github.com/searKing/golang/go@v1.2.117/os/signal/cgo/include/boost/predef/hardware/simd.h (about)

     1  /*
     2  Copyright Charly Chevalier 2015
     3  Copyright Joel Falcou 2015
     4  Distributed under the Boost Software License, Version 1.0.
     5  (See accompanying file LICENSE_1_0.txt or copy at
     6  http://www.boost.org/LICENSE_1_0.txt)
     7  */
     8  
     9  #include <boost/predef/hardware/simd/x86.h>
    10  #include <boost/predef/hardware/simd/x86_amd.h>
    11  #include <boost/predef/hardware/simd/arm.h>
    12  #include <boost/predef/hardware/simd/ppc.h>
    13  
    14  #ifndef BOOST_PREDEF_HARDWARE_SIMD_H
    15  #define BOOST_PREDEF_HARDWARE_SIMD_H
    16  
    17  #include <boost/predef/version_number.h>
    18  
    19  /* tag::reference[]
    20  = Using the `BOOST_HW_SIMD_*` predefs
    21  
    22  SIMD predefs depend on compiler options. For example, you will have to add the
    23  option `-msse3` to clang or gcc to enable SSE3. SIMD predefs are also inclusive.
    24  This means that if SSE3 is enabled, then every other extensions with a lower
    25  version number will implicitly be enabled and detected. However, some extensions
    26  are CPU specific, they may not be detected nor enabled when an upper version is
    27  enabled.
    28  
    29  NOTE: SSE(1) and SSE2 are automatically enabled by default when using x86-64
    30  architecture.
    31  
    32  To check if any SIMD extension has been enabled, you can use:
    33  
    34  [source]
    35  ----
    36  #include <boost/predef/hardware/simd.h>
    37  #include <iostream>
    38  
    39  int main()
    40  {
    41  #if defined(BOOST_HW_SIMD_AVAILABLE)
    42      std::cout << "SIMD detected!" << std::endl;
    43  #endif
    44      return 0;
    45  }
    46  ----
    47  
    48  When writing SIMD specific code, you may want to check if a particular extension
    49  has been detected. To do so you have to use the right architecture predef and
    50  compare it. Those predef are of the form `BOOST_HW_SIMD_"ARCH"` (where `"ARCH"`
    51  is either `ARM`, `PPC`, or `X86`). For example, if you compile code for x86
    52  architecture, you will have to use `BOOST_HW_SIMD_X86`. Its value will be the
    53  version number of the most recent SIMD extension detected for the architecture.
    54  
    55  To check if an extension has been enabled:
    56  
    57  [source]
    58  ----
    59  #include <boost/predef/hardware/simd.h>
    60  #include <iostream>
    61  
    62  int main()
    63  {
    64  #if BOOST_HW_SIMD_X86 >= BOOST_HW_SIMD_X86_SSE3_VERSION
    65      std::cout << "This is SSE3!" << std::endl;
    66  #endif
    67      return 0;
    68  }
    69  ----
    70  
    71  NOTE: The *_VERSION* defines that map version number to actual real
    72  identifiers. This way it is easier to write comparisons without messing up with
    73  version numbers.
    74  
    75  To *"strictly"* check the most recent detected extension:
    76  
    77  [source]
    78  ----
    79  #include <boost/predef/hardware/simd.h>
    80  #include <iostream>
    81  
    82  int main()
    83  {
    84  #if BOOST_HW_SIMD_X86 == BOOST_HW_SIMD_X86_SSE3_VERSION
    85      std::cout << "This is SSE3 and this is the most recent enabled extension!"
    86          << std::endl;
    87  #endif
    88      return 0;
    89  }
    90  ----
    91  
    92  Because of the version systems of predefs and of the inclusive property of SIMD
    93  extensions macros, you can easily check for ranges of supported extensions:
    94  
    95  [source]
    96  ----
    97  #include <boost/predef/hardware/simd.h>
    98  #include <iostream>
    99  
   100  int main()
   101  {
   102  #if BOOST_HW_SIMD_X86 >= BOOST_HW_SIMD_X86_SSE2_VERSION &&\
   103      BOOST_HW_SIMD_X86 <= BOOST_HW_SIMD_X86_SSSE3_VERSION
   104      std::cout << "This is SSE2, SSE3 and SSSE3!" << std::endl;
   105  #endif
   106      return 0;
   107  }
   108  ----
   109  
   110  NOTE: Unlike gcc and clang, Visual Studio does not allow you to specify precisely
   111  the SSE variants you want to use, the only detections that will take place are
   112  SSE, SSE2, AVX and AVX2. For more informations,
   113      see [@https://msdn.microsoft.com/en-us/library/b0084kay.aspx here].
   114  
   115  
   116  */ // end::reference[]
   117  
   118  // We check if SIMD extension of multiples architectures have been detected,
   119  // if yes, then this is an error!
   120  //
   121  // NOTE: _X86_AMD implies _X86, so there is no need to check for it here!
   122  //
   123  #if defined(BOOST_HW_SIMD_ARM_AVAILABLE) && defined(BOOST_HW_SIMD_PPC_AVAILABLE) ||\
   124      defined(BOOST_HW_SIMD_ARM_AVAILABLE) && defined(BOOST_HW_SIMD_X86_AVAILABLE) ||\
   125      defined(BOOST_HW_SIMD_PPC_AVAILABLE) && defined(BOOST_HW_SIMD_X86_AVAILABLE)
   126  #   error "Multiple SIMD architectures detected, this cannot happen!"
   127  #endif
   128  
   129  #if defined(BOOST_HW_SIMD_X86_AVAILABLE) && defined(BOOST_HW_SIMD_X86_AMD_AVAILABLE)
   130      // If both standard _X86 and _X86_AMD are available,
   131      // then take the biggest version of the two!
   132  #   if BOOST_HW_SIMD_X86 >= BOOST_HW_SIMD_X86_AMD
   133  #      define BOOST_HW_SIMD BOOST_HW_SIMD_X86
   134  #   else
   135  #      define BOOST_HW_SIMD BOOST_HW_SIMD_X86_AMD
   136  #   endif
   137  #endif
   138  
   139  #if !defined(BOOST_HW_SIMD)
   140      // At this point, only one of these two is defined
   141  #   if defined(BOOST_HW_SIMD_X86_AVAILABLE)
   142  #      define BOOST_HW_SIMD BOOST_HW_SIMD_X86
   143  #   endif
   144  #   if defined(BOOST_HW_SIMD_X86_AMD_AVAILABLE)
   145  #      define BOOST_HW_SIMD BOOST_HW_SIMD_X86_AMD
   146  #   endif
   147  #endif
   148  
   149  #if defined(BOOST_HW_SIMD_ARM_AVAILABLE)
   150  #   define BOOST_HW_SIMD BOOST_HW_SIMD_ARM
   151  #endif
   152  
   153  #if defined(BOOST_HW_SIMD_PPC_AVAILABLE)
   154  #   define BOOST_HW_SIMD BOOST_HW_SIMD_PPC
   155  #endif
   156  
   157  #if defined(BOOST_HW_SIMD)
   158  #   define BOOST_HW_SIMD_AVAILABLE
   159  #else
   160  #   define BOOST_HW_SIMD BOOST_VERSION_NUMBER_NOT_AVAILABLE
   161  #endif
   162  
   163  #define BOOST_HW_SIMD_NAME "Hardware SIMD"
   164  
   165  #endif
   166  
   167  #include <boost/predef/detail/test.h>
   168  BOOST_PREDEF_DECLARE_TEST(BOOST_HW_SIMD, BOOST_HW_SIMD_NAME)