êëþ÷åâîé ôðàãìåíò äåìîíñòðàöèîííîé ïðîãðàììû CRC.c
Êîìïèëèðóåì åå Microsoft Visual C++ â ðåæèìå ìàêñèìàëüíîé îïòèìèçàöèè (êëþ÷ Ox — "cl.exe /Ox crc.c") è çàãðóæàåì ïîëó÷åííûé obj â äèçàññåìáëåð:
.text:00000000 _CRC proc near
.text:00000000
.text:00000000 var_1 = dword ptr -1
.text:00000000 arg_0 = dword ptr 7
.text:00000000 arg_4 = dword ptr 0Bh
.text:00000000
.text:00000000 51 push ecx
.text:00000001 8B 54 24 0C mov edx, [esp+1+arg_4]
.text:00000005 32 C9 xor cl, cl
.text:00000007 33 C0 xor eax, eax
.text:00000009 88 4C 24 00 mov byte ptr [esp+1+var_1], cl
.text:0000000D 85 D2 test edx, edx
.text:0000000F 7E 16 jle short loc_27
.text:00000011 53 push ebx
.text:00000012 56 push esi
.text:00000013 8B 74 24 10 mov esi, [esp+9+arg_0]
.text:00000017
.text:00000017 loc_17:
.text:00000017 8A 1C 30 mov bl, [eax+esi]
.text:0000001A 02 CB add cl, bl
.text:0000001C 40 inc eax
.text:0000001D 3B C2 cmp eax, edx
.text:0000001F 7C F6 jl short loc_17
.text:00000021 5E pop esi
.text:00000022 88 4C 24 04 mov byte ptr [esp+5+var_1], cl
.text:00000026 5B pop ebx
.text:00000027
.text:00000027 loc_27:
.text:00000027 8B 44 24 00 mov eax, [esp+1+var_1]
.text:0000002B 25 FF 00 00+ and eax, 0FFh
.text:00000030 F7 D8 neg eax
.text:00000032 59 pop ecx
.text:00000033 C3 retn
.text:00000033 _CRC endp
