libhoomd/computes_gpu/HarmonicDihedralForceComputeGPU.cc

   1 /*
   2 Highly Optimized Object-oriented Many-particle Dynamics -- Blue Edition
   3 (HOOMD-blue) Open Source Software License Copyright 2009-2014 The Regents of
   4 the University of Michigan All rights reserved.
   5
   6 HOOMD-blue may contain modifications ("Contributions") provided, and to which
   7 copyright is held, by various Contributors who have granted The Regents of the
   8 University of Michigan the right to modify and/or distribute such Contributions.
   9
  10 You may redistribute, use, and create derivate works of HOOMD-blue, in source
  11 and binary forms, provided you abide by the following conditions:
  12
  13 * Redistributions of source code must retain the above copyright notice, this
  14 list of conditions, and the following disclaimer both in the code and
  15 prominently in any materials provided with the distribution.
  16
  17 * Redistributions in binary form must reproduce the above copyright notice, this
  18 list of conditions, and the following disclaimer in the documentation and/or
  19 other materials provided with the distribution.
  20
  21 * All publications and presentations based on HOOMD-blue, including any reports
  22 or published results obtained, in whole or in part, with HOOMD-blue, will
  23 acknowledge its use according to the terms posted at the time of submission on:
  24 http://codeblue.umich.edu/hoomd-blue/citations.html
  25
  26 * Any electronic documents citing HOOMD-Blue will link to the HOOMD-Blue website:
  27 http://codeblue.umich.edu/hoomd-blue/
  28
  29 * Apart from the above required attributions, neither the name of the copyright
  30 holder nor the names of HOOMD-blue's contributors may be used to endorse or
  31 promote products derived from this software without specific prior written
  32 permission.
  33
  34 Disclaimer
  35
  36 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER AND CONTRIBUTORS ``AS IS'' AND
  37 ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  38 WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND/OR ANY
  39 WARRANTIES THAT THIS SOFTWARE IS FREE OF INFRINGEMENT ARE DISCLAIMED.
  40
  41 IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
  42 INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  43 BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  44 DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  45 LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
  46 OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  47 ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  48 */
  49
  50 // Maintainer: dnlebard
  51
  52 /*! \file HarmonicDihedralForceComputeGPU.cc
  53     \brief Defines HarmonicDihedralForceComputeGPU
  54 */
  55
  56 #ifdef WIN32
  57 #pragma warning( push )
  58 #pragma warning( disable : 4244 )
  59 #endif
  60
  61 #include "HarmonicDihedralForceComputeGPU.h"
  62
  63 #include <boost/python.hpp>
  64 using namespace boost::python;
  65
  66 #include <boost/bind.hpp>
  67 using namespace boost;
  68
  69 using namespace std;
  70
  71 /*! \param sysdef System to compute bond forces on
  72 */
  73 HarmonicDihedralForceComputeGPU::HarmonicDihedralForceComputeGPU(boost::shared_ptr<SystemDefinition> sysdef)
  74     : HarmonicDihedralForceCompute(sysdef)
  75     {
  76     // can't run on the GPU if there aren't any GPUs in the execution configuration
  77     if (!exec_conf->isCUDAEnabled())
  78         {
  79         m_exec_conf->msg->error() << "Creating a DihedralForceComputeGPU with no GPU in the execution configuration" << endl;
  80         throw std::runtime_error("Error initializing DihedralForceComputeGPU");
  81         }
  82
  83     // allocate and zero device memory
  84     GPUArray<Scalar4> params(m_dihedral_data->getNTypes(),exec_conf);
  85     m_params.swap(params);
  86
  87     m_tuner.reset(new Autotuner(32, 1024, 32, 5, 100000, "harmonic_dihedral", this->m_exec_conf));
  88     }
  89
  90 HarmonicDihedralForceComputeGPU::~HarmonicDihedralForceComputeGPU()
  91     {
  92     }
  93
  94 /*! \param type Type of the dihedral to set parameters for
  95     \param K Stiffness parameter for the force computation
  96     \param sign the sign of the cosine term
  97         \param multiplicity the multiplicity of the cosine term
  98
  99     Sets parameters for the potential of a particular dihedral type and updates the
 100     parameters on the GPU.
 101 */
 102 void HarmonicDihedralForceComputeGPU::setParams(unsigned int type, Scalar K, int sign, unsigned int multiplicity)
 103     {
 104     HarmonicDihedralForceCompute::setParams(type, K, sign, multiplicity);
 105
 106     ArrayHandle<Scalar4> h_params(m_params, access_location::host, access_mode::readwrite);
 107     // update the local copy of the memory
 108     h_params.data[type] = make_scalar4(Scalar(K), Scalar(sign), Scalar(multiplicity), Scalar(0.0));
 109     }
 110
 111 /*! Internal method for computing the forces on the GPU.
 112     \post The force data on the GPU is written with the calculated forces
 113
 114     \param timestep Current time step of the simulation
 115
 116     Calls gpu_compute_harmonic_dihedral_forces to do the dirty work.
 117 */
 118 void HarmonicDihedralForceComputeGPU::computeForces(unsigned int timestep)
 119     {
 120     // start the profile
 121     if (m_prof) m_prof->push(exec_conf, "Harmonic Dihedral");
 122
 123     ArrayHandle<DihedralData::members_t> d_gpu_dihedral_list(m_dihedral_data->getGPUTable(), access_location::device,access_mode::read);
 124     ArrayHandle<unsigned int> d_n_dihedrals(m_dihedral_data->getNGroupsArray(), access_location::device, access_mode::read);
 125     ArrayHandle<unsigned int> d_dihedrals_ABCD(m_dihedral_data->getGPUPosTable(), access_location::device, access_mode::read);
 126
 127     // the dihedral table is up to date: we are good to go. Call the kernel
 128     ArrayHandle<Scalar4> d_pos(m_pdata->getPositions(), access_location::device, access_mode::read);
 129     BoxDim box = m_pdata->getGlobalBox();
 130
 131     ArrayHandle<Scalar4> d_force(m_force,access_location::device,access_mode::overwrite);
 132     ArrayHandle<Scalar> d_virial(m_virial,access_location::device,access_mode::overwrite);
 133     ArrayHandle<Scalar4> d_params(m_params, access_location::device, access_mode::read);
 134
 135     // run the kernel in parallel on all GPUs
 136     this->m_tuner->begin();
 137     gpu_compute_harmonic_dihedral_forces(d_force.data,
 138                                          d_virial.data,
 139                                          m_virial.getPitch(),
 140                                          m_pdata->getN(),
 141                                          d_pos.data,
 142                                          box,
 143                                          d_gpu_dihedral_list.data,
 144                                          d_dihedrals_ABCD.data,
 145                                          m_dihedral_data->getGPUTableIndexer().getW(),
 146                                          d_n_dihedrals.data,
 147                                          d_params.data,
 148                                          m_dihedral_data->getNTypes(),
 149                                          this->m_tuner->getParam(),
 150                                          m_exec_conf->getComputeCapability());
 151     if (exec_conf->isCUDAErrorCheckingEnabled())
 152         CHECK_CUDA_ERROR();
 153     this->m_tuner->end();
 154
 155     if (m_prof) m_prof->pop(exec_conf);
 156     }
 157
 158 void export_HarmonicDihedralForceComputeGPU()
 159     {
 160     class_<HarmonicDihedralForceComputeGPU, boost::shared_ptr<HarmonicDihedralForceComputeGPU>, bases<HarmonicDihedralForceCompute>, boost::noncopyable >
 161     ("HarmonicDihedralForceComputeGPU", init< boost::shared_ptr<SystemDefinition> >())
 162     ;
 163     }