RunCPUSettings.h

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/*
Copyright (C) 2024 Scott Grauer-Gray
 
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
 
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.
 
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
*/
 
#ifndef RUNCPUSETTINGS_H_
#define RUNCPUSETTINGS_H_
 
#include <vector>
#include <array>
#include <thread>
#include <set>
 
//check if running on ARM architecture
#if defined(COMPILING_FOR_ARM)
#include <arm_neon.h> //needed for float16_t type
#endif
 
//define and set CPU vectorization options using preprocessor
//needed to determine what code gets compiled to support vectorization
#define AVX_256_DEFINE 0
#define AVX_256_F16_DEFINE 1
#define AVX_512_DEFINE 2
#define AVX_512_F16_DEFINE 3
#define NEON_DEFINE 4
#define NO_VECTORIZATION 5
#if defined(COMPILING_FOR_ARM) //NEON supported on ARM but AVX is not
#define CPU_VECTORIZATION_DEFINE NEON_DEFINE
#else
//by default CPU vectorization during compilation via Makefile
//use AVX 512 if not set during compilation
#if defined(AVX_512_VECTORIZATION)
#define CPU_VECTORIZATION_DEFINE AVX_512_DEFINE
#elif defined(AVX_512_F16_VECTORIZATION)
#define CPU_VECTORIZATION_DEFINE AVX_512_F16_DEFINE
#elif defined(AVX_256_VECTORIZATION)
#define CPU_VECTORIZATION_DEFINE AVX_256_DEFINE
#elif defined(AVX_256_F16_VECTORIZATION)
#define CPU_VECTORIZATION_DEFINE AVX_256_F16_DEFINE
#else
#define CPU_VECTORIZATION_DEFINE AVX_512_DEFINE
#endif //defined(AVX_512_VECTORIZATION)
#endif //COMPILING_FOR_ARM
 
namespace run_cpu {
 
constexpr std::string_view kSimulateSingleCPU{"SimulateSingleCPU"};
 
const unsigned int kNumThreadsCPU{std::thread::hardware_concurrency()};
 
const unsigned int kMinNumThreadsRun{std::min(kNumThreadsCPU, 4u)};
 
const std::array<unsigned int, 2> kParallelParamsDefault{
  {kNumThreadsCPU, 1}};
 
#if defined(DEFAULT_PARALLEL_PARAMS_ONLY)
 
const std::set<std::array<unsigned int, 2>> kParallelParameterAltOptions{};
 
#elif defined(LIMITED_ALT_PARALLEL_PARAMS)
 
const std::set<std::array<unsigned int, 2>> kParallelParameterAltOptions{
  { kNumThreadsCPU, 1},
  { kNumThreadsCPU / 2, 1}};
 
#else
 
const std::set<std::array<unsigned int, 2>> kParallelParameterAltOptions{
  { kNumThreadsCPU, 1}, 
  { (3 * kNumThreadsCPU) / 4 , 1}, 
  { kNumThreadsCPU / 2, 1},
  { kNumThreadsCPU / 4, 1},
  { kNumThreadsCPU / 8, 1}};
 
#endif
 
};
 
#endif /* RUNCPUSETTINGS_H_ */