C++ to MIPS - Small issue with if statements - c++

Question

C++ Program:
int main()
{
char string[256];
int i=0;
char *result = NULL; // NULL pointer
// Obtain string from user
scanf("%255s", string);
// Search string for letter t.
// Result is pointer to first t (if it exists)
// or NULL pointer if it does not exist
while(string[i] != '\0')
{
if(string[i] == 't')
{
result = &string[i];
break; // exit from while loop early
}
i++;
}
if(result != NULL)
printf("Matching character is %c\n", *result);
else
printf("No match found\n");
}
MIPS code that I have:
.globl main
.text
# main
main:
li $v0,4 # Load value 4
la $a0, msg0 # Load array
syscall
li $v0,8 # Load value 8
la $a0,string # Load array
syscall # Syscall
li $v0,4 # Load immediate value 4
la $a0, string # Load array
syscall # Syscall
la $t0, string # array
la $t1, result # array
lb $t2, result # array
while:
lb $t3, 0($t0)
beq $t3, $0, if2 # if !=0
beq $t3, 't', if # If = "t"
addi $t0, $t0,1 # i++
j while # Jump to While
if:
sw $t3, result # Save result to memory
li $v0,4 # Load value 4
la $a0, found # Load array
syscall # Syscall
j exit
j if2 # Jump to if2
if2:
li $v0,4 # Load value 4
la $a0, notfound # Load array
syscall # Syscall
j exit
exit:
li $v0, 10
syscall # Exit
.data
msg0: .asciiz "Enter Word: "
string: .byte 0:256
i: .word 0
result: .word 0
found: .asciiz "Found!"
notfound: .asciiz "Not Found"
The MIPS code I wrote seems to be working but I think its not following the C++ code structure above. I also think that I have messed up something with if statements but can't figure out what and how to fix it. Any suggestion how I can improve it?
Thanks

Answer 1

I think that the mips code follows the C code quite closely. The main difference is that it practically inlined the the test at the end of the function into the branch to optimize a branch away. While loops have a tendency to look unintuitive in assembly. They are usually compiled to something that looks more like:
if(test) {
do {
body;
} while(test);
}

Answer 2

Like #user2229152 said, you've removed the final check (if(result != NULL)) and moved the prints to your if and if2 blocks.
So your assembly code essentially corresponds to this:
while(string[i] != '\0')
{
if(string[i] != 't')
{
i++;
} else
{
result = &string[i];
printf("Found!");
goto exit;
}
}
printf("Not found");
exit: