return MIR_Move.create(PPC_MOVE, L(lhs), L(rhs));
  final OPT_Instruction makeMoveInstruction(OPT_Register lhs,                                             OPT_Register rhs) {    if (rhs.isFloatingPoint() && lhs.isFloatingPoint()) {      return MIR_Move.create(PPC_FMR, D(lhs), D(rhs));    } else if (rhs.isInteger() && lhs.isInteger()) { // integer      return MIR_Move.create(PPC_MOVE, R(lhs), R(rhs));    } else      throw new OPT_OptimizingCompilerException("RegAlloc",                                                 "unknown register:",                                                 lhs.toString());  }