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;
}
