src/gromacs/mdlib/nbnxn_search_simd_2xnn.h

   1 /*
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   3  *
   4  * Copyright (c) 2012,2013,2014,2015,2016,2017,2018, by the GROMACS development team, led by
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  35
  36 #if GMX_SIMD_REAL_WIDTH >= 2*NBNXN_CPU_CLUSTER_I_SIZE
  37 #define STRIDE_S  (GMX_SIMD_REAL_WIDTH/2)
  38 #else
  39 #define STRIDE_S  NBNXN_CPU_CLUSTER_I_SIZE
  40 #endif
  41
  42 /* Copies PBC shifted i-cell packed atom coordinates to working array */
  43 static inline void
  44 icell_set_x_simd_2xnn(int ci,
  45                       real shx, real shy, real shz,
  46                       int gmx_unused stride, const real *x,
  47                       nbnxn_list_work_t *work)
  48 {
  49     int   ia;
  50     real *x_ci_simd = work->x_ci_simd;
  51
  52     ia = xIndexFromCi<NbnxnLayout::Simd2xNN>(ci);
  53
  54     store(x_ci_simd + 0*GMX_SIMD_REAL_WIDTH, loadU1DualHsimd(x + ia + 0*STRIDE_S + 0) + SimdReal(shx) );
  55     store(x_ci_simd + 1*GMX_SIMD_REAL_WIDTH, loadU1DualHsimd(x + ia + 1*STRIDE_S + 0) + SimdReal(shy) );
  56     store(x_ci_simd + 2*GMX_SIMD_REAL_WIDTH, loadU1DualHsimd(x + ia + 2*STRIDE_S + 0) + SimdReal(shz) );
  57     store(x_ci_simd + 3*GMX_SIMD_REAL_WIDTH, loadU1DualHsimd(x + ia + 0*STRIDE_S + 2) + SimdReal(shx) );
  58     store(x_ci_simd + 4*GMX_SIMD_REAL_WIDTH, loadU1DualHsimd(x + ia + 1*STRIDE_S + 2) + SimdReal(shy) );
  59     store(x_ci_simd + 5*GMX_SIMD_REAL_WIDTH, loadU1DualHsimd(x + ia + 2*STRIDE_S + 2) + SimdReal(shz) );
  60 }
  61
  62 /* SIMD code for checking and adding cluster-pairs to the list using coordinates in packed format.
  63  *
  64  * Checks bouding box distances and possibly atom pair distances.
  65  * This is an accelerated version of make_cluster_list_simple.
  66  *
  67  * \param[in]     gridj               The j-grid
  68  * \param[in,out] nbl                 The pair-list to store the cluster pairs in
  69  * \param[in]     icluster            The index of the i-cluster
  70  * \param[in]     firstCell           The first cluster in the j-range, using i-cluster size indexing
  71  * \param[in]     lastCell            The last cluster in the j-range, using i-cluster size indexing
  72  * \param[in]     excludeSubDiagonal  Exclude atom pairs with i-index > j-index
  73  * \param[in]     x_j                 Coordinates for the j-atom, in SIMD packed format
  74  * \param[in]     rlist2              The squared list cut-off
  75  * \param[in]     rbb2                The squared cut-off for putting cluster-pairs in the list based on bounding box distance only
  76  * \param[in,out] numDistanceChecks   The number of distance checks performed
  77  */
  78 static inline void
  79 makeClusterListSimd2xnn(const nbnxn_grid_t *      gridj,
  80                         nbnxn_pairlist_t *        nbl,
  81                         int                       icluster,
  82                         int                       firstCell,
  83                         int                       lastCell,
  84                         bool                      excludeSubDiagonal,
  85                         const real * gmx_restrict x_j,
  86                         real                      rlist2,
  87                         float                     rbb2,
  88                         int * gmx_restrict        numDistanceChecks)
  89 {
  90     using namespace gmx;
  91     const real * gmx_restrict           x_ci_simd = nbl->work->x_ci_simd;
  92     const nbnxn_bb_t * gmx_restrict     bb_ci     = nbl->work->bb_ci;
  93
  94     SimdReal                            jx_S, jy_S, jz_S;
  95
  96     SimdReal                            dx_S0, dy_S0, dz_S0;
  97     SimdReal                            dx_S2, dy_S2, dz_S2;
  98
  99     SimdReal                            rsq_S0;
 100     SimdReal                            rsq_S2;
 101
 102     SimdBool                            wco_S0;
 103     SimdBool                            wco_S2;
 104     SimdBool                            wco_any_S;
 105
 106     SimdReal                            rc2_S;
 107
 108     gmx_bool                            InRange;
 109     float                               d2;
 110     int                                 xind_f, xind_l;
 111
 112     int jclusterFirst = cjFromCi<NbnxnLayout::Simd2xNN>(firstCell);
 113     int jclusterLast  = cjFromCi<NbnxnLayout::Simd2xNN>(lastCell);
 114     GMX_ASSERT(jclusterLast >= jclusterFirst, "We should have a non-empty j-cluster range, since the calling code should have ensured a non-empty cell range");
 115
 116     rc2_S   = SimdReal(rlist2);
 117
 118     InRange = FALSE;
 119     while (!InRange && jclusterFirst <= jclusterLast)
 120     {
 121 #if NBNXN_SEARCH_BB_SIMD4
 122         d2 = subc_bb_dist2_simd4(0, bb_ci, jclusterFirst, gridj->bbj);
 123 #else
 124         d2 = subc_bb_dist2(0, bb_ci, jclusterFirst, gridj->bbj);
 125 #endif
 126         *numDistanceChecks += 2;
 127
 128         /* Check if the distance is within the distance where
 129          * we use only the bounding box distance rbb,
 130          * or within the cut-off and there is at least one atom pair
 131          * within the cut-off.
 132          */
 133         if (d2 < rbb2)
 134         {
 135             InRange = TRUE;
 136         }
 137         else if (d2 < rlist2)
 138         {
 139             xind_f  = xIndexFromCj<NbnxnLayout::Simd2xNN>(cjFromCi<NbnxnLayout::Simd2xNN>(gridj->cell0) + jclusterFirst);
 140
 141             jx_S  = loadDuplicateHsimd(x_j + xind_f + 0*STRIDE_S);
 142             jy_S  = loadDuplicateHsimd(x_j + xind_f + 1*STRIDE_S);
 143             jz_S  = loadDuplicateHsimd(x_j + xind_f + 2*STRIDE_S);
 144
 145             /* Calculate distance */
 146             dx_S0            = load<SimdReal>(x_ci_simd + 0*GMX_SIMD_REAL_WIDTH) - jx_S;
 147             dy_S0            = load<SimdReal>(x_ci_simd + 1*GMX_SIMD_REAL_WIDTH) - jy_S;
 148             dz_S0            = load<SimdReal>(x_ci_simd + 2*GMX_SIMD_REAL_WIDTH) - jz_S;
 149             dx_S2            = load<SimdReal>(x_ci_simd + 3*GMX_SIMD_REAL_WIDTH) - jx_S;
 150             dy_S2            = load<SimdReal>(x_ci_simd + 4*GMX_SIMD_REAL_WIDTH) - jy_S;
 151             dz_S2            = load<SimdReal>(x_ci_simd + 5*GMX_SIMD_REAL_WIDTH) - jz_S;
 152
 153             /* rsq = dx*dx+dy*dy+dz*dz */
 154             rsq_S0           = norm2(dx_S0, dy_S0, dz_S0);
 155             rsq_S2           = norm2(dx_S2, dy_S2, dz_S2);
 156
 157             wco_S0           = (rsq_S0 < rc2_S);
 158             wco_S2           = (rsq_S2 < rc2_S);
 159
 160             wco_any_S        = wco_S0 || wco_S2;
 161
 162             InRange          = anyTrue(wco_any_S);
 163
 164             *numDistanceChecks += 2*GMX_SIMD_REAL_WIDTH;
 165         }
 166         if (!InRange)
 167         {
 168             jclusterFirst++;
 169         }
 170     }
 171     if (!InRange)
 172     {
 173         return;
 174     }
 175
 176     InRange = FALSE;
 177     while (!InRange && jclusterLast > jclusterFirst)
 178     {
 179 #if NBNXN_SEARCH_BB_SIMD4
 180         d2 = subc_bb_dist2_simd4(0, bb_ci, jclusterLast, gridj->bbj);
 181 #else
 182         d2 = subc_bb_dist2(0, bb_ci, jclusterLast, gridj->bbj);
 183 #endif
 184         *numDistanceChecks += 2;
 185
 186         /* Check if the distance is within the distance where
 187          * we use only the bounding box distance rbb,
 188          * or within the cut-off and there is at least one atom pair
 189          * within the cut-off.
 190          */
 191         if (d2 < rbb2)
 192         {
 193             InRange = TRUE;
 194         }
 195         else if (d2 < rlist2)
 196         {
 197             xind_l  = xIndexFromCj<NbnxnLayout::Simd2xNN>(cjFromCi<NbnxnLayout::Simd2xNN>(gridj->cell0) + jclusterLast);
 198
 199             jx_S  = loadDuplicateHsimd(x_j + xind_l + 0*STRIDE_S);
 200             jy_S  = loadDuplicateHsimd(x_j + xind_l + 1*STRIDE_S);
 201             jz_S  = loadDuplicateHsimd(x_j + xind_l + 2*STRIDE_S);
 202
 203             /* Calculate distance */
 204             dx_S0            = load<SimdReal>(x_ci_simd + 0*GMX_SIMD_REAL_WIDTH) - jx_S;
 205             dy_S0            = load<SimdReal>(x_ci_simd + 1*GMX_SIMD_REAL_WIDTH) - jy_S;
 206             dz_S0            = load<SimdReal>(x_ci_simd + 2*GMX_SIMD_REAL_WIDTH) - jz_S;
 207             dx_S2            = load<SimdReal>(x_ci_simd + 3*GMX_SIMD_REAL_WIDTH) - jx_S;
 208             dy_S2            = load<SimdReal>(x_ci_simd + 4*GMX_SIMD_REAL_WIDTH) - jy_S;
 209             dz_S2            = load<SimdReal>(x_ci_simd + 5*GMX_SIMD_REAL_WIDTH) - jz_S;
 210
 211             /* rsq = dx*dx+dy*dy+dz*dz */
 212             rsq_S0           = norm2(dx_S0, dy_S0, dz_S0);
 213             rsq_S2           = norm2(dx_S2, dy_S2, dz_S2);
 214
 215             wco_S0           = (rsq_S0 < rc2_S);
 216             wco_S2           = (rsq_S2 < rc2_S);
 217
 218             wco_any_S        = wco_S0 || wco_S2;
 219
 220             InRange          = anyTrue(wco_any_S);
 221
 222             *numDistanceChecks += 2*GMX_SIMD_REAL_WIDTH;
 223         }
 224         if (!InRange)
 225         {
 226             jclusterLast--;
 227         }
 228     }
 229
 230     if (jclusterFirst <= jclusterLast)
 231     {
 232         for (int jcluster = jclusterFirst; jcluster <= jclusterLast; jcluster++)
 233         {
 234             /* Store cj and the interaction mask */
 235             nbl->cj[nbl->ncj].cj   = cjFromCi<NbnxnLayout::Simd2xNN>(gridj->cell0) + jcluster;
 236             nbl->cj[nbl->ncj].excl = get_imask_simd_2xnn(excludeSubDiagonal, icluster, jcluster);
 237             nbl->ncj++;
 238         }
 239         /* Increase the closing index in i super-cell list */
 240         nbl->ci[nbl->nci].cj_ind_end = nbl->ncj;
 241     }
 242 }
 243
 244 #undef STRIDE_S