어셈블리어 - MASM

TITLE Calculating a Factorial                   (Fact.asm)

.386

.MODEL flat,stdcall

INCLUDE SmallWin.inc

.STACK 4096

.code

main PROC

push 12 ; calculate 12 factorial

call Factorial ; calculate factorial (eax)

INVOKE ExitProcess,0

main ENDP

Factorial PROC

push ebp

mov  ebp,esp

mov  eax,[ebp+8] ; get n

cmp  eax,0 ; n < 0?

ja   L1 ; yes: continue

mov  eax,1 ; no: return 1

jmp  L2

L1: dec  eax

push eax ; Factorial(n-1)

call Factorial

mov  ebx,[ebp+8]   ; get n

mul  ebx           ; ax = ax * bx

L2: pop  ebp ; return EAX

ret  4 ; clean up stack

Factorial ENDP

END main