Assembler: ARM: String in Sting

Hey guys, I need some help with my assembler program. My code does not count correctly at the hits. Can someone improve my code and comment everything out?

Here you will find the task:

Aims: Implementing algorithms in assembler programs with the smallest possible code size, as well as handling the debugger and simulator.

preparation Think of a subroutine (function) that should search for a character string in a text. The function receives the start address of the text to be searched (a string) and the start address of the character string to be searched for (a string) in registers R0 and R1. The number of times the character string to be searched for was found in the text should be returned in register R0. If the character string to be searched for is empty, the function returns the value 0. If the text to be searched is an empty string, the function returns the value 0. Possible calls: int searchStringInString (char *, char *); int main (void) { int number; char * text = "hello all right?"; char * search string = "ll"; char * empty string = ; Number = searchStringInString (text, search string); Number = searchStringInString (text, empty string); Number = searchStringInString (empty string, search string); Number = searchStringInString (empty string, empty string); return 0; } Think about further test cases

My Code is this:

@ 1. The address of the text to be searched is expected in R0. @ 2. The address of the text to be searched for is expected in R1. @ 3. R0 should point to an empty string, @ 4. or the searched text cannot be found, @ 5. the value 0 is returned in R0. @ 6. If R1 points to an empty string, the value 0 is returned in R0 .file "searchStringInString.S" .text .align 2 .global searchStringInString .type searchStringInString,% function

searchStringInString:

push {r5, r6}

mov r3, # 0

LDRB r4, [r0] @ String LDRB r5, [r1] @ search string

@ empty string CMP r4, # 0 BEQ end CMP r5, # 0 BEQ end

loop:

LDRB r4, [r0], # 1

LDRB r6, [r1]

CMP r4, # 0 BEQ end

CMP r4, r6 ESD innerloop

innerloop:

LDRB r4, [r5], # 1 LDRB r6, [r1, # 1]!

CMP r6, # 0 BEQ hit

CMP r4, r6 BEQ innerloop ESD loop

hit:

ADD r3, r3, # 1 B loop

end:

MOV r0, r3 Pop {r5, r6} MOV pc, lr

.size searchStringInString,.-searchStringInString