#include <stddef.h>
#include <string.h>
#include <assert.h>

#undef ODD
#define ODD(x) (((short)(x)) & 1)	/* word ops are faster */

/*
 * compare n bytes efficientlty
 *
 * odd/even handled correctly
 *
 *   ++jrb  bammi@dsrgsun.ces.cwru.edu
 */

int bcmp(src, dst, n)
const register void * src;
const register void * dst;
register size_t n;
{
    assert ((src != NULL) && (dst != NULL));

    if((src != dst) && (n > 0))
    {
	register size_t l, w;
	
	switch(ODD(src) + ODD(dst))
	{
	  case 2: /* ODD ODD */
	    if(*(char *)dst++ != *(char *)src++)
		return 1;
	    n--;
	    /* fall thru */
	    
	  case 0: /* EVEN EVEN */
	    l = (n >> 2); /* # of longs */
	    n -= (l << 2);
	    w = (n >> 1); /* # of words */
	    n -= (w << 1); /* n == # of residual bytes */
	    while(l--)
		if( *((long *)dst)++ != *((long *)src)++ )
		    return 1;
	    while(w--)
		if( *((short *)dst)++ != *((short *)src)++ )
		    return 1;
	    /* fall thru */
	  case 1: /* ODD/EVEN or EVEN/ODD */
	    while(n--)
		if( *(char *)dst++ != *(char *)src++ )
		    return 1;
	}
    }
     return 0;
}