Question

Consider the following 'C' expression

x = (a + b) * (a + b+ c) * a + b;

How many temporary variables (in minimum) are required to generate the equivalent 3-address code for the above expression?

• A. 4
• B. 3
• C. 2
• D. 1

Answer 1

The correct option is D 1

x = (a+ b) * (a + b + c)* a + b

$t_1=a+b$

$c=t_1+c$

$t_1=t_1\ast c$

$t_1=t_1\ast a$

$t_1=t_1+b$

$x=t_1$

Only 1 temporary variable is needed.