Computer Systems Fundamentals

#include <stdio.h>

int main(void) {
    int x = 17;
    int y = 25;
    printf("%d\n", x + y);

    return 0;
}

#include <stdio.h>

int main(void) {
    int x, y, z;
    x = 17;
    y = 25;
    z = x + y;
    printf("%d", z);
    printf("\n");
    return 0;
}

main:                    #  x, y, z in $t0, $t1, $t2,
    li   $t0, 17         # x = 17;

    li   $t1, 25         # y = 25;

    add  $t2, $t1, $t0   # z = x + y

    move $a0, $t2        # printf("%d", a0);
    li   $v0, 1
    syscall

    li   $a0, '\n'       # printf("%c", '\n');
    li   $v0, 11
    syscall

    li   $v0, 0          # return 0
    jr   $ra

#include <stdio.h>

int main(void) {
    int x;

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

    if ((x & 1) == 0) {
        printf("Even\n");
    } else {
        printf("Odd\n");
    }

    return 0;
}

#include <stdio.h>

int main(void) {
    int x, v0;

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

    v0 = x & 1;
    if (v0 == 1) goto odd;
        printf("Even\n");
    goto end;
odd:
        printf("Odd\n");
end:
    return 0;
}

main:
    la   $a0, string0    # printf("Enter a number: ");
    li   $v0, 4
    syscall

    li   $v0, 5          # scanf("%d", x);
    syscall

    and  $t0, $v0, 1     # if (x & 1 == 0) {
    beq  $t0, 1, odd

    la   $a0, string1    # printf("Even\n");
    li   $v0, 4
    syscall

    b end

odd:                     # else
    la   $a0, string2    # printf("Odd\n");
    li   $v0, 4
    syscall

end:
    li   $v0, 0          # return 0
    jr   $ra

    .data
string0:
    .asciiz "Enter a number: "
string1:
    .asciiz "Even\n"
string2:
    .asciiz "Odd\n"

#include <stdio.h>

int main(void) {
    for (int i = 1; i <= 10; i++) {
        printf("%d\n", i);
    }
    return 0;
}

#include <stdio.h>

int main(void) {
    int i;
    i = 1;
loop:
    if (i > 10) goto end;
        i++;
        printf("%d", i);
        printf("\n");
    goto loop;
end:
    return 0;
}

main:                 # int main(void) {
                      # int i;  // in register $t0

    li    $t0, 1      # i = 1;

loop:                 # loop:
    bgt  $t0, 10 end  # if (i > 10) goto end;

    move $a0, $t0     #   printf("%d" i);
    li   $v0, 1
    syscall

    li   $a0, '\n'      # printf("%c", '\n');
    li   $v0, 11
    syscall

    add  $t0, $t0 1   #   i++;

    b    loop         # goto loop;

end:
    li   $v0, 0       # return 0
    jr   $ra

#include <stdio.h>

int main(void) {
    int sum = 0;

    for (int i = 0; i <= 100; i++) {
        sum += i * i;
    }

    printf("%d\n", sum);

    return 0;
}

#include <stdio.h>

// sum of first 100 squares.

int main(void) {
    int i, sum, t3;

    sum = 0;
    i = 0;
    loop:
       if (i > 100) goto end;
       t3 = i * i;
       sum = sum + t3;
       i = i + 1;
    goto loop;

end:
    printf("%d", sum);
    printf("\n");

    return 0;
}

main:
    li  $t0, 0          # sum = 0;
    li  $t1, 0          # i = 0

loop:
    bgt $t1, 100 end    # if (i > 100) goto end;
    mul $t3, $t1, $t1   # t3 = i * i;
    add $t0, $t0, $t3   # sum = sum + t3;

    add $t1, $t1, 1     # i = i + 1;
    b   loop

end:
    move $a0, $t0      # printf("%d", sum);
    li   $v0, 1
    syscall

    li   $a0, '\n'      # printf("%c", '\n');
    li   $v0, 11
    syscall

    li   $v0, 0         # return 0
    jr   $ra