Question

Q: Given the following 3-address code

1: a = 1
2: b = 2
3: c = a + b
4: d = c - a
5: if( d < 20 ) goto 11
6: d = b * d
7: if( d > 20 ) goto 11
8: d = a + b
9: e = e + 1
10: goto 6
11: b = a + b
12: e = c - a
13: if( e < d ) goto 3
14: a = b * d
15: b = a – d



(a) What are the basic blocks for the code segment?


(b) Draw the control flow graph (CFG) for the code once you have determined the basic block.



Given the following 3-address code

1: a = 1
2: b = 2
3: c = a + b
4: d = c - a
5: if( d < 20 ) goto 11
6: d = b * d
7: if( d > 20 ) goto 11
8: d = a + b
9: e = e + 1
10: goto 6
11: b = a + b
12: e = c - a
13: if( e < d ) goto 3
14: a = b * d
15: b = a – d



(a) What are the basic blocks for the code segment?


(b) Draw the control flow graph (CFG) for the code once you have determined the basic block.