newlib/winsup/mingw/mingwex/wmemcmp.c

33 lines
759 B
C

/* This source code was extracted from the Q8 package created and placed
in the PUBLIC DOMAIN by Doug Gwyn <gwyn@arl.mil>
last edit: 1999/11/05 gwyn@arl.mil
Implements subclause 7.24 of ISO/IEC 9899:1999 (E).
It supports an encoding where all char codes are mapped
to the *same* code values within a wchar_t or wint_t,
so long as no other wchar_t codes are used by the program.
*/
#include <wchar.h>
int
wmemcmp(s1, s2, n)
register const wchar_t *s1;
register const wchar_t *s2;
size_t n;
{
if ( n == 0 || s1 == s2 )
return 0; /* even for NULL pointers */
if ( (s1 != NULL) != (s2 != NULL) )
return s2 == NULL ? 1 : -1; /* robust */
for ( ; n > 0; ++s1, ++s2, --n )
if ( *s1 != *s2 )
return *s1 - *s2;
return 0;
}