I'm converting C code to Mips code
The C code is
int main(void) {
int i;
int data [10] = { 10, -2, 5, 22, 99, 0, -5, 8, 30, 7};
for(i=0; i<10; i++){
printf("%d\n", data[i]);
}
return 0;
}
my Mips code is
.data
data: .space 10
enter: .asciiz "\n"
.text
.globl main
main:
addi $s0, $zero, 10
add $t0, $zero, $zero
sw $s0, data($t0)
addi $s0, $zero, -2
addi $t0, $t0, 4
sw $s0, data($t0)
addi $s0, $zero, 5
addi $t0, $t0, 4
sw $s0, data($t0)
addi $s0, $zero, 22
addi $t0, $t0, 4
sw $s0, data($t0)
addi $s0, $zero, 99
addi $t0, $t0, 4
sw $s0, data($t0)
addi $s0, $zero, 0
addi $t0, $t0, 4
sw $s0, data($t0)
addi $s0, $zero, -5
addi $t0, $t0, 4
sw $s0, data($t0)
addi $s0, $zero, 8
addi $t0, $t0, 4
sw $s0, data($t0)
addi $s0, $zero, 30
addi $t0, $t0, 4
sw $s0, data($t0)
addi $s0, $zero, 7
addi $t0, $t0, 4
sw $s0, data($t0)
addi $t0, $zero, 0
Loop: slti $t1, $t0, 10
beq $t1, $zero, Exit
mul $t2, $t0, 4
li $v0, 1
lw $a0, data($t2)
syscall
li $v0, 4
la $a0, enter
syscall
addi $t0, $t0, 1
j Loop
Exit:
end:
li $v0, 10
syscall
s1 is for saving a value.
t0 is for index
t1 is a flag for slt
t1 multiply 4 is t2
you should just focus on
li $v0, 4
la $a0, enter
syscall
it prints
10-2522990-58307
dddddddddddddddddddddddddddddddddddasdfasdfasdfasdfasdfasdfasdf
plz help me dddddddddddddddddddddddddddddddddddddd
You haven't reserved enough memory for your data array. .space 10 reserves 10 bytes of memory, but you're trying to store 10 words (40 bytes). So you end up overwriting the newline character.
If you change the declaration to data: .space 40 you should get the expected output.
Related
Recently, I am learning MIPS. Professor give us an example of his code, asking us to find out the value. My problem is that after I type in his code, the run time exception comes out at " lw $t1, 0($s0) ".
line 8: Runtime exception at 0x0040001c: address out of range 0x00000000
Can someone helps me?
addi $t7, $zero,0x10010000
lw $t0, 20($t7)
srl $t0, $t0, 16
andi $t0, $t0, 0x00000FF
andi $s0, $t7, 16
lw $t1, 0($s0)
andi $t1, $t1, 0x0000FF00
srl $t1, $t1, 8
addi $s0, $s0, -8
lw $t2, 0($s0)
sll $t2, $t2, 24
srl $t2, $t2, 24
addi $s0, $zero, 1
sll $s0, $s0, 4
lw $t3, 0($t7)
srlv $t3, $t3, $s0
andi $t3, $t3, 255
addi $s0, $zero, 1
sll $s0, $s0, 2
add $s0, $s0, $t7
lw $t4, 0($s0)
andi $t4, $t4, 0x00FF0000
srl $t4, $t4, 16
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 have a little problem with my MIPS code, because this not work with "a", I explain better... If I write:
Heeeeello world --> I obtain this output "The 'e' has the biggest number of occurrences, 5"
hi Maaaaaark --> I obtain this output "The '' has the biggest number of occurrences, "
Can someone give me a solution? this is my code:
.data
m1: .asciiz "Give me a string: "
m2: .asciiz "\nThe letter '"
m3: .asciiz "' has the biggest number of occurrences, is present "
m4: .asciiz " times."
.align 2
myArray: .space 104
.text
.globl main
main:
li $v0, 4
la $a0, m1
syscall
addi $sp, $sp, -256
move $s0, $sp
move $a0, $sp
li $a1, 255
li $v0, 8
syscall
move $a0, $s0
jal check_case
move $a0, $v0
move $a1, $v1
jal analizza_stringa
move $a0, $v0
move $a1, $v1
jal stampa_risultato
end_program:
li $v0, 10
syscall
check_case:
move $t0, $a0
while:
lb $t1, ($t0)
beq $t1, 32, ignore_value_and_continue
beq $t1, 10, exit_check_case
bge $t1, 97, continue_check_case
bge $t1, 65, change_case
change_case:
addi $t2, $t1, 32
sb $t2, ($t0)
ignore_value_and_continue:
continue_check_case:
addi $t2, $t2, 1
addi $t0, $t0, 1
j while
exit_check_case:
move $v0, $t0
move $v1, $t2
jr $ra
analizza_stringa:
li $t1, 0
li $t2, 0
li $t3, 0
li $t4, 0
move $t7, $a0
sub $a0, $a0, $v1
sub $t7, $t7, $v1
while_string:
lb $t0, ($a0)
beq $t0, $zero, check_best
beq $t1, 32, ignore_value_and_continue2
ignore_value_and_continue2:
beq $t0, 10, check_best
subi $t3, $t0, 97
mul $t4, $t3, 4
move $t6, $t7
while_occorrenza:
beq $t1, 10, continue
lb $t1,($t6)
bne $t1, $t0, continue2
addi $t5, $t5, 1
continue2:
addi $t6, $t6, 1
j while_occorrenza
continue:
sw $t5, myArray($t4)
li $t5, 0
li $t3, 0
li $t1, 0
addi $a0, $a0, 1
j while_string
check_best:
li $t0, 0
lw $t1, myArray($t0)
addi $t0, $t0, 4
while_check_best:
beq $t0, 104, exit_check
addi $t5, $t5, 1
lw $t4, myArray($t0)
bge $t4, $t1, scambia
j continue_check
scambia:
blt $t4, $t2, continue_check
move $t2, $t4
add $t3, $t5, 97
continue_check:
addi $t0, $t0, 4
j while_check_best
exit_check:
move $v0, $t3
move $v1, $t2
jr $ra
stampa_risultato:
move $t0, $a0
li $v0, 4
la $a0, m2
syscall
li $v0, 11
move $a0, $t0
syscall
li $v0, 4
la $a0, m3
syscall
li $v0, 1
move $a0, $a1
syscall
li $v0, 4
la $a0, m4
syscall
jr $ra
I am trying to translate my fibonacci c code to MIPS assembly code, however, when I run the MIPS code to my MIPS simulator it doesn't seem to end.
C Code:
int fibo(int n)
{
if(n<2) return 1;
else f(n-1)+f(n-2);
}
int main()
{
fibo(5);
}
Assembly Code:
main: addi $sp, $sp, -4
sw $ra, 0($sp)
addi $a0, $zero, 5
jal fibo;
lw $ra, 0($sp)
addi $sp, $sp, 4
fibo: addi $sp, $sp, -12
sw $s0, 0($sp)
sw $s1, 4($sp)
sw $ra, 8($sp)
slti $t0, $a0, 2
beq $t0, $zero, ELSE
addi $v0, $zero, 1
jr $ra
ELSE: addi $s0, $a0, 0
addi $a0, $a0, -1
jal fibo;
addi $s1, $v0, 0
addi $a0, $s0, -2
jal fibo
add $s1, $s1, $v0
j EXIT
EXIT: lw $s0, 0($sp)
lw $s1, 4($sp)
lw $ra, 8($sp)
addi $sp, $sp, 12
jr $ra
A few issues here.
First, your main function was missing its terminating jr $ra, meaning that main fell through into fibo after being executed.
Second, in your if statement, where you return 1, you call jr $ra directly, which means the stack goes unrestored. I swapped this out with a call to j EXIT.
Finally, at the end of your else you add f(n-1) and f(n-2) into $s1. This register should be $v0 as you are intending to return this result.
The fixed up code is as follows:
main:
addi $sp, $sp, -4
sw $ra, 0($sp)
addi $a0, $zero, 5
jal fibo
move $a0 $v0
li $v0 1
syscall
lw $ra, 0($sp)
addi $sp, $sp, 4
jr $ra
fibo:
addi $sp, $sp, -12
sw $s0, 0($sp)
sw $s1, 4($sp)
sw $ra, 8($sp)
slti $t0, $a0, 2
beq $t0, $zero, ELSE
addi $v0, $zero, 1
j EXIT
ELSE:
addi $s0, $a0, 0
addi $a0, $a0, -1
jal fibo
addi $s1, $v0, 0
addi $a0, $s0, -2
jal fibo
add $v0, $s1, $v0
EXIT:
lw $s0, 0($sp)
lw $s1, 4($sp)
lw $ra, 8($sp)
addi $sp, $sp, 12
jr $ra
Here is my code for the same,but it is written in RISC-V
.text
#x5 me n hai
#x7 me output
li x5 7
li x6 2
jal x1 FIB
j EXIT
FIB:
bge x5 x6 REC
addi x7 x5 0
jalr x0 0(x1)
#Handled Base Case
REC:
# Handling Rec. Case
addi sp sp -12
sw x1 0(sp)
sw x5 4(sp)
addi x5 x5 -1
jal x1 FIB
sw x7 8(sp)
lw x5 4(sp)
addi x5 x5 -2
jal x1 FIB
lw x13 8(sp)
add x7 x13 x7
lw x1 0(sp)
addi sp sp 12
jalr x0 0(x1)
EXIT:
In addition to the answer of Konrad (https://stackoverflow.com/a/23185991/3729904), I noticed that there is an error in your algorithm. If n<2 the fib algorithm should return n instead of 1.
This can be fixed changing the line:
addi $v0, $zero, 1
into:
add $v0, $zero, $a0
So i have to write a bubblesort programm in mips using QtSpim for a class but i get an Exception 4 [Adress error in inst/data fetch]. I have searched in other topics and use the .align 2 directive before defining an array for 5 integers but it still isn't getting fixed.
Here's the code:
.text
.globl main
main:
la $t1, array #sets the base adress of the array to t1
la $a0, in_prompt
li $v0, 4
syscall
li $t2, 0 #init to 1
read_loop:
beq $t2, 5, read_key #break if t2 = 5
la $a0, num_prompt
li $v0, 4
syscall #"Give number"
#move $a0, $t2
#li $v0, 1
#syscall #current number to be read
li $v0, 5 #read int. 5 times
syscall
sw $v0, ($t1) #move input from v0 to the array
addi $t1, $t1, 4 #move t1 to the next position in the array
addi $t2, $t2, 1 #increment counter (t2) by 1
j read_loop
read_key:
la $a0, search_q
li $v0, 4
syscall #print query prompt
li $v0, 5
syscall
move $t3, $v0 #number we're looking for (KEY)
move $a0, $t1 #array to pass as arguement
jal bubblesort
move $a0, $v0 #move into a0 the sorted array
move $a1, $t3 #move the KEY into a1 as arguement
jal binarysearch
move $t1, $a0 #move into t1 the array
move $t0, $a1 #move into t0 the KEY
move $t3, $v0 #move into t3 the result of binarySearch
beq $t3, -1, not_found #if key was not found
move $a0, $t0
li $v0, 1
syscall
la $a0, found_pr
li $v0, 4
syscall
j print_array
not_found:
move $a0, $t0
li $v0, 1
syscall
la $a0, not_found_pr
li $v0, 4
syscall
j print_array
print_array:
li $t2, 1 #init to 1
print_loop:
beq $t2, 5, EXIT
lw $a0, ($t1)
li $v0, 1
syscall
addi $t1, $t1, 4
addi $t2, $t2, 1
j print_loop
EXIT:
li $v0, 10
syscall
##############binarysearch#################
binarysearch:
addi $sp, $sp, -24 #reserve space for 6 elements
sw $a0, 0($sp) #push a0 (array)into stack
sw $a1, 4($sp) #push a1(KEY) into stack
sw $s0, 8($sp) #push s0
sw $s1, 12($sp) #push s1
sw $s2, 16($sp) #push s2
sw $ra, 20($sp) #push ra
sw $s3, 24($sp) #push s3
li $s0, 0 #low = 0
li $s1, 4 #high = 4
while:
bgt $s0, $s1, exit_search #if low > high branch
move $a1, $s0 #move into a1 low
move $a2, $s1 #move into a2 high
jal calc_middle #jump to calc_middle
move $s2, $v0 #move into s2 the return value of calc_middle
lw $a0, 0($sp) #restore into a0 the 1st stack el(array)
lw $a1, 4($sp) #restore into a1 the 2nd stack el(KEY)
add $a0, $a0, $s2 #move the array to middle
lw $s3, ($a0) #load into s3 the a[middle]
beq $a1, $s3, exit_search_found #break if KEY == a[middle]
blt $a1, $s3, less_t_middle #if the key is less than the middle element
addi $s0, $s2, 1 #if the key is greater than the middle element set new low
j while
less_t_middle:
addi $s1, $s2, -1 #new high
j while
exit_search_found:
move $v0, $s2 #return found
lw $s0, 8($sp)
lw $s1, 12($sp)
lw $s2, 16($sp)
lw $ra, 20($sp)
addi $sp, $sp, 24
jr $ra
exit_search:
li $v0, -1 #return -1
lw $s0, 8($sp)
lw $s1, 12($sp)
lw $s2, 16($sp)
lw $ra, 20($sp)
addi $sp, $sp, 24
jr $ra
##############calc_middle##################
calc_middle:
add $a1, $a1, $a2
sra $a1, $a1, 1
move $v0, $a1
jr $ra
##############bubblesort###################
bubblesort:
addi $sp, $sp, -12
sw $s0, 0($sp)
sw $s1, 4($sp)
sw $s2, 8($sp)
li $s2, 4 #j = 5
li $s1, 0 #i = 0
outer_loop:
addi $s2, $s2, -1 #i = j - 1
blt $s2, $zero, exit_sort
inner_loop:
bgt $s1, $s2, outer_loop #if i > j - 1
lw $s3, 0($a0) #load into s3 the a[i]
lw $s4, 4($a0) #load into s4 the a[i+1]
bgt $s3, $s4, swap #if a[i] > a[i+1]
addi $s1, $s1, 1 #i++
j inner_loop
swap: move $s0, $s3 #tmp = a[i]
move $s3, $s4 #a[i] = a[i+1]
move $s4, $s0 #a[i+1] = tmp
addi $a0, $a0, 4 #point to the next element ????
addi $s1, $s1, 1 #i++
j inner_loop
exit_sort:
lw $s0, 0($sp)
lw $s1, 4($sp)
lw $s2, 8($sp)
addi $sp, $sp, 8
move $v0, $a0 #pass into v0 the sorted array
jr $ra
.data
.align 2
array: .space 20
in_prompt: .asciiz "Enter 5 numbers:\n"
num_prompt: .asciiz "Give number: "
search_q: .asciiz "what are you looking for?\n"
not_found_pr: .asciiz " not found in array: \n"
found_pr: .asciiz " found in array: \n"