.global _my_strlen			# Export the symbol _my_strlen
	.text						# code section

_my_strlen:
	
	#function prologue
	pushq %rbp
	movq %rsp, %rbp
	movq %rdi, %rsi 			# copy the string pointer to %rsi
	xorq %rax, %rax				# zero %rax to use as a counter

strlen_loop:
	cmpb $0, (%rsi)				# compare byte at %rsi with 0 (null terminator)
	je strlen_end				# if zero, end of string reached
	incq %rax					# increment counter
	incq %rsi					# move to next character
	jmp strlen_loop				# repeat loop

strlen_end:
	
	#function epilogue
	popq %rbp
	ret

#include <iostream>

//declare the assembler function
extern "C" size_t my_strlen(const char* str);

int main(int argc, const char *argv[])
{
	const char* message = "Hello from Assembler";
	size_t length = my_strlen(message);
	std::cout << "Message: " << message << std::endl;
	std::cout << "Length: " << length << std::endl;
	return 0;
}