#serial 5
dnl A replacement for autoconf's AC_FUNC_MEMCMP that detects
dnl the losing memcmp on some x86 Next systems.
AC_DEFUN(jm_AC_FUNC_MEMCMP,
[AC_CACHE_CHECK([for working memcmp], jm_cv_func_memcmp_working,
[AC_TRY_RUN(
[int
main ()
{
/* Some versions of memcmp are not 8-bit clean. */
char c0 = 0x40, c1 = 0x80, c2 = 0x81;
if (memcmp(&c0, &c2, 1) >= 0 || memcmp(&c1, &c2, 1) >= 0)
exit (1);
/* The Next x86 OpenStep bug shows up only when comparing 16 bytes
or more and with at least one buffer not starting on a 4-byte boundary.
William Lewis provided this test program. */
{
char foo[21];
char bar[21];
int i;
for (i = 0; i < 4; i++)
{
char *a = foo + i;
char *b = bar + i;
strcpy (a, "--------01111111");
strcpy (b, "--------10000000");
if (memcmp (a, b, 16) >= 0)
exit (1);
}
exit (0);
}
}],
jm_cv_func_memcmp_working=yes,
jm_cv_func_memcmp_working=no,
jm_cv_func_memcmp_working=no)])
test $jm_cv_func_memcmp_working = no \
&& AC_LIBOBJ(memcmp)
])
AC_DEFUN(jm_FUNC_MEMCMP,
[AC_REQUIRE([jm_AC_FUNC_MEMCMP])dnl
if test $jm_cv_func_memcmp_working = no; then
AC_DEFINE_UNQUOTED(memcmp, rpl_memcmp,
[Define to rpl_memcmp if the replacement function should be used.])
fi
])
