inst.insertBefore(MIR_Move.create(IA32_MOV, M, R(r)));
inst.insertBefore(MIR_Move.create(IA32_MOV, M, new OPT_RegisterOperand(r, VM_TypeReference.Int)));
  private void saveVolatiles(OPT_Instruction inst) {    OPT_PhysicalRegisterSet phys = ir.regpool.getPhysicalRegisterSet();    // Save each GPR.     int i = 0;    for (Enumeration e = phys.enumerateVolatileGPRs();         e.hasMoreElements(); i++) {      OPT_Register r = (OPT_Register)e.nextElement();      int location = saveVolatileGPRLocation[i];      OPT_Operand M = new OPT_StackLocationOperand(true, -location, 4);      inst.insertBefore(MIR_Move.create(IA32_MOV, M, R(r)));    }  }