1/* memcmp -- compare two memory regions.
2   This function is in the public domain.  */
3
4/*
5
6@deftypefn Supplemental int memcmp (const void *@var{x}, const void *@var{y}, @
7  size_t @var{count})
8
9Compares the first @var{count} bytes of two areas of memory.  Returns
10zero if they are the same, a value less than zero if @var{x} is
11lexically less than @var{y}, or a value greater than zero if @var{x}
12is lexically greater than @var{y}.  Note that lexical order is determined
13as if comparing unsigned char arrays.
14
15@end deftypefn
16
17*/
18
19#include <ansidecl.h>
20#include <stddef.h>
21
22int
23memcmp (const PTR str1, const PTR str2, size_t count)
24{
25  register const unsigned char *s1 = (const unsigned char*)str1;
26  register const unsigned char *s2 = (const unsigned char*)str2;
27
28  while (count-- > 0)
29    {
30      if (*s1++ != *s2++)
31	  return s1[-1] < s2[-1] ? -1 : 1;
32    }
33  return 0;
34}
35
36