How can I perform multiplication without the '*' operator?

Question

I was just going through some basic stuff as I am learning C. I came upon a question to multiply a number by 7 without using the * operator. Basically it\'s like this

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Answer 1

It's easy to avoid the '*' operator:

mov eax, 1234h
mov edx, 5678h
imul edx

No '*' in sight. Of course, if you wanted to get into the spirit of it, you could also use the trusty old shift and add algorithm:

mult proc
; Multiplies eax by ebx and places result in edx:ecx
    xor ecx, ecx
    xor edx, edx
mul1:
    test ebx, 1
    jz  mul2
    add ecx, eax
    adc edx, 0
mul2:
    shr ebx, 1
    shl eax, 1
    test ebx, ebx
    jnz  mul1
done:
    ret
mult endp

Of course, with modern processors, all (?) have multiplication instructions, but back when the PDP-11 was shiny and new, code like this saw real use.