Ullman (Compiler Design) Edition 2 Exercise 6.1 Question 1 (Page No. 362)

Question

Construct the DAG for the expression
$((x + y)-((x + y)\ast(x -y))) + ((x+y)\ast(x-y))$

Answer 1

((x+y)−((x+y)∗(x−y))) and ((x+y)∗(x−y)) expression needed to be added together at the end. So according to me, DAG should be following...

 

Answer 2

DAG for the expression ((x+y)−((x+y)∗(x−y)))+((x+y)∗(x−y))

 

Comments

I think you missed this part "minus from the Top should be connected to multiply" because of this condition ((x+y)−((x+y)∗(x−y)))