Can anyone explain me this code
<pre><code>#ifndef EIGHT_BIT
#define THIRTYTWO_BIT // default 32 bit
#endif

#ifdef THIRTYTWO_BIT
#define WORD unsigned long
#define WORDLENGTH 4

#if defined(WIN32) &amp;&amp; !defined(__GNUC__)
#define WORD64  unsigned __int64
#else
#define WORD64  unsigned long long
#endif

// THIRTYTWO_BIT
#endif


#ifdef EIGHT_BIT

#define WORD unsigned short
#define WORDLENGTH 4

// EIGHT_BIT
#endif
</code></pre>
