s.insertBefore(MIR_UnaryAcc.create(IA32_FFREE,D(f)));
s.insertBefore(MIR_Nullary.create(IA32_FFREE,D(f)));
  private static void expandFClear(OPT_Instruction s, OPT_IR ir) {    int nSave = MIR_UnaryNoRes.getVal(s).asIntConstant().value;    int fpStackHeight = ir.MIRInfo.fpStackHeight;    OPT_PhysicalRegisterSet phys = ir.regpool.getPhysicalRegisterSet();    for (int i=nSave; i<fpStackHeight; i++) {      OPT_Register f = phys.getFPR(i);      s.insertBefore(MIR_UnaryAcc.create(IA32_FFREE,D(f)));    }    // Remove the FCLEAR.    s.remove();  }