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
@@ -3781,6 +3781,9 @@
   case Match_UImm10_0:
     return Error(RefineErrorLoc(IDLoc, Operands, ErrorInfo),
                  "expected 10-bit unsigned immediate");
+  case Match_SImm10_0:
+    return Error(RefineErrorLoc(IDLoc, Operands, ErrorInfo),
+                 "expected 10-bit signed immediate");
   case Match_UImm16:
   case Match_UImm16_Relaxed:
     return Error(RefineErrorLoc(IDLoc, Operands, ErrorInfo),
Index: llvm/trunk/lib/Target/Mips/Mips64InstrInfo.td
===================================================================
--- llvm/trunk/lib/Target/Mips/Mips64InstrInfo.td
+++ llvm/trunk/lib/Target/Mips/Mips64InstrInfo.td
@@ -15,9 +15,6 @@
 // Mips Operand, Complex Patterns and Transformations Definitions.
 //===----------------------------------------------------------------------===//
 
-// Signed Operand
-def simm10_64 : Operand<i64>;
-
 // Transformation Function - get Imm - 32.
 def Subtract32 : SDNodeXForm<imm, [{
   return getImm(N, (unsigned)N->getZExtValue() - 32);
Index: llvm/trunk/lib/Target/Mips/MipsInstrInfo.td
===================================================================
--- llvm/trunk/lib/Target/Mips/MipsInstrInfo.td
+++ llvm/trunk/lib/Target/Mips/MipsInstrInfo.td
@@ -465,11 +465,13 @@
     : UImmAsmOperandClass<16, [UImm16RelaxedAsmOperandClass]>;
 def ConstantUImm10AsmOperandClass
     : ConstantUImmAsmOperandClass<10, [UImm16AsmOperandClass]>;
+def ConstantSImm10AsmOperandClass
+    : ConstantSImmAsmOperandClass<10, [ConstantUImm10AsmOperandClass]>;
 def ConstantSImm7Lsl2AsmOperandClass : AsmOperandClass {
   let Name = "SImm7Lsl2";
   let RenderMethod = "addImmOperands";
   let PredicateMethod = "isScaledSImm<7, 2>";
-  let SuperClasses = [ConstantUImm10AsmOperandClass];
+  let SuperClasses = [ConstantSImm10AsmOperandClass];
   let DiagnosticType = "SImm7_Lsl2";
 }
 def ConstantUImm8AsmOperandClass
@@ -746,6 +748,13 @@
         !cast<AsmOperandClass>("ConstantSImm" # I # "AsmOperandClass");
   }
 
+foreach I = {10} in
+  def simm # I # _64 : Operand<i64> {
+    let DecoderMethod = "DecodeSImmWithOffsetAndScale<" # I # ">";
+    let ParserMatchClass =
+        !cast<AsmOperandClass>("ConstantSImm" # I # "AsmOperandClass");
+  }
+
 def simm7_lsl2 : Operand<OtherVT> {
   let EncoderMethod = "getSImm7Lsl2Encoding";
   let DecoderMethod = "DecodeSImmWithOffsetAndScale<" # I # ", 0, 4>";
Index: llvm/trunk/test/MC/Mips/cnmips/invalid.s
===================================================================
--- llvm/trunk/test/MC/Mips/cnmips/invalid.s
+++ llvm/trunk/test/MC/Mips/cnmips/invalid.s
@@ -17,3 +17,7 @@
     ins $2, $3, 32, 1    # CHECK: :[[@LINE]]:17: error: expected 5-bit unsigned immediate
     ins $2, $3, 0, -1    # CHECK: :[[@LINE]]:20: error: expected immediate in range 1 .. 32
     ins $2, $3, 0, 33    # CHECK: :[[@LINE]]:20: error: expected immediate in range 1 .. 32
+    seqi $2, $3, -1025   # CHECK: :[[@LINE]]:18: error: expected 10-bit signed immediate
+    seqi $2, $3, 1024    # CHECK: :[[@LINE]]:18: error: expected 10-bit signed immediate
+    snei $2, $3, -1025   # CHECK: :[[@LINE]]:18: error: expected 10-bit signed immediate
+    snei $2, $3, 1024    # CHECK: :[[@LINE]]:18: error: expected 10-bit signed immediate