Exercise 9.

Consider the following three-address code program (where a quo 2 denotes the quotient in the Euclidean division of a by 2 and a mod b denotes the remainder in the Euclidean division of a by b)

L0:	a := 10
	if a = 2 goto L6
L1:	b := 2
L2:	d := a / 2
	c := a mod b
	if c = 0 goto L5
L3:	if b >= d goto L6
L4:	b := b + 1
	goto L2
L5:	a := a + 1
	goto L1
L6:	p := a

1. Draw a control-flow graph for this program.
2. Identify the loops of this control-flow graph.
3. Indicate the set of live variables at the exit of each basic block. You can give these data-flow sets without any justification.

Note that no optimizations is required in this exercise.

Answer 9