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| 1 # longlong.m4 serial 13 |
| 2 dnl Copyright (C) 1999-2007 Free Software Foundation, Inc. |
| 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 |
| 9 # Define HAVE_LONG_LONG_INT if 'long long int' works. |
| 10 # This fixes a bug in Autoconf 2.61, but can be removed once we |
| 11 # assume 2.62 everywhere. |
| 12 |
| 13 # Note: If the type 'long long int' exists but is only 32 bits large |
| 14 # (as on some very old compilers), HAVE_LONG_LONG_INT will not be |
| 15 # defined. In this case you can treat 'long long int' like 'long int'. |
| 16 |
| 17 AC_DEFUN([AC_TYPE_LONG_LONG_INT], |
| 18 [ |
| 19 AC_CACHE_CHECK([for long long int], [ac_cv_type_long_long_int], |
| 20 [AC_LINK_IFELSE( |
| 21 [_AC_TYPE_LONG_LONG_SNIPPET], |
| 22 [dnl This catches a bug in Tandem NonStop Kernel (OSS) cc -O circa 2004. |
| 23 dnl If cross compiling, assume the bug isn't important, since |
| 24 dnl nobody cross compiles for this platform as far as we know. |
| 25 AC_RUN_IFELSE( |
| 26 [AC_LANG_PROGRAM( |
| 27 [[@%:@include <limits.h> |
| 28 @%:@ifndef LLONG_MAX |
| 29 @%:@ define HALF \ |
| 30 (1LL << (sizeof (long long int) * CHAR_BIT - 2)) |
| 31 @%:@ define LLONG_MAX (HALF - 1 + HALF) |
| 32 @%:@endif]], |
| 33 [[long long int n = 1; |
| 34 int i; |
| 35 for (i = 0; ; i++) |
| 36 { |
| 37 long long int m = n << i; |
| 38 if (m >> i != n) |
| 39 return 1; |
| 40 if (LLONG_MAX / 2 < m) |
| 41 break; |
| 42 } |
| 43 return 0;]])], |
| 44 [ac_cv_type_long_long_int=yes], |
| 45 [ac_cv_type_long_long_int=no], |
| 46 [ac_cv_type_long_long_int=yes])], |
| 47 [ac_cv_type_long_long_int=no])]) |
| 48 if test $ac_cv_type_long_long_int = yes; then |
| 49 AC_DEFINE([HAVE_LONG_LONG_INT], 1, |
| 50 [Define to 1 if the system has the type `long long int'.]) |
| 51 fi |
| 52 ]) |
| 53 |
| 54 # Define HAVE_UNSIGNED_LONG_LONG_INT if 'unsigned long long int' works. |
| 55 # This fixes a bug in Autoconf 2.61, but can be removed once we |
| 56 # assume 2.62 everywhere. |
| 57 |
| 58 # Note: If the type 'unsigned long long int' exists but is only 32 bits |
| 59 # large (as on some very old compilers), AC_TYPE_UNSIGNED_LONG_LONG_INT |
| 60 # will not be defined. In this case you can treat 'unsigned long long int' |
| 61 # like 'unsigned long int'. |
| 62 |
| 63 AC_DEFUN([AC_TYPE_UNSIGNED_LONG_LONG_INT], |
| 64 [ |
| 65 AC_CACHE_CHECK([for unsigned long long int], |
| 66 [ac_cv_type_unsigned_long_long_int], |
| 67 [AC_LINK_IFELSE( |
| 68 [_AC_TYPE_LONG_LONG_SNIPPET], |
| 69 [ac_cv_type_unsigned_long_long_int=yes], |
| 70 [ac_cv_type_unsigned_long_long_int=no])]) |
| 71 if test $ac_cv_type_unsigned_long_long_int = yes; then |
| 72 AC_DEFINE([HAVE_UNSIGNED_LONG_LONG_INT], 1, |
| 73 [Define to 1 if the system has the type `unsigned long long int'.]) |
| 74 fi |
| 75 ]) |
| 76 |
| 77 # Expands to a C program that can be used to test for simultaneous support |
| 78 # of 'long long' and 'unsigned long long'. We don't want to say that |
| 79 # 'long long' is available if 'unsigned long long' is not, or vice versa, |
| 80 # because too many programs rely on the symmetry between signed and unsigned |
| 81 # integer types (excluding 'bool'). |
| 82 AC_DEFUN([_AC_TYPE_LONG_LONG_SNIPPET], |
| 83 [ |
| 84 AC_LANG_PROGRAM( |
| 85 [[/* For now, do not test the preprocessor; as of 2007 there are too many |
| 86 implementations with broken preprocessors. Perhaps this can |
| 87 be revisited in 2012. In the meantime, code should not expect |
| 88 #if to work with literals wider than 32 bits. */ |
| 89 /* Test literals. */ |
| 90 long long int ll = 9223372036854775807ll; |
| 91 long long int nll = -9223372036854775807LL; |
| 92 unsigned long long int ull = 18446744073709551615ULL; |
| 93 /* Test constant expressions. */ |
| 94 typedef int a[((-9223372036854775807LL < 0 && 0 < 9223372036854775807ll) |
| 95 ? 1 : -1)]; |
| 96 typedef int b[(18446744073709551615ULL <= (unsigned long long int) -1 |
| 97 ? 1 : -1)]; |
| 98 int i = 63;]], |
| 99 [[/* Test availability of runtime routines for shift and division. */ |
| 100 long long int llmax = 9223372036854775807ll; |
| 101 unsigned long long int ullmax = 18446744073709551615ull; |
| 102 return ((ll << 63) | (ll >> 63) | (ll < i) | (ll > i) |
| 103 | (llmax / ll) | (llmax % ll) |
| 104 | (ull << 63) | (ull >> 63) | (ull << i) | (ull >> i) |
| 105 | (ullmax / ull) | (ullmax % ull));]]) |
| 106 ]) |
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