if (VM.VerifyAssertions) VM.assert(false);
if (VM.VerifyAssertions) VM._assert(false);
  private OPT_SpaceEffGraphNode regTrueParent(OPT_SpaceEffGraphNode n) {    for (OPT_SpaceEffGraphEdge out = n.firstOutEdge(); 	 out != null; 	 out = out.getNextOut()) {      if (OPT_DepGraphEdge.isRegTrue(out)) {	return out.toNode();      }    }    if (VM.VerifyAssertions) VM.assert(false);    return null;  }