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