Index: lib/Driver/Tools.cpp
===================================================================
--- lib/Driver/Tools.cpp
+++ lib/Driver/Tools.cpp
@@ -957,8 +957,10 @@
   else if (!CPUName.empty()) {
     // Deduce ABI name from CPU name.
     ABIName = llvm::StringSwitch<const char *>(CPUName)
-      .Cases("mips32", "mips32r2", "o32")
-      .Cases("mips64", "mips64r2", "n64")
+      .Cases("mips1", "mips2", "o32")
+      .Cases("mips32", "mips32r2", "mips32r6", "o32")
+      .Cases("mips3", "mips4", "mips5", "n64")
+      .Cases("mips64", "mips64r2", "mips64r6", "n64")
       .Default("");
   }
 
@@ -967,10 +969,12 @@
 
 // Convert ABI name to the GNU tools acceptable variant.
 static StringRef getGnuCompatibleMipsABIName(StringRef ABI) {
-  return llvm::StringSwitch<llvm::StringRef>(ABI)
-    .Case("o32", "32")
-    .Case("n64", "64")
-    .Default(ABI);
+  StringRef RetVal = llvm::StringSwitch<llvm::StringRef>(ABI)
+                         .Case("o32", "32")
+                         .Case("n64", "64")
+                         .Default(ABI);
+  assert(!RetVal.empty());
+  return RetVal;
 }
 
 // Select the MIPS float ABI as determined by -msoft-float, -mhard-float,
Index: test/Driver/mips-as.c
===================================================================
--- test/Driver/mips-as.c
+++ test/Driver/mips-as.c
@@ -147,3 +147,51 @@
 // RUN:   | FileCheck -check-prefix=MIPS-NMSA %s
 // MIPS-NMSA: as{{(.exe)?}}"
 // MIPS-NMSA-NOT: "{{[ A-Za-z\\\/]*}}as{{(.exe)?}}{{.*}}"-mmsa"
+//
+// We've already tested MIPS32r2 and MIPS64r2 thoroughly. Do minimal tests on
+// the remaining CPU's since it was possible to pass on a -mabi with no value
+// when the CPU name is absent from a StringSwitch in getMipsCPUAndABI()
+// RUN: %clang -target mips-linux-gnu -### -no-integrated-as -c %s -mcpu=mips1 \
+// RUN:   2>&1 | FileCheck -check-prefix=MIPS1-EB-AS %s
+// MIPS1-EB-AS: as{{(.exe)?}}" "-march" "mips1" "-mabi" "32" "-EB"
+// MIPS1-EB-AS-NOT: "{{[ A-Za-z\\\/]*}}as{{(.exe)?}}{{.*}}"-KPIC"
+//
+// RUN: %clang -target mips-linux-gnu -### -no-integrated-as -c %s -mcpu=mips2 \
+// RUN:   2>&1 | FileCheck -check-prefix=MIPS2-EB-AS %s
+// MIPS2-EB-AS: as{{(.exe)?}}" "-march" "mips2" "-mabi" "32" "-EB"
+// MIPS2-EB-AS-NOT: "{{[ A-Za-z\\\/]*}}as{{(.exe)?}}{{.*}}"-KPIC"
+//
+// RUN: %clang -target mips-linux-gnu -### -no-integrated-as -c %s -mcpu=mips3 \
+// RUN:   2>&1 | FileCheck -check-prefix=MIPS3-EB-AS %s
+// MIPS3-EB-AS: as{{(.exe)?}}" "-march" "mips3" "-mabi" "64" "-EB"
+// MIPS3-EB-AS-NOT: "{{[ A-Za-z\\\/]*}}as{{(.exe)?}}{{.*}}"-KPIC"
+//
+// RUN: %clang -target mips-linux-gnu -### -no-integrated-as -c %s -mcpu=mips4 \
+// RUN:   2>&1 | FileCheck -check-prefix=MIPS4-EB-AS %s
+// MIPS4-EB-AS: as{{(.exe)?}}" "-march" "mips4" "-mabi" "64" "-EB"
+// MIPS4-EB-AS-NOT: "{{[ A-Za-z\\\/]*}}as{{(.exe)?}}{{.*}}"-KPIC"
+//
+// RUN: %clang -target mips-linux-gnu -### -no-integrated-as -c %s -mcpu=mips5 \
+// RUN:   2>&1 | FileCheck -check-prefix=MIPS5-EB-AS %s
+// MIPS5-EB-AS: as{{(.exe)?}}" "-march" "mips5" "-mabi" "64" "-EB"
+// MIPS5-EB-AS-NOT: "{{[ A-Za-z\\\/]*}}as{{(.exe)?}}{{.*}}"-KPIC"
+//
+// RUN: %clang -target mips-linux-gnu -### -no-integrated-as -c %s -mcpu=mips32 \
+// RUN:   2>&1 | FileCheck -check-prefix=MIPS32-EB-AS %s
+// MIPS32-EB-AS: as{{(.exe)?}}" "-march" "mips32" "-mabi" "32" "-EB"
+// MIPS32-EB-AS-NOT: "{{[ A-Za-z\\\/]*}}as{{(.exe)?}}{{.*}}"-KPIC"
+//
+// RUN: %clang -target mips-linux-gnu -### -no-integrated-as -c %s -mcpu=mips32r6 \
+// RUN:   2>&1 | FileCheck -check-prefix=MIPS32R6-EB-AS %s
+// MIPS32R6-EB-AS: as{{(.exe)?}}" "-march" "mips32r6" "-mabi" "32" "-EB"
+// MIPS32R6-EB-AS-NOT: "{{[ A-Za-z\\\/]*}}as{{(.exe)?}}{{.*}}"-KPIC"
+//
+// RUN: %clang -target mips-linux-gnu -### -no-integrated-as -c %s -mcpu=mips64 \
+// RUN:   2>&1 | FileCheck -check-prefix=MIPS64-EB-AS %s
+// MIPS64-EB-AS: as{{(.exe)?}}" "-march" "mips64" "-mabi" "64" "-EB"
+// MIPS64-EB-AS-NOT: "{{[ A-Za-z\\\/]*}}as{{(.exe)?}}{{.*}}"-KPIC"
+//
+// RUN: %clang -target mips-linux-gnu -### -no-integrated-as -c %s -mcpu=mips64r6 \
+// RUN:   2>&1 | FileCheck -check-prefix=MIPS64R6-EB-AS %s
+// MIPS64R6-EB-AS: as{{(.exe)?}}" "-march" "mips64r6" "-mabi" "64" "-EB"
+// MIPS64R6-EB-AS-NOT: "{{[ A-Za-z\\\/]*}}as{{(.exe)?}}{{.*}}"-KPIC"