In the following code, we have omitted the definitions of constants M and N:

#define M

#define N

int arith$($int x$,$ int y$)\{$

int result $=0$;

result $=$ x$*$M $+$ y$/$N;

return result;

$\}$

We compiled this code for particular values of M and N$.$ The compiler optimized the multiplication and division using the methods discussed in Chaper $2\mathrm{.}3.$ The following is a translation of the generated machine code back into C:

int optarith$($int x$,$ int y$)\{$

int t $=$ x;

x $<<=6$;

x $-=$ t$*1$;

if $($y $<0)$ y $+=15$;