Optimized Inline Function for ntohl and htonl

endian.h

// Using the X86 instruction bswap and gcc inline assembly 

inline unsigned int ntohl(unsigned int x)
{
  asm("bswapl %1" : "=a" (x) : "a"(x));
}

inline unsigned int htonl(unsigned int x)
{
  asm("bswapl %1" : "=a" (x) : "a"(x));
}