src/gromacs/nbnxm/pairlist_simd_2xmm.h

   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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  36 /*! \internal \file
  37  *
  38  * \brief
  39  * Declares inline-friendly code for making 2xNN pairlists
  40  *
  41  * \author Berk Hess <hess@kth.se>
  42  * \ingroup module_nbnxm
  43  */
  44
  45
  46 //! Stride of the packed x coordinate array
  47 static constexpr int c_xStride2xNN = (GMX_SIMD_REAL_WIDTH >= 2 * c_nbnxnCpuIClusterSize)
  48                                              ? GMX_SIMD_REAL_WIDTH / 2
  49                                              : c_nbnxnCpuIClusterSize;
  50
  51 //! Copies PBC shifted i-cell packed atom coordinates to working array
  52 static inline void icell_set_x_simd_2xnn(int  ci,
  53                                          real shx,
  54                                          real shy,
  55                                          real shz,
  56                                          int gmx_unused        stride,
  57                                          const real*           x,
  58                                          NbnxnPairlistCpuWork* work)
  59 {
  60     real* x_ci_simd = work->iClusterData.xSimd.data();
  61
  62     const int ia = xIndexFromCi<NbnxnLayout::Simd2xNN>(ci);
  63
  64     store(x_ci_simd + 0 * GMX_SIMD_REAL_WIDTH,
  65           loadU1DualHsimd(x + ia + 0 * c_xStride2xNN + 0) + SimdReal(shx));
  66     store(x_ci_simd + 1 * GMX_SIMD_REAL_WIDTH,
  67           loadU1DualHsimd(x + ia + 1 * c_xStride2xNN + 0) + SimdReal(shy));
  68     store(x_ci_simd + 2 * GMX_SIMD_REAL_WIDTH,
  69           loadU1DualHsimd(x + ia + 2 * c_xStride2xNN + 0) + SimdReal(shz));
  70     store(x_ci_simd + 3 * GMX_SIMD_REAL_WIDTH,
  71           loadU1DualHsimd(x + ia + 0 * c_xStride2xNN + 2) + SimdReal(shx));
  72     store(x_ci_simd + 4 * GMX_SIMD_REAL_WIDTH,
  73           loadU1DualHsimd(x + ia + 1 * c_xStride2xNN + 2) + SimdReal(shy));
  74     store(x_ci_simd + 5 * GMX_SIMD_REAL_WIDTH,
  75           loadU1DualHsimd(x + ia + 2 * c_xStride2xNN + 2) + SimdReal(shz));
  76 }
  77
  78 /*! \brief SIMD code for checking and adding cluster-pairs to the list using coordinates in packed format.
  79  *
  80  * Checks bounding box distances and possibly atom pair distances.
  81  * This is an accelerated version of make_cluster_list_simple.
  82  *
  83  * \param[in]     jGrid               The j-grid
  84  * \param[in,out] nbl                 The pair-list to store the cluster pairs in
  85  * \param[in]     icluster            The index of the i-cluster
  86  * \param[in]     firstCell           The first cluster in the j-range, using i-cluster size indexing
  87  * \param[in]     lastCell            The last cluster in the j-range, using i-cluster size indexing
  88  * \param[in]     excludeSubDiagonal  Exclude atom pairs with i-index > j-index
  89  * \param[in]     x_j                 Coordinates for the j-atom, in SIMD packed format
  90  * \param[in]     rlist2              The squared list cut-off
  91  * \param[in]     rbb2                The squared cut-off for putting cluster-pairs in the list based on bounding box distance only
  92  * \param[in,out] numDistanceChecks   The number of distance checks performed
  93  */
  94 static inline void makeClusterListSimd2xnn(const Grid&       jGrid,
  95                                            NbnxnPairlistCpu* nbl,
  96                                            int               icluster,
  97                                            int               firstCell,
  98                                            int               lastCell,
  99                                            bool              excludeSubDiagonal,
 100                                            const real* gmx_restrict x_j,
 101                                            real                     rlist2,
 102                                            float                    rbb2,
 103                                            int* gmx_restrict numDistanceChecks)
 104 {
 105     using namespace gmx;
 106     const real* gmx_restrict x_ci_simd    = nbl->work->iClusterData.xSimd.data();
 107     const BoundingBox* gmx_restrict bb_ci = nbl->work->iClusterData.bb.data();
 108
 109     SimdReal jx_S, jy_S, jz_S;
 110
 111     SimdReal dx_S0, dy_S0, dz_S0;
 112     SimdReal dx_S2, dy_S2, dz_S2;
 113
 114     SimdReal rsq_S0;
 115     SimdReal rsq_S2;
 116
 117     SimdBool wco_S0;
 118     SimdBool wco_S2;
 119     SimdBool wco_any_S;
 120
 121     SimdReal rc2_S;
 122
 123     int jclusterFirst = cjFromCi<NbnxnLayout::Simd2xNN, 0>(firstCell);
 124     int jclusterLast  = cjFromCi<NbnxnLayout::Simd2xNN, 1>(lastCell);
 125     GMX_ASSERT(jclusterLast >= jclusterFirst,
 126                "We should have a non-empty j-cluster range, since the calling code should have "
 127                "ensured a non-empty cell range");
 128
 129     rc2_S = SimdReal(rlist2);
 130
 131     bool InRange = false;
 132     while (!InRange && jclusterFirst <= jclusterLast)
 133     {
 134         const float d2 = clusterBoundingBoxDistance2(bb_ci[0], jGrid.jBoundingBoxes()[jclusterFirst]);
 135         *numDistanceChecks += 2;
 136
 137         /* Check if the distance is within the distance where
 138          * we use only the bounding box distance rbb,
 139          * or within the cut-off and there is at least one atom pair
 140          * within the cut-off.
 141          */
 142         if (d2 < rbb2)
 143         {
 144             InRange = true;
 145         }
 146         else if (d2 < rlist2)
 147         {
 148             const int xind_f = xIndexFromCj<NbnxnLayout::Simd2xNN>(
 149                     cjFromCi<NbnxnLayout::Simd2xNN, 0>(jGrid.cellOffset()) + jclusterFirst);
 150
 151             jx_S = loadDuplicateHsimd(x_j + xind_f + 0 * c_xStride2xNN);
 152             jy_S = loadDuplicateHsimd(x_j + xind_f + 1 * c_xStride2xNN);
 153             jz_S = loadDuplicateHsimd(x_j + xind_f + 2 * c_xStride2xNN);
 154
 155             /* Calculate distance */
 156             dx_S0 = load<SimdReal>(x_ci_simd + 0 * GMX_SIMD_REAL_WIDTH) - jx_S;
 157             dy_S0 = load<SimdReal>(x_ci_simd + 1 * GMX_SIMD_REAL_WIDTH) - jy_S;
 158             dz_S0 = load<SimdReal>(x_ci_simd + 2 * GMX_SIMD_REAL_WIDTH) - jz_S;
 159             dx_S2 = load<SimdReal>(x_ci_simd + 3 * GMX_SIMD_REAL_WIDTH) - jx_S;
 160             dy_S2 = load<SimdReal>(x_ci_simd + 4 * GMX_SIMD_REAL_WIDTH) - jy_S;
 161             dz_S2 = load<SimdReal>(x_ci_simd + 5 * GMX_SIMD_REAL_WIDTH) - jz_S;
 162
 163             /* rsq = dx*dx+dy*dy+dz*dz */
 164             rsq_S0 = norm2(dx_S0, dy_S0, dz_S0);
 165             rsq_S2 = norm2(dx_S2, dy_S2, dz_S2);
 166
 167             wco_S0 = (rsq_S0 < rc2_S);
 168             wco_S2 = (rsq_S2 < rc2_S);
 169
 170             wco_any_S = wco_S0 || wco_S2;
 171
 172             InRange = anyTrue(wco_any_S);
 173
 174             *numDistanceChecks += 2 * GMX_SIMD_REAL_WIDTH;
 175         }
 176         if (!InRange)
 177         {
 178             jclusterFirst++;
 179         }
 180     }
 181     if (!InRange)
 182     {
 183         return;
 184     }
 185
 186     InRange = false;
 187     while (!InRange && jclusterLast > jclusterFirst)
 188     {
 189         const float d2 = clusterBoundingBoxDistance2(bb_ci[0], jGrid.jBoundingBoxes()[jclusterLast]);
 190         *numDistanceChecks += 2;
 191
 192         /* Check if the distance is within the distance where
 193          * we use only the bounding box distance rbb,
 194          * or within the cut-off and there is at least one atom pair
 195          * within the cut-off.
 196          */
 197         if (d2 < rbb2)
 198         {
 199             InRange = true;
 200         }
 201         else if (d2 < rlist2)
 202         {
 203             const int xind_l = xIndexFromCj<NbnxnLayout::Simd2xNN>(
 204                     cjFromCi<NbnxnLayout::Simd2xNN, 0>(jGrid.cellOffset()) + jclusterLast);
 205
 206             jx_S = loadDuplicateHsimd(x_j + xind_l + 0 * c_xStride2xNN);
 207             jy_S = loadDuplicateHsimd(x_j + xind_l + 1 * c_xStride2xNN);
 208             jz_S = loadDuplicateHsimd(x_j + xind_l + 2 * c_xStride2xNN);
 209
 210             /* Calculate distance */
 211             dx_S0 = load<SimdReal>(x_ci_simd + 0 * GMX_SIMD_REAL_WIDTH) - jx_S;
 212             dy_S0 = load<SimdReal>(x_ci_simd + 1 * GMX_SIMD_REAL_WIDTH) - jy_S;
 213             dz_S0 = load<SimdReal>(x_ci_simd + 2 * GMX_SIMD_REAL_WIDTH) - jz_S;
 214             dx_S2 = load<SimdReal>(x_ci_simd + 3 * GMX_SIMD_REAL_WIDTH) - jx_S;
 215             dy_S2 = load<SimdReal>(x_ci_simd + 4 * GMX_SIMD_REAL_WIDTH) - jy_S;
 216             dz_S2 = load<SimdReal>(x_ci_simd + 5 * GMX_SIMD_REAL_WIDTH) - jz_S;
 217
 218             /* rsq = dx*dx+dy*dy+dz*dz */
 219             rsq_S0 = norm2(dx_S0, dy_S0, dz_S0);
 220             rsq_S2 = norm2(dx_S2, dy_S2, dz_S2);
 221
 222             wco_S0 = (rsq_S0 < rc2_S);
 223             wco_S2 = (rsq_S2 < rc2_S);
 224
 225             wco_any_S = wco_S0 || wco_S2;
 226
 227             InRange = anyTrue(wco_any_S);
 228
 229             *numDistanceChecks += 2 * GMX_SIMD_REAL_WIDTH;
 230         }
 231         if (!InRange)
 232         {
 233             jclusterLast--;
 234         }
 235     }
 236
 237     if (jclusterFirst <= jclusterLast)
 238     {
 239         for (int jcluster = jclusterFirst; jcluster <= jclusterLast; jcluster++)
 240         {
 241             /* Store cj and the interaction mask */
 242             nbnxn_cj_t cjEntry;
 243             cjEntry.cj   = cjFromCi<NbnxnLayout::Simd2xNN, 0>(jGrid.cellOffset()) + jcluster;
 244             cjEntry.excl = get_imask_simd_2xnn(excludeSubDiagonal, icluster, jcluster);
 245             nbl->cj.push_back(cjEntry);
 246         }
 247         /* Increase the closing index in the i list */
 248         nbl->ci.back().cj_ind_end = nbl->cj.size();
 249     }
 250 }