blob: 08d0e36300d320478d23bbbced0e46a8905e7ca3 [file] [log] [blame]
# longlong.m4 serial 18
dnl Copyright (C) 1999-2007, 2009-2019 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.
AC_PREREQ([2.62])
# Define HAVE_LONG_LONG_INT if 'long long int' works.
# This can be faster than what's in Autoconf 2.62 through 2.68.
# 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_REQUIRE([AC_TYPE_UNSIGNED_LONG_LONG_INT])
AC_CACHE_CHECK([for long long int], [ac_cv_type_long_long_int],
[ac_cv_type_long_long_int=yes
if test "x${ac_cv_prog_cc_c99-no}" = xno; then
ac_cv_type_long_long_int=$ac_cv_type_unsigned_long_long_int
if test $ac_cv_type_long_long_int = yes; then
dnl Catch a bug in Tandem NonStop Kernel (OSS) cc -O circa 2004.
dnl If cross compiling, assume the bug is not 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=no],
[:])
fi
fi])
if test $ac_cv_type_long_long_int = yes; then
AC_DEFINE([HAVE_LONG_LONG_INT], [1],
[Define to 1 if the system has the type 'long long int'.])
fi
])
# Define HAVE_UNSIGNED_LONG_LONG_INT if 'unsigned long long int' works.
# This can be faster than what's in Autoconf 2.62 through 2.68.
# Note: If the type 'unsigned long long int' exists but is only 32 bits
# large (as on some very old compilers), AC_TYPE_UNSIGNED_LONG_LONG_INT
# will not be defined. In this case you can treat 'unsigned long long int'
# like 'unsigned long int'.
AC_DEFUN([AC_TYPE_UNSIGNED_LONG_LONG_INT],
[
AC_CACHE_CHECK([for unsigned long long int],
[ac_cv_type_unsigned_long_long_int],
[ac_cv_type_unsigned_long_long_int=yes
if test "x${ac_cv_prog_cc_c99-no}" = xno; then
AC_LINK_IFELSE(
[_AC_TYPE_LONG_LONG_SNIPPET],
[],
[ac_cv_type_unsigned_long_long_int=no])
fi])
if test $ac_cv_type_unsigned_long_long_int = yes; then
AC_DEFINE([HAVE_UNSIGNED_LONG_LONG_INT], [1],
[Define to 1 if the system has the type 'unsigned long long int'.])
fi
])
# Expands to a C program that can be used to test for simultaneous support
# of 'long long' and 'unsigned long long'. We don't want to say that
# 'long long' is available if 'unsigned long long' is not, or vice versa,
# because too many programs rely on the symmetry between signed and unsigned
# integer types (excluding 'bool').
AC_DEFUN([_AC_TYPE_LONG_LONG_SNIPPET],
[
AC_LANG_PROGRAM(
[[/* For now, do not test the preprocessor; as of 2007 there are too many
implementations with broken preprocessors. Perhaps this can
be revisited in 2012. In the meantime, code should not expect
#if to work with literals wider than 32 bits. */
/* Test literals. */
long long int ll = 9223372036854775807ll;
long long int nll = -9223372036854775807LL;
unsigned long long int ull = 18446744073709551615ULL;
/* Test constant expressions. */
typedef int a[((-9223372036854775807LL < 0 && 0 < 9223372036854775807ll)
? 1 : -1)];
typedef int b[(18446744073709551615ULL <= (unsigned long long int) -1
? 1 : -1)];
int i = 63;]],
[[/* Test availability of runtime routines for shift and division. */
long long int llmax = 9223372036854775807ll;
unsigned long long int ullmax = 18446744073709551615ull;
return ((ll << 63) | (ll >> 63) | (ll < i) | (ll > i)
| (llmax / ll) | (llmax % ll)
| (ull << 63) | (ull >> 63) | (ull << i) | (ull >> i)
| (ullmax / ull) | (ullmax % ull));]])
])