include/tools/simdsupport.hxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  *
   9  */
  10
  11 // IMPORTANT: Having CPU-specific routines turned out to be a maintenance
  12 // problem, because of various problems such as compilers moving CPU-specific
  13 // code out of #ifdef code into static initialization or our code using C++
  14 // features that caused the compiler to emit code that used CPU-specific
  15 // instructions (even cpuid.hxx isn't safe, see the comment there).
  16 // The only safe usage is using CPU-specific code that's always available,
  17 // such as SSE2-specific code for x86_64. Do not use for anything else
  18 // unless you really know what you are doing (and you check git history
  19 // to learn from past problems).
  20
  21 // Determine the compiler support for SIMD compiler intrinsics.
  22 // This changes from one compiled unit to the other, depending if
  23 // the support has been detected and if the compiled unit contains
  24 // code using intrinsics or not. So we have to (re)set them again
  25 // every time this file has been included.
  26
  27 // In other words... DO NOT ADD "#pragma once" here
  28
  29 #undef LO_SSE2_AVAILABLE
  30 #undef LO_SSSE3_AVAILABLE
  31 #undef LO_AVX_AVAILABLE
  32 #undef LO_AVX2_AVAILABLE
  33 #undef LO_AVX512F_AVAILABLE
  34
  35 #if defined(_MSC_VER) // VISUAL STUDIO COMPILER
  36
  37 // With MSVC using -arch is in fact not necessary for being able
  38 // to use CPU intrinsics, code using AVX512F intrinsics will compile
  39 // even if compiled with -arch:AVX, the -arch option really only affects
  40 // instructions generated for C/C++ code.
  41 #if defined(_M_X64) || defined(_M_X86)
  42 // As such, if we're building for X86 or X64, support for these is always available
  43 // with MSVC2019+.
  44 #define LO_SSE2_AVAILABLE
  45 #define LO_SSSE3_AVAILABLE
  46 #define LO_AVX_AVAILABLE
  47 #define LO_AVX2_AVAILABLE
  48 #define LO_AVX512F_AVAILABLE
  49 #include <intrin.h>
  50 #include <immintrin.h>
  51 #endif
  52
  53 #else // compiler Clang and GCC
  54
  55 #if defined(__SSE2__) || defined(__x86_64__) // SSE2 is required for X64
  56 #define LO_SSE2_AVAILABLE
  57 #include <emmintrin.h>
  58 #endif // defined(__SSE2__)
  59
  60 #if defined(__SSSE3__)
  61 #define LO_SSSE3_AVAILABLE
  62 #include <tmmintrin.h>
  63 #endif // defined(__SSSE3__)
  64
  65 #if defined(__AVX__)
  66 #define LO_AVX_AVAILABLE
  67 #include <immintrin.h>
  68 #endif // defined(__AVX__)
  69
  70 #if defined(__AVX2__)
  71 #define LO_AVX2_AVAILABLE
  72 #include <immintrin.h>
  73 #endif // defined(__AVX2__)
  74
  75 #if defined(__AVX512F__)
  76 #define LO_AVX512F_AVAILABLE
  77 #include <immintrin.h>
  78 #else
  79 #endif // defined(__AVX512F__)
  80
  81 #endif // end compiler Clang and GCC
  82
  83 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */