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Use a more robust detection of __builtin_bswap funtions for Clang. Fix Clang lack of __builtin_bswap16 in some releases. To be conservative only, fallback to byteswap.h if __linux__ is defined. Fix intrinsic_test so that <cstdint> isn't required.

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This commit is contained in:
Beman
2013-05-16 17:22:38 -04:00
parent 4066443d89
commit 9a1d520572
2 changed files with 25 additions and 11 deletions
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28
include/boost/endian/detail/intrinsic.hpp
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@ -9,37 +9,46 @@
#ifndef BOOST_ENDIAN_INTRINSIC_HPP
#define BOOST_ENDIAN_INTRINSIC_HPP
// Allow user to force BOOST_ENDIAN_NO_INTRINSICS in case they aren't available for a
// particular platform/compiler combination. Please report such platform/compiler
// combinations to the Boost mailing list.
#ifndef BOOST_ENDIAN_NO_INTRINSICS
#ifndef __has_builtin // Optional of course
#define __has_builtin(x) 0 // Compatibility with non-clang compilers
#endif
#if (defined(__clang__) && __has_builtin(__builtin_bswap16)) \
// GCC and Clang recent versions provide intrinsic byte swaps via builtins
#if (defined(__clang__) && __has_builtin(__builtin_bswap32) && __has_builtin(__builtin_bswap64)) \
|| (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)
// Clang has a similar problem, but their feature test macros make it easier to detect
# if (defined(__clang__) && __has_builtin(__builtin_bswap16)) \
|| (defined(__GNUC__) &&(__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."
// Linux systems provide the byteswap.h header, with
#elif defined(__linux__)
// don't check for obsolete forms defined(linux) and defined(__linux) on the theory that
// compilers that predefine only these are so old that byteswap.h probably isn't present.
# define BOOST_ENDIAN_INTRINSIC_MSG "byteswap.h 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
#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).
# define BOOST_ENDIAN_INTRINSIC_MSG "_byteswap_ushort, etc."
# define BOOST_ENDIAN_INTRINSIC_MSG "cstdlib _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)
@ -49,4 +58,5 @@
# define BOOST_ENDIAN_INTRINSIC_MSG "no byte swap intrinsics"
#endif
#endif // BOOST_ENDIAN_INTRINSIC_HPP
#endif // BOOST_ENDIAN_NO_INTRINSICS
#endif // BOOST_ENDIAN_INTRINSIC_HPP

8
test/intrinsic_test.cpp
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@ -3,10 +3,14 @@
// Distributed under the Boost Software License, Version 1.0.
// http://www.boost.org/LICENSE_1_0.txt
#include "intrinsic.hpp"
#include "test.hpp"
#include <iostream>
#include <cassert>
#include <cstdint>
//#include <cstdint>
typedef unsigned short uint16_t;
typedef unsigned int uint32_t;
typedef unsigned long long uint64_t;
int main()
{