Homework 3 MIPS Instruction Set and Matrix Multiplication in MIPS

CSCI 2500 — Computer Organization
Homework 3 (document version 1.2)
ˆ This homework is to be completed individually. Do not share your code with anyone else.
ˆ You must use MIPS for the programming portion of homework assignment, and your code
must successfully execute on Submitty to obtain full credit.
ˆ Please put all of your MIPS code into the single hw3.s source file.
Homework Specifications
For this individual homework assignment, you will work on a mixture of textbook problems and
MIPS code.
First, start with some “warm-up” exercises, which you will not submit as part of this assignment.
In other words, do these “warm-up” exercises as practice and to prepare to work on the actual
problems you will submit for credit.
Warm-Up Exercises (for Practice)
1. Textbook Problem 2.7
2. Textbook Problem 2.15
3. Textbook Problem 2.24
Homework Problems (to Submit for Credit)
Use whatever software you like to write your answers to the textbook problems below. You must
produce a PDF to submit for this assignment. Please name your PDF hw3.pdf. These will be
manually graded by our TAs.
1. Textbook Problem 2.8
2. Textbook Problem 2.16
3. Textbook Problem 2.18 (all sub-parts)
4. Textbook Problem 2.25 (all sub-parts)
Coding Problem (to Submit for Credit)
Implement matrix multiplication, this time using MIPS. More specifically, you will read in two
matrices from the user and multiply them together. As with Homework 1, if you need a refresher
in how matrix multiplication works, look in a math textbook or check out Wikipedia!
The first matrix is an n × k matrix, while the second matrix is a k × m matrix. Therefore, the
result will be an n × m matrix. Use the read_int system call (syscall) to read in n, k, and m,
as well as each unsigned integer matrix value.
One approach you could take is to store these important values in your .data section as follows
(with sample hard-coded values shown):
.data
n: .word 4
k: .word 3
m: .word 4
Once you have your matrix sizes defined, dynamically allocate memory to store the actual matrices.
This would be equivalent to calling malloc() or calloc() in C to allocate memory on the heap.
And remember that each integer is one word (or four bytes) in size.
Example Program Execution
On the next page is an example MIPS program execution that you can use to better understand
how your program should work, how you can test your code, and what output formatting to use
for Submitty. Also use test cases from Homework 1 to test your MIPS code.
Note that you must input each value on a separate line in MIPS. And you can assume that the
input given to your program is valid.
When displaying a matrix, each line must start with ‘[’ and end with ‘]’ (as with Homework 1),
but in this assignment, left justify the columns by using TAB (‘\t’) characters as follows:
[12\t34\t5567\t]
[8\t9\t123\t]
[45\t67\t8\t]
[9\t10\t11\t]
This will display this 4 × 3 matrix as follows:
[12 34 5567 ]
[8 9 123 ]
[45 67 8 ]
[9 10 11 ]
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(spim) load "hw3.s"
(spim) run
Please enter values for n, k, and m:
4
3
4
Please enter values for the first matrix (4x3):
10
20
30
40
50
60
70
80
90
100
110
120
Please enter values for the second matrix (3x4):
0
10
0
20
30
0
40
0
0
50
0
60
[10 20 30 ]
[40 50 60 ]
[70 80 90 ]
[100 110 120 ]
multiplied by
[0 10 0 20 ]
[30 0 40 0 ]
[0 50 0 60 ]
equals
[600 1600 800 2000 ]
[1500 3400 2000 4400 ]
[2400 5200 3200 6800 ]
[3300 7000 4400 9200 ]
(spim)
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Error Checking
Given the complexity of this assignment, you can assume that all input values are valid unsigned
integers. You can also assume that the correct number of values is given for each matrix. In other
words, you do not need to validate the user input.
Submission Instructions
For this assignment, you will submit both your code and your PDF (i.e., hw3.pdf) with your
answers to the textbook problems to submit.
Before you submit your code, be sure that you have clearly commented your code (this should not
be an after-thought). Further, your code should have a clear and logical organization. Use registers
appropriately, and create reusable procedures (just be sure to manage the stack properly).
To submit your assignment (and also perform final testing of your code), please use Submitty.
Please put all of your MIPS code into the single hw3.s source file.
Note that the test cases for this assignment will be available on Submitty a few days before the
due date and will include hidden test cases.
Also as a reminder, your code must successfully execute on Submitty to obtain credit for this
assignment.
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