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- # longlong.m4 serial 19
- dnl Copyright (C) 1999-2007, 2009-2021 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(
- [[
-
- long long int ll = 9223372036854775807ll;
- long long int nll = -9223372036854775807LL;
- unsigned long long int ull = 18446744073709551615ULL;
-
- typedef int a[((-9223372036854775807LL < 0 && 0 < 9223372036854775807ll)
- ? 1 : -1)];
- typedef int b[(18446744073709551615ULL <= (unsigned long long int) -1
- ? 1 : -1)];
- int i = 63;]],
- [[
- 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));]])
- ])
|