Bug oder richtiges verhalten?

#include <avr/io.h>

#include "main.h"

int main(void)

{

        DDRD = 0xFF;

        PORTD = 0xFF;

        return 0;

}

[...]

avr-gcc -c -mmcu=atmega8 -I. -gstabs   -O2 -Wall -Wstrict-prototypes -std=gnu99 -Wa,-adhlns=main.lst -DF_CPU=16000000UL -Wl,--relax,--gc-sections main.c -o main.o 

avr-gcc -mmcu=atmega8 -I. -gstabs   -O2 -Wall -Wstrict-prototypes -std=gnu99 -Wa,-adhlns=main.o -DF_CPU=16000000UL -Wl,--relax,--gc-sections main.o   --output main.elf     -lm

[...]

0000005e <main>:

  5e:  8f ef         ldi  r24, 0xFF  ; 255

  60:  81 bb         out  0x11, r24  ; 17

  62:  82 bb         out  0x12, r24  ; 18

  64:  80 e0         ldi  r24, 0x00  ; 0

  66:  90 e0         ldi  r25, 0x00  ; 0

  68:  08 95         ret