I'm currently trying to code a function to divide integers in MIPS. I am supposed to use a division algorithm using this flowchart:
Here is the code that I have created:
.data
.text
main:
addi $a0, $0, 7
addi $a1, $0, 4
jal divide
addi $a0, $v1, 0
addi $v0, $0, 1
syscall
addi $v0, $0, 10
syscall
divide: # $a0/$s0 = Dividend-Remainder / $a1/$s1 = Divisor / $v1 = Quotient
# Initialize
addi $s0, $a0, 0
addi $s1, $a1, 0
addi $t0, $0, 0 # Counter = $t0
addi $t1, $0, 33 # Number of loops = $t1
# Start of loop
start:
# Step 1 : Subtract the divisor register from the remainder register and place in remainder register
sub $s0, $s0, $s1
# Step 2 : Test the remainder register. If < 0 go to part B, otherwise go to part A
addi $t3, $0, 0
slt $t2, $t3, $s0
beq $t2, $zero, partB
# Step 2A : Shift quotient register to the left, and make least significant bit 1
sll $v1, $v1, 1
ori $v1, $v1, 1
j after # Skip step 2B
# Step 2B : Add divisor to remainder and place sum in remainder register
partB:
add $s0, $s1, $s0
# Shift quotient register to left and make least significant bit 0
sll $v1, $v1, 1
after:
# Step 3 : Shift divisor right 1 bit
srl $s1, $s1, 1
# Increment counter
addi $t0, $t0, 1
# Test loop
bne $t0, $t1, start
jr $ra
I've been trying to catch my error but so far I have been unable to find it. When I run the code I get -1073741825 for the output.
Can someone check my logic and tell me what I'm doing wrong?
Related
The Programm compiles just fine but as soon as i give input this error is thrown:
"Error in line 28: Runtime exception at 0x0040002c: address out of range 0x00000001
Processing terminated due to errors."
Here ist the code for my programm:
.data
line: .space 80
.text
main:
# read line from stdin
li $v0, 8
la $a0, line
li $a1, 80
syscall
# call caesar_line
li $a0, 1
jal caesar_line
# return 0
li $v0, 0
jr $ra
caesar_line:
# save start of line
move $t0, $a0
# loop through line
loop:
# load the character from memory
move $t1, $a0
lb $a0, 0($t1)
beqz $a0, end_loop
jal caesar_char
sb $v0, 0($t1)
addi $t1, $t1, 1
move $a0, $t1
j loop
end_loop:
# print line
li $v0, 4
move $a0, $t0
syscall
jr $ra
caesar_char:
# check if c is lowercase
blt $a0, 'a', upper
bgt $a0, 'z', not_alpha
addi $a1, $a1, 'a'
jal caesar_helper
j done
upper:
# check if c is uppercase
blt $a0, 'A', not_alpha
bgt $a0, 'Z', not_alpha
addi $a1, $a1, 'A'
jal caesar_helper
j done
not_alpha:
# not an alphabetical character
move $v0, $a0
j done
caesar_helper:
# subtract base from c
sub $t0, $a0, $a2 # $t0 = c - base
# add distance + 26 to c
addi $t0, $t0, 26 # $t0 += 26
add $t0, $t0, $a1 # $t0 += distance
# calculate c % 26
li $t1, 26 # $t1 = 26
div $t0, $t1 , $t1 # $lo = c % 26
mflo $t0
# add base to c
add $v0, $t0, $a2 # $v0 = c + base
done:
jr $ra
Not even ChatGBT could find an error.
The code should shift all chars of an string by a certain amount, but as soon as it is run the error above is thrown.
Our assignment is to implement a refined bitwise division algorithm in MIPS.
Basically in the refined program, we load the dividend into the LO bits of the 64 bit register and the remainder will accumulate in the HI bits, which are originally all set to 0.
Then we simply test if HI (our remainder) > = divisor.
If our accumulating remainder is not currently > = divisor, we simply left shift the entire register and fill in with a 0. This is the beginning of our quotient. As the dividend bits move into HI, we will finally have a situation where HI > =
divisor. Then we will subtract the divisor from HI, shift the entire register left, and fill in with a 1.
In short, we can simply continue to shift all 64 bits left, filling in with a 0 when HI < divisor, subtracting the divisor from HI and filling in with a 1 when HI > = divisor.
In our homework, we are to write a program to accept two positive numbers (16 bit signed numbers) from the console, divide the former by the latter.
I put the divisor in $t0, the remainder in $t3, and the dividend in $t2. $t3 and $t2 are both 16 bits, and together they pair up to be a 32-bit register. Somehow, my program returns a really funky quotient: the least significant few bits are correct, but the most significant is always 1; somehow I can't get rid of the 1, no matter how many bits I shift left. For instance, if the dividend is 1000, by shifting left, instead of getting 0001 0000, I actually get 10000 - MSB is always 1. Could someone please take a look at my program and give me some suggestions? Thanks a lot!
.data
GETA: .asciiz "Enter Dividend: "
GETB: .asciiz "Enter Divisor: "
QT: .asciiz "Quotient = "
RM: .asciiz "Remainder = "
NL: .asciiz "\n"
.text
main:
li $v0, 4 #Prompt for a dividend
la $a0, GETA
syscall
li $v0, 5 #Read dividend from user
syscall
move $t2, $v0 #dividend in $t2
li $v0, 4 #Prompt for a divisor
la $a0, GETB
syscall
li $v0, 5 #Read divisor from user
syscall
move $t0, $v0 #divisor in $t0
addi $t4, $zero, 17 #counter
j Loop
Loop:
slt $t1, $t3, $t0 #if remainder < divisor, $t1=1
beq $t1, $zero, subroutine #remainder >= divisor, $t1=0
#if remainder < divisor
sll $t3, $t3, 1 #shift remainder by to left by 1
andi $t5, $t2, 32768 #get MSB of $t2
bne $zero, $t5, updateRemainder1 #MSB of $t2 is 1
#MSB of $t2 is 0
sll $t2, $t2, 1 #shift dividend to left by 1
addi $t4, $t4, -1 #decrease counter by 1
bne $zero, $t4, Loop
j Exit
subroutine:
sub $t3, $t3, $t0 #subtract divisor from remainder
sll $t3, $t3, 1 #shift remainder by to left by 1
andi $t5, $t2, 32768 #get MSB of $t2
bne $zero, $t5, updateRemainder2 #MSB of $t2 is 1
#MSB of $t2 is 0
sll $t2, $t2, 1 #shift dividend to left by 1
ori $t2, $t2, 1 #fill in LSB of $t2 with a 1
addi $t4, $t4, -1 #decrease counter by 1
bne $zero, $t4, Loop
j Exit
updateRemainder1:
ori $t3, $t3, 1 #set LSB of remainder to 1
sll $t2, $t2, 1 #shift dividend to left by 1
addi $t4, $t4, -1 #decrease counter by 1
bne $zero, $t4, Loop
j Exit
updateRemainder2:
ori $t3, $t3, 1 #set LSB of remainder to 1
sll $t2, $t2, 1 #shift dividend to left by 1
ori $t2, $t2, 1 #fill in LSB of $t2 with a 1
addi $t4, $t4, -1 #decrease counter by 1
bne $zero, $t4, Loop
j Exit
Exit:
sub $t2, $t2, 524288
li $v0, 4 #print out output line
la $a0, QT
syscall
li $v0, 1 #print out quotient
move $a0, $t2
syscall
li $v0, 4 #print out new line
la $a0, NL
syscall
li $v0, 4 #print out output line
la $a0, RM
syscall
li $v0, 1 #print out remainder
move $a0, $t3
syscall
li $v0, 10
syscall
I have some problem when I'm writing a sorting program in MIPS.
The function of this program is like this: Input 10 integers from keyboard and print them out, then sort them and print the sorted array again.
But the output is different from what I expect, some numbers are not sorted, would someone help me?
.data
str1: .asciiz "Please input integer numbers, maximum 10: \n"
str2: .asciiz "The 10 integer numbers you input are: \n"
str3: .asciiz "The numbers you entered are sorted as: \n"
array: .space 40
space: .asciiz " "
.text
.globl main
main:
la $t6, array #load the address of array into $t6
move $t7, $t6
addi $t7, $t7, 40 #point $t7 to the end of the array
jal readin
la $t6, array
la $a0, str2
li $v0, 4
syscall
jal print1 #print out the array before sort
la $t0, array #put the address of array into $t0
add $t0, $t0, 40 #put $t0 to the end of the array
move $t1, $zero #set $t1 as counter of the outerloop
li $t2, 10 #set $t2 as number of the outerloop
la $t3, array #put the address to $t3
jal innerloop
la $a0, str3
li $v0, 4
syscall
la $t3, array
#move $t7, $t3
#add $t7, $t7, 40
jal print2
li $v0, 10
syscall
innerloop:
lb $t4, 0($t3)
lb $t5, 4($t3)
bgt $t4, $t5, swap
addi $t3, $t3, 4
blt $t3, $t0, innerloop #if $t3 < $t0, keep in the innerloop to check two #neighbor numbers
jal outerloop #jump to outerloop if one round is finished
swap:
sb $t4, 4($t3)
sb $t5, 0($t3)
addi $t3, $t3, 4
#sll $t3, $t3, 2
blt $t3, $t0, innerloop #
jr $ra
outerloop:
la $t3, array
addi $t1, $t1, 1 #add the outerloop counter $t1 by one,
addi $t0, $t0, -1
blt $t1, $t2, innerloop #if $t1 < $t2, keep searching
jr $ra
readin:
la $a0, str1 #print str1
li $v0, 4
syscall
li $v0, 5 #read in the number
syscall
sb $v0, ($t6) #store the number in the array
add $t6, $t6, 4
blt $t6, $t7, readin
jr $ra
print1:
lb $a0, ($t6)
li $v0, 1
syscall
li $a0, 32
li $v0, 11 # syscall number for printing character
syscall
add $t6, $t6, 4
blt $t6, $t7, print1
jr $ra
print2:
lb $a0, ($t3)
li $v0, 1
syscall
li $a0, 32
li $v0, 11 # syscall number for printing character
syscall
add $t3, $t3, 4
blt $t3, $t0, print2
jr $ra
And the result in SPIM is like this:
Please input integer numbers, maximum 10:
44
Please input integer numbers, maximum 10:
11
Please input integer numbers, maximum 10:
33
Please input integer numbers, maximum 10:
22
Please input integer numbers, maximum 10:
66
Please input integer numbers, maximum 10:
55
Please input integer numbers, maximum 10:
99
Please input integer numbers, maximum 10:
77
Please input integer numbers, maximum 10:
88
Please input integer numbers, maximum 10:
24
The 10 integer numbers you input are:
44 11 33 22 66 55 99 77 88 24 The numbers you entered are sorted as:
11 33 22 44 55 66 77 88 24 32
Would someone please explain to me why there is a 32 in the end and why they are not sorted properly?
Hi I have to write a program in MIPS that does a bubble sort and then prints the sorted array and plays a note(s). I am having trouble getting it to execute in Mars and I am wondering what I need to add to my program:
.include "ec2_data.asm" # load values into array
add $s0, $zero, 0x10010000
add $t0, $zero, 0x10010000 #how many times to loop
addi $t1, $zero, 0 #initilize the counter
addi $t2, $zero ,0 #initilize position x
addi $t3, $zero, 4 #initilize position y
lw $s2, $t3($s0) #get second position of $s0=y
LOOP:
addi $t0, $t0, -1 #subtract one from the counter
slt $t4, $s1, $s2 #t4 set to 1 if x > y
beqz $t4, BREAK #if t0 is zero (x<y) we dont' have to sort, so go to break
# sort:
add $t5, $zero, $s1 #temp. stores the value of x in t5
add $s1, $zero, $s2 #moves the value of y into x
add $s2, $zero, $t5 #moves the value of x into y
sw $s1, $t2($s0) #save the new x to register
sw $s2, $t3($s0) #save the new y to register
j BREAK
BREAK:
#in here: check to see if we have reached the end
#if not, increment t2 and t3 by 4 to get the next values and jump back to loop to go again
beq $t0, $zero, END #if we are done with the array, go to end
addi $t2, $t2, 4
addi $t3, $t3, 4
j LOOP #jump back to loop again
END:
li $v0, 1 # print integer
syscall
addi $a0, $0, 0xA # load line code into register
addi $v0, $0, 0xB # print new line
syscall
addi $v0, $zero, 33 # midi out synchronous
addi $a0, $zero, 60 # Middle-C
addi $a1, $zero, 250 # ms
addi $a2, $zero, 120 # some instrument
addi $a3, $zero, 64 # some volume
add $a0, $t7, $zero # load value into $a0
syscall # play note!
addi $t6, $t6, 4 # shift memory location by 32 bits
addi $s1, $s1, 1 # increment counter ++
j loop # loop
Exit:
li $v0, 10 # load exit code
syscall # exit
If by "having trouble getting it to execute", you mean it acts strange with the .include file, then you might not have a required option checked in MARS. Go to the Settings menu and check the box for "Initialize Program Counter to global Main if defined". That seems to be something that has to be in effect for included files to work - and for some reason, it isn't turned on by default.
I'm stuck on an exercise, and am unsure how to proceed. This is the exercise:
Write a MIPS assembly language procedure, Test, that accepts 2 integers as arguments and
returns 0 if the integers are equal, 1 if the first is less than the second, and 2 if the first is greater
than the second.
Write a MIPS assembly language program that reads in 2 integers, calls the procedure Test, then
outputs one of the following messages:
The integers are equal
The first integer is less than the second
The first integer is greater than the second
What would be an example to carry this out? Mips is very confusing to me, as I'm used to Java. Thank you.
EDIT: Here is the program I am using as a foundation, since I am unsure where to start:
.data
str1: .asciiz "Please Enter Integer 1: " # a
str2: .asciiz "Please Enter Integer 2: " # a
str3: .asciiz "The sum is " # a
newline: .asciiz "\n" # g
.text
main: addi $v0, $zero, 4
la $a0, str1
syscall
addi $v0, $zero, 5
syscall
add $s0, $zero, $v0
addi $v0, $zero, 4
la $a0, str2
syscall
addi $v0, $zero, 5
syscall
add $s1, $zero, $v0
L1: beq $s1, $zero, cont
addi $v0, $zero, 1
add $a0, $s0, $zero
addi $s1, $s1, -1
syscall
j L1
cont: addi $v0, $zero, 4
la $a0, newline
syscall
addi $v0, $zero, 10
syscall
jr $ra
To check whether one register's value is smaller than another register's value, we can use the
set-on-less-than instruction, which also has a set-on-less-than-immediate counterpart.
slt $r0, $r3, $r4
()if r3 < r4, r0 is set to 1
else r0 is set to 0
slti $r0, $r3, 10
()if r3 < 10, r0 is set to 1
else r0 is set to 0
slt and slti are similar to beq or bne, however, there are two di fferences. First, they test
whether one value is smaller than another value and, second, they don't branch to some
address, but, instead, set a flag, stored in the fi rst operand.