In MIPS assembly language Write a function named bitcount th

In MIPS assembly language

Write a function named bitcount that returns the number of 1-bit in the input argument that is an unsigned integer (contained in register $a0), and a test driver (main function) to test the function bitcount. The test driver prompts the user for a decimal unsigned integer, calls bitcount and then displays the result. For example, if the user gives 17 as the input, the program displays \"The number of 1-bit is 2\".

Thanks in advance!

Solution

Solution:

.data

msg1: .asciiz \" Please enter the value:\"

msg2: .asciiz \" the number of 1-bit is \"

.text

main:

li $v0,4

la $a0, msg1

jal count_ bit

syscall

li $v0,4 #instruction to print the string

la $a0, msg2

add $t0, $0, $v0

li $v0,1 #instruction to print the integer

li $t0,5

syscall

count_bit: addi $sp, $sp, -8 # instruction to create stack space

sw $ra, 4($sp) # instruction to save return address

sw $s0, 0($sp) # instruction to save $s0

add $v0, $0, $0 # instruction to initialize $v0 to 0

beq $a0, $0, close # instruction to check whether user input suppose n==0, if true,return

andi $s0, $a0, 1 # instruction for bit = n & 0n1

srl $a0, $a0, 1 # instruction to shift right logical, n >> 1

jal count_bit # instruction for recursive call

add $v0, $v0, $s0

close: lw $ra, 4($sp) # instruction to restore $ra

lw $s0, 0($sp) # instruction to restore $s0

addi $sp, $sp, 8 # instruction to restore stack

jr $ra