IP Endianness in x64 Assembly: Big-Endian Network Byte Order to ASCII | Single-Pass div Algorithm Without inet_ntoa
Network packet IP addresses arrive in Big-Endian byte order inside sockaddr_in. x86/x64 Little-Endian architecture reverses the bytes on load — naive printing yields 5.1.168.192 instead of 192.168.1.5. The standard two-pass approach (convert forward, then reverse string) wastes memory cycles. Single-pass backward-build: start reading from the last IP octet (offset 7), write ASCII digits to the end of the output buffer, work backward simultaneously — the string forms correctly in one pass. Each octet uses div bl to extract decimal digits, add 0x30 to convert to ASCII, dot separator skipped on last octet via cmp rcx,4.
