Implements simple returns and call args for Mips.

src/IceRegistersMIPS32.h

 //===- subzero/src/IceRegistersMIPS32.h - Register information --*- C++ -*-===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
 /// This file declares the registers and their encodings for MIPS32.
 ///
 //===----------------------------------------------------------------------===//
 
 #ifndef SUBZERO_SRC_ICEREGISTERSMIPS32_H
 #define SUBZERO_SRC_ICEREGISTERSMIPS32_H
 
 #include "IceDefs.h"
 #include "IceInstMIPS32.def"
 #include "IceTypes.h"
 
 namespace Ice {
 
 namespace RegMIPS32 {
 
 /// 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, scratch, preserved, stackptr, frameptr, isInt,    \
-          isFP)                                                                \
+          isI64Pair, isFP32, isFP64, isVec128, alias_init)                     \
+                                                                               \
   val,
   REGMIPS32_TABLE
 #undef X
       Reg_NUM,
 #define X(val, init) val init,
   REGMIPS32_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, scratch, preserved, stackptr, frameptr, isInt,    \
-          isFP)                                                                \
+          isI64Pair, isFP32, isFP64, isVec128, alias_init)                     \
+                                                                               \
   Encoded_##val encode,
   REGMIPS32_GPR_TABLE
 #undef X
       Encoded_Not_GPR = -1
 };
 
 // TODO(jvoung): Floating point and vector registers...
 // Need to model overlap and difference in encoding too.
 
 static inline GPRRegister getEncodedGPR(int32_t RegNum) {
   assert(Reg_GPR_First <= RegNum && RegNum <= Reg_GPR_Last);
   return GPRRegister(RegNum - Reg_GPR_First);
 }
 
 } // end of namespace RegMIPS32
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICEREGISTERSMIPS32_H