register unsigned char global_var asm ("r4");unsigned char test (void){ unsigned char temp; global_var = 0x55; 0: 85 e5 ldi r24, 0x55 ; 85 2: 48 2e mov r4, r24 temp = global_var; return temp;} 4: 85 e5 ldi r24, 0x55 ; 85 6: 08 95 ret