C->do_freq_based_layout()) {     Block_List worklist;     Block* root_blk = get_block(0);     for (uint i = 0; i < root_blk->num_preds(); i++) {       Block *pb = get_block_for_node(root_blk->pred(i));       if (pb->has_uncommon_code()) {         worklist.push(pb);       }     }     while (worklist.size() > 0) {       Block* uct = worklist.pop();       