Annotation of embedaddon/libiconv/srcm4/longlong.m4, revision 1.1.1.3

1.1.1.3 ! misho       1: # longlong.m4 serial 18
        !             2: dnl Copyright (C) 1999-2007, 2009-2019 Free Software Foundation, Inc.
1.1       misho       3: dnl This file is free software; the Free Software Foundation
                      4: dnl gives unlimited permission to copy and/or distribute it,
                      5: dnl with or without modifications, as long as this notice is preserved.
                      6: 
                      7: dnl From Paul Eggert.
                      8: 
1.1.1.3 ! misho       9: AC_PREREQ([2.62])
        !            10: 
1.1       misho      11: # Define HAVE_LONG_LONG_INT if 'long long int' works.
1.1.1.3 ! misho      12: # This can be faster than what's in Autoconf 2.62 through 2.68.
1.1       misho      13: 
                     14: # Note: If the type 'long long int' exists but is only 32 bits large
                     15: # (as on some very old compilers), HAVE_LONG_LONG_INT will not be
                     16: # defined. In this case you can treat 'long long int' like 'long int'.
                     17: 
                     18: AC_DEFUN([AC_TYPE_LONG_LONG_INT],
                     19: [
1.1.1.2   misho      20:   AC_REQUIRE([AC_TYPE_UNSIGNED_LONG_LONG_INT])
1.1       misho      21:   AC_CACHE_CHECK([for long long int], [ac_cv_type_long_long_int],
1.1.1.2   misho      22:      [ac_cv_type_long_long_int=yes
                     23:       if test "x${ac_cv_prog_cc_c99-no}" = xno; then
                     24:         ac_cv_type_long_long_int=$ac_cv_type_unsigned_long_long_int
                     25:         if test $ac_cv_type_long_long_int = yes; then
                     26:           dnl Catch a bug in Tandem NonStop Kernel (OSS) cc -O circa 2004.
                     27:           dnl If cross compiling, assume the bug is not important, since
                     28:           dnl nobody cross compiles for this platform as far as we know.
                     29:           AC_RUN_IFELSE(
                     30:             [AC_LANG_PROGRAM(
                     31:                [[@%:@include <limits.h>
                     32:                  @%:@ifndef LLONG_MAX
                     33:                  @%:@ define HALF \
                     34:                           (1LL << (sizeof (long long int) * CHAR_BIT - 2))
                     35:                  @%:@ define LLONG_MAX (HALF - 1 + HALF)
                     36:                  @%:@endif]],
                     37:                [[long long int n = 1;
                     38:                  int i;
                     39:                  for (i = 0; ; i++)
                     40:                    {
                     41:                      long long int m = n << i;
                     42:                      if (m >> i != n)
                     43:                        return 1;
                     44:                      if (LLONG_MAX / 2 < m)
                     45:                        break;
                     46:                    }
                     47:                  return 0;]])],
                     48:             [],
                     49:             [ac_cv_type_long_long_int=no],
                     50:             [:])
                     51:         fi
                     52:       fi])
1.1       misho      53:   if test $ac_cv_type_long_long_int = yes; then
                     54:     AC_DEFINE([HAVE_LONG_LONG_INT], [1],
1.1.1.3 ! misho      55:       [Define to 1 if the system has the type 'long long int'.])
1.1       misho      56:   fi
                     57: ])
                     58: 
                     59: # Define HAVE_UNSIGNED_LONG_LONG_INT if 'unsigned long long int' works.
1.1.1.3 ! misho      60: # This can be faster than what's in Autoconf 2.62 through 2.68.
1.1       misho      61: 
                     62: # Note: If the type 'unsigned long long int' exists but is only 32 bits
                     63: # large (as on some very old compilers), AC_TYPE_UNSIGNED_LONG_LONG_INT
                     64: # will not be defined. In this case you can treat 'unsigned long long int'
                     65: # like 'unsigned long int'.
                     66: 
                     67: AC_DEFUN([AC_TYPE_UNSIGNED_LONG_LONG_INT],
                     68: [
                     69:   AC_CACHE_CHECK([for unsigned long long int],
                     70:     [ac_cv_type_unsigned_long_long_int],
1.1.1.2   misho      71:     [ac_cv_type_unsigned_long_long_int=yes
                     72:      if test "x${ac_cv_prog_cc_c99-no}" = xno; then
                     73:        AC_LINK_IFELSE(
                     74:          [_AC_TYPE_LONG_LONG_SNIPPET],
                     75:          [],
                     76:          [ac_cv_type_unsigned_long_long_int=no])
                     77:      fi])
1.1       misho      78:   if test $ac_cv_type_unsigned_long_long_int = yes; then
                     79:     AC_DEFINE([HAVE_UNSIGNED_LONG_LONG_INT], [1],
1.1.1.3 ! misho      80:       [Define to 1 if the system has the type 'unsigned long long int'.])
1.1       misho      81:   fi
                     82: ])
                     83: 
                     84: # Expands to a C program that can be used to test for simultaneous support
                     85: # of 'long long' and 'unsigned long long'. We don't want to say that
                     86: # 'long long' is available if 'unsigned long long' is not, or vice versa,
                     87: # because too many programs rely on the symmetry between signed and unsigned
                     88: # integer types (excluding 'bool').
                     89: AC_DEFUN([_AC_TYPE_LONG_LONG_SNIPPET],
                     90: [
                     91:   AC_LANG_PROGRAM(
                     92:     [[/* For now, do not test the preprocessor; as of 2007 there are too many
1.1.1.2   misho      93:          implementations with broken preprocessors.  Perhaps this can
                     94:          be revisited in 2012.  In the meantime, code should not expect
                     95:          #if to work with literals wider than 32 bits.  */
1.1       misho      96:       /* Test literals.  */
                     97:       long long int ll = 9223372036854775807ll;
                     98:       long long int nll = -9223372036854775807LL;
                     99:       unsigned long long int ull = 18446744073709551615ULL;
                    100:       /* Test constant expressions.   */
                    101:       typedef int a[((-9223372036854775807LL < 0 && 0 < 9223372036854775807ll)
1.1.1.2   misho     102:                      ? 1 : -1)];
1.1       misho     103:       typedef int b[(18446744073709551615ULL <= (unsigned long long int) -1
1.1.1.2   misho     104:                      ? 1 : -1)];
1.1       misho     105:       int i = 63;]],
                    106:     [[/* Test availability of runtime routines for shift and division.  */
                    107:       long long int llmax = 9223372036854775807ll;
                    108:       unsigned long long int ullmax = 18446744073709551615ull;
                    109:       return ((ll << 63) | (ll >> 63) | (ll < i) | (ll > i)
1.1.1.2   misho     110:               | (llmax / ll) | (llmax % ll)
                    111:               | (ull << 63) | (ull >> 63) | (ull << i) | (ull >> i)
                    112:               | (ullmax / ull) | (ullmax % ull));]])
1.1       misho     113: ])

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