Computing Machinery I
Assignment 2
Integer Multiplication using Add and Shift Operations
Create an ARMv8 assembly language program that implements the following integer multiplication program:
include stdio.h
define FALSE 0
define TRUE 1
int main
int multiplier, multiplicand, product, i, negative;
long int result, temp1, temp2;
Initialize variables
multiplicand 16843010;
multiplier 70;
product 0;
Print out initial values of variables
printfmultiplier 0x08x d multiplicand 0x08x dnn,
multiplier, multiplier, multiplicand, multiplicand;
Determine if multiplier is negative
negative multiplier 0 ? TRUE : FALSE;
Do repeated add and shift
for i 0; i 32; i
if multiplier 0x1
product product multiplicand;
Arithmetic shift right the combined product and multiplier
multiplier multiplier 1;
if product 0x1
multiplier multiplier 0x80000000;
else
multiplier multiplier 0x7FFFFFFF;
product product 1;
Adjust product register if multiplier is negative
if negative
product product multiplicand;
Print out product and multiplier
printfproduct 0x08x multiplier 0x08xn,
product, multiplier;
Combine product and multiplier together
temp1 long intproduct 0xFFFFFFFF;
temp1 temp1 32;
temp2 long intmultiplier 0xFFFFFFFF;
result temp1 temp2;
Print out 64bit result
printf64bit result 0x016lx ldn, result, result;
return 0;
Be sure to use 32bit registers for variables declared using int, and 64bit registers for variables declared using long int. Use m4 macros to name the registers to make your code more readable. Name the program assign2a.asm. Optimize your code so that it uses as few instructions as possible.
Also run the program in gdb, displaying the contents of key registers as the program executes; you should show that the algorithm is working as expected. Capture the gdb session using the Unix command script and name the output file script.txt.
Create a second version of the program called assign2b.asm that uses 522133279 for the multiplicand, and 200 for the multiplier. Also create a third version of the program called assign2c.asm that uses 252645136 for the multiplicand, and 256 for the multiplier.
Other Requirements
Make sure your code is properly formatted into columns, is readable and fully documented, and includes identifying information at the top of each file. You must comment each line of assembly code. Your code should also be well designed: make sure it is well organized, clear, and concise.
New Skills Needed for this Assignment:
Use of bitwise logical and shift operations
Use of branching and condition code tests
Understanding of hexadecimal and binary numbers
Submit the following:
Your assembly source code files for the 3 programs, and your script output file. Use the Assignment 2 Dropbox Folder in D2L to submit electronically. The TA will assemble and run your programs to test them. Be sure to name your programs and script file as described above.
Computing Machinery I
Assignment 2 Grading
Student:
Functionality:
Correct calculation of product 4
Use of bit masking 6
Use of shift instructions 3
Display to screen 3
Optimization 3
Script showing gdb session 3
Complete documentation and commenting 4
Formatting use of columns and white space 4
Design quality 2
Version 2 2
Version 3 2
Total 36