digraph CFG {
  node [fontname="Helvetica"];
  n931 [label="START", shape=ellipse, style=filled, color=gray];
  n931 -> n939;
  n939 [label="10", shape=box];
  n939 -> n940;
  n940 [label="CALL square", shape=box, style=filled, color=orange];
  n940 -> n933;
  n940 -> n942;
  n933 [label="START square(x)", shape=ellipse, style=filled, color=green];
  n933 -> n936;
  n936 [label="x", shape=box];
  n936 -> n937;
  n937 [label="x", shape=box];
  n937 -> n938;
  n938 [label="x * x", shape=box];
  n938 -> n934;
  n934 [label="END square(x)", shape=ellipse, style=filled, color=green];
  n934 -> n942;
  n942 [label="RET square", shape=box, style=filled, color=orange];
  n942 -> n932;
  n932 [label="END", shape=ellipse, style=filled, color=gray];
}