Practice Problem $35$

Suppose we want to generate assembly code for the following $C$ function:

int shift$\_$left$2\_$rightn$($int $x,$ int $n)$

$\{$

$x<mn\; id="EditorElement\_6048334">2</mn>$;

$xn$;

return $x$;

$146$ Chapter $3$ Machine$-$Level Representation of Programs

The code that follows is a portion of the assembly code that performs the actual

shifts and leaves the final value in register reax. Two key instructions have

been omitted. Parameters $x$ and $n$ are stored at memory locations with offsets

$8$ and $12,$ respectively, relative to the address in register $8$ebp.

movl $12(8$ebp$),8$ecx Get $n$

movl $8(8$ebp$),$ qeax Get $x$

$x<mn\; id="EditorElement\_6047817">2</mn>$

$x>n$

Fill in the missing instructions, following the annotations on the right. The right

shift should be performed arithmetically.