diff --git a/lib/Target/Mips/Mips.td b/lib/Target/Mips/Mips.td
index 6ea6013bc85..2fbcb39213a 100644
--- a/lib/Target/Mips/Mips.td
+++ b/lib/Target/Mips/Mips.td
@@ -85,20 +85,34 @@ def FeatureBitCount    : SubtargetFeature<"bitcount", "HasBitCount", "true",
                                 "Enable 'count leading bits' instructions.">;
 def FeatureFPIdx       : SubtargetFeature<"fpidx", "HasFPIdx", "true",
                                 "Enable 'FP indexed load/store' instructions.">;
+def FeatureMips1       : SubtargetFeature<"mips1", "MipsArchVersion", "Mips1",
+                                "Mips I ISA Support [highly experimental]">;
+def FeatureMips2       : SubtargetFeature<"mips2", "MipsArchVersion", "Mips2",
+                                "Mips II ISA Support [highly experimental]",
+                                [FeatureMips1]>;
 def FeatureMips32      : SubtargetFeature<"mips32", "MipsArchVersion", "Mips32",
                                 "Mips32 ISA Support",
-                                [FeatureCondMov, FeatureBitCount]>;
+                                [FeatureMips2, FeatureCondMov,
+                                 FeatureBitCount]>;
 def FeatureMips32r2    : SubtargetFeature<"mips32r2", "MipsArchVersion",
                                 "Mips32r2", "Mips32r2 ISA Support",
                                 [FeatureMips32, FeatureSEInReg, FeatureSwap,
                                  FeatureFPIdx]>;
+// FIXME: Need to check whether FPIdx belongs in the MIPS-III or MIPS-IV Implies
+//        list but for now it doesn't matter since FPIdx isn't actually attached
+//        to any instructions.
+def FeatureMips3       : SubtargetFeature<"mips3", "MipsArchVersion", "Mips3",
+                                "MIPS III ISA Support [highly experimental]",
+                                [FeatureMips2, FeatureGP64Bit, FeatureFP64Bit]>;
 def FeatureMips4       : SubtargetFeature<"mips4", "MipsArchVersion",
                                 "Mips4", "MIPS IV ISA Support",
-                                [FeatureGP64Bit, FeatureFP64Bit, FeatureFPIdx,
-                                 FeatureCondMov]>;
+                                [FeatureMips3, FeatureFPIdx, FeatureCondMov]>;
+def FeatureMips5       : SubtargetFeature<"mips5", "MipsArchVersion", "Mips5",
+                                "MIPS V ISA Support [highly experimental]",
+                                [FeatureMips4]>;
 def FeatureMips64      : SubtargetFeature<"mips64", "MipsArchVersion",
                                 "Mips64", "Mips64 ISA Support",
-                                [FeatureMips4, FeatureMips32, FeatureFPIdx]>;
+                                [FeatureMips5, FeatureMips32, FeatureFPIdx]>;
 def FeatureMips64r2    : SubtargetFeature<"mips64r2", "MipsArchVersion",
                                 "Mips64r2", "Mips64r2 ISA Support",
                                 [FeatureMips64, FeatureMips32r2]>;
@@ -126,9 +140,14 @@ def FeatureCnMips     : SubtargetFeature<"cnmips", "HasCnMips",
 class Proc<string Name, list<SubtargetFeature> Features>
  : Processor<Name, MipsGenericItineraries, Features>;
 
+def : Proc<"mips1", [FeatureMips1, FeatureO32]>;
+def : Proc<"mips2", [FeatureMips2, FeatureO32]>;
 def : Proc<"mips32", [FeatureMips32, FeatureO32]>;
 def : Proc<"mips32r2", [FeatureMips32r2, FeatureO32]>;
+
+def : Proc<"mips3", [FeatureMips3, FeatureN64]>;
 def : Proc<"mips4", [FeatureMips4, FeatureN64]>;
+def : Proc<"mips5", [FeatureMips5, FeatureN64]>;
 def : Proc<"mips64", [FeatureMips64, FeatureN64]>;
 def : Proc<"mips64r2", [FeatureMips64r2, FeatureN64]>;
 def : Proc<"mips16", [FeatureMips16, FeatureO32]>;
diff --git a/lib/Target/Mips/MipsSubtarget.cpp b/lib/Target/Mips/MipsSubtarget.cpp
index 02228da65c2..6675ad42aab 100644
--- a/lib/Target/Mips/MipsSubtarget.cpp
+++ b/lib/Target/Mips/MipsSubtarget.cpp
@@ -107,6 +107,19 @@ MipsSubtarget::MipsSubtarget(const std::string &TT, const std::string &CPU,
   // Initialize scheduling itinerary for the specified CPU.
   InstrItins = getInstrItineraryForCPU(CPUName);
 
+  // Don't even attempt to generate code for MIPS-I, MIPS-II, MIPS-III, and
+  // MIPS-V. They have not been tested and currently exist for the integrated
+  // assembler only.
+  if (MipsArchVersion == Mips1)
+    report_fatal_error("Code generation for MIPS-I is not implemented", false);
+  if (MipsArchVersion == Mips2)
+    report_fatal_error("Code generation for MIPS-II is not implemented", false);
+  if (MipsArchVersion == Mips3)
+    report_fatal_error("Code generation for MIPS-III is not implemented",
+                       false);
+  if (MipsArchVersion == Mips5)
+    report_fatal_error("Code generation for MIPS-V is not implemented", false);
+
   // Assert exactly one ABI was chosen.
   assert(MipsABI != UnknownABI);
   assert((((getFeatureBits() & Mips::FeatureO32) != 0) +
diff --git a/lib/Target/Mips/MipsSubtarget.h b/lib/Target/Mips/MipsSubtarget.h
index 3c70f825e1f..666e9397483 100644
--- a/lib/Target/Mips/MipsSubtarget.h
+++ b/lib/Target/Mips/MipsSubtarget.h
@@ -37,7 +37,8 @@ public:
   };
 
 protected:
-  enum MipsArchEnum { Mips32, Mips32r2, Mips4, Mips64, Mips64r2 };
+  enum MipsArchEnum { Mips1, Mips2, Mips32, Mips32r2, Mips3, Mips4, Mips5,
+                      Mips64, Mips64r2 };
 
   // Mips architecture version
   MipsArchEnum MipsArchVersion;
diff --git a/test/MC/Mips/mips1/valid-xfail.s b/test/MC/Mips/mips1/valid-xfail.s
index 2ffeaa968b4..784338cc371 100644
--- a/test/MC/Mips/mips1/valid-xfail.s
+++ b/test/MC/Mips/mips1/valid-xfail.s
@@ -2,8 +2,7 @@
 # they aren't implemented yet).
 # This test is set up to XPASS if any instruction generates an encoding.
 #
-# FIXME: Test MIPS-I instead of MIPS32
-# RUN: not llvm-mc %s -triple=mips-unknown-linux -show-encoding -mcpu=mips32 | not FileCheck %s
+# RUN: not llvm-mc %s -triple=mips-unknown-linux -show-encoding -mcpu=mips1 | not FileCheck %s
 # CHECK-NOT: encoding
 # XFAIL: *
 
diff --git a/test/MC/Mips/mips1/valid.s b/test/MC/Mips/mips1/valid.s
index 925ee7637d1..4ad74acb537 100644
--- a/test/MC/Mips/mips1/valid.s
+++ b/test/MC/Mips/mips1/valid.s
@@ -1,7 +1,6 @@
 # Instructions that are valid
 #
-# FIXME: Test MIPS-I instead of MIPS32
-# RUN: llvm-mc %s -triple=mips-unknown-linux -show-encoding -mcpu=mips32 | FileCheck %s
+# RUN: llvm-mc %s -triple=mips-unknown-linux -show-encoding -mcpu=mips1 | FileCheck %s
 
 	.set noat
 	abs.d	$f7,$f25          # CHECK: encoding:
diff --git a/test/MC/Mips/mips2/valid-xfail.s b/test/MC/Mips/mips2/valid-xfail.s
index 2f82f5c96f9..e8b8666da6e 100644
--- a/test/MC/Mips/mips2/valid-xfail.s
+++ b/test/MC/Mips/mips2/valid-xfail.s
@@ -2,8 +2,7 @@
 # they aren't implemented yet).
 # This test is set up to XPASS if any instruction generates an encoding.
 #
-# FIXME: Test MIPS-II instead of MIPS32
-# RUN: not llvm-mc %s -triple=mips-unknown-linux -show-encoding -mcpu=mips32 | not FileCheck %s
+# RUN: not llvm-mc %s -triple=mips-unknown-linux -show-encoding -mcpu=mips2 | not FileCheck %s
 # CHECK-NOT: encoding
 # XFAIL: *
 
diff --git a/test/MC/Mips/mips2/valid.s b/test/MC/Mips/mips2/valid.s
index 96e55a59787..dc4a8b6ea91 100644
--- a/test/MC/Mips/mips2/valid.s
+++ b/test/MC/Mips/mips2/valid.s
@@ -1,7 +1,6 @@
 # Instructions that are valid
 #
-# FIXME: Test MIPS-II instead of MIPS32
-# RUN: llvm-mc %s -triple=mips-unknown-linux -show-encoding -mcpu=mips32 | FileCheck %s
+# RUN: llvm-mc %s -triple=mips-unknown-linux -show-encoding -mcpu=mips2 | FileCheck %s
 
 	.set noat
 	abs.d	$f7,$f25            # CHECK: encoding
diff --git a/test/MC/Mips/mips3/valid-xfail.s b/test/MC/Mips/mips3/valid-xfail.s
index 42fa09f20a2..329dde12a24 100644
--- a/test/MC/Mips/mips3/valid-xfail.s
+++ b/test/MC/Mips/mips3/valid-xfail.s
@@ -2,8 +2,7 @@
 # they aren't implemented yet).
 # This test is set up to XPASS if any instruction generates an encoding.
 #
-# FIXME: Test MIPS-III instead of MIPS-IV
-# RUN: not llvm-mc %s -triple=mips-unknown-linux -show-encoding -mcpu=mips4 | not FileCheck %s
+# RUN: not llvm-mc %s -triple=mips-unknown-linux -show-encoding -mcpu=mips3 | not FileCheck %s
 # CHECK-NOT: encoding
 # XFAIL: *
 
diff --git a/test/MC/Mips/mips3/valid.s b/test/MC/Mips/mips3/valid.s
index 79443923ad6..68f97038d4a 100644
--- a/test/MC/Mips/mips3/valid.s
+++ b/test/MC/Mips/mips3/valid.s
@@ -1,7 +1,6 @@
 # Instructions that are valid
 #
-# FIXME: Test MIPS-III instead of MIPS-IV
-# RUN: llvm-mc %s -triple=mips64-unknown-linux -show-encoding -mcpu=mips4 | FileCheck %s
+# RUN: llvm-mc %s -triple=mips64-unknown-linux -show-encoding -mcpu=mips3 | FileCheck %s
 
 	.set noat
 	abs.d	$f7,$f25 # CHECK: encoding
diff --git a/test/MC/Mips/mips5/valid-xfail.s b/test/MC/Mips/mips5/valid-xfail.s
index 85d961b47a3..3c211d6c05d 100644
--- a/test/MC/Mips/mips5/valid-xfail.s
+++ b/test/MC/Mips/mips5/valid-xfail.s
@@ -2,8 +2,7 @@
 # they aren't implemented yet).
 # This test is set up to XPASS if any instruction generates an encoding.
 #
-# FIXME: Test MIPS-V instead of MIPS64
-# RUN: not llvm-mc %s -triple=mips64-unknown-linux -show-encoding -mcpu=mips64   | not FileCheck %s
+# RUN: not llvm-mc %s -triple=mips64-unknown-linux -show-encoding -mcpu=mips5   | not FileCheck %s
 # CHECK-NOT: encoding
 # XFAIL: *
 
diff --git a/test/MC/Mips/mips5/valid.s b/test/MC/Mips/mips5/valid.s
index 94be22929f2..f82181fd7c8 100644
--- a/test/MC/Mips/mips5/valid.s
+++ b/test/MC/Mips/mips5/valid.s
@@ -1,7 +1,6 @@
 # Instructions that are valid
 #
-# FIXME: Test MIPS-V instead of MIPS64
-# RUN: llvm-mc %s -triple=mips64-unknown-linux -show-encoding -mcpu=mips64   | FileCheck %s
+# RUN: llvm-mc %s -triple=mips64-unknown-linux -show-encoding -mcpu=mips5   | FileCheck %s
 
         .set noat
 	abs.d	$f7,$f25 # CHECK: encoding