This is a follow up of my previous question which I edited:
How to remove a comma from string input
I managed to fix the infinite loop, and found a way to increment through the string. My code now can, iterate through a string(eg. 123,456) find the address of the "," and stores in $t4.
But what I can't figure out is how to shift all the numbers towards the left to remove the "," from the string(should look like this in the memory 123,456 -> 123456)
I'm using native MIPS instructions. If you could help me out like that, I would really appreciate it.
.globl main
.globl main2
.globl main3
.globl firstNumCountChr
.globl firstNumIncrem
.globl secondNumCountChr
.globl secondNumIncrem
.globl thirdNumCountChr
.globl thirdNumInCrem
.data
prompt1: .asciiz "Enter first number:"
prompt2: .asciiz "Enter second number:"
prompt3: .asciiz "Enter third number:"
.text
# 0x10000000 will store first number
# 0x10000008 will store second number
# 0x10000010 will store third number
main:
#display prompt1
addi $v0, $0, 4
lui $a0, 0x1000
syscall
#Input first number
lui $a0, 0x1000
ori $a0, 0x0000 #reads number into memory(0x10000000)
addi $a1, $0, 8 #7 characters
addi $v0, $0, 8
syscall
#removing comma of first number
add $t1, $0, $0 #$t1 is the counter set to 0
add $t3, $0, 0x2c # 0x2c is acsii of "," in hex
firstNumCountChr:
lb $t2, 0($a0) #load first byte from address in $a0
beq $t2, $0, firstNumRemoveComma #if $t2 == 0 go to firstNumRemoveComma
or $0, $0, $0 #NOP
bne $t2, $t3, firstNumIncrem #branch if symbol doesn't equal ","
or $0, $0, $0
add $t4, $a0, $0 #$t4 will save position of ","
firstNumIncrem:
addi $a0, $a0, 1 #increment address
addi $t1, $t1, 1 #increment counter
j firstNumCountChr #loop
firstNumRemoveComma:
beq $t4, $0, main2 #branch if $t4 == 0 (no comma) to main2
or $0, $0, $0 #NOP
main2:
#display prompt2
addi $v0, $0, 4
lui $a0, 0x1000
addi $a0, $a0, 20
syscall
#inputing second number
lui $a0, 0x1000
ori $a0, 0x0008 #reads number into memory(0x10000008)
addi $a1,$0, 8 #7 characters
addi $v0, $0, 8
syscall
#removing comma of second number
addi $t1, 0 # $t1 is the counter set to 0
add $t3, 0x2c # 0x2c is acsii of "," in hex
secondNumCountChr:
lb $t2, 0($a0) # load first byte from address in $a0
beq $t2, $0, end # if $t2 == 0 go to end
or $0, $0, $0 # NOP
bne $t2, $t3, secondNumIncrem # branch if symbol doesn't equal ","
or $0, $0, $0 # NOP
add $t4, $a0, $0 # $t4 will save position of ","
secondNumIncrem:
addi $a0, $a0, 1 #increment address
addi $t1, $t1, 1 #increment counter
j secondNumCountChr #loop
main3:
#display prompt3
addi $v0, $0, 4
lui $a0, 0x1000
addi $a0, $a0, 41
syscall
#inputting third number
lui $a0, 0x1000
ori $a0, 0x0010 #reads number into memory(0x10000010)
addi $a1, $0, 8 #7 characters
addi $v0,$0, 8
syscall
#removing comma of third number
addi $t1, 0 #$t1 is the counter set to 0
add $t3, 0x2c # 0x2c is acsii of "," in hex
thirdNumCountChr:
lb $t2, 0($a0) #load first byte from address in $a0
beq $t2, $0, end # if $t2 == 0 go to end
or $0, $0, $0
bne $t2, $t3, thirdNumInCrem # branch if symbol doesn't equal ","
or $0, $0, $0
add $t4, $a0, $0 # $t4 will save position of ","
thirdNumInCrem:
addi $a0, $a0, 1 #increment address
addi $t1, $t1, 1 #increment counter
j thirdNumCountChr #loop
end:
add $0, $0, $0
Related
I need to write a program in which the output will be the number of sentences and average number of words. The code is working perfectly for counting the sentences, but for the second task, it doesn't work. I'm using branch if equal with the current char and the register in which I've declared the ascii value for space which is 32. With this code, the output for the average words is the total number of characters from the whole input. I can't understand how it can count every character when the beq is clearly incorrect. (I've also tried with emptySpace: .asciiz " ", but it's not working)
This is what I got so far:
.data
str_input: .space 256
dot: .asciiz "."
msg1: .asciiz "Number of sentences: "
msg2: .asciiz "\nAverage number of words: "
.text
li $v0, 8 #read string
la $a0, str_input #address of str_input vo $a0
li $a1, 256 #256 max
la $a2, dot
lb $a2, 0($a2)
li $a3, 32
syscall
addi $t4, $zero, 0 #counter for words
addi $t5, $zero, 0 #counter for sentences
or $t0, $a0, $zero #$t0 pointer to array
start:
lb $t1, 0($t0) #$t1 current char
beqz $t1, end
jal check
addiu $t0, $t0, 1
j start
chech:
beq $t1, $a2, IsDot
beq $t1, $a3, IsEmptySpace
IsDot:
addi $t5, $t5, 1
jr $ra
IsEmptySpace:
addi $t4, $t4, 1
jr $ra
end:
la $a0, msg1 #address of msg1 in $a0
li $v0, 4 #load string in $v0
syscall
add $a0, $t5, $zero
li $v0, 1
syscall #print number of sentences
addi $t4, $t4, 1 #add the last word
div $t4, $t5 #divide number of words with number of sentences
mflo $t6
la $a0, msg2 #address of msg2
li $v0, 4 #load string in $v0
syscall
add $a0, $t6, $zero
li $v0, 1
syscall
[Solved]
We were tasked with writing a bubble sort in MIPS and printing both the unsorted and sorted arrays
I've written the following code to accomplish this.
But when I go to run it, the original array prints as I would expect
Original Array
[34, 23, -1, -2, 0]
But then it prints this for the sorted array.
Sorted Array
[173496791, 1818324585, 1920090400, 686433, 1919898378]
(the Unicode squares do print)
array: .word 34, 23, -1, -2, 0, 89
length: .word 6
original: .asciiz "Original Array\n"
sorted: .asciiz "\nSorted Array\n"
.text
# main()
main:
la $a2, length
lw $a2, 0($a2) # a2 <= n_element
add $t9, $0, $0 # t9 : counter
la $a1, array # a1 = &array[0]
addi $t0, $0, 0 # for t0=0 to
addi $a2, $a2, -1 # because we do [i+1]
#says prints original array
la $a0, original
li $v0, 4
syscall
#prints array
jal print
#printing the string saying sorted
la $a0, sorted
li $v0, 4
syscall
#after printing original we reset the values?
la $a2, length
lw $a2, 0($a2) # a2 <= n_element
add $t9, $0, $0 # t9 : counter
add $t8, $0, $0 # t10 : counter 2
la $a1, array # a1 = &array[0]
addi $t0, $0, 0 # for t0=0 to
addi $a2, $a2, -1 # because we do [i+1]
#see if that worked it did
li $s0, 1 #boolean swapped = false 0=false 1=true
outerLoop:
beqz $s0, exit #if flag is false exit
li $s0, 0
addi $a1, $a1, 4 # next array offset
addi $t9, $t9, 1 # counter++
move $t8 $0
sub $s2, $a2, $t9
innerLoop:
bge $t8, $s2, exitInner
lw $t7, 0($a1) # t7 = array[i]
lw $t8, 4($a1) # t8 = array[i+1]
ble $t7, $t8, skip #if array[i]<= arr[i+1] skip the swapping
sw $t8, 0($a1) #a[i+1] = a[1]
sw $t7, 4($a1) #a[i] = a[i+1]
li $s0, 1#flag update
skip:
addi $t8, $t8, 1 #count
addi $a1, $a1, 4
j innerLoop
exitInner:
j outerLoop
exit:
la $a2, length
lw $a2, 0($a2) # a2 <= n_element
add $t9, $0, $0 # t9 : counter
addi $a2, $a2, -1 # because we do [i+1]
jal print
j quit#end Program
#print array
print:
lw $t7,0($a1) # t7 = array[i]
lw $t8,4($a1) # t8 = array[i+1]
add $a0, $t7, 0
addi $v0, $0, 1 #print int using system call the value stored in a0
syscall
addi $a0, $0, 0x20 # ascii 0x20 = ' '
addi $v0, $0, 11
syscall
addi $a1, $a1, 4 # next array offset
addi $t9, $t9, 1 # counter++
beq $t9, $a2, return #return to the where we were we were at beforehand
j print
return:
jr $ra
quit:
addi $v0, $0, 10
syscall
I think these are memory locations? I'm not sure why it's printing that as it is because I reset my counter values before trying to print. So the question is. Why am I printing memory locations? if that is what is happening
I was sorting in place so I had to reset the array before the print function.
This is the C code that i have been converted so far. it gives me some error that i have been included in the following code. i don't understand which part is wrong in this c to mips conversion?
char ch[10];
int i;
for (i = 0; i != 10; i++)
ch[i] = ch[i] – 32
.data
.text
li $v0 4
syscall
#$s1 = i, $s0 base address of ch
addi $s1, $0, 0 #i =0
addi $t0, $0, 10 #t0 = 10
loop: beq $t0, $s1, end
add $t1, $s1, $s0
lw $t2, 0($t1)
addi $t2, $t2, -32
sw $t2, 0($t1)
addi $s1, $s1, 1
j loop
end:
My output:
Runtime exception at 0x00400018: address out of range 0x00000000
From the C code you are converting a char type array and in MIPS you should use lb instead of lw.
In order to print out you need a main: label and also you should declare an array like .byte or .space
You should usesyscall 11 to print a character or syscall 4 to print
string.
I have added some of these mentioned above to your code hope it helps.
.data
#ch: .byte 'a','b','c','d','e'
ch: .space 10
.text
main:
li $v0, 8 #read character
li $a1, 10 #load the space
la $a0, ch
syscall
li $v0,11 #print character
syscall
li $v0,10 # exit program
syscall
addi $s1, $0, 0 #i = 0
addi $t0, $0, 10 # $t0 = 10
loop: beq $t0, $s1, end
add $t1, $s1, $s0
lb $t2, ch($t1)
addi $t2, $t2, -32
sb $t2, ch($t1)
addi $s1, $s1, 1
j loop
end:
I am trying to add numbers that are in base 5.
Im supposed to prompt the user for 2 separate base 5 number in the form XXXXXX.XXXXX, and then add them.
My current problem is that I am getting an error when I am loading the last digit into a register, so I can start the calculation.
please help! Thanks
.data
str: .space 13 # XXXXXX.XXXXX hold 12 chars + 0x00
str2: .space 13
sum: .space 14
printstr: .space 13
printstr2: .space 13
printsum: .space 14
message1: .asciiz "Enter a base 5 number A: "
message2: .asciiz "Enter a base 5 number B: "
message3: .asciiz "Sum of A and B: "
newline: .asciiz "\n"
.text
main:
#get number A
li $v0, 4
la $a0, message1
syscall
li $v0, 8
li $a1, 13
la $a0, str
syscall
li $v0, 4
la $a0, newline
syscall
#get number B
li $v0, 4
la $a0, message2
syscall
li $v0, 8
li $a1, 13
la $a0, str2
syscall
li $v0, 4
la $a0, newline
syscall
#pointer to input string A
la $s1, str
addi $s1, $s1, 12
#pointer to input string A
la $s2, str2
addi $s2, $s2, 12
#pointer to sum
la $s3, sum
addi $s3, $s3, 13
#other variables
li $t0, 0 # inital carry is 0
li $t1, 1 # counter for looping through string
li $t2, 5 # base 5
loop:
lb $t3, ($s1) ############################# PROBLEM HERE######
lb $t4, ($s2)
beq $t3, '.', next
beq $t4, '.', next
subi $t3, $t3, 0x30
subi $t4, $t4, 0x30
add $t5, $t3, $t4
add $t5, $t5, $t0
div $t5, $t2
mflo $t0
mfhi $t5
addi $t5, $t5, 0x30
sb $t5, ($s3)
subi $s1, $s1, 1
subi $s2, $s2, 1
subi $s3, $s3, 1
addi $t1, $t1, 1
ble $t1, 13, loop
addi $t0, $t0, 0x30
sb $t0, ($s3)
next:
subi $s1, $s1, 1
subi $s2, $s2, 1
#subi $s3, $s3, 1
addi $t1, $t1, 1
j loop
PRINT: #print the sum
exit:
li $v0, 10
syscall
You set up $s1 to point past str and decrement it backwards. Your loop: termination is the ble $t1,13,loop. When that completes, $s1 is pointing to the start of the .data section (i.e. 0x10010000).
But, then, you "fall through" to next: [probably wrong] and decrement $s1 so it has the value 0x1000ffff. Then, you do j loop so the fetch is now coming from an address one byte below the start of the .data segment (i.e. memory that does not exist)
That's the source of the crash. You probably need a jump inst after the ble to continue on to some other code.
But, also, when you do beq $t3,'.',next you go to next: and decrement both pointers. Unless you restrict your input there is no guarantee that both $s1 and $s2 both point to '.' at the same time, so you only want to decrement one of them. (e.g. suppose you had str: 12.3 and str2: 123.41)
So, you may need some code to align the two numbers with respect to their decimal points beforehand.
I have a trouble. I tried to make a binary search algorithm using recursion in mips assembly, but I have some errors that I don't understand how to solve them.
I have an array of 10 integers and I assume that the array is sorted.
this is my code, I appreciate any help and thanks in advance..
.data
arr: .word 40
arrMsg: .asciiz "Enter the array : \n"
posMsg: .asciiz "This value exist in the array and its position is "
pos: .word 0
newline: .asciiz "\n"
valMsg: .asciiz "Enter the value you search for : \n"
val: .word 0
notfound:.asciiz "the value doesn't exist in the array !! \n"
.text
main:
# print the array message
li $v0, 4
la $a0, arrMsg
syscall
# read the array from the user
# put $s0 = i
add $s0, $zero, $zero # i = 0
for:
beq $s0, 40, end
li $v0, 5
syscall
sw $v0, arr($s0) # input arr[i]
addi $s0, $s0, 4 # i = i + 4
j for
end:
# print value message
li $v0, 4
la $a0, valMsg
syscall
# read the value from the user
li $v0, 5
syscall
# store the value in the val variable
sw $v0, val
################################################
## put $s0 = start , $s1 = middle , $s2 = end ##
################################################
li $s0, 0
li $s2, 9
jal BinarySearch
li $v0, 10
syscall
############################################################################################################
BinarySearch:
# middle = (start + end ) / 2
add $t0, $s0, $s2 # $t0 = start + end
sra $s1, $t0, 1 # $s1 = $t0 / 2
# save $ra in the stack
addi $sp, $sp, -4
sw $ra, 0($sp)
# base case
ble $s2, $s0, returnNegative1 # if (end <= start)
lw $t1, arr($s1) # $t1 = arr[middle]
lw $t2, val # $t2 = val
beq $t1, $t2, returnMiddle # if (arr[middle] == val)
blt $t2, $t1, returnFirstPart # if (val < arr[middle])
bgt $t2, $t1, returnLastPart # if (val > arr[middle])
returnNegative1:
li $v0, -1
j Exit
returnMiddle:
move $v0, $s1 # return middle
j Exit
returnFirstPart:
move $t3, $s1 # temp = middle
addi $t3, $t3, -1 # temp --
move $s2, $t3 # end = temp
jal BinarySearch
j Exit
returnLastPart:
move $t3, $s1 # temp = middle
addi $t3, $t3, 1 # temp++
move $s0, $t3 # start = temp
jal BinarySearch
j Exit
Exit:
lw $ra, 0($sp)
addi $sp, $sp, 4`
jr $ra
lw $t1, arr($s1) # $t1 = arr[middle]
this is the problem as it is not really the right index as integer takes 4 bytes
so the middle you get from
add $t0, $s0, $s2 # $t0 = start + end
sra $s1, $t0, 1 # $s1 = $t0 / 2
is just the logical address not the real one you will need to multiply it with 4
mul $s4, $s1,4
and then use $s4 as an address
lw $t1, arr($s4) # $t1 = arr[middle]
also there is a mistake with the stopping condition it should be
if (end < start) not (<=)
and sorry for my English