factorial.asm

factorial(unsigned int):
        mov     eax, 1     ; The default return value eax=1
        test    edi, edi   ; Check if the input parameter n is 0
        je      .L1        ; If n is 0, just return
.L2:                       ; Loop return variable
        imul    eax, edi   ; eax = eax*n
        sub     edi, 1     ; n = n-1
        jne     .L2        ; Loop if n is non-zero
.L1:                       ; Jump label for n==0 case
        ret                ; Return result in eax