I$\text{'}$m trying to create an assembly language program based off this java program that calculates the $0$s in a $32-$bit positive integer. I have to do it in MIPSzy which is a limited form of MIPS. MIPSzy only allows you to use registers $($$t$0-$$t$6)$ and the following commands: lw$,$sw$,$ addi, add, sub, mul, mult, mflo, beq, bne, slt$,$ j$,$ jal and jr$.$

java code:

public class CountZeroBits $\{$

public static void main$($String$[]$ args$)\{$

Scanner scanner $=$ new Scanner$($System$.$in$)$;

$//$ Input value from the user

System.out.print$("$Enter a $32-$bit positive number: $")$;

int input $=$ scanner.nextInt$()$;

$//$ Call the countZeros method and print the result

int result $=$ countZeros$($input$)$;

System.out.println$("$Number of $0\text{'}$s: $"+$ result$)$;

$\}$

$//$ Function to count the number of $0\text{'}$s in a $32-$bit positive number

static int countZeros$($int num$)\{$

int count $=0$;

for $($int i $=0$; i $<32$; i$++)\{$

if $(($num & $1)==0)\{$

count$++$;

$\}$

num $>>=1$;

$\}$

return count;

$\}$

$\}$

This is what i have so far but something isnt right. This program goes into a simulator where i can put an input value and pull it from $8196.$ The beginning should be accurate. I$\text{'}$m trying to use the repeating subtraction algorithm to calculate how many times you get a remainder $1$ after continuously subtracting $2$ from the input in order to calculate the total number of $0$s$.$ In the example using $10.$ I should be subtracting $2$ from $10$ until it gets to $0,$ the counter should go to $5.2$ should then be subtracted from $5$ until you get to $1.$ a remainder counter should increase, then you subtract $2$ from $1$ which should give you technically another remainder which leaves you with a total of $2.$ then subtract $2$ from $32$ to give you $30$ total $0$s for $10.$

addi $t$0,$ $zero, $8200$ # Output location

BegLoop:

addi $t$6,$ $zero, $8192$ # Check if input ready

lw $t$5,0($$t$6)$

beq $t$5,$ $zero, NoInput # If no input, exit loop

addi $t$6,$ $zero, $8196$ # Input location

lw $t$1,0($$t$6)$ # Load input number

addi $t$2,$ $zero, $0$ # Initialize counter for times $2$ subtracted

addi $t$3,$ $zero, $0$ # Initialize counter for remainders

addi $t$4,$ $zero, $2$ # Initialize $2$ for subtraction

Loop:

slt $t$5,$ $t$1,$ $t$4$ # Check if input is less than $2$

beq $t$5,$ $zero, SubtractTwo # If not less, continue subtracting

NoInput:

addi $t$0,$ $zero, $32$ # Load $32$ into $t$0$ for addition

add $t$0,$ $t$0,$ $t$3$ # Add remainder count to $32$

sw $t$0,0($$t$0)$ # Output count of $0$ bits to memory location $8200$

j BegLoop # Restart loop for next input

SubtractTwo:

sub $t$1,$ $t$1,$ $t$4$ # Subtract $2$ from input

addi $t$2,$ $t$2,1$ # Increment counter for times $2$ subtracted

slt $t$5,$ $t$1,$ $zero # Check if input is negative

beq $t$5,$ $zero, Loop # If not negative, continue subtracting

addi $t$3,$ $t$3,-1$ # Decrement counter for remainders

j SubtractTwo # Continue subtracting $2$ until reaching $0$ or $1$