELLibDirs, MIPS64ELLibDirs + llvm::array_lengthof(MIPS64ELLibDirs));
+    TripleAliases.append(
+      MIPS64ELTriples, MIPS64ELTriples + llvm::array_lengthof(MIPS64ELTriples));
+    MultiarchLibDirs.append(
+      MIPSELLibDirs, MIPSELLibDirs + llvm::array_lengthof(MIPSELLibDirs));
+    MultiarchTripleAliases.append(
+      MIPSELTriples, MIPSELTriples + llvm::array_lengthof(MIPSELTriples));
+    break;
   case llvm::Triple::ppc:
     LibDirs.append(PPCLibDirs, PPCLibDirs + llvm::array_lengthof(PPCLibDirs));
     TripleAliases.append(
@@ -1349,7 +1382,9 @@
       // crtbegin.o without the subdirectory.
       StringRef MultiarchSuffix
         = (TargetArch == llvm::Triple::x86_64 ||
-           TargetArch == llvm::Triple::ppc64) ? "/64" : "/32";
+           TargetArch == llvm::Triple::ppc64 ||
+           TargetArch == llvm::Triple::mips64 ||
+           TargetArch == llvm::Triple::mips64el) ? "/64" : "/32";
       if (llvm::sys::fs::exists(LI->path() + MultiarchSuffix + "/crtbegin.o")) {
         GCCMultiarchSuffix = MultiarchSuffix.str();
       } else {