COMP1521 2022T3 Q3 — MIPS control flow

COMP1521 2022T3 Q3 · 10 marks · MIPS
Topic: MIPS control flow · Source: https://cgi.cse.unsw.edu.au/~cs1521/26T1/resources/practice_exams.html

Summary: Read numbers until the sum reaches 42, then print the sum

You have been given 22t3final_q3.s ,
a MIPS assembler program that reads 1 number and then prints it.

Add code to 22t3final_q3.s to make it equivalent to this C program:

// read numbers until their sum is >= 42, print their sum

#include <stdio.h>

int main ( void ) {
int sum = 0 ;
while ( sum < 42 ) {
int x ;
scanf ( "%d" , & x );
sum += x ;
}
printf ( "%d \n " , sum );
return 0 ;
}

In other words, it should read numbers until their sum is ≥ 42 and then print their sum.

For example:

1521 mipsy 22t3final_q3.s
10
20
25
55
1521 mipsy 22t3final_q3.s
20
22
42
1521 mipsy 22t3final_q3.s
100
100
1521 mipsy 22t3final_q3.s
10
10
10
10
10
50

No error checking is required.

Your program can assume its input contains only integers.

Your program can assume these integers sum to ≥at least 42.

Your program should print one and only one line of output.

This line of output should contain one integer, a newline, and nothing else.

You can assume the value of the expression can be represented as a signed 32 bit value.
In other words, you can assume overflow/underflow does not occur.

Your solution must be in MIPS only.

Your solution must not be in C , C++ , Python , or any other language.