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// (C) Copyright John Maddock 2012.
// (C) Copyright Dynatrace 2017.
// Use, modification and distribution are subject to the
// Boost Software License, Version 1.0. (See accompanying file
// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
// See http://www.boost.org/libs/config for most recent version.
// MACRO: BOOST_HAS_INT128
// TITLE: __int128
// DESCRIPTION: The platform supports __int128.
#include <cstdlib>
#include <stdio.h>
#include <limits.h>
namespace boost_has_int128{
#ifdef __GNUC__
__extension__ typedef __int128 my_int128_t;
__extension__ typedef unsigned __int128 my_uint128_t;
#else
typedef __int128 my_int128_t;
typedef unsigned __int128 my_uint128_t;
#endif
my_uint128_t volatile g_ui128 = 0;
unsigned long volatile g_ul = 0;
int test()
{
my_int128_t si128 = 0;
(void)&si128;
// Some compilers have seriously broken __int128 implementations, so we need to do a little more than simply check if we can declare variables with __int128...
// #1: check __int128 size
if (sizeof(my_uint128_t) < (128 / CHAR_BIT))
{
fputs("Type too small.", stderr);
return 1;
}
// #2: check result of computation with __int128
my_uint128_t p1 = 1;
my_uint128_t p2 = 1;
unsigned int i = 0;
for (; i < 180; i++)
{
g_ui128 = p1 + p2;
if (g_ui128 < p1)
{
fputs("Unexpected overflow.", stderr);
return 1;
}
p2 = p1;
p1 = g_ui128;
}
g_ul = static_cast<unsigned long>((g_ui128 >> 92) & 0xFFFFFFFFUL);
g_ul -= 1216382273UL;
if (g_ul != 0)
{
fputs("Incorrect computation result.", stderr);
return 1;
}
return 0;
}
}
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