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35 /*! \libinternal \file
37 * \brief Declarations for GPU implementation of Leap-Frog.
39 * \author Artem Zhmurov <zhmurov@gmail.com>
41 * \ingroup module_mdlib
44 #ifndef GMX_MDLIB_LEAPFROG_GPU_H
45 #define GMX_MDLIB_LEAPFROG_GPU_H
50 # include "gromacs/gpu_utils/devicebuffer.cuh"
51 # include "gromacs/gpu_utils/gputraits.cuh"
54 # include "gromacs/gpu_utils/devicebuffer_sycl.h"
55 # include "gromacs/gpu_utils/gputraits_sycl.h"
56 using float3 = Float3;
61 #include "gromacs/gpu_utils/hostallocator.h"
62 #include "gromacs/pbcutil/pbc.h"
63 #include "gromacs/pbcutil/pbc_aiuc.h"
64 #include "gromacs/utility/arrayref.h"
74 /*! \brief Sets the number of different temperature coupling values
76 * This is needed to template the kernel
77 * \todo Unify with similar enum in CPU update module
79 enum class NumTempScaleValues
81 None = 0, //!< No temperature coupling
82 Single = 1, //!< Single T-scaling value (one group)
83 Multiple = 2, //!< Multiple T-scaling values, need to use T-group indices
84 Count = 3 //!< Number of valid values
87 /*! \brief Different variants of the Parrinello-Rahman velocity scaling
89 * This is needed to template the kernel
90 * \todo Unify with similar enum in CPU update module
92 enum class VelocityScalingType
94 None = 0, //!< Do not apply velocity scaling (not a PR-coupling run or step)
95 Diagonal = 1, //!< Apply velocity scaling using a diagonal matrix
96 Count = 2 //!< Number of valid values
103 /*! \brief Constructor.
105 * \param[in] deviceContext Device context (dummy in CUDA).
106 * \param[in] deviceStream Device stream to use.
107 * \param[in] numTempScaleValues Number of temperature scale groups.
109 LeapFrogGpu(const DeviceContext& deviceContext, const DeviceStream& deviceStream, int numTempScaleValues);
114 * Integrates the equation of motion using Leap-Frog algorithm.
115 * Updates coordinates and velocities on the GPU. The current coordinates are saved for constraints.
117 * \param[in,out] d_x Coordinates to update
118 * \param[out] d_xp Place to save the values of initial coordinates coordinates to.
119 * \param[in,out] d_v Velocities (will be updated).
120 * \param[in] d_f Forces.
121 * \param[in] dt Timestep.
122 * \param[in] doTemperatureScaling If velocities should be scaled for temperature coupling.
123 * \param[in] tcstat Temperature coupling data.
124 * \param[in] doParrinelloRahman If current step is a Parrinello-Rahman pressure coupling step.
125 * \param[in] dtPressureCouple Period between pressure coupling steps
126 * \param[in] prVelocityScalingMatrix Parrinello-Rahman velocity scaling matrix
128 void integrate(const DeviceBuffer<float3> d_x,
129 DeviceBuffer<float3> d_xp,
130 DeviceBuffer<float3> d_v,
131 const DeviceBuffer<float3> d_f,
133 const bool doTemperatureScaling,
134 gmx::ArrayRef<const t_grp_tcstat> tcstat,
135 const bool doParrinelloRahman,
136 const float dtPressureCouple,
137 const matrix prVelocityScalingMatrix);
139 /*! \brief Set the integrator
141 * Allocates memory for inverse masses, and, if needed for temperature scaling factor(s)
142 * and temperature coupling groups. Copies inverse masses and temperature coupling groups
145 * \param[in] numAtoms Number of atoms in the system.
146 * \param[in] inverseMasses Inverse masses of atoms.
147 * \param[in] tempScaleGroups Maps the atom index to temperature scale value.
149 void set(const int numAtoms, const real* inverseMasses, const unsigned short* tempScaleGroups);
151 /*! \brief Class with hardware-specific interfaces and implementations.*/
155 //! GPU context object
156 const DeviceContext& deviceContext_;
158 const DeviceStream& deviceStream_;
159 //! GPU kernel launch config
160 KernelLaunchConfig kernelLaunchConfig_;
164 //! 1/mass for all atoms (GPU)
165 DeviceBuffer<float> d_inverseMasses_;
166 //! Current size of the reciprocal masses array
167 int numInverseMasses_ = -1;
168 //! Maximum size of the reciprocal masses array
169 int numInverseMassesAlloc_ = -1;
171 //! Number of temperature coupling groups (zero = no coupling)
172 int numTempScaleValues_ = 0;
173 /*! \brief Array with temperature scaling factors.
174 * This is temporary solution to remap data from t_grp_tcstat into plain array.
176 * \todo Replace with better solution.
178 gmx::HostVector<float> h_lambdas_;
179 //! Device-side temperature scaling factors
180 DeviceBuffer<float> d_lambdas_;
181 //! Current size of the array with temperature scaling factors (lambdas)
182 int numLambdas_ = -1;
183 //! Maximum size of the array with temperature scaling factors (lambdas)
184 int numLambdasAlloc_ = -1;
187 //! Array that maps atom index onto the temperature scaling group to get scaling parameter
188 DeviceBuffer<unsigned short> d_tempScaleGroups_;
189 //! Current size of the temperature coupling groups array
190 int numTempScaleGroups_ = -1;
191 //! Maximum size of the temperature coupling groups array
192 int numTempScaleGroupsAlloc_ = -1;
194 //! Vector with diagonal elements of the Parrinello-Rahman pressure coupling velocity rescale factors
195 float3 prVelocityScalingMatrixDiagonal_;