• 1) 1, 2 , 1, 2, 1, 1, 1, 1
• 2) 1, 1, 2, 1, 2, 1, 2, 2
• 3) mov für Speicherzugriff; in/out für IO-Zugriff
• 4) ?

• A E X
• A E X
• A X E
• A X E
• AE AE AE
• A E E
• E X A

• 1) 2^16 adressen, an jeder adresse liegen 8 bit; 2^16 * 8bit = 64 KB; -48 KB für programm = 16 KB ⇒ 1024

• 2) 20kb
• 3)

movl 8(%esp), %eax
xorl %ebx, %ebx
orb %al, %bl
shrl $8, %eax
shll $8, %ebx
orb %al, %bl
shrl $8, %eax
shll $8, %ebx
orb %al, %bl
shrl $8, %eax
shll $8, %ebx
orb %al, %bl
movl %ebx, 4(%esp)
ret

alternativ:

movl 8(%esp), %eax
movl %ah, %bl
movl %al, %bh
shrl $16, %eax
shll $16, %ebx
movl %ah, %bl
movl %al, %bh
movl %ebx, 4(%esp)
ret

• 1) tanx → taylor reihe; div → newton-raphson / shift / subtraktion; mul → addition / shift
• 2) (steht nirgends schnell):

#define unsigned int ui
#define unsigned short us
 
ui mult(us x, us y) {
    ui sum = 0;
    for (int i = 0; i < y; i++) sum += x;
    return sum;
}

• 1)

#define unsigned int ui
 
ui fibo(ui x) {
    ui res;
    if (x < 2) {
        res = 1;
        goto more;
    }
    x = x - 1;
    res = fibo(x);
    x = x - 1;
    res = res + fibo(x);
    more: return res;
}

Assembler:

 movl 4(%esp), %ebx
 cmpl $2, %ebx
 jge else
 movl $1, %eax
 ret
else:
 subl $1, %ebx
 pushl %ebx
 call fibo
 subl $4, %esp
 movl %eax, %ecx
 subl $1, %ebx
 pushl %ebx
 call fibo
 subl $4, %esp
 addl %ecx, %eax
 ret

???