Q. 15 The program below uses six temporary variables a,b,c,d,e, f
a = 1
b = 10
c = 20
d = a+b
e = c+d
f = c+e
b = c+e
e = b+f
d = 5+e
return d+f
Assuming that all operations take their operands from register, what is the
minimum number of registers needed to execute this program without spilling ?
(A) 2
(B) 3
(C) 4
(D) 6
Answer: (B)
Explanation:
