How could you compute 4 * $8 + $8 ?

Answer:

Multiply $8 by four by shifting left two positions, then add it the original $8 .

Example Program

## slowMult.asm
## 
## Program to calculate 5 * x - 74
##
## Register Use:
##  $8   x
##  $9   result

        .text
        .globl  main

main:
        ori      $8, $0, 12           # put x into $8
        
        sll      $, $,       # $ <—— 4x
        
        addu     $, $, $     # $ = 5x
        
        addiu    $, $,-74         # $ = 5x - 74

## End of file

Here is the program. But, there are a few blanks. Fill in the blanks.

The block of documentation at the top of the source file shows how registers are used in the program. This is an essential part of documentation. Testing and debugging is much easier with such a register use table.

QUESTION 13:

Fill in the blanks to finish the program. Put the result in register $9 .