energybuffer.h

#pragma once
#include "ff/precision.h"
#include "math/pow2.h"
#include <type_traits>
 
namespace tinker {
 
template <class F>
inline F toFloatingPoint(fixed g)
{
   static_assert(std::is_same<F, float>::value or std::is_same<F, double>::value, "");
   return static_cast<F>(static_cast<long long>(g)) / 0x100000000ull;
}
 
template <class F>
inline F toFloatingPoint(double g)
{
   static_assert(std::is_same<F, float>::value or std::is_same<F, double>::value, "");
   return g;
}
 
template <class F>
inline F toFloatingPoint(float g)
{
   static_assert(std::is_same<F, float>::value or std::is_same<F, double>::value, "");
   return g;
}
 
}
 
namespace tinker {
inline namespace v1 {
template <class T, size_t Nincr>
struct BufferTraits
{
   static constexpr size_t N = Nincr;
   static constexpr size_t value = pow2Ge(Nincr);
   using type = T;
};
 
template <size_t Nincr>
struct BufferTraits<float, Nincr>
{
   static constexpr size_t N = Nincr;
   static constexpr size_t value = pow2Ge(Nincr);
   using type = fixed;
};
}
 
 
size_t bufferSize();
 
typedef BufferTraits<int, 1> CountBufferTraits;
typedef BufferTraits<e_prec, 1> EnergyBufferTraits;
typedef BufferTraits<v_prec, 6> VirialBufferTraits;
typedef CountBufferTraits::type* CountBuffer;
typedef EnergyBufferTraits::type* EnergyBuffer;
typedef VirialBufferTraits::type (*VirialBuffer)[VirialBufferTraits::value];
 
void bufferAllocate(int flag, EnergyBuffer* pe, VirialBuffer* pv, //
   grad_prec** px, grad_prec** py, grad_prec** pz);
 
void bufferDeallocate(int flag, EnergyBuffer e, VirialBuffer v, //
   grad_prec* gx, grad_prec* gy, grad_prec* gz);
 
void bufferAllocate(int flag, CountBuffer* pc);
 
void bufferDeallocate(int flag, CountBuffer c);
 
int countReduce(const CountBuffer b);
 
energy_prec energyReduce(const EnergyBuffer b);
 
void virialReduce(virial_prec (&)[VirialBufferTraits::N], const VirialBuffer b);
 
void virialReduce(virial_prec (&)[9], const VirialBuffer b);
 
void virialReshape(virial_prec (&output)[9], const virial_prec (&input)[VirialBufferTraits::N]);
 
//====================================================================//
//                                                                    //
//                          Global Variables                          //
//                                                                    //
//====================================================================//
 
TINKER_EXTERN int nelem_buffer;
 
}