GATE | GATE-CS-2014-(Set-3) | Question 44

Consider the basic block given below.

  a = b + c
  c = a + d
  d = b + c
  e = d - b
  a = e + b 

The minimum number of nodes and edges present in the DAG representation of the above basic block respectively are
(A) 6 and 6
(B) 8 and 10
(C) 9 and 12
(D) 4 and 4

Answer: (A)
Explanation: Simplifying the given equations :


d = b + c (given) e = d – b (given)
=> d = b + c and e = c


e = d – b (given) a = e + b (given)
=> a = d

Thus, the given DAG has 6 nodes and 6 edges.

Please comment below if you find anything wrong in the above post.

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