// -*-C++-*-

#define VML_NODEBUG

#include "vecmathlib.h"

#include <cmath>
#include <cstdlib>
#include <iomanip>
#include <iostream>
#include <string>

#include <sys/time.h>
#include <time.h>

using namespace std;
using namespace vecmathlib;



#ifndef __has_builtin
#  define __has_builtin(x) 0 // Compatibility with non-clang compilers
#endif



typedef unsigned long long ticks;
inline ticks getticks()
{
#if __has_builtin(__builtin_readcyclecounter)
  return __builtin_readcyclecounter();
#elif defined __x86_64__
  ticks a, d;
  asm volatile("rdtsc" : "=a" (a), "=d" (d));
  return a | (d << 32);
#elif defined __powerpc__
  unsigned int tbl, tbu, tbu1;
  do {
    asm volatile("mftbu %0": "=r"(tbu));
    asm volatile("mftb %0": "=r"(tbl));
    asm volatile("mftbu %0": "=r"(tbu1));
  } while (tbu != tbu1);
  return ((unsigned long long)tbu << 32) | tbl;
#else
  timeval tv;
  gettimeofday(&tv, NULL);
  return 1000000ULL * tv.tv_sec + tv.tv_usec;
  // timespec ts;
  // clock_gettime(CLOCK_REALTIME, &ts);
  // return 1000000000ULL * ts.tv_sec + ts.tv_nsec;
#endif
}
inline double elapsed(ticks t1, ticks t0)
{
  return t1-t0;
}

double get_sys_time()
{
  timeval tv;
  gettimeofday(&tv, NULL);
  return tv.tv_sec + 1.0e-6 * tv.tv_usec;
  // timespec ts;
  // clock_gettime(CLOCK_REALTIME, &ts);
  // return ts.tv_sec + 1.0e-9 * ts.tv_nsec;
}

double measure_tick()
{
  ticks const rstart = getticks();
  double const wstart = get_sys_time();
  while (get_sys_time() - wstart < 0.1) {
    // do nothing, just wait
  }
  ticks const rend = getticks();
  double const wend = get_sys_time();
  assert(wend-wstart >= 0.09);
  return (wend - wstart) / elapsed(rend, rstart);
}



double global_result = 0.0;
template<typename realvec_t>
void save_result(realvec_t result)
{
  for (int i=0; i<realvec_t::size; ++i) {
    global_result += result[i];
  }
}



template<typename T> inline T nop(T x) { return x; }

#define DECLARE_FUNCTOR(FUNC, XMIN, XMAX)                       \
  template<typename T>                                          \
  struct functor_##FUNC {                                       \
    static typename T::real_t get_xmin() { return XMIN; }       \
    static typename T::real_t get_xmax() { return XMAX; }       \
    static const char* name() { return #FUNC; }                 \
    T operator()(T x) { return FUNC(x); }                       \
  }

DECLARE_FUNCTOR(nop, 0.0, 1.0);

DECLARE_FUNCTOR(acos, -0.5, +0.5);
DECLARE_FUNCTOR(acosh, 0.0, 1.0);
DECLARE_FUNCTOR(asin, -0.5, +0.5);
DECLARE_FUNCTOR(asinh, -1.0, +1.0);
DECLARE_FUNCTOR(atan, -1.0, +1.0);
// DECLARE_FUNCTOR(atan2, 0.0);
DECLARE_FUNCTOR(atanh, -0.5, +0.5);
DECLARE_FUNCTOR(cbrt, -1.0, 1.0);
DECLARE_FUNCTOR(ceil, -1.0, +1.0);
// DECLARE_FUNCTOR(copysign, 0.0);
DECLARE_FUNCTOR(cos, 0.0, 1.0);
DECLARE_FUNCTOR(cosh, 0.0, 1.0);
DECLARE_FUNCTOR(exp, 0.0, 1.0);
DECLARE_FUNCTOR(exp10, 0.0, 1.0);
DECLARE_FUNCTOR(exp2, 0.0, 1.0);
DECLARE_FUNCTOR(expm1, 0.0, 1.0);
DECLARE_FUNCTOR(fabs, -1.0, 1.0);
DECLARE_FUNCTOR(floor, -1.0, +1.0);
// DECLARE_FUNCTOR(fdim, 0.0);
// DECLARE_FUNCTOR(fma, 0.0);
// DECLARE_FUNCTOR(fmax, 0.0);
// DECLARE_FUNCTOR(fmin, 0.0);
// DECLARE_FUNCTOR(fmod, 0.0);
// DECLARE_FUNCTOR(frexp, 0.0);
// DECLARE_FUNCTOR(hypot, 0.0);
// DECLARE_FUNCTOR(ilogb, 0.0);
// DECLARE_FUNCTOR(isfinite, 0.0);
// DECLARE_FUNCTOR(isinf, 0.0);
// DECLARE_FUNCTOR(isnan, 0.0);
// DECLARE_FUNCTOR(isnormal, 0.0);
// DECLARE_FUNCTOR(ldexp, 0.0);
// DECLARE_FUNCTOR(ldexp, 0.0);
DECLARE_FUNCTOR(log, 1.0, 2.0);
DECLARE_FUNCTOR(log10, 1.0, 2.0);
DECLARE_FUNCTOR(log1p, 0.0, 1.0);
DECLARE_FUNCTOR(log2, 1.0, 2.0);
// DECLARE_FUNCTOR(nextafter, 0.0);
// DECLARE_FUNCTOR(pow, 0.0);
DECLARE_FUNCTOR(rcp, 1.0, 2.0);
// DECLARE_FUNCTOR(remainder, 0.0);
DECLARE_FUNCTOR(rint, -1.0, +1.0);
DECLARE_FUNCTOR(round, -1.0, +1.0);
DECLARE_FUNCTOR(rsqrt, 0.0, 1.0);
// DECLARE_FUNCTOR(signbit, 0.0);
DECLARE_FUNCTOR(sin, 0.0, 1.0);
DECLARE_FUNCTOR(sinh, -1.0, +1.0);
DECLARE_FUNCTOR(sqrt, 0.0, 1.0);
DECLARE_FUNCTOR(tan, 0.0, 1.0);
DECLARE_FUNCTOR(tanh, -1.0, +1.0);
DECLARE_FUNCTOR(trunc, -1.0, +1.0);



template<typename realvec_t, template<typename> class func_t>
double run_bench()
{
  const int numiters = 10000000;
  
  typedef typename realvec_t::real_t real_t;
  const real_t xmin = func_t<realvec_t>::get_xmin();
  const real_t xmax = func_t<realvec_t>::get_xmax();
  realvec_t x0, dx;
  for (int i=0; i<realvec_t::size; ++i) {
    x0.set_elt(i, xmin + (xmax - xmin) / numiters * i / realvec_t::size);
    dx.set_elt(i, (xmax - xmin) / numiters);
  }
  realvec_t x, y;
  ticks t0, t1;
  double const cycles_per_tick = 1.0; // measure_tick();
  
  func_t<realvec_t> func;
  t0 = getticks();
  x = y = x0;
  for (int n=0; n<numiters; ++n) {
    y += func(x);
    x += dx;
  }
  t1 = getticks();
  save_result(y);
  
  return cycles_per_tick * elapsed(t1,t0) * realvec_t::size / numiters;
}

template<typename realvec_t, template<typename> class func_t>
void bench_type_func()
{
  cout << "   "
       << setw(-5) << func_t<realvec_t>::name() << " "
       << setw(18) << realvec_t::name() << ": " << flush;
  double const cycles = run_bench<realvec_t, func_t>();
  cout << cycles << " cycles\n" << flush;
}

template<template<typename> class func_t>
void bench_func()
{
  cout << "\n"
       << "Benchmarking " << func_t<float_vec>().name() << ":\n";
  
//   bench_type_func<realpseudovec<float,1>, func_t>();
//   // bench_type_func<realbuiltinvec<float,1>, func_t>();
//   bench_type_func<realtestvec<float,1>, func_t>();
// #ifdef VECMATHLIB_HAVE_VEC_FLOAT_1
//   bench_type_func<realvec<float,1>, func_t>();
// #endif
// #ifdef VECMATHLIB_HAVE_VEC_FLOAT_2
//   bench_type_func<realpseudovec<float,2>, func_t>();
//   // bench_type_func<realbuiltinvec<float,2>, func_t>();
//   // bench_type_func<realtestvec<float,2>, func_t>();
//   bench_type_func<realvec<float,2>, func_t>();
// #endif
// #ifdef VECMATHLIB_HAVE_VEC_FLOAT_4
//   bench_type_func<realpseudovec<float,4>, func_t>();
//   // bench_type_func<realbuiltinvec<float,4>, func_t>();
//   // bench_type_func<realtestvec<float,4>, func_t>();
//   bench_type_func<realvec<float,4>, func_t>();
// #endif
// #ifdef VECMATHLIB_HAVE_VEC_FLOAT_8
//   bench_type_func<realpseudovec<float,8>, func_t>();
//   // bench_type_func<realbuiltinvec<float,8>, func_t>();
//   // bench_type_func<realtestvec<float,8>, func_t>();
//   bench_type_func<realvec<float,8>, func_t>();
// #endif
  
//   bench_type_func<realpseudovec<double,1>, func_t>();
//   // bench_type_func<realbuiltinvec<double,1>, func_t>();
//   bench_type_func<realtestvec<double,1>, func_t>();
// #ifdef VECMATHLIB_HAVE_VEC_DOUBLE_1
//   bench_type_func<realvec<double,1>, func_t>();
// #endif
// #ifdef VECMATHLIB_HAVE_VEC_DOUBLE_2
//   bench_type_func<realpseudovec<double,2>, func_t>();
//   // bench_type_func<realbuiltinvec<double,2>, func_t>();
//   // bench_type_func<realtestvec<double,2>, func_t>();
//   bench_type_func<realvec<double,2>, func_t>();
// #endif
#ifdef VECMATHLIB_HAVE_VEC_DOUBLE_4
  bench_type_func<realpseudovec<double,4>, func_t>();
  // bench_type_func<realbuiltinvec<double,4>, func_t>();
  // bench_type_func<realtestvec<double,4>, func_t>();
  bench_type_func<realvec<double,4>, func_t>();
#endif
}

void bench()
{
  bench_func<functor_nop>();
  
  bench_func<functor_acos>();
  bench_func<functor_acosh>();
  bench_func<functor_asin>();
  bench_func<functor_asinh>();
  bench_func<functor_atan>();
  // bench_func<functor_atan2>();
  bench_func<functor_atanh>();
  bench_func<functor_cbrt>();
  bench_func<functor_ceil>();
  // bench_func<functor_copysign>();
  bench_func<functor_cos>();
  bench_func<functor_cosh>();
  bench_func<functor_exp>();
  bench_func<functor_exp10>();
  bench_func<functor_exp2>();
  bench_func<functor_expm1>();
  bench_func<functor_fabs>();
  bench_func<functor_floor>();
  // bench_func<functor_fdim>();
  // bench_func<functor_fma>();
  // bench_func<functor_fmax>();
  // bench_func<functor_fmin>();
  // bench_func<functor_fmod>();
  // bench_func<functor_frexp>();
  // bench_func<functor_hypot>();
  // bench_func<functor_ilogb>();
  // bench_func<functor_isfinite>();
  // bench_func<functor_isinf>();
  // bench_func<functor_isnan>();
  // bench_func<functor_isnormal>();
  // bench_func<functor_ldexp>();
  // bench_func<functor_ldexp>();
  bench_func<functor_log>();
  bench_func<functor_log10>();
  bench_func<functor_log1p>();
  bench_func<functor_log2>();
  // bench_func<functor_nextafter>();
  // bench_func<functor_pow>();
  bench_func<functor_rcp>();
  // bench_func<functor_remainder>();
  bench_func<functor_rint>();
  bench_func<functor_round>();
  bench_func<functor_rsqrt>();
  // bench_func<functor_signbit>();
  bench_func<functor_sin>();
  bench_func<functor_sinh>();
  bench_func<functor_sqrt>();
  bench_func<functor_tan>();
  bench_func<functor_tanh>();
  bench_func<functor_trunc>();
}



int main(int argc, char** argv)
{
  using namespace vecmathlib;

  cout << "Benchmarking math functions:\n";
  
  bench();
  
  // Checking global accumulator to prevent optimisation
  if (! std::isfinite(global_result)) {
    cout << "\n"
         << "WARNING: Global accumulator is not finite\n";
  }
  
  return 0;
}