# longlong.m4 serial 17

dnl Copyright (C) 1999-2007, 2009-2018 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 2.61, and 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 fixes a bug in Autoconf 2.61, and 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));]])

])