runner_doiact_vec.c 62.2 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
    /* Loop through particles in cell j until they are not in range of pi. */
James Willis's avatar
James Willis committed
290
291
292
    while (temp <= cj->count &&
           (sort_i[first_pi].d + (pi->h * kernel_gamma + dx_max - rshift) >
            sort_j[temp].d))
293
      temp++;
294

295
    max_index_i[first_pi] = temp;
296

297
    /* Populate max_index_i for remaining particles that are within range. */
James Willis's avatar
James Willis committed
298
    for (int i = first_pi + 1; i < ci->count; i++) {
299
      temp = max_index_i[i - 1];
300
      pi = &parts_i[sort_i[i].i];
301

James Willis's avatar
James Willis committed
302
303
304
      while (temp <= cj->count &&
             (sort_i[i].d + (pi->h * kernel_gamma + dx_max - rshift) >
              sort_j[temp].d))
305
        temp++;
James Willis's avatar
James Willis committed
306

307
      max_index_i[i] = temp;
308
    }
James Willis's avatar
James Willis committed
309
  } else {
310
311
    /* Make sure that max index is set to first particle in cj.*/
    max_index_i[ci->count - 1] = 0;
312
  }
James Willis's avatar
James Willis committed
313

James Willis's avatar
James Willis committed
314
315
  /* Find the rightmost active particle in cell j that interacts with any
   * particle in cell i. */
316
  last_pj = -1;
317
  active_id = last_pj;
James Willis's avatar
James Willis committed
318
319
  while (last_pj < cj->count &&
         sort_j[last_pj + 1].d - hj_max - dx_max < di_max) {
320
    last_pj++;
321
    /* Store the index of the particle if it is active. */
James Willis's avatar
James Willis committed
322
323
    if (part_is_active_no_debug(&parts_j[sort_j[last_pj].i], max_active_bin))
      active_id = last_pj;
324
  }
James Willis's avatar
James Willis committed
325

326
  /* Set the last active pj in range of any particle in cell i. */
327
  last_pj = active_id;
328

329
  /* Find the maximum index into cell i for each particle in range in cell j. */
330
  if (last_pj > 0) {
331

332
333
    /* Start from the last particle in cell i. */
    temp = ci->count - 1;
334

335
    const struct part *pj = &parts_j[sort_j[last_pj].i];
336

337
    /* Loop through particles in cell i until they are not in range of pj. */
James Willis's avatar
James Willis committed
338
339
340
    while (temp > 0 &&
           sort_j[last_pj].d - dx_max - (pj->h * kernel_gamma) <
               sort_i[temp].d - rshift)
341
      temp--;
342

343
    max_index_j[last_pj] = temp;
344

345
    /* Populate max_index_j for remaining particles that are within range. */
James Willis's avatar
James Willis committed
346
    for (int i = last_pj - 1; i >= 0; i--) {
347
      temp = max_index_j[i + 1];
348
      pj = &parts_j[sort_j[i].i];
349

James Willis's avatar
James Willis committed
350
351
352
      while (temp > 0 &&
             sort_j[i].d - dx_max - (pj->h * kernel_gamma) <
                 sort_i[temp].d - rshift)
353
        temp--;
354

355
      max_index_j[i] = temp;
356
    }
James Willis's avatar
James Willis committed
357
  } else {
358
    /* Make sure that max index is set to last particle in ci.*/
James Willis's avatar
James Willis committed
359
    max_index_j[0] = ci->count - 1;
360
  }
361

James Willis's avatar
James Willis committed
362
363
  *init_pi = first_pi;
  *init_pj = last_pj;
364
365
}

366
__attribute__((always_inline)) INLINE static void populate_max_index_no_cache_force(
James Willis's avatar
James Willis committed
367
368
    const struct cell *ci, const struct cell *cj,
    const struct entry *restrict sort_i, const struct entry *restrict sort_j,
369
370
371
372
    const float dx_max, const float rshift, 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,
    const struct engine *e) {
373

374
375
  const struct part *restrict parts_i = ci->parts;
  const struct part *restrict parts_j = cj->parts;
James Willis's avatar
James Willis committed
376

377
  int first_pi = 0, last_pj = cj->count - 1;
378
379
380
381
382
383
384
385
386
387
388
  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;
  while (first_pi > 0 && sort_i[first_pi - 1].d + dx_max + hi_max > dj_min) {
    first_pi--;
    /* Store the index of the particle if it is active. */
    if (part_is_active(&parts_i[sort_i[first_pi].i], e)) active_id = first_pi;
  }
389

390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
  /* 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];

    /* Loop through particles in cell j until they are not in range of pi. */
    while (temp <= cj->count &&
           (sort_i[first_pi].d + (pi->h * kernel_gamma + dx_max - rshift) >
            sort_j[temp].d))
      temp++;

    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];

      while (temp <= cj->count &&
             (sort_i[i].d + (pi->h * kernel_gamma + dx_max - rshift) >
              sort_j[temp].d))
        temp++;

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

426
427
428
429
430
431
432
433
434
  /* 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 &&
         sort_j[last_pj + 1].d - hj_max - dx_max < di_max) {
    last_pj++;
    /* Store the index of the particle if it is active. */
    if (part_is_active(&parts_j[sort_j[last_pj].i], e)) active_id = last_pj;
435
  }
James Willis's avatar
James Willis committed
436

437
438
  /* Set the last active pj in range of any particle in cell i. */
  last_pj = active_id;
Matthieu Schaller's avatar
Matthieu Schaller committed
439

440
441
  /* Find the maximum index into cell i for each particle in range in cell j. */
  if (last_pj > 0) {
Matthieu Schaller's avatar
Matthieu Schaller committed
442

443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
    /* Start from the last particle in cell i. */
    temp = ci->count - 1;

    const struct part *pj = &parts_j[sort_j[last_pj].i];

    /* Loop through particles in cell i until they are not in range of pj. */
    while (temp > 0 &&
           sort_j[last_pj].d - dx_max - (pj->h * kernel_gamma) <
               sort_i[temp].d - rshift)
      temp--;

    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];

      while (temp > 0 &&
             sort_j[i].d - dx_max - (pj->h * kernel_gamma) <
                 sort_i[temp].d - rshift)
        temp--;

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

473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
  int first_pi_est = first_pi;
  int max_index_i_last = max_index_i[ci->count - 1];

  if(max_index_j[0] < first_pi) {
    first_pi = max_index_j[0];

    for(int i=first_pi; i<ci->count; i++) {
      max_index_i[i] = last_pj;
    }

  }
  
  if(max_index_i_last > last_pj) {
    last_pj = max_index_i_last;

    for(int i=0; i<=last_pj; i++) {
      max_index_j[i] = first_pi_est;
    }

  }

James Willis's avatar
James Willis committed
494
495
  *init_pi = first_pi;
  *init_pj = last_pj;
496
}
497

James Willis's avatar
James Willis committed
498
#endif /* WITH_VECTORIZATION */
499
500

/**
James Willis's avatar
James Willis committed
501
502
 * @brief Compute the cell self-interaction (non-symmetric) using vector
 * intrinsics with one particle pi at a time.
503
504
505
506
 *
 * @param r The #runner.
 * @param c The #cell.
 */
James Willis's avatar
James Willis committed
507
508
__attribute__((always_inline)) INLINE void runner_doself1_density_vec(
    struct runner *r, struct cell *restrict c) {
509
510

#ifdef WITH_VECTORIZATION
511
  const struct engine *e = r->e;
512
513
514
515
516
517
  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
518

519
520
  const timebin_t max_active_bin = e->max_active_bin;

521
522
  vector v_hi, v_vix, v_viy, v_viz, v_hig2, v_r2;

James Willis's avatar
James Willis committed
523
  TIMER_TIC
524

525
526
  if (!cell_is_active(c, e)) return;

527
  if (!cell_are_part_drifted(c, e)) error("Interacting undrifted cell.");
528

James Willis's avatar
James Willis committed
529
  /* Get the particle cache from the runner and re-allocate
530
   * the cache if it is not big enough for the cell. */
531
  struct cache *restrict cell_cache = &r->ci_cache;
James Willis's avatar
James Willis committed
532
533
534

  if (cell_cache->count < count) {
    cache_init(cell_cache, count);
535
536
  }

James Willis's avatar
James Willis committed
537
  /* Read the particles from the cell and store them locally in the cache. */
James Willis's avatar
James Willis committed
538
  cache_read_particles(c, cell_cache);
539
540
541
542

  /* Create secondary cache to store particle interactions. */
  struct c2_cache int_cache;
  int icount = 0, icount_align = 0;
543
544
545
546
547
548
549
550

  /* 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? */
551
    if (!part_is_active_no_debug(pi, max_active_bin)) continue;
552
553
554
555
556

    vector pix, piy, piz;

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

James Willis's avatar
James Willis committed
557
    /* Fill particle pi vectors. */
558
559
560
561
562
563
564
565
566
567
568
    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
569
    /* Reset cumulative sums of update vectors. */
James Willis's avatar
James Willis committed
570
571
572
    vector rhoSum, rho_dhSum, wcountSum, wcount_dhSum, div_vSum, curlvxSum,
        curlvySum, curlvzSum;

James Willis's avatar
James Willis committed
573
    /* Get the inverse of hi. */
574
    vector v_hi_inv;
James Willis's avatar
James Willis committed
575

576
    v_hi_inv = vec_reciprocal(v_hi);
James Willis's avatar
James Willis committed
577

578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
    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;
594
595
596
597
598
599
600
601

      /* 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];
      }
602
603
604
605
606
    }

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

James Willis's avatar
James Willis committed
607
608
    /* Find all of particle pi's interacions and store needed values in the
     * secondary cache.*/
609
610
611
612
613
614
    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]);
615

616
617
618
      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
619

620
      /* Compute the pairwise distance. */
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
      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
637

638
      /* Form a mask from r2 < hig2 and r2 > 0.*/
James Willis's avatar
James Willis committed
639
640
      mask_t v_doi_mask, v_doi_mask_self_check, v_doi_mask2,
          v_doi_mask2_self_check;
641
      int doi_mask, doi_mask_self_check, doi_mask2, doi_mask2_self_check;
642

James Willis's avatar
James Willis committed
643
      /* Form r2 > 0 mask and r2 < hig2 mask. */
644
      vec_create_mask(v_doi_mask_self_check, vec_cmp_gt(v_r2.v, vec_setzero()));
645
      vec_create_mask(v_doi_mask, vec_cmp_lt(v_r2.v, v_hig2.v));
646

James Willis's avatar
James Willis committed
647
      /* Form r2 > 0 mask and r2 < hig2 mask. */
James Willis's avatar
James Willis committed
648
649
      vec_create_mask(v_doi_mask2_self_check,
                      vec_cmp_gt(v_r2_2.v, vec_setzero()));
650
      vec_create_mask(v_doi_mask2, vec_cmp_lt(v_r2_2.v, v_hig2.v));
651

652
653
654
655
656
657
      /* 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
658

659
660
661
      /* Combine the two masks. */
      doi_mask = doi_mask & doi_mask_self_check;
      doi_mask2 = doi_mask2 & doi_mask2_self_check;
662

James Willis's avatar
James Willis committed
663
664
      /* If there are any interactions left pack interaction values into c2
       * cache. */
665
      if (doi_mask) {
James Willis's avatar
James Willis committed
666
667
        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
668
669
                          &wcount_dhSum, &div_vSum, &curlvxSum, &curlvySum,
                          &curlvzSum, v_hi_inv, v_vix, v_viy, v_viz);
670
      }
James Willis's avatar
James Willis committed
671
672
673
674
675
676
677
      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);
      }
678
679
    }

James Willis's avatar
James Willis committed
680
    /* Perform padded vector remainder interactions if any are present. */
Matthieu Schaller's avatar
Matthieu Schaller committed
681
682
683
    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
684
685
686
687
                        &icount_align);

    /* Initialise masks to true in case remainder interactions have been
     * performed. */
688
    mask_t int_mask, int_mask2;
689
690
    vec_init_mask_true(int_mask);
    vec_init_mask_true(int_mask2);
691
692

    /* Perform interaction with 2 vectors. */
James Willis's avatar
James Willis committed
693
694
695
696
697
698
    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
699
700
          &div_vSum, &curlvxSum, &curlvySum, &curlvzSum, int_mask, int_mask2,
          0);
701
702
    }

James Willis's avatar
James Willis committed
703
704
705
706
707
708
709
710
711
712
    /* 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]);
713
714
715
716
717

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

James Willis's avatar
James Willis committed
718
  TIMER_TOC(timer_doself_density);
719
#endif /* WITH_VECTORIZATION */
720
721
}

722
/**
James Willis's avatar
James Willis committed
723
 * @brief Compute the force cell self-interaction (non-symmetric) using vector
724
725
726
727
728
729
730
731
732
733
734
735
 * 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
736
  const int num_vec_proc = 1;
737

738
  const timebin_t max_active_bin = e->max_active_bin;
James Willis's avatar
James Willis committed
739

740
741
742
743
744
745
  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
746
  TIMER_TIC;
747
748
749

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

750
  if (!cell_are_part_drifted(c, e)) error("Interacting undrifted cell.");
751
752
753
754
755
756
757
758
759
760

  /* 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. */
761
  cache_read_force_particles(c, cell_cache);
762

James Willis's avatar
James Willis committed
763
#ifdef SWIFT_DEBUG_CHECKS
James Willis's avatar
James Willis committed
764
  for (int i = 0; i < count; i++) {
James Willis's avatar
James Willis committed
765
766
767
768
769
770
771
    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
772
773
  /* Loop over the particles in the cell. */
  for (int pid = 0; pid < count; pid++) {
774

James Willis's avatar
James Willis committed
775
776
    /* Get a pointer to the ith particle. */
    pi = &parts[pid];
777

James Willis's avatar
James Willis committed
778
779
    /* Is the ith particle active? */
    if (!part_is_active_no_debug(pi, max_active_bin)) continue;
780

James Willis's avatar
James Willis committed
781
    vector pix, piy, piz;
782

James Willis's avatar
James Willis committed
783
    const float hi = cell_cache->h[pid];
784

James Willis's avatar
James Willis committed
785
786
787
788
789
790
791
792
    /* 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]);
793

James Willis's avatar
James Willis committed
794
795
796
797
798
    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]);
799

James Willis's avatar
James Willis committed
800
801
    const float hig2 = hi * hi * kernel_gamma2;
    v_hig2.v = vec_set1(hig2);
802

James Willis's avatar
James Willis committed
803
804
805
    /* Reset cumulative sums of update vectors. */
    vector a_hydro_xSum, a_hydro_ySum, a_hydro_zSum, h_dtSum, v_sigSum,
        entropy_dtSum;
806

James Willis's avatar
James Willis committed
807
808
    /* Get the inverse of hi. */
    vector v_hi_inv;
809

James Willis's avatar
James Willis committed
810
    v_hi_inv = vec_reciprocal(v_hi);
811

James Willis's avatar
James Willis committed
812
813
814
815
816
817
    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();
818

James Willis's avatar
James Willis committed
819
820
821
822
823
    /* 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;
824

James Willis's avatar
James Willis committed
825
      count_align += pad;
James Willis's avatar
James Willis committed
826

James Willis's avatar
James Willis committed
827
828
829
830
831
832
833
      /* 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;
834
835
        cell_cache->rho[i] = 1.f;
        cell_cache->grad_h[i] = 1.f;
836
        cell_cache->pOrho2[i] = 1.f;
837
838
        cell_cache->balsara[i] = 1.f;
        cell_cache->soundspeed[i] = 1.f;
James Willis's avatar
James Willis committed
839
      }
840
841
    }

James Willis's avatar
James Willis committed
842
    vector pjx, pjy, pjz, hj, hjg2;
843

James Willis's avatar
James Willis committed
844
845
846
    /* 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)) {
847

James Willis's avatar
James Willis committed
848
849
850
851
852
853
      /* 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);
854

James Willis's avatar
James Willis committed
855
856
      /* Compute the pairwise distance. */
      vector v_dx, v_dy, v_dz;
857

James Willis's avatar
James Willis committed
858
859
860
      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);
861

James Willis's avatar
James Willis committed
862
863
864
      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);
865

James Willis's avatar
James Willis committed
866
867
868
      /* Form r2 > 0 mask, r2 < hig2 mask and r2 < hjg2 mask. */
      mask_t v_doi_mask, v_doi_mask_self_check;
      int doi_mask;
869

James Willis's avatar
James Willis committed
870
871
      /* Form r2 > 0 mask.*/
      vec_create_mask(v_doi_mask_self_check, vec_cmp_gt(v_r2.v, vec_setzero()));
872

James Willis's avatar
James Willis committed
873
874
875
876
      /* 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));
877

James Willis's avatar
James Willis committed
878
      /* Combine all 3 masks and form integer mask. */
879
      vec_combine_masks(v_doi_mask, v_doi_mask_self_check);
James Willis's avatar
James Willis committed
880
      doi_mask = vec_form_int_mask(v_doi_mask);
881

James Willis's avatar
James Willis committed
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
      /* 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);
      }
902

James Willis's avatar
James Willis committed
903
    } /* Loop over all other particles. */
904

James Willis's avatar
James Willis committed
905
906
907
908
909
910
    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
911

James Willis's avatar
James Willis committed
912
  } /* loop over all particles. */
913

James Willis's avatar
James Willis committed
914
  TIMER_TOC(timer_doself_force);
915
916
917
#endif /* WITH_VECTORIZATION */
}

918
/**
James Willis's avatar
James Willis committed
919
920
 * @brief Compute the density interactions between a cell pair (non-symmetric)
 * using vector intrinsics.
921
922
923
924
 *
 * @param r The #runner.
 * @param ci The first #cell.
 * @param cj The second #cell.
925
926
 * @param sid The direction of the pair
 * @param shift The shift vector to apply to the particles in ci.
927
 */
James Willis's avatar
James Willis committed
928
void runner_dopair1_density_vec(struct runner *r, struct cell *ci,
929
930
                                struct cell *cj, const int sid,
                                const double *shift) {
931
932
933

#ifdef WITH_VECTORIZATION
  const struct engine *restrict e = r->e;
934
  const timebin_t max_active_bin = e->max_active_bin;
935

James Willis's avatar
James Willis committed
936
  vector v_hi, v_vix, v_viy, v_viz, v_hig2;
937
938
939

  TIMER_TIC;

940
941
942
943
944
  /* 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
945
946
  const struct entry *restrict sort_i = ci->sort[sid];
  const struct entry *restrict sort_j = cj->sort[sid];
947

948
949
950
951
952
953
954
955
956
#ifdef SWIFT_DEBUG_CHECKS
  /* Check that the dx_max_sort values in the cell are indeed an upper
     bound on particle movement. */
  for (int pid = 0; pid < ci->count; pid++) {
    const struct part *p = &ci->parts[sort_i[pid].i];
    const float d = p->x[0] * runner_shift[sid][0] +
                    p->x[1] * runner_shift[sid][1] +
                    p->x[2] * runner_shift[sid][2];
    if (fabsf(d - sort_i[pid].d) - ci->dx_max_sort >
957
        1.0e-4 * max(fabsf(d), ci->dx_max_sort_old))
958
959
960
961
962
963
      error(
          "particle shift diff exceeds dx_max_sort in cell ci. ci->nodeID=%d "
          "cj->nodeID=%d d=%e sort_i[pid].d=%e ci->dx_max_sort=%e "
          "ci->dx_max_sort_old=%e",
          ci->nodeID, cj->nodeID, d, sort_i[pid].d, ci->dx_max_sort,
          ci->dx_max_sort_old);
964
965
966
967
968
969
970
  }
  for (int pjd = 0; pjd < cj->count; pjd++) {
    const struct part *p = &cj->parts[sort_j[pjd].i];
    const float d = p->x[0] * runner_shift[sid][0] +
                    p->x[1] * runner_shift[sid][1] +
                    p->x[2] * runner_shift[sid][2];
    if (fabsf(d - sort_j[pjd].d) - cj->dx_max_sort >
971
        1.0e-4 * max(fabsf(d), cj->dx_max_sort_old))
972
973
974
975
976
977
      error(
          "particle shift diff exceeds dx_max_sort in cell cj. cj->nodeID=%d "
          "ci->nodeID=%d d=%e sort_j[pjd].d=%e cj->dx_max_sort=%e "
          "cj->dx_max_sort_old=%e",
          cj->nodeID, ci->nodeID, d, sort_j[pjd].d, cj->dx_max_sort,
          cj->dx_max_sort_old);
978
979
980
  }
#endif /* SWIFT_DEBUG_CHECKS */

981
982
983
984
985
986
987
988
989
  /* 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;
990
  const float dx_max = (ci->dx_max_sort + cj->dx_max_sort);
991
992

  /* Check if any particles are active and return if there are not. */
Matthieu Schaller's avatar
Matthieu Schaller committed
993
994
995
  int numActive = 0;
  for (int pid = count_i - 1;
       pid >= 0 && sort_i[pid].d + hi_max + dx_max > dj_min; pid--) {
996
    struct part *restrict pi = &parts_i[sort_i[pid].i];
997
    if (part_is_active_no_debug(pi, max_active_bin)) {
998
999
      numActive++;
      break;
Matthieu Schaller's avatar
Matthieu Schaller committed
1000
    }
1001
  }
1002

Matthieu Schaller's avatar
Matthieu Schaller committed
1003
  if (!numActive) {
James Willis's avatar