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Rework intrinsic.hpp to handle GCC and Clang __builtin_bswap* if available. Add test program.

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Beman
2013-05-16 10:40:18 -04:00
parent 88268249a9
commit 4066443d89
3 changed files with 66 additions and 15 deletions
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55
include/boost/endian/detail/intrinsic.hpp
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@@ -1,27 +1,52 @@
// Copyright (C) 2012 David Stone
// Distributed under the Boost Software License, Version 1.0.
// http://www.boost.org/LICENSE_1_0.txt
//
// See http://www.boost.org/libs/endian/ for documentation.
// endian/detail/intrinsic.hpp -------------------------------------------------------//
// Copyright (C) 2012 David Stone
// Copyright Beman Dawes 2013
// Distributed under the Boost Software License, Version 1.0.
// http://www.boost.org/LICENSE_1_0.txt
#ifndef BOOST_ENDIAN_INTRINSIC_HPP
#define BOOST_ENDIAN_INTRINSIC_HPP
#if ((defined __GNUC__ && !defined(__MINGW32__)) || defined __clang__)
#include <byteswap.h>
#define BOOST_ENDIAN_INTRINSIC_BYTE_SWAP_2 bswap_16
#define BOOST_ENDIAN_INTRINSIC_BYTE_SWAP_4 bswap_32
#define BOOST_ENDIAN_INTRINSIC_BYTE_SWAP_8 bswap_64
#ifndef __has_builtin // Optional of course
#define __has_builtin(x) 0 // Compatibility with non-clang compilers
#endif
#if (defined(__clang__) && __has_builtin(__builtin_bswap16)) \
|| (defined(__GNUC__ ) && \
(__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3)))
# define BOOST_ENDIAN_INTRINSIC_MSG "__builtin_bswap16, etc."
// prior to 4.8, gcc did not provide __builtin_bswap16 on some platforms so we emulate it
// see http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52624
# if defined(__clang__) || __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 8)
# define BOOST_ENDIAN_INTRINSIC_BYTE_SWAP_2(x) __builtin_bswap16(x)
# else
# define BOOST_ENDIAN_INTRINSIC_BYTE_SWAP_2(x) __builtin_bswap32((x) << 16)
# endif
# define BOOST_ENDIAN_INTRINSIC_BYTE_SWAP_4(x) __builtin_bswap32(x)
# define BOOST_ENDIAN_INTRINSIC_BYTE_SWAP_8(x) __builtin_bswap64(x)
#elif ((defined __GNUC__ && !defined(__MINGW32__)) || defined(__clang__))
# define BOOST_ENDIAN_INTRINSIC_MSG "__builtin_bswap_16, etc."
# include <byteswap.h>
# define BOOST_ENDIAN_INTRINSIC_BYTE_SWAP_2(x) bswap_16(x)
# define BOOST_ENDIAN_INTRINSIC_BYTE_SWAP_4(x) bswap_32(x)
# define BOOST_ENDIAN_INTRINSIC_BYTE_SWAP_8(x) bswap_64(x)
#elif defined _MSC_VER
// Microsoft documents these as being compatible since Windows 95 and specificly
// lists runtime library support since Visual Studio 2003 (aka 7.1).
#include <cstdlib>
#define BOOST_ENDIAN_INTRINSIC_BYTE_SWAP_2 _byteswap_ushort
#define BOOST_ENDIAN_INTRINSIC_BYTE_SWAP_4 _byteswap_ulong
#define BOOST_ENDIAN_INTRINSIC_BYTE_SWAP_8 _byteswap_uint64
# define BOOST_ENDIAN_INTRINSIC_MSG "_byteswap_ushort, etc."
# include <cstdlib>
# define BOOST_ENDIAN_INTRINSIC_BYTE_SWAP_2(x) _byteswap_ushort(x)
# define BOOST_ENDIAN_INTRINSIC_BYTE_SWAP_4(x) _byteswap_ulong(x)
# define BOOST_ENDIAN_INTRINSIC_BYTE_SWAP_8(x) _byteswap_uint64(x)
#else
#define BOOST_ENDIAN_NO_INTRINSICS
# define BOOST_ENDIAN_NO_INTRINSICS
# define BOOST_ENDIAN_INTRINSIC_MSG "no byte swap intrinsics"
#endif
#endif // BOOST_ENDIAN_INTRINSIC_HPP

2
test/converter_test.cpp
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@@ -239,6 +239,8 @@ namespace
int cpp_main(int, char * [])
{
cout << "byte swap intrinsics: " BOOST_ENDIAN_INTRINSIC_MSG << endl;
//std::cerr << std::hex;
cout << "int16_t" << endl;

24
test/intrinsic_test.cpp Normal file
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@@ -0,0 +1,24 @@
// Copyright Beman Dawes 2013
// Distributed under the Boost Software License, Version 1.0.
// http://www.boost.org/LICENSE_1_0.txt
#include "intrinsic.hpp"
#include <iostream>
#include <cassert>
#include <cstdint>
int main()
{
std::cout << "BOOST_ENDIAN_INTRINSIC_MSG: " BOOST_ENDIAN_INTRINSIC_MSG << std::endl;
#ifndef BOOST_ENDIAN_NO_INTRINSICS
uint16_t x2 = 0x1122U;
assert(BOOST_ENDIAN_INTRINSIC_BYTE_SWAP_2(x2) == 0x2211U);
uint32_t x4 = 0x11223344UL;
assert(BOOST_ENDIAN_INTRINSIC_BYTE_SWAP_4(x4) == 0x44332211UL);
uint64_t x8 = 0x1122334455667788U;
assert(BOOST_ENDIAN_INTRINSIC_BYTE_SWAP_8(x8) == 0x8877665544332211ULL);
#endif
return 0;
}