src/gromacs/nbnxm/kerneldispatch.cpp

   1 /*
   2  * This file is part of the GROMACS molecular simulation package.
   3  *
   4  * Copyright (c) 2012,2013,2014,2015,2016 by the GROMACS development team.
   5  * Copyright (c) 2017,2018,2019,2020,2021, by the GROMACS development team, led by
   6  * Mark Abraham, David van der Spoel, Berk Hess, and Erik Lindahl,
   7  * and including many others, as listed in the AUTHORS file in the
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   9  *
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  36
  37 #include "gmxpre.h"
  38
  39 #include "gromacs/gmxlib/nrnb.h"
  40 #include "gromacs/gmxlib/nonbonded/nb_free_energy.h"
  41 #include "gromacs/gmxlib/nonbonded/nonbonded.h"
  42 #include "gromacs/math/vectypes.h"
  43 #include "gromacs/mdlib/enerdata_utils.h"
  44 #include "gromacs/mdlib/force.h"
  45 #include "gromacs/mdlib/gmx_omp_nthreads.h"
  46 #include "gromacs/mdtypes/enerdata.h"
  47 #include "gromacs/mdtypes/forceoutput.h"
  48 #include "gromacs/mdtypes/forcerec.h"
  49 #include "gromacs/mdtypes/inputrec.h"
  50 #include "gromacs/mdtypes/interaction_const.h"
  51 #include "gromacs/mdtypes/md_enums.h"
  52 #include "gromacs/mdtypes/mdatom.h"
  53 #include "gromacs/mdtypes/nblist.h"
  54 #include "gromacs/mdtypes/simulation_workload.h"
  55 #include "gromacs/nbnxm/gpu_data_mgmt.h"
  56 #include "gromacs/nbnxm/nbnxm.h"
  57 #include "gromacs/simd/simd.h"
  58 #include "gromacs/timing/wallcycle.h"
  59 #include "gromacs/utility/enumerationhelpers.h"
  60 #include "gromacs/utility/fatalerror.h"
  61 #include "gromacs/utility/gmxassert.h"
  62 #include "gromacs/utility/real.h"
  63
  64 #include "kernel_common.h"
  65 #include "nbnxm_gpu.h"
  66 #include "nbnxm_gpu_data_mgmt.h"
  67 #include "nbnxm_simd.h"
  68 #include "pairlistset.h"
  69 #include "pairlistsets.h"
  70 #include "kernels_reference/kernel_gpu_ref.h"
  71 #define INCLUDE_KERNELFUNCTION_TABLES
  72 #include "kernels_reference/kernel_ref.h"
  73 #ifdef GMX_NBNXN_SIMD_2XNN
  74 #    include "kernels_simd_2xmm/kernels.h"
  75 #endif
  76 #ifdef GMX_NBNXN_SIMD_4XN
  77 #    include "kernels_simd_4xm/kernels.h"
  78 #endif
  79 #undef INCLUDE_FUNCTION_TABLES
  80
  81 /*! \brief Clears the energy group output buffers
  82  *
  83  * \param[in,out] out  nbnxn kernel output struct
  84  */
  85 static void clearGroupEnergies(nbnxn_atomdata_output_t* out)
  86 {
  87     std::fill(out->Vvdw.begin(), out->Vvdw.end(), 0.0_real);
  88     std::fill(out->Vc.begin(), out->Vc.end(), 0.0_real);
  89     std::fill(out->VSvdw.begin(), out->VSvdw.end(), 0.0_real);
  90     std::fill(out->VSc.begin(), out->VSc.end(), 0.0_real);
  91 }
  92
  93 /*! \brief Reduce the group-pair energy buffers produced by a SIMD kernel
  94  * to single terms in the output buffers.
  95  *
  96  * The SIMD kernels produce a large number of energy buffer in SIMD registers
  97  * to avoid scattered reads and writes.
  98  *
  99  * \tparam        unrollj         The unroll size for j-particles in the SIMD kernel
 100  * \param[in]     numGroups       The number of energy groups
 101  * \param[in]     numGroups_2log  Log2 of numGroups, rounded up
 102  * \param[in,out] out             Struct with energy buffers
 103  */
 104 template<int unrollj>
 105 static void reduceGroupEnergySimdBuffers(int numGroups, int numGroups_2log, nbnxn_atomdata_output_t* out)
 106 {
 107     const int unrollj_half = unrollj / 2;
 108     /* Energies are stored in SIMD registers with size 2^numGroups_2log */
 109     const int numGroupsStorage = (1 << numGroups_2log);
 110
 111     const real* gmx_restrict vVdwSimd     = out->VSvdw.data();
 112     const real* gmx_restrict vCoulombSimd = out->VSc.data();
 113     real* gmx_restrict vVdw               = out->Vvdw.data();
 114     real* gmx_restrict vCoulomb           = out->Vc.data();
 115
 116     /* The size of the SIMD energy group buffer array is:
 117      * numGroups*numGroups*numGroupsStorage*unrollj_half*simd_width
 118      */
 119     for (int i = 0; i < numGroups; i++)
 120     {
 121         for (int j1 = 0; j1 < numGroups; j1++)
 122         {
 123             for (int j0 = 0; j0 < numGroups; j0++)
 124             {
 125                 int c = ((i * numGroups + j1) * numGroupsStorage + j0) * unrollj_half * unrollj;
 126                 for (int s = 0; s < unrollj_half; s++)
 127                 {
 128                     vVdw[i * numGroups + j0] += vVdwSimd[c + 0];
 129                     vVdw[i * numGroups + j1] += vVdwSimd[c + 1];
 130                     vCoulomb[i * numGroups + j0] += vCoulombSimd[c + 0];
 131                     vCoulomb[i * numGroups + j1] += vCoulombSimd[c + 1];
 132                     c += unrollj + 2;
 133                 }
 134             }
 135         }
 136     }
 137 }
 138
 139 static int getCoulombKernelType(const Nbnxm::KernelSetup& kernelSetup, const interaction_const_t& ic)
 140 {
 141
 142     if (EEL_RF(ic.eeltype) || ic.eeltype == CoulombInteractionType::Cut)
 143     {
 144         return coulktRF;
 145     }
 146     else
 147     {
 148         if (kernelSetup.ewaldExclusionType == Nbnxm::EwaldExclusionType::Table)
 149         {
 150             if (ic.rcoulomb == ic.rvdw)
 151             {
 152                 return coulktTAB;
 153             }
 154             else
 155             {
 156                 return coulktTAB_TWIN;
 157             }
 158         }
 159         else
 160         {
 161             if (ic.rcoulomb == ic.rvdw)
 162             {
 163                 return coulktEWALD;
 164             }
 165             else
 166             {
 167                 return coulktEWALD_TWIN;
 168             }
 169         }
 170     }
 171 }
 172
 173 static int getVdwKernelType(const Nbnxm::KernelSetup&       kernelSetup,
 174                             const nbnxn_atomdata_t::Params& nbatParams,
 175                             const interaction_const_t&      ic)
 176 {
 177     if (ic.vdwtype == VanDerWaalsType::Cut)
 178     {
 179         switch (ic.vdw_modifier)
 180         {
 181             case InteractionModifiers::None:
 182             case InteractionModifiers::PotShift:
 183                 switch (nbatParams.ljCombinationRule)
 184                 {
 185                     case LJCombinationRule::Geometric: return vdwktLJCUT_COMBGEOM;
 186                     case LJCombinationRule::LorentzBerthelot: return vdwktLJCUT_COMBLB;
 187                     case LJCombinationRule::None: return vdwktLJCUT_COMBNONE;
 188                     default: gmx_incons("Unknown combination rule");
 189                 }
 190             case InteractionModifiers::ForceSwitch: return vdwktLJFORCESWITCH;
 191             case InteractionModifiers::PotSwitch: return vdwktLJPOTSWITCH;
 192             default:
 193                 std::string errorMsg =
 194                         gmx::formatString("Unsupported VdW interaction modifier %s (%d)",
 195                                           enumValueToString(ic.vdw_modifier),
 196                                           static_cast<int>(ic.vdw_modifier));
 197                 gmx_incons(errorMsg);
 198         }
 199     }
 200     else if (ic.vdwtype == VanDerWaalsType::Pme)
 201     {
 202         if (ic.ljpme_comb_rule == LongRangeVdW::Geom)
 203         {
 204             return vdwktLJEWALDCOMBGEOM;
 205         }
 206         else
 207         {
 208             /* At setup we (should have) selected the C reference kernel */
 209             GMX_RELEASE_ASSERT(kernelSetup.kernelType == Nbnxm::KernelType::Cpu4x4_PlainC,
 210                                "Only the C reference nbnxn SIMD kernel supports LJ-PME with LB "
 211                                "combination rules");
 212             return vdwktLJEWALDCOMBLB;
 213         }
 214     }
 215     else
 216     {
 217         std::string errorMsg = gmx::formatString("Unsupported VdW interaction type %s (%d)",
 218                                                  enumValueToString(ic.vdwtype),
 219                                                  static_cast<int>(ic.vdwtype));
 220         gmx_incons(errorMsg);
 221     }
 222 }
 223
 224 /*! \brief Dispatches the non-bonded N versus M atom cluster CPU kernels.
 225  *
 226  * OpenMP parallelization is performed within this function.
 227  * Energy reduction, but not force and shift force reduction, is performed
 228  * within this function.
 229  *
 230  * \param[in]     pairlistSet   Pairlists with local or non-local interactions to compute
 231  * \param[in]     kernelSetup   The non-bonded kernel setup
 232  * \param[in,out] nbat          The atomdata for the interactions
 233  * \param[in]     ic            Non-bonded interaction constants
 234  * \param[in]     shiftVectors  The PBC shift vectors
 235  * \param[in]     stepWork      Flags that tell what to compute
 236  * \param[in]     clearF        Enum that tells if to clear the force output buffer
 237  * \param[out]    vCoulomb      Output buffer for Coulomb energies
 238  * \param[out]    vVdw          Output buffer for Van der Waals energies
 239  * \param[in]     wcycle        Pointer to cycle counting data structure.
 240  */
 241 static void nbnxn_kernel_cpu(const PairlistSet&             pairlistSet,
 242                              const Nbnxm::KernelSetup&      kernelSetup,
 243                              nbnxn_atomdata_t*              nbat,
 244                              const interaction_const_t&     ic,
 245                              gmx::ArrayRef<const gmx::RVec> shiftVectors,
 246                              const gmx::StepWorkload&       stepWork,
 247                              int                            clearF,
 248                              real*                          vCoulomb,
 249                              real*                          vVdw,
 250                              gmx_wallcycle*                 wcycle)
 251 {
 252
 253     const nbnxn_atomdata_t::Params& nbatParams = nbat->params();
 254
 255     const int coulkt = getCoulombKernelType(kernelSetup, ic);
 256     const int vdwkt  = getVdwKernelType(kernelSetup, nbatParams, ic);
 257
 258     gmx::ArrayRef<const NbnxnPairlistCpu> pairlists = pairlistSet.cpuLists();
 259
 260     auto shiftVecPointer = as_rvec_array(shiftVectors.data());
 261
 262     int gmx_unused nthreads = gmx_omp_nthreads_get(emntNonbonded);
 263     wallcycle_sub_start(wcycle, ewcsNONBONDED_CLEAR);
 264 #pragma omp parallel for schedule(static) num_threads(nthreads)
 265     for (gmx::index nb = 0; nb < pairlists.ssize(); nb++)
 266     {
 267         // Presently, the kernels do not call C++ code that can throw,
 268         // so no need for a try/catch pair in this OpenMP region.
 269         nbnxn_atomdata_output_t* out = &nbat->out[nb];
 270
 271         if (clearF == enbvClearFYes)
 272         {
 273             clearForceBuffer(nbat, nb);
 274
 275             clear_fshift(out->fshift.data());
 276         }
 277
 278         if (nb == 0)
 279         {
 280             wallcycle_sub_stop(wcycle, ewcsNONBONDED_CLEAR);
 281             wallcycle_sub_start(wcycle, ewcsNONBONDED_KERNEL);
 282         }
 283
 284         // TODO: Change to reference
 285         const NbnxnPairlistCpu* pairlist = &pairlists[nb];
 286
 287         if (!stepWork.computeEnergy)
 288         {
 289             /* Don't calculate energies */
 290             switch (kernelSetup.kernelType)
 291             {
 292                 case Nbnxm::KernelType::Cpu4x4_PlainC:
 293                     nbnxn_kernel_noener_ref[coulkt][vdwkt](pairlist, nbat, &ic, shiftVecPointer, out);
 294                     break;
 295 #ifdef GMX_NBNXN_SIMD_2XNN
 296                 case Nbnxm::KernelType::Cpu4xN_Simd_2xNN:
 297                     nbnxm_kernel_noener_simd_2xmm[coulkt][vdwkt](pairlist, nbat, &ic, shiftVecPointer, out);
 298                     break;
 299 #endif
 300 #ifdef GMX_NBNXN_SIMD_4XN
 301                 case Nbnxm::KernelType::Cpu4xN_Simd_4xN:
 302                     nbnxm_kernel_noener_simd_4xm[coulkt][vdwkt](pairlist, nbat, &ic, shiftVecPointer, out);
 303                     break;
 304 #endif
 305                 default: GMX_RELEASE_ASSERT(false, "Unsupported kernel architecture");
 306             }
 307         }
 308         else if (out->Vvdw.size() == 1)
 309         {
 310             /* A single energy group (pair) */
 311             out->Vvdw[0] = 0;
 312             out->Vc[0]   = 0;
 313
 314             switch (kernelSetup.kernelType)
 315             {
 316                 case Nbnxm::KernelType::Cpu4x4_PlainC:
 317                     nbnxn_kernel_ener_ref[coulkt][vdwkt](pairlist, nbat, &ic, shiftVecPointer, out);
 318                     break;
 319 #ifdef GMX_NBNXN_SIMD_2XNN
 320                 case Nbnxm::KernelType::Cpu4xN_Simd_2xNN:
 321                     nbnxm_kernel_ener_simd_2xmm[coulkt][vdwkt](pairlist, nbat, &ic, shiftVecPointer, out);
 322                     break;
 323 #endif
 324 #ifdef GMX_NBNXN_SIMD_4XN
 325                 case Nbnxm::KernelType::Cpu4xN_Simd_4xN:
 326                     nbnxm_kernel_ener_simd_4xm[coulkt][vdwkt](pairlist, nbat, &ic, shiftVecPointer, out);
 327                     break;
 328 #endif
 329                 default: GMX_RELEASE_ASSERT(false, "Unsupported kernel architecture");
 330             }
 331         }
 332         else
 333         {
 334             /* Calculate energy group contributions */
 335             clearGroupEnergies(out);
 336
 337             int unrollj = 0;
 338
 339             switch (kernelSetup.kernelType)
 340             {
 341                 case Nbnxm::KernelType::Cpu4x4_PlainC:
 342                     unrollj = c_nbnxnCpuIClusterSize;
 343                     nbnxn_kernel_energrp_ref[coulkt][vdwkt](pairlist, nbat, &ic, shiftVecPointer, out);
 344                     break;
 345 #ifdef GMX_NBNXN_SIMD_2XNN
 346                 case Nbnxm::KernelType::Cpu4xN_Simd_2xNN:
 347                     unrollj = GMX_SIMD_REAL_WIDTH / 2;
 348                     nbnxm_kernel_energrp_simd_2xmm[coulkt][vdwkt](
 349                             pairlist, nbat, &ic, shiftVecPointer, out);
 350                     break;
 351 #endif
 352 #ifdef GMX_NBNXN_SIMD_4XN
 353                 case Nbnxm::KernelType::Cpu4xN_Simd_4xN:
 354                     unrollj = GMX_SIMD_REAL_WIDTH;
 355                     nbnxm_kernel_energrp_simd_4xm[coulkt][vdwkt](pairlist, nbat, &ic, shiftVecPointer, out);
 356                     break;
 357 #endif
 358                 default: GMX_RELEASE_ASSERT(false, "Unsupported kernel architecture");
 359             }
 360
 361             if (kernelSetup.kernelType != Nbnxm::KernelType::Cpu4x4_PlainC)
 362             {
 363                 switch (unrollj)
 364                 {
 365                     case 2:
 366                         reduceGroupEnergySimdBuffers<2>(nbatParams.nenergrp, nbatParams.neg_2log, out);
 367                         break;
 368                     case 4:
 369                         reduceGroupEnergySimdBuffers<4>(nbatParams.nenergrp, nbatParams.neg_2log, out);
 370                         break;
 371                     case 8:
 372                         reduceGroupEnergySimdBuffers<8>(nbatParams.nenergrp, nbatParams.neg_2log, out);
 373                         break;
 374                     default: GMX_RELEASE_ASSERT(false, "Unsupported j-unroll size");
 375                 }
 376             }
 377         }
 378     }
 379     wallcycle_sub_stop(wcycle, ewcsNONBONDED_KERNEL);
 380
 381     if (stepWork.computeEnergy)
 382     {
 383         reduce_energies_over_lists(nbat, pairlists.ssize(), vVdw, vCoulomb);
 384     }
 385 }
 386
 387 static void accountFlops(t_nrnb*                    nrnb,
 388                          const PairlistSet&         pairlistSet,
 389                          const nonbonded_verlet_t&  nbv,
 390                          const interaction_const_t& ic,
 391                          const gmx::StepWorkload&   stepWork)
 392 {
 393     const bool usingGpuKernels = nbv.useGpu();
 394
 395     int enr_nbnxn_kernel_ljc = eNRNB;
 396     if (EEL_RF(ic.eeltype) || ic.eeltype == CoulombInteractionType::Cut)
 397     {
 398         enr_nbnxn_kernel_ljc = eNR_NBNXN_LJ_RF;
 399     }
 400     else if ((!usingGpuKernels && nbv.kernelSetup().ewaldExclusionType == Nbnxm::EwaldExclusionType::Analytical)
 401              || (usingGpuKernels && Nbnxm::gpu_is_kernel_ewald_analytical(nbv.gpu_nbv)))
 402     {
 403         enr_nbnxn_kernel_ljc = eNR_NBNXN_LJ_EWALD;
 404     }
 405     else
 406     {
 407         enr_nbnxn_kernel_ljc = eNR_NBNXN_LJ_TAB;
 408     }
 409     int enr_nbnxn_kernel_lj = eNR_NBNXN_LJ;
 410     if (stepWork.computeEnergy)
 411     {
 412         /* In eNR_??? the nbnxn F+E kernels are always the F kernel + 1 */
 413         enr_nbnxn_kernel_ljc += 1;
 414         enr_nbnxn_kernel_lj += 1;
 415     }
 416
 417     inc_nrnb(nrnb, enr_nbnxn_kernel_ljc, pairlistSet.natpair_ljq_);
 418     inc_nrnb(nrnb, enr_nbnxn_kernel_lj, pairlistSet.natpair_lj_);
 419     /* The Coulomb-only kernels are offset -eNR_NBNXN_LJ_RF+eNR_NBNXN_RF */
 420     inc_nrnb(nrnb, enr_nbnxn_kernel_ljc - eNR_NBNXN_LJ_RF + eNR_NBNXN_RF, pairlistSet.natpair_q_);
 421
 422     if (ic.vdw_modifier == InteractionModifiers::ForceSwitch)
 423     {
 424         /* We add up the switch cost separately */
 425         inc_nrnb(nrnb,
 426                  eNR_NBNXN_ADD_LJ_FSW + (stepWork.computeEnergy ? 1 : 0),
 427                  pairlistSet.natpair_ljq_ + pairlistSet.natpair_lj_);
 428     }
 429     if (ic.vdw_modifier == InteractionModifiers::PotSwitch)
 430     {
 431         /* We add up the switch cost separately */
 432         inc_nrnb(nrnb,
 433                  eNR_NBNXN_ADD_LJ_PSW + (stepWork.computeEnergy ? 1 : 0),
 434                  pairlistSet.natpair_ljq_ + pairlistSet.natpair_lj_);
 435     }
 436     if (ic.vdwtype == VanDerWaalsType::Pme)
 437     {
 438         /* We add up the LJ Ewald cost separately */
 439         inc_nrnb(nrnb,
 440                  eNR_NBNXN_ADD_LJ_EWALD + (stepWork.computeEnergy ? 1 : 0),
 441                  pairlistSet.natpair_ljq_ + pairlistSet.natpair_lj_);
 442     }
 443 }
 444
 445 void nonbonded_verlet_t::dispatchNonbondedKernel(gmx::InteractionLocality   iLocality,
 446                                                  const interaction_const_t& ic,
 447                                                  const gmx::StepWorkload&   stepWork,
 448                                                  int                        clearF,
 449                                                  const t_forcerec&          fr,
 450                                                  gmx_enerdata_t*            enerd,
 451                                                  t_nrnb*                    nrnb)
 452 {
 453     const PairlistSet& pairlistSet = pairlistSets().pairlistSet(iLocality);
 454
 455     switch (kernelSetup().kernelType)
 456     {
 457         case Nbnxm::KernelType::Cpu4x4_PlainC:
 458         case Nbnxm::KernelType::Cpu4xN_Simd_4xN:
 459         case Nbnxm::KernelType::Cpu4xN_Simd_2xNN:
 460             nbnxn_kernel_cpu(
 461                     pairlistSet,
 462                     kernelSetup(),
 463                     nbat.get(),
 464                     ic,
 465                     fr.shift_vec,
 466                     stepWork,
 467                     clearF,
 468                     enerd->grpp.energyGroupPairTerms[NonBondedEnergyTerms::CoulombSR].data(),
 469                     fr.haveBuckingham
 470                             ? enerd->grpp.energyGroupPairTerms[NonBondedEnergyTerms::BuckinghamSR].data()
 471                             : enerd->grpp.energyGroupPairTerms[NonBondedEnergyTerms::LJSR].data(),
 472                     wcycle_);
 473             break;
 474
 475         case Nbnxm::KernelType::Gpu8x8x8:
 476             Nbnxm::gpu_launch_kernel(gpu_nbv, stepWork, iLocality);
 477             break;
 478
 479         case Nbnxm::KernelType::Cpu8x8x8_PlainC:
 480             nbnxn_kernel_gpu_ref(
 481                     pairlistSet.gpuList(),
 482                     nbat.get(),
 483                     &ic,
 484                     fr.shift_vec,
 485                     stepWork,
 486                     clearF,
 487                     nbat->out[0].f,
 488                     nbat->out[0].fshift.data(),
 489                     enerd->grpp.energyGroupPairTerms[NonBondedEnergyTerms::CoulombSR].data(),
 490                     fr.haveBuckingham
 491                             ? enerd->grpp.energyGroupPairTerms[NonBondedEnergyTerms::BuckinghamSR].data()
 492                             : enerd->grpp.energyGroupPairTerms[NonBondedEnergyTerms::LJSR].data());
 493             break;
 494
 495         default: GMX_RELEASE_ASSERT(false, "Invalid nonbonded kernel type passed!");
 496     }
 497
 498     accountFlops(nrnb, pairlistSet, *this, ic, stepWork);
 499 }
 500
 501 void nonbonded_verlet_t::dispatchFreeEnergyKernel(gmx::InteractionLocality       iLocality,
 502                                                   const t_forcerec&              fr,
 503                                                   gmx::ArrayRef<const gmx::RVec> coords,
 504                                                   gmx::ForceWithShiftForces* forceWithShiftForces,
 505                                                   gmx::ArrayRef<const real>  chargeA,
 506                                                   gmx::ArrayRef<const real>  chargeB,
 507                                                   gmx::ArrayRef<const int>   typeA,
 508                                                   gmx::ArrayRef<const int>   typeB,
 509                                                   t_lambda*                  fepvals,
 510                                                   gmx::ArrayRef<const real>  lambda,
 511                                                   gmx_enerdata_t*            enerd,
 512                                                   const gmx::StepWorkload&   stepWork,
 513                                                   t_nrnb*                    nrnb)
 514 {
 515     const auto nbl_fep = pairlistSets().pairlistSet(iLocality).fepLists();
 516
 517     /* When the first list is empty, all are empty and there is nothing to do */
 518     if (!pairlistSets().params().haveFep || nbl_fep[0]->nrj == 0)
 519     {
 520         return;
 521     }
 522
 523     int donb_flags = 0;
 524     /* Add short-range interactions */
 525     donb_flags |= GMX_NONBONDED_DO_SR;
 526
 527     if (stepWork.computeForces)
 528     {
 529         donb_flags |= GMX_NONBONDED_DO_FORCE;
 530     }
 531     if (stepWork.computeVirial)
 532     {
 533         donb_flags |= GMX_NONBONDED_DO_SHIFTFORCE;
 534     }
 535     if (stepWork.computeEnergy)
 536     {
 537         donb_flags |= GMX_NONBONDED_DO_POTENTIAL;
 538     }
 539
 540     gmx::EnumerationArray<FreeEnergyPerturbationCouplingType, real> dvdl_nb      = { 0 };
 541     int                                                             kernelFlags  = donb_flags;
 542     gmx::ArrayRef<const real>                                       kernelLambda = lambda;
 543     gmx::ArrayRef<real>                                             kernelDvdl   = dvdl_nb;
 544
 545     gmx::ArrayRef<real> energygrp_elec = enerd->grpp.energyGroupPairTerms[NonBondedEnergyTerms::CoulombSR];
 546     gmx::ArrayRef<real> energygrp_vdw = enerd->grpp.energyGroupPairTerms[NonBondedEnergyTerms::LJSR];
 547
 548     GMX_ASSERT(gmx_omp_nthreads_get(emntNonbonded) == nbl_fep.ssize(),
 549                "Number of lists should be same as number of NB threads");
 550
 551     wallcycle_sub_start(wcycle_, ewcsNONBONDED_FEP);
 552 #pragma omp parallel for schedule(static) num_threads(nbl_fep.ssize())
 553     for (gmx::index th = 0; th < nbl_fep.ssize(); th++)
 554     {
 555         try
 556         {
 557             gmx_nb_free_energy_kernel(*nbl_fep[th],
 558                                       coords,
 559                                       forceWithShiftForces,
 560                                       fr,
 561                                       chargeA,
 562                                       chargeB,
 563                                       typeA,
 564                                       typeB,
 565                                       kernelFlags,
 566                                       kernelLambda,
 567                                       kernelDvdl,
 568                                       energygrp_elec,
 569                                       energygrp_vdw,
 570                                       nrnb);
 571         }
 572         GMX_CATCH_ALL_AND_EXIT_WITH_FATAL_ERROR
 573     }
 574
 575     if (fepvals->sc_alpha != 0)
 576     {
 577         enerd->dvdl_nonlin[FreeEnergyPerturbationCouplingType::Vdw] +=
 578                 dvdl_nb[FreeEnergyPerturbationCouplingType::Vdw];
 579         enerd->dvdl_nonlin[FreeEnergyPerturbationCouplingType::Coul] +=
 580                 dvdl_nb[FreeEnergyPerturbationCouplingType::Coul];
 581     }
 582     else
 583     {
 584         enerd->dvdl_lin[FreeEnergyPerturbationCouplingType::Vdw] +=
 585                 dvdl_nb[FreeEnergyPerturbationCouplingType::Vdw];
 586         enerd->dvdl_lin[FreeEnergyPerturbationCouplingType::Coul] +=
 587                 dvdl_nb[FreeEnergyPerturbationCouplingType::Coul];
 588     }
 589
 590     /* If we do foreign lambda and we have soft-core interactions
 591      * we have to recalculate the (non-linear) energies contributions.
 592      */
 593     if (fepvals->n_lambda > 0 && stepWork.computeDhdl && fepvals->sc_alpha != 0)
 594     {
 595         gmx::EnumerationArray<FreeEnergyPerturbationCouplingType, real> lam_i;
 596         kernelFlags = (donb_flags & ~(GMX_NONBONDED_DO_FORCE | GMX_NONBONDED_DO_SHIFTFORCE))
 597                       | GMX_NONBONDED_DO_FOREIGNLAMBDA;
 598         kernelLambda = lam_i;
 599         kernelDvdl   = dvdl_nb;
 600         gmx::ArrayRef<real> energygrp_elec =
 601                 enerd->foreign_grpp.energyGroupPairTerms[NonBondedEnergyTerms::CoulombSR];
 602         gmx::ArrayRef<real> energygrp_vdw =
 603                 enerd->foreign_grpp.energyGroupPairTerms[NonBondedEnergyTerms::LJSR];
 604
 605         for (gmx::index i = 0; i < 1 + enerd->foreignLambdaTerms.numLambdas(); i++)
 606         {
 607             std::fill(std::begin(dvdl_nb), std::end(dvdl_nb), 0);
 608             for (int j = 0; j < static_cast<int>(FreeEnergyPerturbationCouplingType::Count); j++)
 609             {
 610                 lam_i[j] = (i == 0 ? lambda[j] : fepvals->all_lambda[j][i - 1]);
 611             }
 612             reset_foreign_enerdata(enerd);
 613 #pragma omp parallel for schedule(static) num_threads(nbl_fep.ssize())
 614             for (gmx::index th = 0; th < nbl_fep.ssize(); th++)
 615             {
 616                 try
 617                 {
 618                     gmx_nb_free_energy_kernel(*nbl_fep[th],
 619                                               coords,
 620                                               forceWithShiftForces,
 621                                               fr,
 622                                               chargeA,
 623                                               chargeB,
 624                                               typeA,
 625                                               typeB,
 626                                               kernelFlags,
 627                                               kernelLambda,
 628                                               kernelDvdl,
 629                                               energygrp_elec,
 630                                               energygrp_vdw,
 631                                               nrnb);
 632                 }
 633                 GMX_CATCH_ALL_AND_EXIT_WITH_FATAL_ERROR
 634             }
 635
 636             sum_epot(enerd->foreign_grpp, enerd->foreign_term);
 637             enerd->foreignLambdaTerms.accumulate(
 638                     i,
 639                     enerd->foreign_term[F_EPOT],
 640                     dvdl_nb[FreeEnergyPerturbationCouplingType::Vdw]
 641                             + dvdl_nb[FreeEnergyPerturbationCouplingType::Coul]);
 642         }
 643     }
 644     wallcycle_sub_stop(wcycle_, ewcsNONBONDED_FEP);
 645 }