src/BenchKernelD3Q19Aa.c

   1 // --------------------------------------------------------------------------
   2 //
   3 // Copyright
   4 //   Markus Wittmann, 2016-2017
   5 //   RRZE, University of Erlangen-Nuremberg, Germany
   6 //   markus.wittmann -at- fau.de or hpc -at- rrze.fau.de
   7 //
   8 //   Viktor Haag, 2016
   9 //   LSS, University of Erlangen-Nuremberg, Germany
  10 //
  11 //  This file is part of the Lattice Boltzmann Benchmark Kernels (LbmBenchKernels).
  12 //
  13 //  LbmBenchKernels is free software: you can redistribute it and/or modify
  14 //  it under the terms of the GNU General Public License as published by
  15 //  the Free Software Foundation, either version 3 of the License, or
  16 //  (at your option) any later version.
  17 //
  18 //  LbmBenchKernels is distributed in the hope that it will be useful,
  19 //  but WITHOUT ANY WARRANTY; without even the implied warranty of
  20 //  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21 //  GNU General Public License for more details.
  22 //
  23 //  You should have received a copy of the GNU General Public License
  24 //  along with LbmBenchKernels.  If not, see <http://www.gnu.org/licenses/>.
  25 //
  26 // --------------------------------------------------------------------------
  27 #include "BenchKernelD3Q19AaCommon.h"
  28
  29 #include "Memory.h"
  30 #include "Vtk.h"
  31 #include "LikwidIf.h"
  32
  33 #include <inttypes.h>
  34 #include <math.h>
  35
  36 #ifdef _OPENMP
  37         #include <omp.h>
  38 #endif
  39
  40 void FNAME(D3Q19AaKernel)(LatticeDesc * ld, KernelData * kernelData, CaseData * cd)
  41 {
  42         Assert(ld != NULL);
  43         Assert(kernelData != NULL);
  44         Assert(cd != NULL);
  45
  46         Assert(cd->Omega > 0.0);
  47         Assert(cd->Omega < 2.0);
  48
  49         KernelData * kd = (KernelData *)kernelData;
  50
  51
  52         int nX = ld->Dims[0];
  53         int nY = ld->Dims[1];
  54         int nZ = ld->Dims[2];
  55
  56         int * gDims = kd->GlobalDims;
  57
  58         int oX = kd->Offsets[0];
  59         int oY = kd->Offsets[1];
  60         int oZ = kd->Offsets[2];
  61
  62         KernelDataAa * kda = KDA(kd);
  63
  64         int blk[3];
  65         blk[0] = kda->Blk[0];
  66         blk[1] = kda->Blk[1];
  67         blk[2] = kda->Blk[2];
  68
  69         PdfT omega = cd->Omega;
  70         PdfT omegaEven = omega;
  71         PdfT magicParam = 1.0 / 12.0;
  72         //  1/4: best stability;
  73         // 1/12: removes third-order advection error (best advection);
  74         //  1/6: removes fourth-order diffusion error (best diffusion);
  75         // 3/16: exact location of bounce back for poiseuille flow
  76
  77         PdfT omegaOdd = 1.0/( 0.5 + magicParam/(1.0/omega - 0.5) );
  78
  79         PdfT evenPart = 0.0;
  80         PdfT oddPart = 0.0;
  81         PdfT dir_indep_trm = 0.0;
  82
  83         PdfT w_0 = 1.0 /  3.0;
  84         PdfT w_1 = 1.0 / 18.0;
  85         PdfT w_2 = 1.0 / 36.0;
  86
  87         PdfT w_1_x3 = w_1 * 3.0;        PdfT w_1_nine_half = w_1 * 9.0/2.0;     PdfT w_1_indep = 0.0;
  88         PdfT w_2_x3 = w_2 * 3.0;        PdfT w_2_nine_half = w_2 * 9.0/2.0;     PdfT w_2_indep = 0.0;
  89
  90         PdfT ux, uy, uz, ui;
  91         PdfT dens;
  92
  93         // Declare pdf_N, pdf_E, pdf_S, pdf_W, ...
  94         #define X(name, idx, idxinv, x, y, z)   PdfT JOIN(pdf_,name);
  95         D3Q19_LIST
  96         #undef X
  97
  98         PdfT * src = kd->Pdfs[0];
  99
 100         int maxIterations = cd->MaxIterations;
 101
 102         #ifdef VTK_OUTPUT
 103                 if (cd->VtkOutput) {
 104                         kd->PdfsActive = src;
 105                         VtkWrite(ld, kd, cd, -1);
 106                 }
 107         #endif
 108
 109         #ifdef STATISTICS
 110                 kd->PdfsActive = src;
 111                 KernelStatistics(kd, ld, cd, 0);
 112         #endif
 113
 114
 115         int nThreads = 1;
 116
 117         #ifdef _OPENMP
 118         nThreads = omp_get_max_threads();
 119         #endif
 120
 121         for (int iter = 0; iter < maxIterations; iter += 2) {
 122
 123                 // --------------------------------------------------------------------
 124                 // even time step
 125
 126                 X_LIKWID_START("aa-even");
 127
 128                 // {{{
 129
 130                 #ifdef _OPENMP
 131                 #pragma omp parallel for default(none) \
 132                                 shared(gDims,src, w_0, w_1, w_2, omegaEven, omegaOdd, \
 133                                 w_1_x3, w_2_x3, w_1_nine_half, w_2_nine_half, cd, \
 134                                 oX, oY, oZ, nX, nY, nZ, blk, nThreads, ld) \
 135                                 private(ux, uy, uz, ui, dens, dir_indep_trm, \
 136                                         pdf_C, \
 137                                         pdf_N, pdf_E, pdf_S, pdf_W, \
 138                                         pdf_NE, pdf_SE, pdf_SW, pdf_NW, \
 139                                         pdf_T, pdf_TN, pdf_TE, pdf_TS, pdf_TW, \
 140                                         pdf_B, pdf_BN, pdf_BE, pdf_BS, pdf_BW, \
 141                                         evenPart, oddPart, w_1_indep, w_2_indep)
 142                 #endif
 143
 144                 for (int i = 0; i < nThreads; ++i) {
 145
 146                         int threadStartX = nX / nThreads * i;
 147                         int threadEndX   = nX / nThreads * (i + 1);
 148
 149                         if (nX % nThreads > 0) {
 150                                 if (nX % nThreads > i) {
 151                                         threadStartX += i;
 152                                         threadEndX   += i + 1;
 153                                 }
 154                                 else {
 155                                         threadStartX += nX % nThreads;
 156                                         threadEndX   += nX % nThreads;
 157                                 }
 158                         }
 159
 160                         for (int bX = oX + threadStartX; bX < threadEndX + oX; bX += blk[0]) {
 161                         for (int bY = oY; bY < nY + oY; bY += blk[1]) {
 162                         for (int bZ = oZ; bZ < nZ + oZ; bZ += blk[2]) {
 163
 164                                 int eX = MIN(bX + blk[0], threadEndX + oX);
 165                                 int eY = MIN(bY + blk[1], nY + oY);
 166                                 int eZ = MIN(bZ + blk[2], nZ + oZ);
 167
 168                                 // printf("%d: %d-%d  %d-%d  %d-%d  %d - %d\n", omp_get_thread_num(), bZ, eZ, bY, eY, bX, eX, threadStartX, threadEndX);
 169
 170                                 for (int x = bX; x < eX; ++x) {
 171                                 for (int y = bY; y < eY; ++y) {
 172                                 for (int z = bZ; z < eZ; ++z) {
 173
 174
 175                                         if (ld->Lattice[L_INDEX_4(ld->Dims, x - oX, y - oY, z - oZ)] == LAT_CELL_OBSTACLE) {
 176                                                 continue;
 177                                         }
 178
 179                                         #define I(x, y, z, dir) P_INDEX_5(gDims, (x), (y), (z), (dir))
 180
 181
 182                                         // Load PDFs of local cell: pdf_N = src[I(x, y, z, D3Q19_N)]; ...
 183                                         #define X(name, idx, idxinv, _x, _y, _z)        JOIN(pdf_,name) = src[I(x, y, z, idx)];
 184                                         D3Q19_LIST
 185                                         #undef X
 186
 187 // #define LID_DRIVEN_CAVITY
 188
 189 #ifdef LID_DRIVEN_CAVITY
 190
 191                                         if (z == nZ - 4 + oZ && x > 3 + oX && x < (nX - 4 + oX) && y > 3 + oY  && y < (nY - 4 + oY)) {
 192                                                 ux = 0.1 * 0.577;
 193                                                 uy = 0.0;
 194                                                 uz = 0.0;
 195
 196                                         } else {
 197         #endif
 198                                                 ux = pdf_E + pdf_NE + pdf_SE + pdf_TE + pdf_BE -
 199                                                          pdf_W - pdf_NW - pdf_SW - pdf_TW - pdf_BW;
 200                                                 uy = pdf_N + pdf_NE + pdf_NW + pdf_TN + pdf_BN -
 201                                                          pdf_S - pdf_SE - pdf_SW - pdf_TS - pdf_BS;
 202                                                 uz = pdf_T + pdf_TE + pdf_TW + pdf_TN + pdf_TS -
 203                                                          pdf_B - pdf_BE - pdf_BW - pdf_BN - pdf_BS;
 204         #ifdef LID_DRIVEN_CAVITY
 205                                         }
 206         #endif
 207
 208                                         dens = pdf_C +
 209                                                         pdf_N  + pdf_E  + pdf_S  + pdf_W  +
 210                                                         pdf_NE + pdf_SE + pdf_SW + pdf_NW +
 211                                                         pdf_T  + pdf_TN + pdf_TE + pdf_TS + pdf_TW +
 212                                                         pdf_B  + pdf_BN + pdf_BE + pdf_BS + pdf_BW;
 213
 214                                         dir_indep_trm = dens - (ux * ux + uy * uy + uz * uz)*3.0/2.0;
 215
 216                                         // direction: w_0
 217                                         src[I(x,   y,   z, D3Q19_C)]  = pdf_C - omegaEven*(pdf_C - w_0*dir_indep_trm);
 218
 219                                         // direction: w_1
 220                                         w_1_indep = w_1*dir_indep_trm;
 221
 222                                         ui = uy;
 223                                         evenPart = omegaEven*( 0.5*(pdf_N + pdf_S) - ui*ui*w_1_nine_half - w_1_indep );
 224                                         oddPart = omegaOdd*(0.5*(pdf_N - pdf_S) - ui*w_1_x3 );
 225                                         src[I(x, y, z, D3Q19_S)]  = pdf_N - evenPart - oddPart;
 226                                         src[I(x, y, z, D3Q19_N)]  = pdf_S - evenPart + oddPart;
 227
 228                                         ui = ux;
 229                                         evenPart = omegaEven*( 0.5*(pdf_E + pdf_W) - ui*ui*w_1_nine_half - w_1_indep );
 230                                         oddPart = omegaOdd*(0.5*(pdf_E - pdf_W) - ui*w_1_x3 );
 231                                         src[I(x, y, z, D3Q19_W)]  = pdf_E - evenPart - oddPart;
 232                                         src[I(x, y, z, D3Q19_E)]  = pdf_W - evenPart + oddPart;
 233
 234                                         ui = uz;
 235                                         evenPart = omegaEven*( 0.5*(pdf_T + pdf_B) - ui*ui*w_1_nine_half - w_1_indep );
 236                                         oddPart = omegaOdd*(0.5*(pdf_T - pdf_B) - ui*w_1_x3 );
 237                                         src[I(x, y, z, D3Q19_B)]  = pdf_T - evenPart - oddPart;
 238                                         src[I(x, y, z, D3Q19_T)]  = pdf_B - evenPart + oddPart;
 239
 240                                         // direction: w_2
 241                                         w_2_indep = w_2*dir_indep_trm;
 242
 243                                         ui = -ux + uy;
 244                                         evenPart = omegaEven*( 0.5*(pdf_NW + pdf_SE) - ui*ui*w_2_nine_half - w_2_indep );
 245                                         oddPart = omegaOdd*(0.5*(pdf_NW - pdf_SE) - ui*w_2_x3 );
 246                                         src[I(x, y, z, D3Q19_SE)] = pdf_NW - evenPart - oddPart;
 247                                         src[I(x, y, z, D3Q19_NW)] = pdf_SE - evenPart + oddPart;
 248
 249                                         ui = ux + uy;
 250                                         evenPart = omegaEven*( 0.5*(pdf_NE + pdf_SW) - ui*ui*w_2_nine_half - w_2_indep );
 251                                         oddPart = omegaOdd*(0.5*(pdf_NE - pdf_SW) - ui*w_2_x3 );
 252                                         src[I(x, y, z, D3Q19_SW)] = pdf_NE - evenPart - oddPart;
 253                                         src[I(x, y, z, D3Q19_NE)] = pdf_SW - evenPart + oddPart;
 254
 255                                         ui = -ux + uz;
 256                                         evenPart = omegaEven*( 0.5*(pdf_TW + pdf_BE) - ui*ui*w_2_nine_half - w_2_indep );
 257                                         oddPart = omegaOdd*(0.5*(pdf_TW - pdf_BE) - ui*w_2_x3 );
 258                                         src[I(x, y, z, D3Q19_BE)] = pdf_TW - evenPart - oddPart;
 259                                         src[I(x, y, z, D3Q19_TW)] = pdf_BE - evenPart + oddPart;
 260
 261                                         ui = ux + uz;
 262                                         evenPart = omegaEven*( 0.5*(pdf_TE + pdf_BW) - ui*ui*w_2_nine_half - w_2_indep );
 263                                         oddPart = omegaOdd*(0.5*(pdf_TE - pdf_BW) - ui*w_2_x3 );
 264                                         src[I(x, y, z, D3Q19_BW)] = pdf_TE - evenPart - oddPart;
 265                                         src[I(x, y, z, D3Q19_TE)] = pdf_BW - evenPart + oddPart;
 266
 267                                         ui = -uy + uz;
 268                                         evenPart = omegaEven*( 0.5*(pdf_TS + pdf_BN) - ui*ui*w_2_nine_half - w_2_indep );
 269                                         oddPart = omegaOdd*(0.5*(pdf_TS - pdf_BN) - ui*w_2_x3 );
 270                                         src[I(x, y, z, D3Q19_BN)] = pdf_TS - evenPart - oddPart;
 271                                         src[I(x, y, z, D3Q19_TS)] = pdf_BN - evenPart + oddPart;
 272
 273                                         ui = uy + uz;
 274                                         evenPart = omegaEven*( 0.5*(pdf_TN + pdf_BS) - ui*ui*w_2_nine_half - w_2_indep );
 275                                         oddPart = omegaOdd*(0.5*(pdf_TN - pdf_BS) - ui*w_2_x3 );
 276                                         src[I(x, y, z, D3Q19_BS)] = pdf_TN - evenPart - oddPart;
 277                                         src[I(x, y, z, D3Q19_TN)] = pdf_BS - evenPart + oddPart;
 278
 279                                         #undef I
 280                                 } } } // z, y, x (from inner to outer)
 281                         } } } // z, y, x (from inner to outer)
 282
 283                 } // loop over threads
 284
 285                 // }}}
 286
 287                 X_LIKWID_STOP("aa-even");
 288
 289                 #ifdef STATISTICS
 290                 kd->PdfsActive = src;
 291                 KernelStatistics(kd, ld, cd, iter);
 292                 #endif
 293
 294                 // Fixup bounce back PDFs.
 295                 #ifdef _OPENMP
 296                 #pragma omp parallel for default(none) \
 297                                 shared(kd, src)
 298                 #endif
 299                 for (int i = 0; i < kd->nBounceBackPdfs; ++i) {
 300                         src[kd->BounceBackPdfsSrc[i]] = src[kd->BounceBackPdfsDst[i]];
 301                 }
 302
 303                 // save current iteration
 304                 kda->Iteration = iter;
 305
 306                 #ifdef VERIFICATION
 307                 kd->PdfsActive = src;
 308                 KernelAddBodyForce(kd, ld, cd);
 309                 #endif
 310
 311                 #ifdef VTK_OUTPUT
 312                 if (cd->VtkOutput && (iter % cd->VtkModulus) == 0) {
 313                         kd->PdfsActive = src;
 314                         VtkWrite(ld, kd, cd, iter);
 315                 }
 316                 #endif
 317
 318                 #ifdef STATISTICS
 319                 kd->PdfsActive = src;
 320                 KernelStatistics(kd, ld, cd, iter);
 321                 #endif
 322
 323                 // --------------------------------------------------------------------
 324                 // odd time step
 325
 326
 327                 X_LIKWID_START("aa-odd");
 328
 329                 // {{{
 330
 331                 #ifdef _OPENMP
 332                 #pragma omp parallel for default(none) \
 333                                 shared(gDims,src, w_0, w_1, w_2, omegaEven, omegaOdd, \
 334                                 w_1_x3, w_2_x3, w_1_nine_half, w_2_nine_half, cd, \
 335                                 oX, oY, oZ, nX, nY, nZ, blk, nThreads) \
 336                                 private(ux, uy, uz, ui, dens, dir_indep_trm, \
 337                                         pdf_C, \
 338                                         pdf_N, pdf_E, pdf_S, pdf_W, \
 339                                         pdf_NE, pdf_SE, pdf_SW, pdf_NW, \
 340                                         pdf_T, pdf_TN, pdf_TE, pdf_TS, pdf_TW, \
 341                                         pdf_B, pdf_BN, pdf_BE, pdf_BS, pdf_BW, \
 342                                         evenPart, oddPart, w_1_indep, w_2_indep)
 343                 #endif
 344
 345                 for (int i = 0; i < nThreads; ++i) {
 346
 347                         int threadStartX = nX / nThreads * i;
 348                         int threadEndX   = nX / nThreads * (i + 1);
 349
 350                         if (nX % nThreads > 0) {
 351                                 if (nX % nThreads > i) {
 352                                         threadStartX += i;
 353                                         threadEndX   += i + 1;
 354                                 }
 355                                 else {
 356                                         threadStartX += nX % nThreads;
 357                                         threadEndX   += nX % nThreads;
 358                                 }
 359                         }
 360
 361                         for (int bX = oX + threadStartX; bX < threadEndX + oX; bX += blk[0]) {
 362                         for (int bY = oY; bY < nY + oY; bY += blk[1]) {
 363                         for (int bZ = oZ; bZ < nZ + oZ; bZ += blk[2]) {
 364
 365                                 // Must do everything here, else it would break collapse.
 366                                 int eZ = MIN(bZ + blk[2], nZ + oZ);
 367                                 int eY = MIN(bY + blk[1], nY + oY);
 368                                 int eX = MIN(bX + blk[0], threadEndX + oX);
 369
 370                                 for (int x = bX; x < eX; ++x) {
 371                                 for (int y = bY; y < eY; ++y) {
 372                                 for (int z = bZ; z < eZ; ++z) {
 373
 374                                         #define I(x, y, z, dir) P_INDEX_5(gDims, (x), (y), (z), (dir))
 375
 376                                         // Load PDFs of local cell: pdf_N = src[I(x, y, z, D3Q19_N)]; ...
 377                                         #define X(name, idx, idxinv, _x, _y, _z)        JOIN(pdf_,name) = src[I(x - _x, y - _y, z - _z, idxinv)];
 378                                         D3Q19_LIST
 379                                         #undef X
 380
 381
 382 // #define LID_DRIVEN_CAVITY
 383
 384 #ifdef LID_DRIVEN_CAVITY
 385
 386                                         if (z == nZ - 4 + oZ && x > 3 + oX && x < (nX - 4 + oX) && y > 3 + oY  && y < (nY - 4 + oY)) {
 387                                                 ux = 0.1 * 0.577;
 388                                                 uy = 0.0;
 389                                                 uz = 0.0;
 390
 391                                         } else {
 392 #endif
 393                                                 ux = pdf_E + pdf_NE + pdf_SE + pdf_TE + pdf_BE -
 394                                                          pdf_W - pdf_NW - pdf_SW - pdf_TW - pdf_BW;
 395                                                 uy = pdf_N + pdf_NE + pdf_NW + pdf_TN + pdf_BN -
 396                                                          pdf_S - pdf_SE - pdf_SW - pdf_TS - pdf_BS;
 397                                                 uz = pdf_T + pdf_TE + pdf_TW + pdf_TN + pdf_TS -
 398                                                          pdf_B - pdf_BE - pdf_BW - pdf_BN - pdf_BS;
 399 #ifdef LID_DRIVEN_CAVITY
 400                                         }
 401 #endif
 402
 403                                         dens = pdf_C +
 404                                                         pdf_N  + pdf_E  + pdf_S  + pdf_W  +
 405                                                         pdf_NE + pdf_SE + pdf_SW + pdf_NW +
 406                                                         pdf_T  + pdf_TN + pdf_TE + pdf_TS + pdf_TW +
 407                                                         pdf_B  + pdf_BN + pdf_BE + pdf_BS + pdf_BW;
 408
 409                                         dir_indep_trm = dens - (ux * ux + uy * uy + uz * uz)*3.0/2.0;
 410
 411                                         // direction: w_0
 412                                         src[I(x,   y,   z, D3Q19_C)]  = pdf_C - omegaEven*(pdf_C - w_0*dir_indep_trm);
 413
 414                                         // direction: w_1
 415                                         w_1_indep = w_1*dir_indep_trm;
 416
 417                                         ui = uy;
 418                                         evenPart = omegaEven*( 0.5*(pdf_N + pdf_S) - ui*ui*w_1_nine_half - w_1_indep );
 419                                         oddPart = omegaOdd*(0.5*(pdf_N - pdf_S) - ui*w_1_x3 );
 420                                         src[I(x, y + 1,   z, D3Q19_N)]  = pdf_N - evenPart - oddPart;
 421                                         src[I(x, y - 1,   z, D3Q19_S)]  = pdf_S - evenPart + oddPart;
 422
 423                                         ui = ux;
 424                                         evenPart = omegaEven*( 0.5*(pdf_E + pdf_W) - ui*ui*w_1_nine_half - w_1_indep );
 425                                         oddPart = omegaOdd*(0.5*(pdf_E - pdf_W) - ui*w_1_x3 );
 426                                         src[I(x + 1,   y,   z, D3Q19_E)]  = pdf_E - evenPart - oddPart;
 427                                         src[I(x - 1,   y,   z, D3Q19_W)]  = pdf_W - evenPart + oddPart;
 428
 429                                         ui = uz;
 430                                         evenPart = omegaEven*( 0.5*(pdf_T + pdf_B) - ui*ui*w_1_nine_half - w_1_indep );
 431                                         oddPart = omegaOdd*(0.5*(pdf_T - pdf_B) - ui*w_1_x3 );
 432                                         src[I(x,   y, z + 1, D3Q19_T)]  = pdf_T - evenPart - oddPart;
 433                                         src[I(x,   y, z - 1, D3Q19_B)]  = pdf_B - evenPart + oddPart;
 434
 435                                         // direction: w_2
 436                                         w_2_indep = w_2*dir_indep_trm;
 437
 438                                         ui = -ux + uy;
 439                                         evenPart = omegaEven*( 0.5*(pdf_NW + pdf_SE) - ui*ui*w_2_nine_half - w_2_indep );
 440                                         oddPart = omegaOdd*(0.5*(pdf_NW - pdf_SE) - ui*w_2_x3 );
 441                                         src[I(x - 1, y + 1,   z, D3Q19_NW)] = pdf_NW - evenPart - oddPart;
 442                                         src[I(x + 1, y - 1,   z, D3Q19_SE)] = pdf_SE - evenPart + oddPart;
 443
 444                                         ui = ux + uy;
 445                                         evenPart = omegaEven*( 0.5*(pdf_NE + pdf_SW) - ui*ui*w_2_nine_half - w_2_indep );
 446                                         oddPart = omegaOdd*(0.5*(pdf_NE - pdf_SW) - ui*w_2_x3 );
 447                                         src[I(x + 1, y + 1,   z, D3Q19_NE)] = pdf_NE - evenPart - oddPart;
 448                                         src[I(x - 1, y - 1,   z, D3Q19_SW)] = pdf_SW - evenPart + oddPart;
 449
 450                                         ui = -ux + uz;
 451                                         evenPart = omegaEven*( 0.5*(pdf_TW + pdf_BE) - ui*ui*w_2_nine_half - w_2_indep );
 452                                         oddPart = omegaOdd*(0.5*(pdf_TW - pdf_BE) - ui*w_2_x3 );
 453                                         src[I(x - 1,   y, z + 1, D3Q19_TW)] = pdf_TW - evenPart - oddPart;
 454                                         src[I(x + 1,   y, z - 1, D3Q19_BE)] = pdf_BE - evenPart + oddPart;
 455
 456                                         ui = ux + uz;
 457                                         evenPart = omegaEven*( 0.5*(pdf_TE + pdf_BW) - ui*ui*w_2_nine_half - w_2_indep );
 458                                         oddPart = omegaOdd*(0.5*(pdf_TE - pdf_BW) - ui*w_2_x3 );
 459                                         src[I(x + 1,   y, z + 1, D3Q19_TE)] = pdf_TE - evenPart - oddPart;
 460                                         src[I(x - 1,   y, z - 1, D3Q19_BW)] = pdf_BW - evenPart + oddPart;
 461
 462                                         ui = -uy + uz;
 463                                         evenPart = omegaEven*( 0.5*(pdf_TS + pdf_BN) - ui*ui*w_2_nine_half - w_2_indep );
 464                                         oddPart = omegaOdd*(0.5*(pdf_TS - pdf_BN) - ui*w_2_x3 );
 465                                         src[I(x, y - 1, z + 1, D3Q19_TS)] = pdf_TS - evenPart - oddPart;
 466                                         src[I(x, y + 1, z - 1, D3Q19_BN)] = pdf_BN - evenPart + oddPart;
 467
 468                                         ui = uy + uz;
 469                                         evenPart = omegaEven*( 0.5*(pdf_TN + pdf_BS) - ui*ui*w_2_nine_half - w_2_indep );
 470                                         oddPart = omegaOdd*(0.5*(pdf_TN - pdf_BS) - ui*w_2_x3 );
 471                                         src[I(x, y + 1, z + 1, D3Q19_TN)] = pdf_TN - evenPart - oddPart;
 472                                         src[I(x, y - 1, z - 1, D3Q19_BS)] = pdf_BS - evenPart + oddPart;
 473
 474
 475                                         #undef I
 476                                 } } } // z, y, x (from inner to outer)
 477                         } } } // z, y, x (from inner to outer)
 478                 } // loop over threads
 479
 480                 // }}}
 481
 482                 // Stop counters before bounce back. Else computing loop balance will be incorrect.
 483
 484                 X_LIKWID_STOP("aa-odd");
 485
 486                 // Fixup bounce back PDFs.
 487                 #ifdef _OPENMP
 488                 #pragma omp parallel for default(none) \
 489                                 shared(kd, src)
 490                 #endif
 491                 for (int i = 0; i < kd->nBounceBackPdfs; ++i) {
 492                         src[kd->BounceBackPdfsDst[i]] = src[kd->BounceBackPdfsSrc[i]];
 493                 }
 494
 495                 // save current iteration
 496                 kda->Iteration = iter + 1;
 497
 498                 #ifdef VERIFICATION
 499                 kd->PdfsActive = src;
 500                 KernelAddBodyForce(kd, ld, cd);
 501                 #endif
 502
 503                 #ifdef VTK_OUTPUT
 504                 if (cd->VtkOutput && (iter + 1 % cd->VtkModulus) == 0) {
 505                         kd->PdfsActive = src;
 506                         VtkWrite(ld, kd, cd, iter + 1);
 507                 }
 508                 #endif
 509
 510                 #ifdef STATISTICS
 511                 kd->PdfsActive = src;
 512                 KernelStatistics(kd, ld, cd, iter + 1);
 513                 #endif // }}}
 514
 515
 516         } // for (int iter = 0; ...
 517
 518         #ifdef VTK_OUTPUT
 519
 520         if (cd->VtkOutput) {
 521                 kd->PdfsActive = src;
 522                 VtkWrite(ld, kd, cd, maxIterations);
 523         }
 524
 525         #endif
 526
 527         return;
 528 }
 529