/** * Does the current state of the algorithm optimistically assume that two nodes are congruent? * Note: this can return false even if the value numbers are currently the same. * * @param v1 first vertex * @param v2 second vertex * @return whether the notes are assumed to be congruent */ private boolean checkCongruence(ValueGraphVertex v1, ValueGraphVertex v2) { if (v1 == v2) { return true; } // make sure the two nodes have the same label if (v1.getLabel() != v2.getLabel()) { return false; } // make sure that the operands match int arity = v1.getArity(); for (int i = 0; i < arity; i++) { ValueGraphVertex target1 = v1.getTarget(i); ValueGraphVertex target2 = v2.getTarget(i); // if either target is null, then that particular control // flow path is never realized, so assume TOP if ((target1 == null) || (target2 == null)) { continue; } if (target1.getValueNumber() != target2.getValueNumber()) { return false; } } return true; }