OPT_Register r = symbolicRegisters[i];
    private void renameSymbolicRegisters(OPT_Register[] symbolicRegisters) {      int n = ir.getNumberOfSymbolicRegisters();      Stack[] S = new Stack[n + 1];      for (int i = 0; i < S.length; i++) {        S[i] = new Stack();        // populate the Stacks with initial names for        // each parameter, and push "null" for other symbolic registers        if (i >= symbolicRegisters.length) continue;        OPT_Register r = symbolicRegisters[i];        // If a register's name is "null", that means the        // register has not yet been defined.        S[i].push(null);      }      OPT_BasicBlock entry = ir.cfg.entry();      OPT_DefUse.clearDU(ir);      numPredProcessed = new int[ir.getMaxBasicBlockNumber()];      search(entry, S);      OPT_DefUse.recomputeSSA(ir);      rectifyPhiTypes();    }