Week 04 Laboratory Exercises

In the files for this lab, you have been given grade.s, a MIPS assembler program which reads a number and always prints FL:

1092 mipsy grade.s
Enter a mark: 100
FL

Add code to grade.s to make it equivalent to this C program:

// read a mark and print the corresponding UNSW grade

#include <stdio.h>

int main(void) {
    int mark;

    printf("Enter a mark: ");
    scanf("%d", &mark);

    if (mark < 50) {
        printf("FL\n");
    } else if (mark < 65) {
        printf("PS\n");
    } else if (mark < 75) {
        printf("CR\n");
    } else if (mark < 85) {
        printf("DN\n");
    } else {
        printf("HD\n");
    }

    return 0;
}

For example:

1092 mipsy grade.s
Enter a mark: 42
FL
1092 mipsy grade.s
Enter a mark: 72
CR
1092 mipsy grade.s
Enter a mark: 89
HD

When you think your program is working, you can use autotest to run some simple automated tests:

1092 autotest grade 

When you are finished working on this exercise, you must submit your work by running give:

give dp1092 lab04_grade grade.s

You must run give before Monday 28 September 09:00 (2026-09-28 09:00:00) to obtain the marks for this lab exercise. Note that this is an individual exercise, the work you submit with give must be entirely your own.

In the files for this lab, you have been given a MIPS assembler program count.s, which reads a number and prints 42:

1092 mipsy count.s
Enter a number: 13
42

Add code to count.s to make it equivalent to this C program:

// read a number n and print the integers 1..n one per line

#include <stdio.h>

int main(void) {
    int number, i;

    printf("Enter a number: ");
    scanf("%d", &number);

    i = 1;
    while (i <= number) {
        printf("%d\n", i);
        i = i + 1;
    }

    return 0;
}

For example:

1092 mipsy count.s
Enter a number: 4
1
2
3
4
1092 mipsy count.s
Enter a number: 10
1
2
3
4
5
6
7
8
9
10

When you think your program is working, you can use autotest to run some simple automated tests:

1092 autotest count 

When you are finished working on this exercise, you must submit your work by running give:

give dp1092 lab04_count count.s

You must run give before Monday 28 September 09:00 (2026-09-28 09:00:00) to obtain the marks for this lab exercise. Note that this is an individual exercise, the work you submit with give must be entirely your own.

In the files for this lab, you have been given seven_eleven.s, a MIPS assembler program which reads a number and prints 42:

1092 mipsy seven_eleven.s
Enter a number: 13
42

Add code to seven_eleven.s to make it equivalent to this C program:

// Read a number and print positive multiples of 7 or 11 < n

#include <stdio.h>

int main(void) {
    int number, i;

    printf("Enter a number: ");
    scanf("%d", &number);

    i = 1;
    while (i < number) {
        if (i % 7 == 0 || i % 11 == 0) {
            printf("%d\n", i);
        }
        i = i + 1;
    }

    return 0;
}

For example:

1092 mipsy seven_eleven.s
Enter a number: 15
7
11
14
1092 mipsy seven_eleven.s
Enter a number: 42
7
11
14
21
22
28
33
35

When you think your program is working, you can use autotest to run some simple automated tests:

1092 autotest seven_eleven 

When you are finished working on this exercise, you must submit your work by running give:

give dp1092 lab04_seven_eleven seven_eleven.s

You must run give before Monday 28 September 09:00 (2026-09-28 09:00:00) to obtain the marks for this lab exercise. Note that this is an individual exercise, the work you submit with give must be entirely your own.

In the files for this lab, you have been given a MIPS assembler program sequence.s, which reads a number and prints 42:

1092 mipsy sequence.s
Enter the starting number: 13
42

Add code to sequence.s to make it equivalent to this C program:

// Read three numbers `start`, `stop`, `step`
// Print the integers bwtween `start` and `stop` moving in increments of size `step`

#include <stdio.h>

int main(void) {
    int start, stop, step;

    printf("Enter the starting number: ");
    scanf("%d", &start);

    printf("Enter the stopping number: ");
    scanf("%d", &stop);

    printf("Enter the step size: ");
    scanf("%d", &step);

    if (stop < start) {
        if (step < 0) {
            for (int i = start; i >= stop; i += step) {
                printf("%d\n", i);
            }
        }
    }

    if (stop > start) {
        if (step > 0) {
            for (int i = start; i <= stop; i += step) {
                printf("%d\n", i);
            }
        }
    }

    return 0;
}

For example:

1092 mipsy sequence.s
Enter the starting number: 1
Enter the stopping number: 10
Enter the step size: 2
1
3
5
7
9
1092 mipsy sequence.s
Enter the starting number: 1
Enter the stopping number: -10
Enter the step size: -2
1
-1
-3
-5
-7
-9

When you think your program is working, you can use autotest to run some simple automated tests:

1092 autotest sequence 

When you are finished working on this exercise, you must submit your work by running give:

give dp1092 lab04_sequence sequence.s

You must run give before Monday 28 September 09:00 (2026-09-28 09:00:00) to obtain the marks for this lab exercise. Note that this is an individual exercise, the work you submit with give must be entirely your own.

You have been given mips_calculator_if.s, a MIPS assembler program that reads two integers and an operation number.

Add code to mips_calculator_if.s to make it equivalent to this C program:

#include <stdio.h>

int main(void) {
    int first;
    int second;
    int operation;
    int result;

    scanf("%d", &first);
    scanf("%d", &second);
    scanf("%d", &operation);

    if (operation == 1) {
        result = first + second;
        printf("Result: %d\n", result);
    } else if (operation == 2) {
        result = first - second;
        printf("Result: %d\n", result);
    } else if (operation == 3) {
        result = first * second;
        printf("Result: %d\n", result);
    } else if (operation == 4) {
        if (second == 0) {
            printf("Cannot divide by zero\n");
        } else {
            result = first / second;
            printf("Result: %d\n", result);
        }
    }

    return 0;
}

The operation is represented by a number:

1 = addition
2 = subtraction
3 = multiplication
4 = integer division

For example:

1092 mipsy  -f mips_calculator_if.s
8
3
1
Result: 11

1092 mipsy  -f mips_calculator_if.s
8
3
4
Result: 2

When you think your program is working, you can use autotest to run some simple automated tests:

1092 autotest mips_calculator_if 

When you are finished working on this exercise, you must submit your work by running give:

give dp1092 lab04_mips_calculator_if mips_calculator_if.s

You must run give before Monday 28 September 09:00 (2026-09-28 09:00:00) to obtain the marks for this lab exercise. Note that this is an individual exercise, the work you submit with give must be entirely your own.