private Cost computeRefCostSum(LoopHeaderChord loop, Vector<RefGroup> refGroups) { Cost lc = new Cost(); int l = refGroups.size(); for (int i = 0; i < l; i++) { RefGroup rg = refGroups.elementAt(i); SubscriptExpr se = rg.getRepresentative(); Cost cost = computeRefCost(loop, se); if (cost == null) continue; lc.add(cost); } return lc; }