tsc.h

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/*
    Copyright (C) 2009-2014 Matthias Kretz <kretz@kde.org>
 
    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) version 3.
 
    This library 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
    Library General Public License for more details.
 
    You should have received a copy of the GNU Library General Public License
    along with this library; see the file COPYING.LIB.  If not, write to
    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
    Boston, MA 02110-1301, USA.
 
*/
 
#ifndef SRC_INCLUDE_SMASH_TSC_H_
#define SRC_INCLUDE_SMASH_TSC_H_
 
#ifndef USE_NANOBENCHMARKING_CODE
#error "Nanobenchmark code tried to be used without enabling it via CMake."
#else
 
#include <cstdint>
#include <iosfwd>
 
#ifdef _MSC_VER
#include <intrin.h>
#pragma intrinsic(__rdtsc)
#endif
 
namespace smash {
 
class TimeStampCounter {
 public:
  void start();
 
  void stop();
 
  uint64_t cycles() const;
 
 private:
  union Data {
    uint64_t a;
    unsigned int b[2];
  };
  Data m_start;
  Data m_end;
};
 
inline void TimeStampCounter::start() {
#ifdef VC_IMPL_MIC
  asm volatile("xor %%eax,%%eax\n\tcpuid\n\trdtsc"
               : "=a"(m_start.b[0]), "=d"(m_start.b[1])::"ebx", "ecx");
#elif defined _MSC_VER
  unsigned int tmp;
  m_start.a = __rdtscp(&tmp);
#else
  asm volatile("rdtscp" : "=a"(m_start.b[0]), "=d"(m_start.b[1])::"ecx");
#endif
}
 
inline void TimeStampCounter::stop() {
#ifdef VC_IMPL_MIC
  asm volatile("xor %%eax,%%eax\n\tcpuid\n\trdtsc"
               : "=a"(m_end.b[0]), "=d"(m_end.b[1])::"ebx", "ecx");
#elif defined _MSC_VER
  unsigned int tmp;
  m_end.a = __rdtscp(&tmp);
#else
  asm volatile("rdtscp" : "=a"(m_end.b[0]), "=d"(m_end.b[1])::"ecx");
#endif
}
 
inline uint64_t TimeStampCounter::cycles() const { return m_end.a - m_start.a; }
 
std::ostream &operator<<(std::ostream &out, const TimeStampCounter &tsc);
 
}  // namespace smash
 
#endif  // USE_NANOBENCHMARKING_CODE
#endif  // SRC_INCLUDE_SMASH_TSC_H_