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. 1
• D. 2

Answer 1

The correct option is D 2

x = (a+b)* (a+b+c)*a+b
$\Downarrow$
3- Address code
$t_1=a+b$
$t_2=t_1+c$
$t_2=t_1\text{*}{t}_2$
$t_2=t_2\text{*}a$
$x=t_2+b$
Only 2 temperory variables are needed.