主题:都来看看这道题,难.
这题是双字转ASCII的,你们看看谁能看懂,主要是里面的算法.
dwtoa proc dwValue:DWORD, lpBuffer:DWORD
push ebx
push esi
push edi
mov eax, dwValue
mov edi, [lpBuffer]
or eax,eax
jnz sign
zero:
mov word ptr [edi],30h
jmp dw2asc
sign:
jns pos
mov byte ptr [edi],'-'
neg eax
inc edi
pos:
mov ecx,429496730
mov esi, edi
.while (eax > 0)
mov ebx,eax
mul ecx
mov eax,edx
lea edx,[edx*4+edx]
add edx,edx
sub ebx,edx
add bl,'0'
mov [edi],bl
inc edi
.endw
mov byte ptr [edi], 0
.while (esi < edi)
dec edi
mov al, [esi]
mov ah, [edi]
mov [edi], al
mov [esi], ah
inc esi
.endw
dw2asc:
pop edi
pop esi
pop ebx
ret
dwtoa endp[em19][em19][em18][em18]
dwtoa proc dwValue:DWORD, lpBuffer:DWORD
push ebx
push esi
push edi
mov eax, dwValue
mov edi, [lpBuffer]
or eax,eax
jnz sign
zero:
mov word ptr [edi],30h
jmp dw2asc
sign:
jns pos
mov byte ptr [edi],'-'
neg eax
inc edi
pos:
mov ecx,429496730
mov esi, edi
.while (eax > 0)
mov ebx,eax
mul ecx
mov eax,edx
lea edx,[edx*4+edx]
add edx,edx
sub ebx,edx
add bl,'0'
mov [edi],bl
inc edi
.endw
mov byte ptr [edi], 0
.while (esi < edi)
dec edi
mov al, [esi]
mov ah, [edi]
mov [edi], al
mov [esi], ah
inc esi
.endw
dw2asc:
pop edi
pop esi
pop ebx
ret
dwtoa endp[em19][em19][em18][em18]