diff --git a/lib/Target/X86/X86InstrFormats.td b/lib/Target/X86/X86InstrFormats.td
index 79187e9a76d..2e4f4cafccc 100644
--- a/lib/Target/X86/X86InstrFormats.td
+++ b/lib/Target/X86/X86InstrFormats.td
@@ -39,7 +39,8 @@ def MRM_E8 : Format<39>;
 def MRM_F0 : Format<40>;
 def MRM_F8 : Format<41>;
 def MRM_F9 : Format<42>;
-def RawFrmImm16 : Format<43>;
+def RawFrmImm8 : Format<43>;
+def RawFrmImm16 : Format<44>;
 
 // ImmType - This specifies the immediate type used by an instruction. This is
 // part of the ad-hoc solution used to emit machine instruction encodings by our
diff --git a/lib/Target/X86/X86InstrInfo.h b/lib/Target/X86/X86InstrInfo.h
index eb0e4b80127..2e7e0636378 100644
--- a/lib/Target/X86/X86InstrInfo.h
+++ b/lib/Target/X86/X86InstrInfo.h
@@ -311,12 +311,17 @@ namespace X86II {
     MRM_F0 = 40,
     MRM_F8 = 41,
     MRM_F9 = 42,
+
+    /// RawFrmImm8 - This is used for the ENTER instruction, which has two
+    /// immediates, the first of which is a 16-bit immediate (specified by
+    /// the imm encoding) and the second is a 8-bit fixed value.
+    RawFrmImm8 = 43,
     
     /// RawFrmImm16 - This is used for CALL FAR instructions, which have two
     /// immediates, the first of which is a 16 or 32-bit immediate (specified by
     /// the imm encoding) and the second is a 16-bit fixed value.  In the AMD
     /// manual, this operand is described as pntr16:32 and pntr16:16
-    RawFrmImm16 = 43,
+    RawFrmImm16 = 44,
 
     FormMask       = 63,
 
@@ -528,6 +533,7 @@ namespace X86II {
     case X86II::AddRegFrm:
     case X86II::MRMDestReg:
     case X86II::MRMSrcReg:
+    case X86II::RawFrmImm8:
     case X86II::RawFrmImm16:
        return -1;
     case X86II::MRMDestMem:
diff --git a/lib/Target/X86/X86InstrInfo.td b/lib/Target/X86/X86InstrInfo.td
index 462acb681e7..8db1dc76de4 100644
--- a/lib/Target/X86/X86InstrInfo.td
+++ b/lib/Target/X86/X86InstrInfo.td
@@ -757,8 +757,8 @@ let isCall = 1 in
 
 // Constructing a stack frame.
 
-def ENTER : I<0xC8, RawFrm, (outs), (ins i16imm:$len, i8imm:$lvl),
-              "enter\t$len, $lvl", []>;
+def ENTER : Ii16<0xC8, RawFrmImm8, (outs), (ins i16imm:$len, i8imm:$lvl),
+                 "enter\t$len, $lvl", []>;
 
 // Tail call stuff.
 
diff --git a/lib/Target/X86/X86MCCodeEmitter.cpp b/lib/Target/X86/X86MCCodeEmitter.cpp
index 9564fe0b92d..ed39abd119a 100644
--- a/lib/Target/X86/X86MCCodeEmitter.cpp
+++ b/lib/Target/X86/X86MCCodeEmitter.cpp
@@ -828,6 +828,13 @@ EncodeInstruction(const MCInst &MI, raw_ostream &OS,
     EmitByte(BaseOpcode, CurByte, OS);
     break;
       
+  case X86II::RawFrmImm8:
+    EmitByte(BaseOpcode, CurByte, OS);
+    EmitImmediate(MI.getOperand(CurOp++),
+                  X86II::getSizeOfImm(TSFlags), getImmFixupKind(TSFlags),
+                  CurByte, OS, Fixups);
+    EmitImmediate(MI.getOperand(CurOp++), 1, FK_Data_1, CurByte, OS, Fixups);
+    break;
   case X86II::RawFrmImm16:
     EmitByte(BaseOpcode, CurByte, OS);
     EmitImmediate(MI.getOperand(CurOp++),
diff --git a/test/MC/AsmParser/X86/x86_instructions.s b/test/MC/AsmParser/X86/x86_instructions.s
index 16fafa6ef2d..d0f6dbfc1a6 100644
--- a/test/MC/AsmParser/X86/x86_instructions.s
+++ b/test/MC/AsmParser/X86/x86_instructions.s
@@ -293,3 +293,15 @@ sldt	%cx
 lcall	*0xbadeface
 ljmp	*0xbadeface
 
+
+// rdar://8444631
+// CHECK: enter	$31438, $0
+// CHECK: encoding: [0xc8,0xce,0x7a,0x00]
+// CHECK: enter	$31438, $1
+// CHECK: encoding: [0xc8,0xce,0x7a,0x01]
+// CHECK: enter	$31438, $127
+// CHECK: encoding: [0xc8,0xce,0x7a,0x7f]
+enter $0x7ace,$0
+enter $0x7ace,$1
+enter $0x7ace,$0x7f
+