Adds the X8664 register definition.

src/IceRegistersX8664.h

Index: src/IceRegistersX8664.h
diff --git a/src/IceRegistersX8632.h b/src/IceRegistersX8664.h
similarity index 60%
copy from src/IceRegistersX8632.h
copy to src/IceRegistersX8664.h
index 86ace82533abdd46c013f7c8c214f584862084b5..f503c70ef3ca5b126ef740777b9faf8e43e864d6 100644
--- a/src/IceRegistersX8632.h
+++ b/src/IceRegistersX8664.h
@@ -1,4 +1,4 @@
-//===- subzero/src/IceRegistersX8632.h - Register information ---*- C++ -*-===//
+//===- subzero/src/IceRegistersX8664.h - Register information ---*- C++ -*-===//
 //
 //                        The Subzero Code Generator
 //
@@ -7,42 +7,42 @@
 //
 //===----------------------------------------------------------------------===//
 //
-// This file declares the registers and their encodings for x86-32.
+// This file declares the registers and their encodings for x86-64.
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef SUBZERO_SRC_ICEREGISTERSX8632_H
-#define SUBZERO_SRC_ICEREGISTERSX8632_H
+#ifndef SUBZERO_SRC_ICEREGISTERSX8664_H
+#define SUBZERO_SRC_ICEREGISTERSX8664_H
 
 #include "IceDefs.h"
-#include "IceInstX8632.def"
+#include "IceInstX8664.def"
 #include "IceTypes.h"
 
 namespace Ice {
 
-namespace RegX8632 {
+namespace RegX8664 {
 
 // An enum of every register. The enum value may not match the encoding
 // used to binary encode register operands in instructions.
 enum AllRegisters {
-#define X(val, encode, name, name16, name8, scratch, preserved, stackptr,      \
-          frameptr, isI8, isInt, isFP)                                         \
+#define X(val, encode, name, name32, name16, name8, scratch, preserved,        \
+          stackptr, frameptr, isI8, isInt, isFP)                               \
   val,
-  REGX8632_TABLE
+  REGX8664_TABLE
 #undef X
       Reg_NUM,
 #define X(val, init) val init,
-  REGX8632_TABLE_BOUNDS
+  REGX8664_TABLE_BOUNDS
 #undef X
 };
 
 // An enum of GPR Registers. The enum value does match the encoding used
 // to binary encode register operands in instructions.
 enum GPRRegister {
-#define X(val, encode, name, name16, name8, scratch, preserved, stackptr,      \
-          frameptr, isI8, isInt, isFP)                                         \
+#define X(val, encode, name, name32, name16, name8, scratch, preserved,        \
+          stackptr, frameptr, isI8, isInt, isFP)                               \
   Encoded_##val encode,
-  REGX8632_GPR_TABLE
+  REGX8664_GPR_TABLE
 #undef X
       Encoded_Not_GPR = -1
 };
@@ -50,10 +50,10 @@ enum GPRRegister {
 // An enum of XMM Registers. The enum value does match the encoding used
 // to binary encode register operands in instructions.
 enum XmmRegister {
-#define X(val, encode, name, name16, name8, scratch, preserved, stackptr,      \
-          frameptr, isI8, isInt, isFP)                                         \
+#define X(val, encode, name, name32, name16, name8, scratch, preserved,        \
+          stackptr, frameptr, isI8, isInt, isFP)                               \
   Encoded_##val encode,
-  REGX8632_XMM_TABLE
+  REGX8664_XMM_TABLE
 #undef X
       Encoded_Not_Xmm = -1
 };
@@ -62,20 +62,11 @@ enum XmmRegister {
 // to binary encode register operands in instructions.
 enum ByteRegister {
 #define X(val, encode) Encoded_##val encode,
-  REGX8632_BYTEREG_TABLE
+  REGX8664_BYTEREG_TABLE
 #undef X
       Encoded_Not_ByteReg = -1
 };
 
-// An enum of X87 Stack Registers. The enum value does match the encoding used
-// to binary encode register operands in instructions.
-enum X87STRegister {
-#define X(val, encode, name) Encoded_##val encode,
-  X87ST_REGX8632_TABLE
-#undef X
-      Encoded_Not_X87STReg = -1
-};
-
 static inline GPRRegister getEncodedGPR(int32_t RegNum) {
   assert(Reg_GPR_First <= RegNum && RegNum <= Reg_GPR_Last);
   return GPRRegister(RegNum - Reg_GPR_First);
@@ -87,9 +78,10 @@ static inline XmmRegister getEncodedXmm(int32_t RegNum) {
 }
 
 static inline ByteRegister getEncodedByteReg(int32_t RegNum) {
-  assert(RegNum == Reg_ah || (Reg_GPR_First <= RegNum && RegNum <= Reg_ebx));
+  // In x86-64, AH is not encodable when the REX prefix is used; the same
+  // encoding is used for spl. Therefore, ah needs special handling.
   if (RegNum == Reg_ah)
-    return Encoded_Reg_ah;
+    return Encoded_Reg_spl;
   return ByteRegister(RegNum - Reg_GPR_First);
 }
 
@@ -100,13 +92,8 @@ static inline GPRRegister getEncodedByteRegOrGPR(Type Ty, int32_t RegNum) {
     return getEncodedGPR(RegNum);
 }
 
-static inline X87STRegister getEncodedSTReg(int32_t RegNum) {
-  assert(Encoded_X87ST_First <= RegNum && RegNum <= Encoded_X87ST_Last);
-  return X87STRegister(RegNum);
-}
-
-} // end of namespace RegX8632
+} // end of namespace RegX8664
 
 } // end of namespace Ice
 
-#endif // SUBZERO_SRC_ICEREGISTERSX8632_H
+#endif // SUBZERO_SRC_ICEREGISTERSX8664_H