include/Vc/support.h

0001 /*  This file is part of the Vc library. {{{
0002 Copyright © 2010-2015 Matthias Kretz <kretz@kde.org>
0003
0004 Redistribution and use in source and binary forms, with or without
0005 modification, are permitted provided that the following conditions are met:
0006     * Redistributions of source code must retain the above copyright
0007       notice, this list of conditions and the following disclaimer.
0008     * Redistributions in binary form must reproduce the above copyright
0009       notice, this list of conditions and the following disclaimer in the
0010       documentation and/or other materials provided with the distribution.
0011     * Neither the names of contributing organizations nor the
0012       names of its contributors may be used to endorse or promote products
0013       derived from this software without specific prior written permission.
0014
0015 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
0016 ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
0017 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
0018 DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE FOR ANY
0019 DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
0020 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
0021 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
0022 ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
0023 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
0024 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
0025
0026 }}}*/
0027
0028 #ifndef VC_COMMON_SUPPORT_H_
0029 #define VC_COMMON_SUPPORT_H_
0030
0031 #ifndef VC_GLOBAL_H_
0032 #error "Vc/global.h must be included first!"
0033 #endif
0034
0035 #if defined __x86_64__ || defined __amd64__ || defined __amd64 || defined __x86_64 ||    \
0036     defined _M_AMD64 || defined __i386__
0037 #include <Vc/cpuid.h>
0038 #endif
0039
0040 #if defined(Vc_GCC) && Vc_GCC >= 0x40400 && defined __SSE__
0041 #define Vc_TARGET_NO_SIMD __attribute__((target("no-sse2,no-avx")))
0042 #else
0043 #define Vc_TARGET_NO_SIMD
0044 #endif
0045
0046 #include "common/macros.h"
0047 namespace Vc_VERSIONED_NAMESPACE
0048 {
0049
0050 /**
0051  * \name Micro-Architecture Feature Tests
0052  */
0053 //@{
0054 /**
0055  * \ingroup Utilities
0056  * \headerfile support.h <Vc/support.h>
0057  * Determines the extra instructions supported by the current CPU.
0058  *
0059  * \return A combination of flags from Vc::ExtraInstructions that the current CPU supports.
0060  */
0061 Vc_TARGET_NO_SIMD
0062 unsigned int extraInstructionsSupported();
0063
0064 /**
0065  * \ingroup Utilities
0066  * \headerfile support.h <Vc/support.h>
0067  *
0068  * Tests whether the given implementation is supported by the system the code is executing on.
0069  *
0070  * \return \c true if the OS and hardware support execution of instructions defined by \p impl.
0071  * \return \c false otherwise
0072  *
0073  * \param impl The SIMD target to test for.
0074  */
0075 Vc_TARGET_NO_SIMD bool Vc_VDECL isImplementationSupported(Vc::Implementation impl);
0076
0077 /**
0078  * \internal
0079  * \ingroup Utilities
0080  * \headerfile support.h <Vc/support.h>
0081  *
0082  * Tests whether the given implementation is supported by the system the code is executing on.
0083  *
0084  * \code
0085  * if (!isImplementationSupported<Vc::CurrentImplementation>()) {
0086  *   std::cerr << "This code was compiled with features that this system does not support.\n";
0087  *   return EXIT_FAILURE;
0088  * }
0089  * \endcode
0090  *
0091  * \return \c true if the OS and hardware support execution of instructions defined by \p impl.
0092  * \return \c false otherwise
0093  *
0094  * \tparam Impl The SIMD target to test for.
0095  */
0096 template<typename Impl>
0097 Vc_TARGET_NO_SIMD
0098 static inline bool isImplementationSupported()
0099 {
0100     return isImplementationSupported(Impl::current()) &&
0101            Impl::runs_on(extraInstructionsSupported());
0102 }
0103
0104 /**
0105  * \ingroup Utilities
0106  * \headerfile support.h <Vc/support.h>
0107  *
0108  * Determines the best supported implementation for the current system.
0109  *
0110  * \return The enum value for the best implementation.
0111  */
0112 Vc_TARGET_NO_SIMD
0113 Vc::Implementation bestImplementationSupported();
0114
0115 #ifndef Vc_COMPILE_LIB
0116 /**
0117  * \ingroup Utilities
0118  * \headerfile support.h <Vc/support.h>
0119  *
0120  * Tests that the CPU and Operating System support the vector unit which was compiled for. This
0121  * function should be called before any other Vc functionality is used. It checks whether the program
0122  * will work. If this function returns \c false then the program should exit with a useful error
0123  * message before the OS has to kill it because of an invalid instruction exception.
0124  *
0125  * If the program continues and makes use of any vector features not supported by
0126  * hard- or software then the program will crash.
0127  *
0128  * Example:
0129  * \code
0130  * int main()
0131  * {
0132  *   if (!Vc::currentImplementationSupported()) {
0133  *     std::cerr << "CPU or OS requirements not met for the compiled in vector unit!\n";
0134  *     exit -1;
0135  *   }
0136  *   ...
0137  * }
0138  * \endcode
0139  *
0140  * \return \c true if the OS and hardware support execution of the currently selected SIMD
0141  *                 instructions.
0142  * \return \c false otherwise
0143  */
0144 Vc_TARGET_NO_SIMD
0145 #ifndef DOXYGEN
0146 static
0147 #endif
0148 inline bool currentImplementationSupported()
0149 {
0150     return isImplementationSupported<Vc::CurrentImplementation>();
0151 }
0152 #endif // Vc_COMPILE_LIB
0153 //@}
0154
0155 }
0156
0157 #undef Vc_TARGET_NO_SIMD
0158
0159 #endif // VC_COMMON_SUPPORT_H_