runner_doiact_vec.c 58.8 KB
Newer Older
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
/*******************************************************************************
 * This file is part of SWIFT.
 * Copyright (c) 2016 James Willis (james.s.willis@durham.ac.uk)
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published
 * by the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 ******************************************************************************/

/* Config parameters. */
#include "../config.h"

/* This object's header. */
#include "runner_doiact_vec.h"

26
27
28
/* Local headers. */
#include "active.h"

29
30
31
#ifdef WITH_VECTORIZATION
static const vector kernel_gamma2_vec = FILL_VEC(kernel_gamma2);

James Willis's avatar
James Willis committed
32
33
34
/**
 * @brief Compute the vector remainder interactions from the secondary cache.
 *
Matthieu Schaller's avatar
Matthieu Schaller committed
35
 * @param int_cache (return) secondary #cache of interactions between two
James Willis's avatar
James Willis committed
36
 * particles.
James Willis's avatar
James Willis committed
37
 * @param icount Interaction count.
Matthieu Schaller's avatar
Matthieu Schaller committed
38
 * @param rhoSum (return) #vector holding the cumulative sum of the density
James Willis's avatar
James Willis committed
39
 * update on pi.
Matthieu Schaller's avatar
Matthieu Schaller committed
40
 * @param rho_dhSum (return) #vector holding the cumulative sum of the density
James Willis's avatar
James Willis committed
41
 * gradient update on pi.
Matthieu Schaller's avatar
Matthieu Schaller committed
42
 * @param wcountSum (return) #vector holding the cumulative sum of the wcount
James Willis's avatar
James Willis committed
43
 * update on pi.
Matthieu Schaller's avatar
Matthieu Schaller committed
44
 * @param wcount_dhSum (return) #vector holding the cumulative sum of the wcount
James Willis's avatar
James Willis committed
45
 * gradient update on pi.
Matthieu Schaller's avatar
Matthieu Schaller committed
46
 * @param div_vSum (return) #vector holding the cumulative sum of the divergence
James Willis's avatar
James Willis committed
47
 * update on pi.
Matthieu Schaller's avatar
Matthieu Schaller committed
48
 * @param curlvxSum (return) #vector holding the cumulative sum of the curl of
James Willis's avatar
James Willis committed
49
 * vx update on pi.
Matthieu Schaller's avatar
Matthieu Schaller committed
50
 * @param curlvySum (return) #vector holding the cumulative sum of the curl of
James Willis's avatar
James Willis committed
51
 * vy update on pi.
Matthieu Schaller's avatar
Matthieu Schaller committed
52
 * @param curlvzSum (return) #vector holding the cumulative sum of the curl of
James Willis's avatar
James Willis committed
53
 * vz update on pi.
James Willis's avatar
James Willis committed
54
55
56
57
 * @param v_hi_inv #vector of 1/h for pi.
 * @param v_vix #vector of x velocity of pi.
 * @param v_viy #vector of y velocity of pi.
 * @param v_viz #vector of z velocity of pi.
Matthieu Schaller's avatar
Matthieu Schaller committed
58
 * @param icount_align (return) Interaction count after the remainder
James Willis's avatar
James Willis committed
59
 * interactions have been performed, should be a multiple of the vector length.
James Willis's avatar
James Willis committed
60
 */
James Willis's avatar
James Willis committed
61
__attribute__((always_inline)) INLINE static void calcRemInteractions(
Matthieu Schaller's avatar
Matthieu Schaller committed
62
63
64
65
66
    struct c2_cache *const int_cache, const int icount, vector *rhoSum,
    vector *rho_dhSum, vector *wcountSum, vector *wcount_dhSum,
    vector *div_vSum, vector *curlvxSum, vector *curlvySum, vector *curlvzSum,
    vector v_hi_inv, vector v_vix, vector v_viy, vector v_viz,
    int *icount_align) {
67

68
  mask_t int_mask, int_mask2;
James Willis's avatar
James Willis committed
69
70

  /* Work out the number of remainder interactions and pad secondary cache. */
71
72
73
74
75
76
  *icount_align = icount;
  int rem = icount % (NUM_VEC_PROC * VEC_SIZE);
  if (rem != 0) {
    int pad = (NUM_VEC_PROC * VEC_SIZE) - rem;
    *icount_align += pad;

77
    /* Initialise masks to true. */
78
79
    vec_init_mask_true(int_mask);
    vec_init_mask_true(int_mask2);
80

James Willis's avatar
James Willis committed
81
82
83
    /* Pad secondary cache so that there are no contributions in the interaction
     * function. */
    for (int i = icount; i < *icount_align; i++) {
84
85
86
87
88
89
90
91
      int_cache->mq[i] = 0.f;
      int_cache->r2q[i] = 1.f;
      int_cache->dxq[i] = 0.f;
      int_cache->dyq[i] = 0.f;
      int_cache->dzq[i] = 0.f;
      int_cache->vxq[i] = 0.f;
      int_cache->vyq[i] = 0.f;
      int_cache->vzq[i] = 0.f;
92
93
94
95
    }

    /* Zero parts of mask that represent the padded values.*/
    if (pad < VEC_SIZE) {
James Willis's avatar
James Willis committed
96
      vec_pad_mask(int_mask2, pad);
James Willis's avatar
James Willis committed
97
    } else {
James Willis's avatar
James Willis committed
98
      vec_pad_mask(int_mask, VEC_SIZE - rem);
99
      vec_zero_mask(int_mask2);
100
101
    }

James Willis's avatar
James Willis committed
102
103
    /* Perform remainder interaction and remove remainder from aligned
     * interaction count. */
104
    *icount_align = icount - rem;
James Willis's avatar
James Willis committed
105
106
107
108
109
110
    runner_iact_nonsym_2_vec_density(
        &int_cache->r2q[*icount_align], &int_cache->dxq[*icount_align],
        &int_cache->dyq[*icount_align], &int_cache->dzq[*icount_align],
        v_hi_inv, v_vix, v_viy, v_viz, &int_cache->vxq[*icount_align],
        &int_cache->vyq[*icount_align], &int_cache->vzq[*icount_align],
        &int_cache->mq[*icount_align], rhoSum, rho_dhSum, wcountSum,
James Willis's avatar
James Willis committed
111
112
        wcount_dhSum, div_vSum, curlvxSum, curlvySum, curlvzSum, int_mask,
        int_mask2, 1);
113
114
115
  }
}

James Willis's avatar
James Willis committed
116
/**
James Willis's avatar
James Willis committed
117
118
 * @brief Left-packs the values needed by an interaction into the secondary
 * cache (Supports AVX, AVX2 and AVX512 instruction sets).
James Willis's avatar
James Willis committed
119
120
 *
 * @param mask Contains which particles need to interact.
Matthieu Schaller's avatar
Matthieu Schaller committed
121
 * @param pjd Index of the particle to store into.
James Willis's avatar
James Willis committed
122
123
124
125
126
 * @param v_r2 #vector of the separation between two particles squared.
 * @param v_dx #vector of the x separation between two particles.
 * @param v_dy #vector of the y separation between two particles.
 * @param v_dz #vector of the z separation between two particles.
 * @param cell_cache #cache of all particles in the cell.
Matthieu Schaller's avatar
Matthieu Schaller committed
127
 * @param int_cache (return) secondary #cache of interactions between two
James Willis's avatar
James Willis committed
128
 * particles.
James Willis's avatar
James Willis committed
129
130
 * @param icount Interaction count.
 * @param rhoSum #vector holding the cumulative sum of the density update on pi.
James Willis's avatar
James Willis committed
131
132
133
134
135
136
137
138
139
140
141
142
143
144
 * @param rho_dhSum #vector holding the cumulative sum of the density gradient
 * update on pi.
 * @param wcountSum #vector holding the cumulative sum of the wcount update on
 * pi.
 * @param wcount_dhSum #vector holding the cumulative sum of the wcount gradient
 * update on pi.
 * @param div_vSum #vector holding the cumulative sum of the divergence update
 * on pi.
 * @param curlvxSum #vector holding the cumulative sum of the curl of vx update
 * on pi.
 * @param curlvySum #vector holding the cumulative sum of the curl of vy update
 * on pi.
 * @param curlvzSum #vector holding the cumulative sum of the curl of vz update
 * on pi.
James Willis's avatar
James Willis committed
145
146
147
148
149
 * @param v_hi_inv #vector of 1/h for pi.
 * @param v_vix #vector of x velocity of pi.
 * @param v_viy #vector of y velocity of pi.
 * @param v_viz #vector of z velocity of pi.
 */
James Willis's avatar
James Willis committed
150
__attribute__((always_inline)) INLINE static void storeInteractions(
151
    const int mask, const int pjd, vector *v_r2, vector *v_dx, vector *v_dy,
James Willis's avatar
James Willis committed
152
153
154
155
156
    vector *v_dz, const struct cache *const cell_cache,
    struct c2_cache *const int_cache, int *icount, vector *rhoSum,
    vector *rho_dhSum, vector *wcountSum, vector *wcount_dhSum,
    vector *div_vSum, vector *curlvxSum, vector *curlvySum, vector *curlvzSum,
    vector v_hi_inv, vector v_vix, vector v_viy, vector v_viz) {
James Willis's avatar
James Willis committed
157
158
159

/* Left-pack values needed into the secondary cache using the interaction mask.
 */
160
#if defined(HAVE_AVX2) || defined(HAVE_AVX512_F)
161
162
163
164
165
166
167
  mask_t packed_mask;
  VEC_FORM_PACKED_MASK(mask, packed_mask);

  VEC_LEFT_PACK(v_r2->v, packed_mask, &int_cache->r2q[*icount]);
  VEC_LEFT_PACK(v_dx->v, packed_mask, &int_cache->dxq[*icount]);
  VEC_LEFT_PACK(v_dy->v, packed_mask, &int_cache->dyq[*icount]);
  VEC_LEFT_PACK(v_dz->v, packed_mask, &int_cache->dzq[*icount]);
James Willis's avatar
James Willis committed
168
169
170
171
172
173
174
175
  VEC_LEFT_PACK(vec_load(&cell_cache->m[pjd]), packed_mask,
                &int_cache->mq[*icount]);
  VEC_LEFT_PACK(vec_load(&cell_cache->vx[pjd]), packed_mask,
                &int_cache->vxq[*icount]);
  VEC_LEFT_PACK(vec_load(&cell_cache->vy[pjd]), packed_mask,
                &int_cache->vyq[*icount]);
  VEC_LEFT_PACK(vec_load(&cell_cache->vz[pjd]), packed_mask,
                &int_cache->vzq[*icount]);
176
177
178

  /* Increment interaction count by number of bits set in mask. */
  (*icount) += __builtin_popcount(mask);
179
#else
James Willis's avatar
James Willis committed
180
  /* Quicker to do it serially in AVX rather than use intrinsics. */
James Willis's avatar
James Willis committed
181
  for (int bit_index = 0; bit_index < VEC_SIZE; bit_index++) {
182
183
    if (mask & (1 << bit_index)) {
      /* Add this interaction to the queue. */
184
185
186
187
188
189
190
191
      int_cache->r2q[*icount] = v_r2->f[bit_index];
      int_cache->dxq[*icount] = v_dx->f[bit_index];
      int_cache->dyq[*icount] = v_dy->f[bit_index];
      int_cache->dzq[*icount] = v_dz->f[bit_index];
      int_cache->mq[*icount] = cell_cache->m[pjd + bit_index];
      int_cache->vxq[*icount] = cell_cache->vx[pjd + bit_index];
      int_cache->vyq[*icount] = cell_cache->vy[pjd + bit_index];
      int_cache->vzq[*icount] = cell_cache->vz[pjd + bit_index];
192
193
194
195

      (*icount)++;
    }
  }
196

James Willis's avatar
James Willis committed
197
198
#endif /* defined(HAVE_AVX2) || defined(HAVE_AVX512_F) */

James Willis's avatar
James Willis committed
199
  /* Flush the c2 cache if it has reached capacity. */
James Willis's avatar
James Willis committed
200
  if (*icount >= (C2_CACHE_SIZE - (NUM_VEC_PROC * VEC_SIZE))) {
201
202

    int icount_align = *icount;
James Willis's avatar
James Willis committed
203

James Willis's avatar
James Willis committed
204
    /* Peform remainder interactions. */
Matthieu Schaller's avatar
Matthieu Schaller committed
205
206
207
    calcRemInteractions(int_cache, *icount, rhoSum, rho_dhSum, wcountSum,
                        wcount_dhSum, div_vSum, curlvxSum, curlvySum, curlvzSum,
                        v_hi_inv, v_vix, v_viy, v_viz, &icount_align);
208

209
    mask_t int_mask, int_mask2;
210
211
    vec_init_mask_true(int_mask);
    vec_init_mask_true(int_mask2);
James Willis's avatar
James Willis committed
212
213

    /* Perform interactions. */
214
    for (int j = 0; j < icount_align; j += (NUM_VEC_PROC * VEC_SIZE)) {
James Willis's avatar
James Willis committed
215
      runner_iact_nonsym_2_vec_density(
216
217
218
219
220
          &int_cache->r2q[j], &int_cache->dxq[j], &int_cache->dyq[j],
          &int_cache->dzq[j], v_hi_inv, v_vix, v_viy, v_viz, &int_cache->vxq[j],
          &int_cache->vyq[j], &int_cache->vzq[j], &int_cache->mq[j], rhoSum,
          rho_dhSum, wcountSum, wcount_dhSum, div_vSum, curlvxSum, curlvySum,
          curlvzSum, int_mask, int_mask2, 0);
221
    }
James Willis's avatar
James Willis committed
222
223

    /* Reset interaction count. */
224
225
226
    *icount = 0;
  }
}
227

228
/**
229
230
 * @brief Populates the arrays max_index_i and max_index_j with the maximum
 * indices of
James Willis's avatar
James Willis committed
231
232
233
 * particles into their neighbouring cells. Also finds the first pi that
 * interacts with any particle in cj and the last pj that interacts with any
 * particle in ci.
234
 *
James Willis's avatar
James Willis committed
235
236
237
238
239
240
 * @param ci #cell pointer to ci
 * @param cj #cell pointer to cj
 * @param sort_i #entry array for particle distance in ci
 * @param sort_j #entry array for particle distance in cj
 * @param dx_max maximum particle movement allowed in cell
 * @param rshift cutoff shift
241
242
243
244
 * @param hi_max Maximal smoothing length in cell ci
 * @param hj_max Maximal smoothing length in cell cj
 * @param di_max Maximal position on the axis that can interact in cell ci
 * @param dj_min Minimal position on the axis that can interact in cell ci
245
 * @param max_index_i array to hold the maximum distances of pi particles into
246
 * #cell cj
247
 * @param max_index_j array to hold the maximum distances of pj particles into
248
 * #cell cj
James Willis's avatar
James Willis committed
249
250
 * @param init_pi first pi to interact with a pj particle
 * @param init_pj last pj to interact with a pi particle
251
 * @param max_active_bin The largest time-bin active during this step.
252
 */
253
__attribute__((always_inline)) INLINE static void populate_max_index_no_cache(
James Willis's avatar
James Willis committed
254
255
    const struct cell *ci, const struct cell *cj,
    const struct entry *restrict sort_i, const struct entry *restrict sort_j,
256
257
    const float dx_max, const float rshift, const double hi_max,
    const double hj_max, const double di_max, const double dj_min,
258
    int *max_index_i, int *max_index_j, int *init_pi, int *init_pj,
259
    const timebin_t max_active_bin) {
260

261
262
  const struct part *restrict parts_i = ci->parts;
  const struct part *restrict parts_j = cj->parts;
263

264
  int first_pi = 0, last_pj = cj->count - 1;
265
  int temp;
266

James Willis's avatar
James Willis committed
267
268
  /* Find the leftmost active particle in cell i that interacts with any
   * particle in cell j. */
269
  first_pi = ci->count;
270
  int active_id = first_pi - 1;
271
  while (first_pi > 0 && sort_i[first_pi - 1].d + dx_max + hi_max > dj_min) {
272
    first_pi--;
273
    /* Store the index of the particle if it is active. */
James Willis's avatar
James Willis committed
274
275
    if (part_is_active_no_debug(&parts_i[sort_i[first_pi].i], max_active_bin))
      active_id = first_pi;
276
  }
277

278
279
  /* Set the first active pi in range of any particle in cell j. */
  first_pi = active_id;
280

281
  /* Find the maximum index into cell j for each particle in range in cell i. */
James Willis's avatar
James Willis committed
282
  if (first_pi < ci->count) {
283

284
285
    /* Start from the first particle in cell j. */
    temp = 0;
286

287
    const struct part *pi = &parts_i[sort_i[first_pi].i];
288
289
    const float first_di =
        sort_i[first_pi].d + pi->h * kernel_gamma + dx_max - rshift;
290

291
    /* Loop through particles in cell j until they are not in range of pi. */
292
    while (temp < cj->count - 1 && first_di > sort_j[temp].d) temp++;
293

294
    max_index_i[first_pi] = temp;
295

296
    /* Populate max_index_i for remaining particles that are within range. */
James Willis's avatar
James Willis committed
297
    for (int i = first_pi + 1; i < ci->count; i++) {
298
      temp = max_index_i[i - 1];
299
      pi = &parts_i[sort_i[i].i];
300

301
      const float di = sort_i[i].d + pi->h * kernel_gamma + dx_max - rshift;
302

303
      while (temp < cj->count - 1 && di > sort_j[temp].d) temp++;
James Willis's avatar
James Willis committed
304

305
      max_index_i[i] = temp;
306
    }
James Willis's avatar
James Willis committed
307
  } else {
308
309
    /* Make sure that max index is set to first particle in cj.*/
    max_index_i[ci->count - 1] = 0;
310
  }
James Willis's avatar
James Willis committed
311

James Willis's avatar
James Willis committed
312
313
  /* Find the rightmost active particle in cell j that interacts with any
   * particle in cell i. */
314
  last_pj = -1;
315
  active_id = last_pj;
James Willis's avatar
James Willis committed
316
317
  while (last_pj < cj->count &&
         sort_j[last_pj + 1].d - hj_max - dx_max < di_max) {
318
    last_pj++;
319
    /* Store the index of the particle if it is active. */
James Willis's avatar
James Willis committed
320
321
    if (part_is_active_no_debug(&parts_j[sort_j[last_pj].i], max_active_bin))
      active_id = last_pj;
322
  }
James Willis's avatar
James Willis committed
323

324
  /* Set the last active pj in range of any particle in cell i. */
325
  last_pj = active_id;
326

327
  /* Find the maximum index into cell i for each particle in range in cell j. */
328
  if (last_pj >= 0) {
329

330
331
    /* Start from the last particle in cell i. */
    temp = ci->count - 1;
332

333
    const struct part *pj = &parts_j[sort_j[last_pj].i];
334
335
    const float last_dj =
        sort_j[last_pj].d - dx_max - pj->h * kernel_gamma + rshift;
336

337
    /* Loop through particles in cell i until they are not in range of pj. */
338
    while (temp > 0 && last_dj < sort_i[temp].d) temp--;
339

340
    max_index_j[last_pj] = temp;
341

342
    /* Populate max_index_j for remaining particles that are within range. */
James Willis's avatar
James Willis committed
343
    for (int i = last_pj - 1; i >= 0; i--) {
344
      temp = max_index_j[i + 1];
345
      pj = &parts_j[sort_j[i].i];
346
      const float dj = sort_j[i].d - dx_max - (pj->h * kernel_gamma) + rshift;
347

348
      while (temp > 0 && dj < sort_i[temp].d) temp--;
349

350
      max_index_j[i] = temp;
351
    }
James Willis's avatar
James Willis committed
352
  } else {
353
    /* Make sure that max index is set to last particle in ci.*/
James Willis's avatar
James Willis committed
354
    max_index_j[0] = ci->count - 1;
355
  }
356

James Willis's avatar
James Willis committed
357
358
  *init_pi = first_pi;
  *init_pj = last_pj;
359
360
}

James Willis's avatar
James Willis committed
361
362
363
364
365
__attribute__((always_inline)) INLINE static void
populate_max_index_no_cache_force(const struct cell *ci, const struct cell *cj,
                                  const struct entry *restrict sort_i,
                                  const struct entry *restrict sort_j,
                                  const float dx_max, const float rshift,
James Willis's avatar
James Willis committed
366
367
368
369
370
                                  const double hi_max_raw,
                                  const double hj_max_raw, const double hi_max,
                                  const double hj_max, const double di_max,
                                  const double dj_min, int *max_index_i,
                                  int *max_index_j, int *init_pi, int *init_pj,
371
                                  const timebin_t max_active_bin) {
372

373
374
  const struct part *restrict parts_i = ci->parts;
  const struct part *restrict parts_j = cj->parts;
James Willis's avatar
James Willis committed
375

376
  int first_pi = 0, last_pj = cj->count - 1;
377
378
379
380
381
382
  int temp;

  /* Find the leftmost active particle in cell i that interacts with any
   * particle in cell j. */
  first_pi = ci->count;
  int active_id = first_pi - 1;
James Willis's avatar
James Willis committed
383
384
  while (first_pi > 0 &&
         sort_i[first_pi - 1].d + dx_max + max(hi_max, hj_max) > dj_min) {
385
386
    first_pi--;
    /* Store the index of the particle if it is active. */
James Willis's avatar
James Willis committed
387
388
    if (part_is_active_no_debug(&parts_i[sort_i[first_pi].i], max_active_bin))
      active_id = first_pi;
389
  }
390

391
392
393
394
395
396
397
398
399
400
  /* Set the first active pi in range of any particle in cell j. */
  first_pi = active_id;

  /* Find the maximum index into cell j for each particle in range in cell i. */
  if (first_pi < ci->count) {

    /* Start from the first particle in cell j. */
    temp = 0;

    const struct part *pi = &parts_i[sort_i[first_pi].i];
James Willis's avatar
James Willis committed
401
402
403
    const float first_di = sort_i[first_pi].d +
                           max(pi->h, hj_max_raw) * kernel_gamma + dx_max -
                           rshift;
404
405

    /* Loop through particles in cell j until they are not in range of pi. */
406
    while (temp < cj->count - 1 && first_di > sort_j[temp].d) temp++;
407
408
409
410
411
412
413
414

    max_index_i[first_pi] = temp;

    /* Populate max_index_i for remaining particles that are within range. */
    for (int i = first_pi + 1; i < ci->count; i++) {
      temp = max_index_i[i - 1];
      pi = &parts_i[sort_i[i].i];

James Willis's avatar
James Willis committed
415
416
417
      const float di =
          sort_i[i].d + max(pi->h, hj_max_raw) * kernel_gamma + dx_max - rshift;

418
      while (temp < cj->count - 1 && di > sort_j[temp].d) temp++;
James Willis's avatar
James Willis committed
419

420
      max_index_i[i] = temp;
421
    }
422
423
424
  } else {
    /* Make sure that max index is set to first particle in cj.*/
    max_index_i[ci->count - 1] = 0;
425
426
  }

427
428
429
430
431
  /* Find the rightmost active particle in cell j that interacts with any
   * particle in cell i. */
  last_pj = -1;
  active_id = last_pj;
  while (last_pj < cj->count &&
432
         sort_j[last_pj + 1].d - max(hj_max, hi_max) - dx_max < di_max) {
433
434
    last_pj++;
    /* Store the index of the particle if it is active. */
James Willis's avatar
James Willis committed
435
436
    if (part_is_active_no_debug(&parts_j[sort_j[last_pj].i], max_active_bin))
      active_id = last_pj;
437
  }
James Willis's avatar
James Willis committed
438

439
440
  /* Set the last active pj in range of any particle in cell i. */
  last_pj = active_id;
Matthieu Schaller's avatar
Matthieu Schaller committed
441

442
  /* Find the maximum index into cell i for each particle in range in cell j. */
443
  if (last_pj >= 0) {
Matthieu Schaller's avatar
Matthieu Schaller committed
444

445
446
447
448
    /* Start from the last particle in cell i. */
    temp = ci->count - 1;

    const struct part *pj = &parts_j[sort_j[last_pj].i];
James Willis's avatar
James Willis committed
449
450
    const float last_dj = sort_j[last_pj].d - dx_max -
                          max(pj->h, hi_max_raw) * kernel_gamma + rshift;
451
452

    /* Loop through particles in cell i until they are not in range of pj. */
453
    while (temp > 0 && last_dj < sort_i[temp].d) temp--;
James Willis's avatar
James Willis committed
454

455
456
457
458
459
460
461
    max_index_j[last_pj] = temp;

    /* Populate max_index_j for remaining particles that are within range. */
    for (int i = last_pj - 1; i >= 0; i--) {
      temp = max_index_j[i + 1];
      pj = &parts_j[sort_j[i].i];

James Willis's avatar
James Willis committed
462
463
464
      const float dj = sort_j[i].d - dx_max -
                       (max(pj->h, hi_max_raw) * kernel_gamma) + rshift;

465
      while (temp > 0 && dj < sort_i[temp].d) temp--;
James Willis's avatar
James Willis committed
466

467
      max_index_j[i] = temp;
468
    }
469
470
471
  } else {
    /* Make sure that max index is set to last particle in ci.*/
    max_index_j[0] = ci->count - 1;
472
473
  }

James Willis's avatar
James Willis committed
474
475
  *init_pi = first_pi;
  *init_pj = last_pj;
476
}
477

James Willis's avatar
James Willis committed
478
#endif /* WITH_VECTORIZATION */
479
480

/**
James Willis's avatar
James Willis committed
481
482
 * @brief Compute the cell self-interaction (non-symmetric) using vector
 * intrinsics with one particle pi at a time.
483
484
485
486
 *
 * @param r The #runner.
 * @param c The #cell.
 */
James Willis's avatar
James Willis committed
487
488
__attribute__((always_inline)) INLINE void runner_doself1_density_vec(
    struct runner *r, struct cell *restrict c) {
489
490

#ifdef WITH_VECTORIZATION
491
  const struct engine *e = r->e;
492
493
494
495
496
497
  struct part *restrict pi;
  int count_align;
  int num_vec_proc = NUM_VEC_PROC;

  struct part *restrict parts = c->parts;
  const int count = c->count;
James Willis's avatar
James Willis committed
498

499
500
  const timebin_t max_active_bin = e->max_active_bin;

501
502
  vector v_hi, v_vix, v_viy, v_viz, v_hig2, v_r2;

James Willis's avatar
James Willis committed
503
  TIMER_TIC
504

505
506
  if (!cell_is_active(c, e)) return;

507
  if (!cell_are_part_drifted(c, e)) error("Interacting undrifted cell.");
508

James Willis's avatar
James Willis committed
509
  /* Get the particle cache from the runner and re-allocate
510
   * the cache if it is not big enough for the cell. */
511
  struct cache *restrict cell_cache = &r->ci_cache;
James Willis's avatar
James Willis committed
512
513
514

  if (cell_cache->count < count) {
    cache_init(cell_cache, count);
515
516
  }

James Willis's avatar
James Willis committed
517
  /* Read the particles from the cell and store them locally in the cache. */
James Willis's avatar
James Willis committed
518
  cache_read_particles(c, cell_cache);
519
520
521
522

  /* Create secondary cache to store particle interactions. */
  struct c2_cache int_cache;
  int icount = 0, icount_align = 0;
523
524
525
526
527
528
529
530

  /* Loop over the particles in the cell. */
  for (int pid = 0; pid < count; pid++) {

    /* Get a pointer to the ith particle. */
    pi = &parts[pid];

    /* Is the ith particle active? */
531
    if (!part_is_active_no_debug(pi, max_active_bin)) continue;
532
533
534
535
536

    vector pix, piy, piz;

    const float hi = cell_cache->h[pid];

James Willis's avatar
James Willis committed
537
    /* Fill particle pi vectors. */
538
539
540
541
542
543
544
545
546
547
548
    pix.v = vec_set1(cell_cache->x[pid]);
    piy.v = vec_set1(cell_cache->y[pid]);
    piz.v = vec_set1(cell_cache->z[pid]);
    v_hi.v = vec_set1(hi);
    v_vix.v = vec_set1(cell_cache->vx[pid]);
    v_viy.v = vec_set1(cell_cache->vy[pid]);
    v_viz.v = vec_set1(cell_cache->vz[pid]);

    const float hig2 = hi * hi * kernel_gamma2;
    v_hig2.v = vec_set1(hig2);

James Willis's avatar
James Willis committed
549
    /* Reset cumulative sums of update vectors. */
James Willis's avatar
James Willis committed
550
551
552
    vector rhoSum, rho_dhSum, wcountSum, wcount_dhSum, div_vSum, curlvxSum,
        curlvySum, curlvzSum;

James Willis's avatar
James Willis committed
553
    /* Get the inverse of hi. */
554
    vector v_hi_inv;
James Willis's avatar
James Willis committed
555

556
    v_hi_inv = vec_reciprocal(v_hi);
James Willis's avatar
James Willis committed
557

558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
    rhoSum.v = vec_setzero();
    rho_dhSum.v = vec_setzero();
    wcountSum.v = vec_setzero();
    wcount_dhSum.v = vec_setzero();
    div_vSum.v = vec_setzero();
    curlvxSum.v = vec_setzero();
    curlvySum.v = vec_setzero();
    curlvzSum.v = vec_setzero();

    /* Pad cache if there is a serial remainder. */
    count_align = count;
    int rem = count % (num_vec_proc * VEC_SIZE);
    if (rem != 0) {
      int pad = (num_vec_proc * VEC_SIZE) - rem;

      count_align += pad;
574
575
576
577
578
579
580
581

      /* Set positions to the same as particle pi so when the r2 > 0 mask is
       * applied these extra contributions are masked out.*/
      for (int i = count; i < count_align; i++) {
        cell_cache->x[i] = pix.f[0];
        cell_cache->y[i] = piy.f[0];
        cell_cache->z[i] = piz.f[0];
      }
582
583
584
585
586
    }

    vector pjx, pjy, pjz;
    vector pjx2, pjy2, pjz2;

James Willis's avatar
James Willis committed
587
588
    /* Find all of particle pi's interacions and store needed values in the
     * secondary cache.*/
589
590
591
592
593
594
    for (int pjd = 0; pjd < count_align; pjd += (num_vec_proc * VEC_SIZE)) {

      /* Load 2 sets of vectors from the particle cache. */
      pjx.v = vec_load(&cell_cache->x[pjd]);
      pjy.v = vec_load(&cell_cache->y[pjd]);
      pjz.v = vec_load(&cell_cache->z[pjd]);
595

596
597
598
      pjx2.v = vec_load(&cell_cache->x[pjd + VEC_SIZE]);
      pjy2.v = vec_load(&cell_cache->y[pjd + VEC_SIZE]);
      pjz2.v = vec_load(&cell_cache->z[pjd + VEC_SIZE]);
James Willis's avatar
James Willis committed
599

600
      /* Compute the pairwise distance. */
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
      vector v_dx, v_dy, v_dz;
      vector v_dx_2, v_dy_2, v_dz_2, v_r2_2;

      v_dx.v = vec_sub(pix.v, pjx.v);
      v_dx_2.v = vec_sub(pix.v, pjx2.v);
      v_dy.v = vec_sub(piy.v, pjy.v);
      v_dy_2.v = vec_sub(piy.v, pjy2.v);
      v_dz.v = vec_sub(piz.v, pjz.v);
      v_dz_2.v = vec_sub(piz.v, pjz2.v);

      v_r2.v = vec_mul(v_dx.v, v_dx.v);
      v_r2_2.v = vec_mul(v_dx_2.v, v_dx_2.v);
      v_r2.v = vec_fma(v_dy.v, v_dy.v, v_r2.v);
      v_r2_2.v = vec_fma(v_dy_2.v, v_dy_2.v, v_r2_2.v);
      v_r2.v = vec_fma(v_dz.v, v_dz.v, v_r2.v);
      v_r2_2.v = vec_fma(v_dz_2.v, v_dz_2.v, v_r2_2.v);
James Willis's avatar
James Willis committed
617

618
      /* Form a mask from r2 < hig2 and r2 > 0.*/
James Willis's avatar
James Willis committed
619
620
      mask_t v_doi_mask, v_doi_mask_self_check, v_doi_mask2,
          v_doi_mask2_self_check;
621
      int doi_mask, doi_mask_self_check, doi_mask2, doi_mask2_self_check;
622

James Willis's avatar
James Willis committed
623
      /* Form r2 > 0 mask and r2 < hig2 mask. */
624
      vec_create_mask(v_doi_mask_self_check, vec_cmp_gt(v_r2.v, vec_setzero()));
625
      vec_create_mask(v_doi_mask, vec_cmp_lt(v_r2.v, v_hig2.v));
626

James Willis's avatar
James Willis committed
627
      /* Form r2 > 0 mask and r2 < hig2 mask. */
James Willis's avatar
James Willis committed
628
629
      vec_create_mask(v_doi_mask2_self_check,
                      vec_cmp_gt(v_r2_2.v, vec_setzero()));
630
      vec_create_mask(v_doi_mask2, vec_cmp_lt(v_r2_2.v, v_hig2.v));
631

632
633
634
635
636
637
      /* Form integer masks. */
      doi_mask_self_check = vec_form_int_mask(v_doi_mask_self_check);
      doi_mask = vec_form_int_mask(v_doi_mask);

      doi_mask2_self_check = vec_form_int_mask(v_doi_mask2_self_check);
      doi_mask2 = vec_form_int_mask(v_doi_mask2);
James Willis's avatar
James Willis committed
638

639
640
641
      /* Combine the two masks. */
      doi_mask = doi_mask & doi_mask_self_check;
      doi_mask2 = doi_mask2 & doi_mask2_self_check;
642

James Willis's avatar
James Willis committed
643
644
      /* If there are any interactions left pack interaction values into c2
       * cache. */
645
      if (doi_mask) {
James Willis's avatar
James Willis committed
646
647
        storeInteractions(doi_mask, pjd, &v_r2, &v_dx, &v_dy, &v_dz, cell_cache,
                          &int_cache, &icount, &rhoSum, &rho_dhSum, &wcountSum,
James Willis's avatar
James Willis committed
648
649
                          &wcount_dhSum, &div_vSum, &curlvxSum, &curlvySum,
                          &curlvzSum, v_hi_inv, v_vix, v_viy, v_viz);
650
      }
James Willis's avatar
James Willis committed
651
652
653
654
655
656
657
      if (doi_mask2) {
        storeInteractions(doi_mask2, pjd + VEC_SIZE, &v_r2_2, &v_dx_2, &v_dy_2,
                          &v_dz_2, cell_cache, &int_cache, &icount, &rhoSum,
                          &rho_dhSum, &wcountSum, &wcount_dhSum, &div_vSum,
                          &curlvxSum, &curlvySum, &curlvzSum, v_hi_inv, v_vix,
                          v_viy, v_viz);
      }
658
659
    }

James Willis's avatar
James Willis committed
660
    /* Perform padded vector remainder interactions if any are present. */
Matthieu Schaller's avatar
Matthieu Schaller committed
661
662
663
    calcRemInteractions(&int_cache, icount, &rhoSum, &rho_dhSum, &wcountSum,
                        &wcount_dhSum, &div_vSum, &curlvxSum, &curlvySum,
                        &curlvzSum, v_hi_inv, v_vix, v_viy, v_viz,
James Willis's avatar
James Willis committed
664
665
666
667
                        &icount_align);

    /* Initialise masks to true in case remainder interactions have been
     * performed. */
668
    mask_t int_mask, int_mask2;
669
670
    vec_init_mask_true(int_mask);
    vec_init_mask_true(int_mask2);
671
672

    /* Perform interaction with 2 vectors. */
James Willis's avatar
James Willis committed
673
674
675
676
677
678
    for (int pjd = 0; pjd < icount_align; pjd += (num_vec_proc * VEC_SIZE)) {
      runner_iact_nonsym_2_vec_density(
          &int_cache.r2q[pjd], &int_cache.dxq[pjd], &int_cache.dyq[pjd],
          &int_cache.dzq[pjd], v_hi_inv, v_vix, v_viy, v_viz,
          &int_cache.vxq[pjd], &int_cache.vyq[pjd], &int_cache.vzq[pjd],
          &int_cache.mq[pjd], &rhoSum, &rho_dhSum, &wcountSum, &wcount_dhSum,
James Willis's avatar
James Willis committed
679
680
          &div_vSum, &curlvxSum, &curlvySum, &curlvzSum, int_mask, int_mask2,
          0);
681
682
    }

James Willis's avatar
James Willis committed
683
684
685
686
687
688
689
690
691
692
    /* Perform horizontal adds on vector sums and store result in particle pi.
     */
    VEC_HADD(rhoSum, pi->rho);
    VEC_HADD(rho_dhSum, pi->density.rho_dh);
    VEC_HADD(wcountSum, pi->density.wcount);
    VEC_HADD(wcount_dhSum, pi->density.wcount_dh);
    VEC_HADD(div_vSum, pi->density.div_v);
    VEC_HADD(curlvxSum, pi->density.rot_v[0]);
    VEC_HADD(curlvySum, pi->density.rot_v[1]);
    VEC_HADD(curlvzSum, pi->density.rot_v[2]);
693
694
695
696
697

    /* Reset interaction count. */
    icount = 0;
  } /* loop over all particles. */

James Willis's avatar
James Willis committed
698
  TIMER_TOC(timer_doself_density);
699
#endif /* WITH_VECTORIZATION */
700
701
}

702
/**
James Willis's avatar
James Willis committed
703
 * @brief Compute the force cell self-interaction (non-symmetric) using vector
704
705
706
707
708
709
710
711
712
713
714
715
 * intrinsics with one particle pi at a time.
 *
 * @param r The #runner.
 * @param c The #cell.
 */
__attribute__((always_inline)) INLINE void runner_doself2_force_vec(
    struct runner *r, struct cell *restrict c) {

#ifdef WITH_VECTORIZATION
  const struct engine *e = r->e;
  struct part *restrict pi;
  int count_align;
James Willis's avatar
James Willis committed
716
  const int num_vec_proc = 1;
717

718
  const timebin_t max_active_bin = e->max_active_bin;
James Willis's avatar
James Willis committed
719

720
721
722
723
724
725
  struct part *restrict parts = c->parts;
  const int count = c->count;

  vector v_hi, v_vix, v_viy, v_viz, v_hig2, v_r2;
  vector v_rhoi, v_grad_hi, v_pOrhoi2, v_balsara_i, v_ci;

James Willis's avatar
James Willis committed
726
  TIMER_TIC;
727
728
729

  if (!cell_is_active(c, e)) return;

730
  if (!cell_are_part_drifted(c, e)) error("Interacting undrifted cell.");
731
732
733
734
735
736
737
738
739
740

  /* Get the particle cache from the runner and re-allocate
   * the cache if it is not big enough for the cell. */
  struct cache *restrict cell_cache = &r->ci_cache;

  if (cell_cache->count < count) {
    cache_init(cell_cache, count);
  }

  /* Read the particles from the cell and store them locally in the cache. */
741
  cache_read_force_particles(c, cell_cache);
742

James Willis's avatar
James Willis committed
743
#ifdef SWIFT_DEBUG_CHECKS
James Willis's avatar
James Willis committed
744
  for (int i = 0; i < count; i++) {
James Willis's avatar
James Willis committed
745
746
747
748
749
750
751
    pi = &c->parts[i];
    /* Check that particles have been drifted to the current time */
    if (pi->ti_drift != e->ti_current)
      error("Particle pi not drifted to current time");
  }
#endif

James Willis's avatar
James Willis committed
752
753
  /* Loop over the particles in the cell. */
  for (int pid = 0; pid < count; pid++) {
754

James Willis's avatar
James Willis committed
755
756
    /* Get a pointer to the ith particle. */
    pi = &parts[pid];
James Willis's avatar
James Willis committed
757

James Willis's avatar
James Willis committed
758
759
    /* Is the ith particle active? */
    if (!part_is_active_no_debug(pi, max_active_bin)) continue;
760

James Willis's avatar
James Willis committed
761
    vector pix, piy, piz;
762

James Willis's avatar
James Willis committed
763
    const float hi = cell_cache->h[pid];
764

James Willis's avatar
James Willis committed
765
766
767
768
769
770
771
772
    /* Fill particle pi vectors. */
    pix.v = vec_set1(cell_cache->x[pid]);
    piy.v = vec_set1(cell_cache->y[pid]);
    piz.v = vec_set1(cell_cache->z[pid]);
    v_hi.v = vec_set1(hi);
    v_vix.v = vec_set1(cell_cache->vx[pid]);
    v_viy.v = vec_set1(cell_cache->vy[pid]);
    v_viz.v = vec_set1(cell_cache->vz[pid]);
773

James Willis's avatar
James Willis committed
774
775
776
777
778
    v_rhoi.v = vec_set1(cell_cache->rho[pid]);
    v_grad_hi.v = vec_set1(cell_cache->grad_h[pid]);
    v_pOrhoi2.v = vec_set1(cell_cache->pOrho2[pid]);
    v_balsara_i.v = vec_set1(cell_cache->balsara[pid]);
    v_ci.v = vec_set1(cell_cache->soundspeed[pid]);
779

James Willis's avatar
James Willis committed
780
781
    const float hig2 = hi * hi * kernel_gamma2;
    v_hig2.v = vec_set1(hig2);
782

James Willis's avatar
James Willis committed
783
784
785
    /* Reset cumulative sums of update vectors. */
    vector a_hydro_xSum, a_hydro_ySum, a_hydro_zSum, h_dtSum, v_sigSum,
        entropy_dtSum;
786

James Willis's avatar
James Willis committed
787
788
    /* Get the inverse of hi. */
    vector v_hi_inv;
789

James Willis's avatar
James Willis committed
790
    v_hi_inv = vec_reciprocal(v_hi);
791

James Willis's avatar
James Willis committed
792
793
794
795
796
797
    a_hydro_xSum.v = vec_setzero();
    a_hydro_ySum.v = vec_setzero();
    a_hydro_zSum.v = vec_setzero();
    h_dtSum.v = vec_setzero();
    v_sigSum.v = vec_set1(pi->force.v_sig);
    entropy_dtSum.v = vec_setzero();
798

James Willis's avatar
James Willis committed
799
800
801
802
803
    /* Pad cache if there is a serial remainder. */
    count_align = count;
    int rem = count % (num_vec_proc * VEC_SIZE);
    if (rem != 0) {
      int pad = (num_vec_proc * VEC_SIZE) - rem;
804

James Willis's avatar
James Willis committed
805
      count_align += pad;
James Willis's avatar
James Willis committed
806

James Willis's avatar
James Willis committed
807
808
809
810
811
812
813
      /* Set positions to the same as particle pi so when the r2 > 0 mask is
       * applied these extra contributions are masked out.*/
      for (int i = count; i < count_align; i++) {
        cell_cache->x[i] = pix.f[0];
        cell_cache->y[i] = piy.f[0];
        cell_cache->z[i] = piz.f[0];
        cell_cache->h[i] = 1.f;
814
815
        cell_cache->rho[i] = 1.f;
        cell_cache->grad_h[i] = 1.f;
816
        cell_cache->pOrho2[i] = 1.f;
817
818
        cell_cache->balsara[i] = 1.f;
        cell_cache->soundspeed[i] = 1.f;
James Willis's avatar
James Willis committed
819
      }
820
821
    }

James Willis's avatar
James Willis committed
822
    vector pjx, pjy, pjz, hj, hjg2;
823

James Willis's avatar
James Willis committed
824
825
826
    /* Find all of particle pi's interacions and store needed values in the
     * secondary cache.*/
    for (int pjd = 0; pjd < count_align; pjd += (num_vec_proc * VEC_SIZE)) {
827

James Willis's avatar
James Willis committed
828
829
830
831
832
833
      /* Load 1 set of vectors from the particle cache. */
      pjx.v = vec_load(&cell_cache->x[pjd]);
      pjy.v = vec_load(&cell_cache->y[pjd]);
      pjz.v = vec_load(&cell_cache->z[pjd]);
      hj.v = vec_load(&cell_cache->h[pjd]);
      hjg2.v = vec_mul(vec_mul(hj.v, hj.v), kernel_gamma2_vec.v);
834

James Willis's avatar
James Willis committed
835
836
      /* Compute the pairwise distance. */
      vector v_dx, v_dy, v_dz;
837

James Willis's avatar
James Willis committed
838
839
840
      v_dx.v = vec_sub(pix.v, pjx.v);
      v_dy.v = vec_sub(piy.v, pjy.v);
      v_dz.v = vec_sub(piz.v, pjz.v);
841

James Willis's avatar
James Willis committed
842
843
844
      v_r2.v = vec_mul(v_dx.v, v_dx.v);
      v_r2.v = vec_fma(v_dy.v, v_dy.v, v_r2.v);
      v_r2.v = vec_fma(v_dz.v, v_dz.v, v_r2.v);
845

James Willis's avatar
James Willis committed
846
847
848
      /* Form r2 > 0 mask, r2 < hig2 mask and r2 < hjg2 mask. */
      mask_t v_doi_mask, v_doi_mask_self_check;
      int doi_mask;
849

James Willis's avatar
James Willis committed
850
851
      /* Form r2 > 0 mask.*/
      vec_create_mask(v_doi_mask_self_check, vec_cmp_gt(v_r2.v, vec_setzero()));
852

James Willis's avatar
James Willis committed
853
854
855
856
      /* Form a mask from r2 < hig2 mask and r2 < hjg2 mask. */
      vector v_h2;
      v_h2.v = vec_fmax(v_hig2.v, hjg2.v);
      vec_create_mask(v_doi_mask, vec_cmp_lt(v_r2.v, v_h2.v));
857

James Willis's avatar
James Willis committed
858
      /* Combine all 3 masks and form integer mask. */
859
      vec_combine_masks(v_doi_mask, v_doi_mask_self_check);
James Willis's avatar
James Willis committed
860
      doi_mask = vec_form_int_mask(v_doi_mask);
861

James Willis's avatar
James Willis committed
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
      /* If there are any interactions perform them. */
      if (doi_mask) {
        vector v_hj_inv;
        v_hj_inv = vec_reciprocal(hj);

        /* To stop floating point exceptions for when particle separations are
         * 0.
        */
        v_r2.v = vec_add(v_r2.v, vec_set1(FLT_MIN));

        runner_iact_nonsym_1_vec_force(
            &v_r2, &v_dx, &v_dy, &v_dz, v_vix, v_viy, v_viz, v_rhoi, v_grad_hi,
            v_pOrhoi2, v_balsara_i, v_ci, &cell_cache->vx[pjd],
            &cell_cache->vy[pjd], &cell_cache->vz[pjd], &cell_cache->rho[pjd],
            &cell_cache->grad_h[pjd], &cell_cache->pOrho2[pjd],
            &cell_cache->balsara[pjd], &cell_cache->soundspeed[pjd],
            &cell_cache->m[pjd], v_hi_inv, v_hj_inv, &a_hydro_xSum,
            &a_hydro_ySum, &a_hydro_zSum, &h_dtSum, &v_sigSum, &entropy_dtSum,
            v_doi_mask);
      }
882

James Willis's avatar
James Willis committed
883
    } /* Loop over all other particles. */
884

James Willis's avatar
James Willis committed
885
886
887
888
889
890
    VEC_HADD(a_hydro_xSum, pi->a_hydro[0]);
    VEC_HADD(a_hydro_ySum, pi->a_hydro[1]);
    VEC_HADD(a_hydro_zSum, pi->a_hydro[2]);
    VEC_HADD(h_dtSum, pi->force.h_dt);
    VEC_HMAX(v_sigSum, pi->force.v_sig);
    VEC_HADD(entropy_dtSum, pi->entropy_dt);
James Willis's avatar
James Willis committed
891

James Willis's avatar
James Willis committed
892
  } /* loop over all particles. */
893

James Willis's avatar
James Willis committed
894
  TIMER_TOC(timer_doself_force);
895
896
897
#endif /* WITH_VECTORIZATION */
}

898
/**
James Willis's avatar
James Willis committed
899
900
 * @brief Compute the density interactions between a cell pair (non-symmetric)
 * using vector intrinsics.
901
902
903
904
 *
 * @param r The #runner.
 * @param ci The first #cell.
 * @param cj The second #cell.
905
906
 * @param sid The direction of the pair
 * @param shift The shift vector to apply to the particles in ci.
907
 */
James Willis's avatar
James Willis committed
908
void runner_dopair1_density_vec(struct runner *r, struct cell *ci,
909
910
                                struct cell *cj, const int sid,
                                const double *shift) {
911
912
913

#ifdef WITH_VECTORIZATION
  const struct engine *restrict e = r->e;
914
  const timebin_t max_active_bin = e->max_active_bin;
915

James Willis's avatar
James Willis committed
916
  vector v_hi, v_vix, v_viy, v_viz, v_hig2;
917
918
919

  TIMER_TIC;

920
921
922
923
924
  /* Get the cutoff shift. */
  double rshift = 0.0;
  for (int k = 0; k < 3; k++) rshift += shift[k] * runner_shift[sid][k];

  /* Pick-out the sorted lists. */
Peter W. Draper's avatar
Peter W. Draper committed
925
926
  const struct entry *restrict sort_i = ci->sort[sid];
  const struct entry *restrict sort_j = cj->sort[sid];
927
928
929
930
931
932
933
934
935
936

  /* Get some other useful values. */
  const int count_i = ci->count;
  const int count_j = cj->count;
  const double hi_max = ci->h_max * kernel_gamma - rshift;
  const double hj_max = cj->h_max * kernel_gamma;
  struct part *restrict parts_i = ci->parts;
  struct part *restrict parts_j = cj->parts;
  const double di_max = sort_i[count_i - 1].d - rshift;
  const double dj_min = sort_j[0].d;
937
  const float dx_max = (ci->dx_max_sort + cj->dx_max_sort);
938
939
  const int active_ci = cell_is_active(ci, e);
  const int active_cj = cell_is_active(cj, e);
940
941

  /* Check if any particles are active and return if there are not. */
Matthieu Schaller's avatar
Matthieu Schaller committed
942
  int numActive = 0;
943

James Willis's avatar
James Willis committed
944
  if (active_ci) {
945
    for (int pid = count_i - 1;
James Willis's avatar
James Willis committed
946