汇编-memcpy的实现

memcpystack proc dest,src,cnt        ;cnt is a count of dwords    ;this function has a granularity of dwords    mov edx,src    mov eax,dest    sub eax,edx    sub eax,4    mov ecx,cnt    xchg esp,edx    .repeat        pop dword ptr[esp+eax]        dec ecx    .until zero?    xchg esp,edx    retmemcpystack endpmemcpy1 proc dest,src,cnt        mov edx,src    mov ebx,dest    mov ecx,cnt    .repeat        mov eax,dword ptr[edx]        mov dword ptr[ebx],eax        add edx,4        add eax,4        dec ecx    .until zero?    retmemcpy1 endpmemcpy2 proc dest,src,cnt        mov edx,src    mov ebx,dest    mov ecx,cnt    .repeat        push dword ptr[edx]        pop dword ptr[ebx]        add edx,4        add ebx,4        dec ecx    .until zero?    retmemcpy2 endpmemcpy3 proc dest,src,cnt        mov esi,src    mov edi,dest    mov ecx,cnt    rep movsd    retmemcpy3 endp