How to store the input correctly in MIPS? - mips

Although I have try to input different value ,but the Qtspim still print out the value"0" and the input is also not saved in the register ,I try to find the answer in internet,but it seem like no one have face this problem before.I do it work for 4hrs, I FEEL very frustrated with this.
here is my code ,I try to define whether the input is prime number or not.
# Power program
# ----------------------------------
# Data Segment
.data
request: .asciiz "Enter an integer:"
Yes: .asciiz " is a prime number.\n"
No: .asciiz " is not a prime number\n."
End: .asciiz"End!\n"
Key: .word -1
One: .word 1
# ----------------------------------
# Text/Code Segment
.text
.globl main
main:
lw $t1,One
add $s2,$zero,$zero
lw $s3,One
lw $s0,Key
add $s5,$zero,$zero
j power # call the function power
li $v0, 10 # call code for exit
syscall # system call
.end main
.globl power
power:
j power_loop
power_loop:
la $a0, request # load string request in memory to $a0
li $v0, 4 # print out the string
syscall #prevent Memory address out of bounds
li $v0, 5
syscall
move $s7,$v0
beq $s7, $s0, exit_L #when input =-1 exit
j Prime #otherwise go to define the input whether prime num
Prime:
beq $s7,$t1,result
div $s7,$t1
mthi $t4
beq $t4,$zero,count
addi $t1,$t1,1
j Prime
count: #counting the number of factors
addi $s2,1
addi $t1,$t1,1
result: addi $t1,$zero,1
bne $s2,$s3,resultNo
beq $s2,$s3,resultYes
resultYes: li $v0,1
move $a0,$s7
syscall
add $s2,$zero,$zero
la $a0,Yes
li $v0,4
syscall
j power_loop
resultNo: li $v0,1
move $a0,$s7
syscall
add $s2,$zero,$zero
la $a0,No
li $v0,4
syscall
j power_loop
exit_L:
la $a0,End
li $v0,4
syscall
jr $ra
.end power

Related

MIPS: how can I apply the integer which users input into arithmetic function?

This is my first time coding PCSPIM. I find that there is a little trouble with my code.
.data
user_input: .asciiz "\n\nEnter an Integer for the value of n: "
result_display: .asciiz "\nThe sum from 0 to n is "
Greeting: .asciiz "\n\nThank you!"
.text
main:
#user input
li $v0, 4
la $a0, user_input
syscall
#allow user input
li $v0, 5
syscall
#store the input value into t8
move $t8, $v0
#calculation
addi $s0, $zero, $t8
I wish to use the integer value ($t8) that users input into the #calculation section, but it ends up with error.
addi $t0, $zero, 0
loop1:
add $t0, $t0, $s0
addi $s0, $s0, -1
bne $s0, $zero, loop1
nop
nop
# Display the result
li $v0, 4
la $a0, result_display
syscall
# Print out the result
li $v0, 1
move $a0, $t0
syscall
# Greets the user
li $v0, 4
la $a0, Greeting
syscall
# Exit the program
li $v0, 10
syscall
Sorry for my broken English.
The error is in the way you are using the "addi" instruction. The instruction requires an immediate (number) value to be passed as the third operand and not an architectural register. If you update the "addi" instruction to "addu" the code should work.

MIPS multiplication using addition

sorry, I try to multiply two integers but it doesn't work. I can't find where the problem is.Maybe because of register' names but I don't know how to correct it. I correct many times but it is not successful. Could anyone give me some points?
.data
prompt1: .asciiz "Please enter the first signed (decimal) integer: "
prompt2: .asciiz "Please enter the second signed (decimal) integer: "
result_msg: .asciiz "The result of these two 16-bit integers\' multiplication is: "
.text
.globl main
main:
li $v0, 4 #print prompt
la $a0, prompt1
syscall
li $v0, 5 #read multiplicand
syscall
move $s0, $v0
li $v0, 4 #print prompt
la $a0, prompt2
syscall
li $v0, 5 #read multiplier
syscall
move $s1, $v0
Mult: ori $t0,$zero,1 #mask
move $s3, $0 #initialize the result register
move $t1, $0
loop: beq $s1, $zero, end #if the multiplier is 0 then finished
and $t1, $t0, $s1 #mask
beq $t1, 1, mult_add
beq $t1, 0, shift
mult_add: addu $s3, $s3, $s0 #add to get product
shift:
sll $s0, $s0, 1 #shift multiplicand left
srl $s1, $s1, 1 #shift multiplier right
j loop
end:
jr $ra
result: #input the print_string
li $v0, 4
la $a0, result_msg
syscall
exit:
li $v0, 1 #input result
move $a0, $s3
syscall
li $v0, 10 #exit
syscall
Inspecting your code I see that you jump to label end when you are done multiplying.
The instruction at that label issues a jr $ra which "returns from a function", but I guess you just want to print the result and exit.
Therefore I'd suggest you remove that instruction so as to print the result and exit and maybe remove label result as it is not used anywhere in your code.

Sum of two numbers in MIPS

I'm trying to practice my coding skill in MIPS (this is my first time ever learning an assembly language). I wrote this code below to sum up two user's inputs, and it is correct. However, the code is quite long..so, is there any way to optimize this code so it will be shorter? i need some suggestions. Thanks
.data
n1: .asciiz "enter your first number: "
n2: .asciiz "enter your second number: "
result: .asciiz "result is "
.text
#getting first input.
la $a0, n1
li $v0, 4
syscall
li $v0, 5
syscall
move $t0, $v0
#getting second input.
la $a0, n2
li $v0, 4
syscall
li $v0, 5
syscall
move $t1, $v0
#calculate and print out the result.
la $a0, result
li $v0, 4
syscall
add $t3, $t0, $t1
move $a0, $t3
li $v0, 1
syscall
#end program.
li $v0, 10
syscall
I also have wrote a program to calculate a factorial number. There are better ways to do this?
.data
str: .asciiz "Enter a number: "
result: .asciiz "The result is: "
.text
la $a0, str
li $v0, 4
syscall
li $v0, 5
syscall
move $s0, $v0 # move N into s0
li $s2, 1 # c = 1
li $s1, 1 # fact = 1
LOOP:
blt $s0, $s2, PRINT # if (n < c ) print the result
mul $s1, $s1, $s2 # fact = fact * c
add $s2, $s2, 1 # c = c + 1
j LOOP
PRINT:
la $a0, result
li $v0, 4
syscall
add $a0, $s1, $zero
li $v0, 1
syscall
li $v0, 10
syscall
The programs look ok, except for the use of the temporary registers $t0,...,$t9. These registers are not guaranteed to be preserved when another function is called, or when a syscall is issued. The $s0,...,$s7 registers are preserved across calls.
You need to replace: move $t0, $v0 with move $s0, $v0; move $t1, $v0 with move $s1, $v0 and add $t3, $t0, $t1 with add $s3, $s0, $s1.

What does the following QtSPIM/MIPS code do

What does the following QtSPIM/MIPS code do. Describe by referring to the functions of various blocks of the code (Block1, Block2, …).
Answer the questions in front of certain instructions.
Block1:
.text
main:
li $s4, 0
la $a0, input
li $v0, 4
syscall
li $v0, 5
syscall
move $t0, $v0 #Why do we need this?
Block2:
la $a0, output
li $v0, 4
syscall
move $a0, $t0
li $v0, 1
syscall
la $a0, newline # How will the output change if newline is replaced by newspace defined as “ “?
li $v0, 4
syscall
Block3:
Do:
move $a0, $s4
li $v0, 1
syscall
la $a0, newline
li $v0, 4
syscall
slt $s1, $s4, $t0
addi $s4, $s4, 1
bgt $s1, $zero, Do # Why can’t we use “beq $s1, 1, Do “?
Block4:
Exit:
li $v0, 10
syscall
.data
input: .asciiz "Input a number: "
output: .asciiz "Let me count till "
newline: .asciiz "\n "
So I need help with identifying what the code does... I have the concept I just want o make sure Im properly figuring this out... So I have this so far:
move $t0, $v0 #Why do we need this? --- to store number in t0
la $a0, newline # How will the output change if newline is replaced by newspace defined as “ “?
--- load address of string to be printed into $a0 and adds the space if replaced by newspace
the last one I cant quite figure out...

Take user input and print a floating point array in MIPS

I need to take input from the user a floating point array and then print it. I tried the following code:-
.text
.globl main
main:
la $s0,size
lw $s1,0($s0) # size in $s1
ori $s2,$zero,0 # i in $s2
la $s3,arr # arr in $s3
li $v0,4
la $a0,msg1
syscall
L1:
beq $s2,$s1,DONE
li $v0,6
syscall
swc1 $f0,0($s3)
j UPDATE
UPDATE:
addi $s3,$s3,4
addi $s1,$s1,1
j L1
DONE:
li $v0,4
la $a0,msg2
syscall
la $t0,arr
ori $t1,$zero,0
L2:
beq $t1,$s1,EXIT
lwc1 $f20,0($t0)
li $v0,2
mov.s $f12,$f20
syscall
addi $t0,$t0,4
addi $t1,$t1,1
j L2
EXIT:
li $v0,10
syscall
.data
size: .word 9
arr: .float 0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0
msg1: .asciiz "Enter the elements:-"
msg2: .asciiz "The elements are:-"
When i give the input, there is a runtime exception 'invalid float input' at syscall 6. Please help!!!
I guess you are using , as the decimal point instead of ..
E.g.: instead of entering 3.14159 you are entering 3,14159 which is not expected at least by MARS.
Aside from that, I think the line addi $s1,$s1,1 in your code should be addi $s2,$s2,1, as you seem to be using $s2 to hold the current value of your index counter.