Index: llvm/trunk/lib/Target/Mips/AsmParser/MipsAsmParser.cpp
===================================================================
--- llvm/trunk/lib/Target/Mips/AsmParser/MipsAsmParser.cpp
+++ llvm/trunk/lib/Target/Mips/AsmParser/MipsAsmParser.cpp
@@ -466,6 +466,7 @@
     Match_RequiresSameSrcAndDst,
     Match_NoFCCRegisterForCurrentISA,
     Match_NonZeroOperandForSync,
+    Match_NonZeroOperandForMTCX,
     Match_RequiresPosSizeRange0_32,
     Match_RequiresPosSizeRange33_64,
     Match_RequiresPosSizeUImm6,
@@ -5151,6 +5152,13 @@
     if (Inst.getOperand(0).getImm() != 0 && !hasMips32())
       return Match_NonZeroOperandForSync;
     return Match_Success;
+  case Mips::MFC0:
+  case Mips::MTC0:
+  case Mips::MTC2:
+  case Mips::MFC2:
+    if (Inst.getOperand(2).getImm() != 0 && !hasMips32())
+      return Match_NonZeroOperandForMTCX;
+    return Match_Success;
   // As described the MIPSR6 spec, the compact branches that compare registers
   // must:
   // a) Not use the zero register.
@@ -5292,6 +5300,8 @@
   }
   case Match_NonZeroOperandForSync:
     return Error(IDLoc, "s-type must be zero or unspecified for pre-MIPS32 ISAs");
+  case Match_NonZeroOperandForMTCX:
+    return Error(IDLoc, "selector must be zero for pre-MIPS32 ISAs");
   case Match_MnemonicFail:
     return Error(IDLoc, "invalid instruction");
   case Match_RequiresDifferentSrcAndDst:
Index: llvm/trunk/lib/Target/Mips/MipsInstrInfo.td
===================================================================
--- llvm/trunk/lib/Target/Mips/MipsInstrInfo.td
+++ llvm/trunk/lib/Target/Mips/MipsInstrInfo.td
@@ -2310,12 +2310,14 @@
 /// Move Control Registers From/To CPU Registers
 let AdditionalPredicates = [NotInMicroMips] in {
   def MTC0 : MTC3OP<"mtc0", COP0Opnd, GPR32Opnd, II_MTC0>, MFC3OP_FM<0x10, 4>,
-             ISA_MIPS32;
+             ISA_MIPS1;
   def MFC0 : MFC3OP<"mfc0", GPR32Opnd, COP0Opnd, II_MFC0>, MFC3OP_FM<0x10, 0>,
-             ISA_MIPS32;
+             ISA_MIPS1;
+  def MFC2 : MFC3OP<"mfc2", GPR32Opnd, COP2Opnd, II_MFC2>, MFC3OP_FM<0x12, 0>,
+             ISA_MIPS1;
+  def MTC2 : MTC3OP<"mtc2", COP2Opnd, GPR32Opnd, II_MTC2>, MFC3OP_FM<0x12, 4>,
+             ISA_MIPS1;
 }
-def MFC2 : MFC3OP<"mfc2", GPR32Opnd, COP2Opnd, II_MFC2>, MFC3OP_FM<0x12, 0>;
-def MTC2 : MTC3OP<"mtc2", COP2Opnd, GPR32Opnd, II_MTC2>, MFC3OP_FM<0x12, 4>;
 
 class Barrier<string asmstr, InstrItinClass itin = NoItinerary> :
   InstSE<(outs), (ins), asmstr, [], itin, FrmOther, asmstr>;
Index: llvm/trunk/test/MC/Mips/mips1/invalid-mips32.s
===================================================================
--- llvm/trunk/test/MC/Mips/mips1/invalid-mips32.s
+++ llvm/trunk/test/MC/Mips/mips1/invalid-mips32.s
@@ -8,3 +8,8 @@
 
         sync 0                    # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
         sync 1                    # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
+        mtc0  $4, $5, 1           # CHECK: :[[@LINE]]:{{[0-9]+}}: error: selector must be zero for pre-MIPS32 ISAs
+        mfc0  $4, $5, 1           # CHECK: :[[@LINE]]:{{[0-9]+}}: error: selector must be zero for pre-MIPS32 ISAs
+        mtc2  $4, $5, 1           # CHECK: :[[@LINE]]:{{[0-9]+}}: error: selector must be zero for pre-MIPS32 ISAs
+        mfc2  $4, $5, 1           # CHECK: :[[@LINE]]:{{[0-9]+}}: error: selector must be zero for pre-MIPS32 ISAs
+
Index: llvm/trunk/test/MC/Mips/mips2/invalid-mips32.s
===================================================================
--- llvm/trunk/test/MC/Mips/mips2/invalid-mips32.s
+++ llvm/trunk/test/MC/Mips/mips2/invalid-mips32.s
@@ -18,7 +18,8 @@
         madd      $zero,$9        # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
         maddu     $s3,$gp         # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
         maddu     $24,$s2         # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
-        mfc0      $a2,$14,1       # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
+        mfc0      $4, $5, 1       # CHECK: :[[@LINE]]:{{[0-9]+}}: error: selector must be zero for pre-MIPS32 ISAs
+        mfc2      $4, $5, 1       # CHECK: :[[@LINE]]:{{[0-9]+}}: error: selector must be zero for pre-MIPS32 ISAs
         movf      $gp,$8,$fcc0    # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
         movf      $gp,$8,$fcc7    # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
         movf.d    $f6,$f11,$fcc0  # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
@@ -38,7 +39,8 @@
         movz.s    $f25,$f7,$v1    # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
         msub      $s7,$k1         # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
         msubu     $15,$a1         # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
-        mtc0      $9,$29,3        # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
+        mtc0      $4, $5, 1       # CHECK: :[[@LINE]]:{{[0-9]+}}: error: selector must be zero for pre-MIPS32 ISAs
+        mtc2      $4, $5, 1       # CHECK: :[[@LINE]]:{{[0-9]+}}: error: selector must be zero for pre-MIPS32 ISAs
         mul       $s0,$s4,$at     # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
         sync      1               # CHECK: :[[@LINE]]:{{[0-9]+}}: error: s-type must be zero or unspecified for pre-MIPS32 ISAs
         c.eq.s    $fcc1, $f2, $f8 # CHECK: :[[@LINE]]:{{[0-9]+}}: error: non-zero fcc register doesn't exist in current ISA level
Index: llvm/trunk/test/MC/Mips/mips2/invalid-mips32r2.s
===================================================================
--- llvm/trunk/test/MC/Mips/mips2/invalid-mips32r2.s
+++ llvm/trunk/test/MC/Mips/mips2/invalid-mips32r2.s
@@ -58,7 +58,7 @@
         madd.s  $f1,$f31,$f19,$f25  # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
         maddu   $s3,$gp             # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
         maddu   $t8,$s2             # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
-        mfc0    $a2,$14,1           # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
+        mfc0    $a2,$14,1           # CHECK: :[[@LINE]]:{{[0-9]+}}: error: selector must be zero for pre-MIPS32 ISAs
         mfhc1   $s8,$f24            # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
         movf    $gp,$8,$fcc0        # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
         movf    $gp,$8,$fcc7        # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
@@ -81,7 +81,7 @@
         msub.d  $f10,$f1,$f31,$f18  # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
         msub.s  $f12,$f19,$f10,$f16 # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
         msubu   $t7,$a1             # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
-        mtc0    $t1,$29,3           # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
+        mtc0    $t1,$29,3           # CHECK: :[[@LINE]]:{{[0-9]+}}: error: selector must be zero for pre-MIPS32 ISAs
         mthc1   $zero,$f16          # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
         mul     $s0,$s4,$at         # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
         nmadd.d $f18,$f9,$f14,$f19  # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
Index: llvm/trunk/test/MC/Mips/mips3/invalid-mips32.s
===================================================================
--- llvm/trunk/test/MC/Mips/mips3/invalid-mips32.s
+++ llvm/trunk/test/MC/Mips/mips3/invalid-mips32.s
@@ -7,3 +7,8 @@
         .set noat
 
         sync 1                    # CHECK: :[[@LINE]]:{{[0-9]+}}: error: s-type must be zero or unspecified for pre-MIPS32 ISAs
+        mtc0    $4, $5, 1           # CHECK: :[[@LINE]]:{{[0-9]+}}: error: selector must be zero for pre-MIPS32 ISAs
+        mfc0    $4, $5, 1           # CHECK: :[[@LINE]]:{{[0-9]+}}: error: selector must be zero for pre-MIPS32 ISAs
+        mtc2    $4, $5, 1           # CHECK: :[[@LINE]]:{{[0-9]+}}: error: selector must be zero for pre-MIPS32 ISAs
+        mfc2    $4, $5, 1           # CHECK: :[[@LINE]]:{{[0-9]+}}: error: selector must be zero for pre-MIPS32 ISAs
+
Index: llvm/trunk/test/MC/Mips/mips4/invalid-mips32.s
===================================================================
--- llvm/trunk/test/MC/Mips/mips4/invalid-mips32.s
+++ llvm/trunk/test/MC/Mips/mips4/invalid-mips32.s
@@ -7,3 +7,8 @@
         .set noat
 
         sync 1                    # CHECK: :[[@LINE]]:{{[0-9]+}}: error: s-type must be zero or unspecified for pre-MIPS32 ISAs
+        mtc0    $4, $5, 1           # CHECK: :[[@LINE]]:{{[0-9]+}}: error: selector must be zero for pre-MIPS32 ISAs
+        mfc0    $4, $5, 1           # CHECK: :[[@LINE]]:{{[0-9]+}}: error: selector must be zero for pre-MIPS32 ISAs
+        mtc2    $4, $5, 1           # CHECK: :[[@LINE]]:{{[0-9]+}}: error: selector must be zero for pre-MIPS32 ISAs
+        mfc2    $4, $5, 1           # CHECK: :[[@LINE]]:{{[0-9]+}}: error: selector must be zero for pre-MIPS32 ISAs
+
Index: llvm/trunk/test/MC/Mips/mips4/invalid-mips64.s
===================================================================
--- llvm/trunk/test/MC/Mips/mips4/invalid-mips64.s
+++ llvm/trunk/test/MC/Mips/mips4/invalid-mips64.s
@@ -16,9 +16,9 @@
         madd    $zero,$t1     # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
         maddu   $s3,$gp       # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
         maddu   $t8,$s2       # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
-        mfc0    $a2,$14,1     # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
+        mfc0    $a2,$14,1     # CHECK: :[[@LINE]]:{{[0-9]+}}: error: selector must be zero for pre-MIPS32 ISAs
         msub    $s7,$k1       # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
         msubu   $t7,$a1       # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
-        mtc0    $t1,$29,3     # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
+        mtc0    $t1,$29,3     # CHECK: :[[@LINE]]:{{[0-9]+}}: error: selector must be zero for pre-MIPS32 ISAs
         mul     $s0,$s4,$at   # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
         suxc1   $f12,$k1($t5) # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
Index: llvm/trunk/test/MC/Mips/mips4/invalid-mips64r2.s
===================================================================
--- llvm/trunk/test/MC/Mips/mips4/invalid-mips64r2.s
+++ llvm/trunk/test/MC/Mips/mips4/invalid-mips64r2.s
@@ -19,11 +19,11 @@
         madd    $zero,$t1           # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
         maddu   $s3,$gp             # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
         maddu   $t8,$s2             # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
-        mfc0    $a2,$14,1           # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
+        mfc0    $a2,$14,1           # CHECK: :[[@LINE]]:{{[0-9]+}}: error: selector must be zero for pre-MIPS32 ISAs
         mfhc1   $s8,$f24            # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
         msub    $s7,$k1             # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
         msubu   $t7,$a1             # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
-        mtc0    $t1,$29,3           # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
+        mtc0    $t1,$29,3           # CHECK: :[[@LINE]]:{{[0-9]+}}: error: selector must be zero for pre-MIPS32 ISAs
         mthc1   $zero,$f16          # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
         mul     $s0,$s4,$at         # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
         pause                       # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
Index: llvm/trunk/test/MC/Mips/mips5/invalid-mips32.s
===================================================================
--- llvm/trunk/test/MC/Mips/mips5/invalid-mips32.s
+++ llvm/trunk/test/MC/Mips/mips5/invalid-mips32.s
@@ -7,3 +7,8 @@
         .set noat
 
         sync 1                    # CHECK: :[[@LINE]]:{{[0-9]+}}: error: s-type must be zero or unspecified for pre-MIPS32 ISAs
+        mtc0    $4, $5, 1           # CHECK: :[[@LINE]]:{{[0-9]+}}: error: selector must be zero for pre-MIPS32 ISAs
+        mfc0    $4, $5, 1           # CHECK: :[[@LINE]]:{{[0-9]+}}: error: selector must be zero for pre-MIPS32 ISAs
+        mtc2    $4, $5, 1           # CHECK: :[[@LINE]]:{{[0-9]+}}: error: selector must be zero for pre-MIPS32 ISAs
+        mfc2    $4, $5, 1           # CHECK: :[[@LINE]]:{{[0-9]+}}: error: selector must be zero for pre-MIPS32 ISAs
+
Index: llvm/trunk/test/MC/Mips/mips5/invalid-mips64.s
===================================================================
--- llvm/trunk/test/MC/Mips/mips5/invalid-mips64.s
+++ llvm/trunk/test/MC/Mips/mips5/invalid-mips64.s
@@ -17,8 +17,8 @@
         madd      $zero,$9    # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
         maddu     $s3,$gp     # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
         maddu     $24,$s2     # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
-        mfc0      $a2,$14,1   # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
+        mfc0      $a2,$14,1   # CHECK: :[[@LINE]]:{{[0-9]+}}: error: selector must be zero for pre-MIPS32 ISAs
         msub      $s7,$k1     # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
         msubu     $15,$a1     # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
-        mtc0      $9,$29,3    # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
+        mtc0      $9,$29,3    # CHECK: :[[@LINE]]:{{[0-9]+}}: error: selector must be zero for pre-MIPS32 ISAs
         mul       $s0,$s4,$at # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
Index: llvm/trunk/test/MC/Mips/mips5/invalid-mips64r2.s
===================================================================
--- llvm/trunk/test/MC/Mips/mips5/invalid-mips64r2.s
+++ llvm/trunk/test/MC/Mips/mips5/invalid-mips64r2.s
@@ -23,11 +23,11 @@
         madd      $zero,$9            # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
         maddu     $s3,$gp             # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
         maddu     $24,$s2             # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
-        mfc0      $a2,$14,1           # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
+        mfc0      $a2,$14,1           # CHECK: :[[@LINE]]:{{[0-9]+}}: error: selector must be zero for pre-MIPS32 ISAs
         mfhc1     $s8,$f24            # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
         msub      $s7,$k1             # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
         msubu     $15,$a1             # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
-        mtc0      $9,$29,3            # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
+        mtc0      $9,$29,3            # CHECK: :[[@LINE]]:{{[0-9]+}}: error: selector must be zero for pre-MIPS32 ISAs
         mthc1     $zero,$f16          # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
         mul       $s0,$s4,$at         # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled
         pause                         # CHECK: :[[@LINE]]:{{[0-9]+}}: error: instruction requires a CPU feature not currently enabled