Question

Write a program in MIPS assembly language that implements the DESCENDING bubble sort algorithm to sort a variable-sized array of signed 32-bit integers (words)that are read from the console. Be reminded that in a descending sort, the integers are sorted from the largest to the smallest. A “special value” 99999 will beused to signify the end of the input sequence. This value is not to be considered part of the input data set. However, any value greater than 99999 that is enteredprior to 99999 is considered as a valid input. Zero and negative values are also valid. Empty input sets are also valid. Your program must ask the user if he/shewants to input and sort another array of integers after finishing one round of input and sorting. If yes, then repeat the sort algorithm for the inputs. Use thefollowing algorithm, shown in Java-like syntax:

n=0;

read in;
while in != 99999 {
vals[n]=in;
n++;
read in;
}

for (i=0;i<n-1;i++) {
for (j=0;j<n-1;j++) {
if (vals[j] < vals[j+1]) {
// swap

temp=vals[j];
vals[j]=vals[j+1];
vals[j+1]=temp;
} } }

for (i=0;i<n;i++) {
print vals[i] }
// ask user if he wants to sort another sequence.
Use the following line to set up memory to hold the input:
.data
vals: .space 4000


Important Notes:

1. Program must compile
2. Test cases: Input
i. A descending sorted list
ii. An ascending sorted list
iii. Integers greater than 99999
iv. Negative numbers
v. Mixed- negative and positive
vi. The termination character 99999 is not part of output in any of the above cases
vii. Program asks for a new round of input and sorting.

Answer 1

.data
vals: .space 4000
message1: .asciiz "Enter an integer: 9999 to exit n"
message2: .asciiz "The array contains the following: n"
next_line: .asciiz "n"

.text
.globl main
main:

la $a1, vals # $a1 is the base address of the array
li $a2, 9 # $a2 = 9;

li $t0, 0 # i = 0;
li $t1,9999
loop:
# cout << message1 << endl;
la $a0, message1
li $v0, 4
syscall
li $v0, 5
syscall
beq $v0,$t1,sort
addi $t0,$t0,4
sw $v0, ($a1)
addi $a1, $a1, 4 # move the array over by 1 element
j loop

sort:

la $t4, vals #t0 is number up to outter loop
la $t1, vals #t1 is number comparing to inner loop
addi $t1,$t1,4
la $t8,vals
add $t8,$t0,$t8
la $t9,vals
add $t9,$t0,$t9
addi $t9,$t9,-4
loops: lw $t2,($t4) #get number 1 outter loop
lw $t3,($t1) #get number 2 inner loop
blt $t2,$t3,next #don't need to swap
sw $t3,($t4) #swap
sw $t2,($t1)
next: addi $t1,$t1,4
blt $t1,$t8,loops #inner loop done?
addi $t4,$t4,4 #yes-increment outter loop
move $t1,$t4
addi $t1,$t1,4
blt $t4,$t9,loops #outter loop done?

printArray:
la $a1,vals

la $a0, message2
li $v0, 4
syscall
loop1:
blez $t0, done
li $v0, 1
lw $a0, 0($a1)
syscall
la $a0, next_line
li $v0, 4
syscall
addi $a1, $a1, 4
addi $t0, $t0, -4
j loop1
done:
j done