diff --git a/src/IceInst.h b/src/IceInst.h
index 3067c26..fd0eeea 100644
--- a/src/IceInst.h
+++ b/src/IceInst.h
@@ -161,6 +161,7 @@
 #define X(tag, str, commutative) tag,
     ICEINSTARITHMETIC_TABLE
 #undef X
+        _num
   };
 
   static InstArithmetic *create(Cfg *Func, OpKind Op, Variable *Dest,
@@ -287,6 +288,7 @@
 #define X(tag, str) tag,
     ICEINSTCAST_TABLE
 #undef X
+        _num
   };
 
   static InstCast *create(Cfg *Func, OpKind CastKind, Variable *Dest,
@@ -314,6 +316,7 @@
 #define X(tag, str) tag,
     ICEINSTFCMP_TABLE
 #undef X
+        _num
   };
 
   static InstFcmp *create(Cfg *Func, FCond Condition, Variable *Dest,
@@ -342,6 +345,7 @@
 #define X(tag, str) tag,
     ICEINSTICMP_TABLE
 #undef X
+        _num
   };
 
   static InstIcmp *create(Cfg *Func, ICond Condition, Variable *Dest,
diff --git a/src/IceInstX8632.def b/src/IceInstX8632.def
index 665dd8d..d5e99c3 100644
--- a/src/IceInstX8632.def
+++ b/src/IceInstX8632.def
@@ -22,19 +22,19 @@
   X(Reg_ecx, = Reg_eax + 1,   "ecx",  "cx", "cl", 1, 0, 0, 0, 1, 1, 0)  \
   X(Reg_edx, = Reg_eax + 2,   "edx",  "dx", "dl", 1, 0, 0, 0, 1, 1, 0)  \
   X(Reg_ebx, = Reg_eax + 3,   "ebx",  "bx", "bl", 0, 1, 0, 0, 1, 1, 0)  \
-  X(Reg_esp, = Reg_eax + 4,   "esp",  "sp",     , 0, 0, 1, 0, 0, 1, 0)  \
-  X(Reg_ebp, = Reg_eax + 5,   "ebp",  "bp",     , 0, 1, 0, 1, 0, 1, 0)  \
-  X(Reg_esi, = Reg_eax + 6,   "esi",  "si",     , 0, 1, 0, 0, 0, 1, 0)  \
-  X(Reg_edi, = Reg_eax + 7,   "edi",  "di",     , 0, 1, 0, 0, 0, 1, 0)  \
-  X(Reg_ah,   /*none*/,       "???",      , "ah", 0, 0, 0, 0, 1, 0, 0)  \
-  X(Reg_xmm0, /*none*/,       "xmm0",     ,     , 1, 0, 0, 0, 0, 0, 1)  \
-  X(Reg_xmm1, = Reg_xmm0 + 1, "xmm1",     ,     , 1, 0, 0, 0, 0, 0, 1)  \
-  X(Reg_xmm2, = Reg_xmm0 + 2, "xmm2",     ,     , 1, 0, 0, 0, 0, 0, 1)  \
-  X(Reg_xmm3, = Reg_xmm0 + 3, "xmm3",     ,     , 1, 0, 0, 0, 0, 0, 1)  \
-  X(Reg_xmm4, = Reg_xmm0 + 4, "xmm4",     ,     , 1, 0, 0, 0, 0, 0, 1)  \
-  X(Reg_xmm5, = Reg_xmm0 + 5, "xmm5",     ,     , 1, 0, 0, 0, 0, 0, 1)  \
-  X(Reg_xmm6, = Reg_xmm0 + 6, "xmm6",     ,     , 1, 0, 0, 0, 0, 0, 1)  \
-  X(Reg_xmm7, = Reg_xmm0 + 7, "xmm7",     ,     , 1, 0, 0, 0, 0, 0, 1)  \
+  X(Reg_esp, = Reg_eax + 4,   "esp",  "sp", ""  , 0, 0, 1, 0, 0, 1, 0)  \
+  X(Reg_ebp, = Reg_eax + 5,   "ebp",  "bp", ""  , 0, 1, 0, 1, 0, 1, 0)  \
+  X(Reg_esi, = Reg_eax + 6,   "esi",  "si", ""  , 0, 1, 0, 0, 0, 1, 0)  \
+  X(Reg_edi, = Reg_eax + 7,   "edi",  "di", ""  , 0, 1, 0, 0, 0, 1, 0)  \
+  X(Reg_ah,  = Reg_edi + 1,   "???",  ""  , "ah", 0, 0, 0, 0, 1, 0, 0)  \
+  X(Reg_xmm0, = Reg_ah + 1,   "xmm0", ""  , ""  , 1, 0, 0, 0, 0, 0, 1)  \
+  X(Reg_xmm1, = Reg_xmm0 + 1, "xmm1", ""  , ""  , 1, 0, 0, 0, 0, 0, 1)  \
+  X(Reg_xmm2, = Reg_xmm0 + 2, "xmm2", ""  , ""  , 1, 0, 0, 0, 0, 0, 1)  \
+  X(Reg_xmm3, = Reg_xmm0 + 3, "xmm3", ""  , ""  , 1, 0, 0, 0, 0, 0, 1)  \
+  X(Reg_xmm4, = Reg_xmm0 + 4, "xmm4", ""  , ""  , 1, 0, 0, 0, 0, 0, 1)  \
+  X(Reg_xmm5, = Reg_xmm0 + 5, "xmm5", ""  , ""  , 1, 0, 0, 0, 0, 0, 1)  \
+  X(Reg_xmm6, = Reg_xmm0 + 6, "xmm6", ""  , ""  , 1, 0, 0, 0, 0, 0, 1)  \
+  X(Reg_xmm7, = Reg_xmm0 + 7, "xmm7", ""  , ""  , 1, 0, 0, 0, 0, 0, 1)  \
 //#define X(val, init, name, name16, name8, scratch, preserved, stackptr,
 //          frameptr, isI8, isInt, isFP)
 
@@ -57,15 +57,14 @@
 
 #define ICETYPEX8632_TABLE                \
   /* tag,         cvt, sdss, width */     \
-  X(IceType_void, "?",     , "???")       \
-  X(IceType_i1,   "i",     , "byte ptr")  \
-  X(IceType_i8,   "i",     , "byte ptr")  \
-  X(IceType_i16,  "i",     , "word ptr")  \
-  X(IceType_i32,  "i",     , "dword ptr") \
-  X(IceType_i64,  "i",     , "qword ptr") \
+  X(IceType_void, "?", ""  , "???")       \
+  X(IceType_i1,   "i", ""  , "byte ptr")  \
+  X(IceType_i8,   "i", ""  , "byte ptr")  \
+  X(IceType_i16,  "i", ""  , "word ptr")  \
+  X(IceType_i32,  "i", ""  , "dword ptr") \
+  X(IceType_i64,  "i", ""  , "qword ptr") \
   X(IceType_f32,  "s", "ss", "dword ptr") \
   X(IceType_f64,  "d", "sd", "qword ptr") \
-  X(IceType_NUM,  "?",     , "???")       \
 //#define X(tag, cvt, sdss, width)
 
 #endif // SUBZERO_SRC_ICEINSTX8632_DEF
diff --git a/src/IceTargetLoweringX8632.cpp b/src/IceTargetLoweringX8632.cpp
index 8ee5ac9..4b8bf27 100644
--- a/src/IceTargetLoweringX8632.cpp
+++ b/src/IceTargetLoweringX8632.cpp
@@ -101,6 +101,7 @@
 #define X(val, dflt, swap, C1, C2) _tmp_##val,
       FCMPX8632_TABLE
 #undef X
+          _num
     };
 // Define a set of constants based on high-level table entries.
 #define X(tag, str) static const int _table1_##tag = InstFcmp::tag;
@@ -128,6 +129,7 @@
 #define X(val, C_32, C1_64, C2_64, C3_64) _tmp_##val,
       ICMPX8632_TABLE
 #undef X
+          _num
     };
 // Define a set of constants based on high-level table entries.
 #define X(tag, str) static const int _table1_##tag = InstIcmp::tag;
@@ -155,6 +157,7 @@
 #define X(tag, cvt, sdss, width) _tmp_##tag,
       ICETYPEX8632_TABLE
 #undef X
+          _num
     };
 // Define a set of constants based on high-level table entries.
 #define X(tag, size, align, str) static const int _table1_##tag = tag;
@@ -276,14 +279,14 @@
   static IceString RegNames8[] = {
 #define X(val, init, name, name16, name8, scratch, preserved, stackptr,        \
           frameptr, isI8, isInt, isFP)                                         \
-  "" name8,
+  name8,
     REGX8632_TABLE
 #undef X
   };
   static IceString RegNames16[] = {
 #define X(val, init, name, name16, name8, scratch, preserved, stackptr,        \
           frameptr, isI8, isInt, isFP)                                         \
-  "" name16,
+  name16,
     REGX8632_TABLE
 #undef X
   };
@@ -761,6 +764,9 @@
     Operand *Src1Hi = hiOperand(Src1);
     Variable *T_Lo = NULL, *T_Hi = NULL;
     switch (Inst->getOp()) {
+    case InstArithmetic::_num:
+      llvm_unreachable("Unknown arithmetic operator");
+      break;
     case InstArithmetic::Add:
       _mov(T_Lo, Src0Lo);
       _add(T_Lo, Src1Lo);
@@ -979,6 +985,9 @@
     Variable *T_edx = NULL;
     Variable *T = NULL;
     switch (Inst->getOp()) {
+    case InstArithmetic::_num:
+      llvm_unreachable("Unknown arithmetic operator");
+      break;
     case InstArithmetic::Add:
       _mov(T, Src0);
       _add(T, Src1);
diff --git a/src/IceTypes.def b/src/IceTypes.def
index fc48b9d..3faa5f5 100644
--- a/src/IceTypes.def
+++ b/src/IceTypes.def
@@ -26,7 +26,6 @@
   X(IceType_i64,  8,    1,     "i64")              \
   X(IceType_f32,  4,    4,     "float")            \
   X(IceType_f64,  8,    8,     "double")           \
-  X(IceType_NUM,  0,    0,     "<invalid>")        \
 //#define X(tag, size, align, str)
 
 #endif // SUBZERO_SRC_ICETYPES_DEF
diff --git a/src/IceTypes.h b/src/IceTypes.h
index 21c399d..a919465 100644
--- a/src/IceTypes.h
+++ b/src/IceTypes.h
@@ -24,6 +24,7 @@
 #define X(tag, size, align, str) tag,
   ICETYPE_TABLE
 #undef X
+      IceType_NUM
 };
 
 enum TargetArch {