Reverse bits unsigned char

main.cpp

unsigned char func(unsigned char input) {
	unsigned char output = 0;
	unsigned char mask = 0x80;

	while (input != 0) {
		if (input & 0x01)
			output += mask;

		input >>= 1;
		mask >>= 1;
	}

	return output;
}

unsigned char funcASM(unsigned char input) {
	unsigned char output = 0;

	__asm
	{
		xor al, al;
		xor ah, ah;
		xor bl, bl;

		mov al, 0;	  // output
		mov ah, 0x80; // maska
		mov bl, input;// input

	start:
		test bl, 1;
		jz jump;
		or al, ah;

	jump:
		shr bl, 1;
		shr ah, 1;
		jnz start;

		mov output, al; // al to output
	}

	return output;
}
int main()
{
	printf("0xDA: \n \n");
	printf("0x%x \n", func(0xDA));
	
	printf("0x%x \n", funcASM(0xDA));
}