mc/m4/longlong.m4

73 lines
2.4 KiB
Plaintext
Raw Normal View History

# longlong.m4 serial 10
dnl Copyright (C) 1999-2006 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
dnl with or without modifications, as long as this notice is preserved.
dnl From Paul Eggert.
# Define HAVE_LONG_LONG_INT if 'long long int' works.
# This fixes a bug in Autoconf 2.60, but can be removed once we
# assume 2.61 everywhere.
# Note: If the type 'long long int' exists but is only 32 bits large
# (as on some very old compilers), HAVE_LONG_LONG_INT will not be
# defined. In this case you can treat 'long long int' like 'long int'.
AC_DEFUN([AC_TYPE_LONG_LONG_INT],
[
AC_CACHE_CHECK([for long long int], [ac_cv_type_long_long_int],
[AC_LINK_IFELSE(
[AC_LANG_PROGRAM(
[[long long int ll = 9223372036854775807ll;
long long int nll = -9223372036854775807LL;
typedef int a[((-9223372036854775807LL < 0
&& 0 < 9223372036854775807ll)
? 1 : -1)];
int i = 63;]],
[[long long int llmax = 9223372036854775807ll;
return ((ll << 63) | (ll >> 63) | (ll < i) | (ll > i)
| (llmax / ll) | (llmax % ll));]])],
[dnl This catches a bug in Tandem NonStop Kernel (OSS) cc -O circa 2004.
dnl If cross compiling, assume the bug isn't important, since
dnl nobody cross compiles for this platform as far as we know.
AC_RUN_IFELSE(
[AC_LANG_PROGRAM(
[[@%:@include <limits.h>
@%:@ifndef LLONG_MAX
@%:@ define HALF \
(1LL << (sizeof (long long int) * CHAR_BIT - 2))
@%:@ define LLONG_MAX (HALF - 1 + HALF)
@%:@endif]],
[[long long int n = 1;
int i;
for (i = 0; ; i++)
{
long long int m = n << i;
if (m >> i != n)
return 1;
if (LLONG_MAX / 2 < m)
break;
}
return 0;]])],
[ac_cv_type_long_long_int=yes],
[ac_cv_type_long_long_int=no],
[ac_cv_type_long_long_int=yes])],
[ac_cv_type_long_long_int=no])])
if test $ac_cv_type_long_long_int = yes; then
AC_DEFINE([HAVE_LONG_LONG_INT], 1,
[Define to 1 if the system has the type `long long int'.])
fi
])
# This macro is obsolescent and should go away soon.
AC_DEFUN([gl_AC_TYPE_LONG_LONG],
[
AC_REQUIRE([AC_TYPE_LONG_LONG_INT])
ac_cv_type_long_long=$ac_cv_type_long_long_int
if test $ac_cv_type_long_long = yes; then
AC_DEFINE(HAVE_LONG_LONG, 1,
[Define if you have the 'long long' type.])
fi
])