src/gromacs/mdlib/nbnxn_search_simd_2xnn.h

   1 /*
   2  * This file is part of the GROMACS molecular simulation package.
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   4  * Copyright (c) 2012,2013,2014, by the GROMACS development team, led by
   5  * Mark Abraham, David van der Spoel, Berk Hess, and Erik Lindahl,
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  35
  36 /* Get the half-width SIMD stuff from the kernel utils files */
  37 #include "gromacs/mdlib/nbnxn_kernels/nbnxn_kernel_simd_utils.h"
  38
  39
  40 #if GMX_SIMD_REAL_WIDTH >= 2*NBNXN_CPU_CLUSTER_I_SIZE
  41 #define STRIDE_S  (GMX_SIMD_REAL_WIDTH/2)
  42 #else
  43 #define STRIDE_S  NBNXN_CPU_CLUSTER_I_SIZE
  44 #endif
  45
  46 static gmx_inline gmx_simd_real_t gmx_load_hpr_hilo_pr(const real *a)
  47 {
  48     gmx_mm_hpr       a_S;
  49     gmx_simd_real_t  a_a_S;
  50
  51     gmx_load_hpr(&a_S, a);
  52
  53     gmx_2hpr_to_pr(a_S, a_S, &a_a_S);
  54
  55     return a_a_S;
  56 }
  57
  58 static gmx_inline gmx_simd_real_t gmx_set_2real_shift_pr(const real *a, real shift)
  59 {
  60     gmx_mm_hpr       a0_S, a1_S;
  61     gmx_simd_real_t  a0_a1_S;
  62
  63     gmx_set1_hpr(&a0_S, a[0] + shift);
  64     gmx_set1_hpr(&a1_S, a[1] + shift);
  65
  66     gmx_2hpr_to_pr(a0_S, a1_S, &a0_a1_S);
  67
  68     return a0_a1_S;
  69 }
  70
  71 /* Copies PBC shifted i-cell packed atom coordinates to working array */
  72 static gmx_inline void
  73 icell_set_x_simd_2xnn(int ci,
  74                       real shx, real shy, real shz,
  75                       int gmx_unused na_c,
  76                       int gmx_unused stride, const real *x,
  77                       nbnxn_list_work_t *work)
  78 {
  79     int                     ia;
  80     nbnxn_x_ci_simd_2xnn_t *x_ci;
  81
  82     x_ci = work->x_ci_simd_2xnn;
  83
  84     ia = X_IND_CI_SIMD_2XNN(ci);
  85
  86     x_ci->ix_S0 = gmx_set_2real_shift_pr(x + ia + 0*STRIDE_S + 0, shx);
  87     x_ci->iy_S0 = gmx_set_2real_shift_pr(x + ia + 1*STRIDE_S + 0, shy);
  88     x_ci->iz_S0 = gmx_set_2real_shift_pr(x + ia + 2*STRIDE_S + 0, shz);
  89     x_ci->ix_S2 = gmx_set_2real_shift_pr(x + ia + 0*STRIDE_S + 2, shx);
  90     x_ci->iy_S2 = gmx_set_2real_shift_pr(x + ia + 1*STRIDE_S + 2, shy);
  91     x_ci->iz_S2 = gmx_set_2real_shift_pr(x + ia + 2*STRIDE_S + 2, shz);
  92 }
  93
  94 /* SIMD code for making a pair list of cell ci vs cell cjf-cjl
  95  * for coordinates in packed format.
  96  * Checks bouding box distances and possibly atom pair distances.
  97  * This is an accelerated version of make_cluster_list_simple.
  98  */
  99 static gmx_inline void
 100 make_cluster_list_simd_2xnn(const nbnxn_grid_t *gridj,
 101                             nbnxn_pairlist_t *nbl,
 102                             int ci, int cjf, int cjl,
 103                             gmx_bool remove_sub_diag,
 104                             const real *x_j,
 105                             real rl2, float rbb2,
 106                             int *ndistc)
 107 {
 108     const nbnxn_x_ci_simd_2xnn_t       *work;
 109     const nbnxn_bb_t                   *bb_ci;
 110
 111     gmx_simd_real_t                     jx_S, jy_S, jz_S;
 112
 113     gmx_simd_real_t                     dx_S0, dy_S0, dz_S0;
 114     gmx_simd_real_t                     dx_S2, dy_S2, dz_S2;
 115
 116     gmx_simd_real_t                     rsq_S0;
 117     gmx_simd_real_t                     rsq_S2;
 118
 119     gmx_simd_bool_t                     wco_S0;
 120     gmx_simd_bool_t                     wco_S2;
 121     gmx_simd_bool_t                     wco_any_S;
 122
 123     gmx_simd_real_t                     rc2_S;
 124
 125     gmx_bool                            InRange;
 126     float                               d2;
 127     int                                 xind_f, xind_l, cj;
 128
 129     cjf = CI_TO_CJ_SIMD_2XNN(cjf);
 130     cjl = CI_TO_CJ_SIMD_2XNN(cjl+1) - 1;
 131
 132     work = nbl->work->x_ci_simd_2xnn;
 133
 134     bb_ci = nbl->work->bb_ci;
 135
 136     rc2_S   = gmx_simd_set1_r(rl2);
 137
 138     InRange = FALSE;
 139     while (!InRange && cjf <= cjl)
 140     {
 141 #ifdef NBNXN_SEARCH_BB_SIMD4
 142         d2 = subc_bb_dist2_simd4(0, bb_ci, cjf, gridj->bbj);
 143 #else
 144         d2 = subc_bb_dist2(0, bb_ci, cjf, gridj->bbj);
 145 #endif
 146         *ndistc += 2;
 147
 148         /* Check if the distance is within the distance where
 149          * we use only the bounding box distance rbb,
 150          * or within the cut-off and there is at least one atom pair
 151          * within the cut-off.
 152          */
 153         if (d2 < rbb2)
 154         {
 155             InRange = TRUE;
 156         }
 157         else if (d2 < rl2)
 158         {
 159             xind_f  = X_IND_CJ_SIMD_2XNN(CI_TO_CJ_SIMD_2XNN(gridj->cell0) + cjf);
 160
 161             jx_S  = gmx_load_hpr_hilo_pr(x_j+xind_f+0*STRIDE_S);
 162             jy_S  = gmx_load_hpr_hilo_pr(x_j+xind_f+1*STRIDE_S);
 163             jz_S  = gmx_load_hpr_hilo_pr(x_j+xind_f+2*STRIDE_S);
 164
 165             /* Calculate distance */
 166             dx_S0            = gmx_simd_sub_r(work->ix_S0, jx_S);
 167             dy_S0            = gmx_simd_sub_r(work->iy_S0, jy_S);
 168             dz_S0            = gmx_simd_sub_r(work->iz_S0, jz_S);
 169             dx_S2            = gmx_simd_sub_r(work->ix_S2, jx_S);
 170             dy_S2            = gmx_simd_sub_r(work->iy_S2, jy_S);
 171             dz_S2            = gmx_simd_sub_r(work->iz_S2, jz_S);
 172
 173             /* rsq = dx*dx+dy*dy+dz*dz */
 174             rsq_S0           = gmx_simd_calc_rsq_r(dx_S0, dy_S0, dz_S0);
 175             rsq_S2           = gmx_simd_calc_rsq_r(dx_S2, dy_S2, dz_S2);
 176
 177             wco_S0           = gmx_simd_cmplt_r(rsq_S0, rc2_S);
 178             wco_S2           = gmx_simd_cmplt_r(rsq_S2, rc2_S);
 179
 180             wco_any_S        = gmx_simd_or_b(wco_S0, wco_S2);
 181
 182             InRange          = gmx_simd_anytrue_b(wco_any_S);
 183
 184             *ndistc += 2*GMX_SIMD_REAL_WIDTH;
 185         }
 186         if (!InRange)
 187         {
 188             cjf++;
 189         }
 190     }
 191     if (!InRange)
 192     {
 193         return;
 194     }
 195
 196     InRange = FALSE;
 197     while (!InRange && cjl > cjf)
 198     {
 199 #ifdef NBNXN_SEARCH_BB_SIMD4
 200         d2 = subc_bb_dist2_simd4(0, bb_ci, cjl, gridj->bbj);
 201 #else
 202         d2 = subc_bb_dist2(0, bb_ci, cjl, gridj->bbj);
 203 #endif
 204         *ndistc += 2;
 205
 206         /* Check if the distance is within the distance where
 207          * we use only the bounding box distance rbb,
 208          * or within the cut-off and there is at least one atom pair
 209          * within the cut-off.
 210          */
 211         if (d2 < rbb2)
 212         {
 213             InRange = TRUE;
 214         }
 215         else if (d2 < rl2)
 216         {
 217             xind_l  = X_IND_CJ_SIMD_2XNN(CI_TO_CJ_SIMD_2XNN(gridj->cell0) + cjl);
 218
 219             jx_S  = gmx_load_hpr_hilo_pr(x_j+xind_l+0*STRIDE_S);
 220             jy_S  = gmx_load_hpr_hilo_pr(x_j+xind_l+1*STRIDE_S);
 221             jz_S  = gmx_load_hpr_hilo_pr(x_j+xind_l+2*STRIDE_S);
 222
 223             /* Calculate distance */
 224             dx_S0            = gmx_simd_sub_r(work->ix_S0, jx_S);
 225             dy_S0            = gmx_simd_sub_r(work->iy_S0, jy_S);
 226             dz_S0            = gmx_simd_sub_r(work->iz_S0, jz_S);
 227             dx_S2            = gmx_simd_sub_r(work->ix_S2, jx_S);
 228             dy_S2            = gmx_simd_sub_r(work->iy_S2, jy_S);
 229             dz_S2            = gmx_simd_sub_r(work->iz_S2, jz_S);
 230
 231             /* rsq = dx*dx+dy*dy+dz*dz */
 232             rsq_S0           = gmx_simd_calc_rsq_r(dx_S0, dy_S0, dz_S0);
 233             rsq_S2           = gmx_simd_calc_rsq_r(dx_S2, dy_S2, dz_S2);
 234
 235             wco_S0           = gmx_simd_cmplt_r(rsq_S0, rc2_S);
 236             wco_S2           = gmx_simd_cmplt_r(rsq_S2, rc2_S);
 237
 238             wco_any_S        = gmx_simd_or_b(wco_S0, wco_S2);
 239
 240             InRange          = gmx_simd_anytrue_b(wco_any_S);
 241
 242             *ndistc += 2*GMX_SIMD_REAL_WIDTH;
 243         }
 244         if (!InRange)
 245         {
 246             cjl--;
 247         }
 248     }
 249
 250     if (cjf <= cjl)
 251     {
 252         for (cj = cjf; cj <= cjl; cj++)
 253         {
 254             /* Store cj and the interaction mask */
 255             nbl->cj[nbl->ncj].cj   = CI_TO_CJ_SIMD_2XNN(gridj->cell0) + cj;
 256             nbl->cj[nbl->ncj].excl = get_imask_simd_2xnn(remove_sub_diag, ci, cj);
 257             nbl->ncj++;
 258         }
 259         /* Increase the closing index in i super-cell list */
 260         nbl->ci[nbl->nci].cj_ind_end = nbl->ncj;
 261     }
 262 }
 263
 264 #undef STRIDE_S