Actual source code: feopencl.c

      1: #include <petsc/private/petscfeimpl.h>

      3: #if defined(PETSC_HAVE_OPENCL)

      5: static PetscErrorCode PetscFEDestroy_OpenCL(PetscFE fem)
      6: {
      7:   PetscFE_OpenCL *ocl = (PetscFE_OpenCL *) fem->data;
      8:   PetscErrorCode  ierr;

     11:   clReleaseCommandQueue(ocl->queue_id);
     12:   ocl->queue_id = 0;
     13:   clReleaseContext(ocl->ctx_id);
     14:   ocl->ctx_id = 0;
     15:   PetscFree(ocl);
     16:   return(0);
     17: }

     19: #define CHKSTRINGERROR(MSG) do { string_tail += count; if (string_tail == end_of_buffer) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP, MSG);} while (0)
     20: enum {LAPLACIAN = 0, ELASTICITY = 1};

     22: /* NOTE: This is now broken for vector problems. Must redo loops to respect vector basis elements */
     23: /* dim     Number of spatial dimensions:          2                   */
     24: /* N_b     Number of basis functions:             generated           */
     25: /* N_{bt}  Number of total basis functions:       N_b * N_{comp}      */
     26: /* N_q     Number of quadrature points:           generated           */
     27: /* N_{bs}  Number of block cells                  LCM(N_b, N_q)       */
     28: /* N_{bst} Number of block cell components        LCM(N_{bt}, N_q)    */
     29: /* N_{bl}  Number of concurrent blocks            generated           */
     30: /* N_t     Number of threads:                     N_{bl} * N_{bs}     */
     31: /* N_{cbc} Number of concurrent basis      cells: N_{bl} * N_q        */
     32: /* N_{cqc} Number of concurrent quadrature cells: N_{bl} * N_b        */
     33: /* N_{sbc} Number of serial     basis      cells: N_{bs} / N_q        */
     34: /* N_{sqc} Number of serial     quadrature cells: N_{bs} / N_b        */
     35: /* N_{cb}  Number of serial cell batches:         input               */
     36: /* N_c     Number of total cells:                 N_{cb}*N_{t}/N_{comp} */
     37: static PetscErrorCode PetscFEOpenCLGenerateIntegrationCode(PetscFE fem, char **string_buffer, PetscInt buffer_length, PetscBool useAux, PetscInt N_bl)
     38: {
     39:   PetscFE_OpenCL *ocl = (PetscFE_OpenCL *) fem->data;
     40:   PetscQuadrature q;
     41:   char           *string_tail   = *string_buffer;
     42:   char           *end_of_buffer = *string_buffer + buffer_length;
     43:   char            float_str[]   = "float", double_str[]  = "double";
     44:   char           *numeric_str   = &(float_str[0]);
     45:   PetscInt        op            = ocl->op;
     46:   PetscBool       useField      = PETSC_FALSE;
     47:   PetscBool       useFieldDer   = PETSC_TRUE;
     48:   PetscBool       useFieldAux   = useAux;
     49:   PetscBool       useFieldDerAux= PETSC_FALSE;
     50:   PetscBool       useF0         = PETSC_TRUE;
     51:   PetscBool       useF1         = PETSC_TRUE;
     52:   const PetscReal *points, *weights;
     53:   PetscTabulation T;
     54:   PetscInt        dim, qNc, N_b, N_c, N_q, N_t, p, d, b, c;
     55:   size_t          count;
     56:   PetscErrorCode  ierr;

     59:   PetscFEGetSpatialDimension(fem, &dim);
     60:   PetscFEGetDimension(fem, &N_b);
     61:   PetscFEGetNumComponents(fem, &N_c);
     62:   PetscFEGetQuadrature(fem, &q);
     63:   PetscQuadratureGetData(q, NULL, &qNc, &N_q, &points, &weights);
     64:   if (qNc != 1) SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_SUP, "Only supports scalar quadrature, not %D components\n", qNc);
     65:   N_t  = N_b * N_c * N_q * N_bl;
     66:   /* Enable device extension for double precision */
     67:   if (ocl->realType == PETSC_DOUBLE) {
     68:     PetscSNPrintfCount(string_tail, end_of_buffer - string_tail,
     69: "#if defined(cl_khr_fp64)\n"
     70: "#  pragma OPENCL EXTENSION cl_khr_fp64: enable\n"
     71: "#elif defined(cl_amd_fp64)\n"
     72: "#  pragma OPENCL EXTENSION cl_amd_fp64: enable\n"
     73: "#endif\n",
     74:                               &count);CHKSTRINGERROR("Message to short");
     75:     numeric_str  = &(double_str[0]);
     76:   }
     77:   /* Kernel API */
     78:   PetscSNPrintfCount(string_tail, end_of_buffer - string_tail,
     79: "\n"
     80: "__kernel void integrateElementQuadrature(int N_cb, __global %s *coefficients, __global %s *coefficientsAux, __global %s *jacobianInverses, __global %s *jacobianDeterminants, __global %s *elemVec)\n"
     81: "{\n",
     82:                        &count, numeric_str, numeric_str, numeric_str, numeric_str, numeric_str);CHKSTRINGERROR("Message to short");
     83:   /* Quadrature */
     84:   PetscSNPrintfCount(string_tail, end_of_buffer - string_tail,
     85: "  /* Quadrature points\n"
     86: "   - (x1,y1,x2,y2,...) */\n"
     87: "  const %s points[%d] = {\n",
     88:                        &count, numeric_str, N_q*dim);CHKSTRINGERROR("Message to short");
     89:   for (p = 0; p < N_q; ++p) {
     90:     for (d = 0; d < dim; ++d) {
     91:       PetscSNPrintfCount(string_tail, end_of_buffer - string_tail, "%g,\n", &count, points[p*dim+d]);CHKSTRINGERROR("Message to short");
     92:     }
     93:   }
     94:   PetscSNPrintfCount(string_tail, end_of_buffer - string_tail, "};\n", &count);CHKSTRINGERROR("Message to short");
     95:   PetscSNPrintfCount(string_tail, end_of_buffer - string_tail,
     96: "  /* Quadrature weights\n"
     97: "   - (v1,v2,...) */\n"
     98: "  const %s weights[%d] = {\n",
     99:                        &count, numeric_str, N_q);CHKSTRINGERROR("Message to short");
    100:   for (p = 0; p < N_q; ++p) {
    101:     PetscSNPrintfCount(string_tail, end_of_buffer - string_tail, "%g,\n", &count, weights[p]);CHKSTRINGERROR("Message to short");
    102:   }
    103:   PetscSNPrintfCount(string_tail, end_of_buffer - string_tail, "};\n", &count);CHKSTRINGERROR("Message to short");
    104:   /* Basis Functions */
    105:   PetscFEGetCellTabulation(fem, 1, &T);
    106:   PetscSNPrintfCount(string_tail, end_of_buffer - string_tail,
    107: "  /* Nodal basis function evaluations\n"
    108: "    - basis component is fastest varying, the basis function, then point */\n"
    109: "  const %s Basis[%d] = {\n",
    110:                        &count, numeric_str, N_q*N_b*N_c);CHKSTRINGERROR("Message to short");
    111:   for (p = 0; p < N_q; ++p) {
    112:     for (b = 0; b < N_b; ++b) {
    113:       for (c = 0; c < N_c; ++c) {
    114:         PetscSNPrintfCount(string_tail, end_of_buffer - string_tail, "%g,\n", &count, T->T[0][(p*N_b + b)*N_c + c]);CHKSTRINGERROR("Message to short");
    115:       }
    116:     }
    117:   }
    118:   PetscSNPrintfCount(string_tail, end_of_buffer - string_tail, "};\n", &count);CHKSTRINGERROR("Message to short");
    119:   PetscSNPrintfCount(string_tail, end_of_buffer - string_tail,
    120: "\n"
    121: "  /* Nodal basis function derivative evaluations,\n"
    122: "      - derivative direction is fastest varying, then basis component, then basis function, then point */\n"
    123: "  const %s%d BasisDerivatives[%d] = {\n",
    124:                        &count, numeric_str, dim, N_q*N_b*N_c);CHKSTRINGERROR("Message to short");
    125:   for (p = 0; p < N_q; ++p) {
    126:     for (b = 0; b < N_b; ++b) {
    127:       for (c = 0; c < N_c; ++c) {
    128:         PetscSNPrintfCount(string_tail, end_of_buffer - string_tail, "(%s%d)(", &count, numeric_str, dim);CHKSTRINGERROR("Message to short");
    129:         for (d = 0; d < dim; ++d) {
    130:           if (d > 0) {
    131:             PetscSNPrintfCount(string_tail, end_of_buffer - string_tail, ", %g", &count, T->T[1][((p*N_b + b)*dim + d)*N_c + c]);CHKSTRINGERROR("Message to short");
    132:           } else {
    133:             PetscSNPrintfCount(string_tail, end_of_buffer - string_tail, "%g", &count, T->T[1][((p*N_b + b)*dim + d)*N_c + c]);CHKSTRINGERROR("Message to short");
    134:           }
    135:         }
    136:         PetscSNPrintfCount(string_tail, end_of_buffer - string_tail, "),\n", &count);CHKSTRINGERROR("Message to short");
    137:       }
    138:     }
    139:   }
    140:   PetscSNPrintfCount(string_tail, end_of_buffer - string_tail, "};\n", &count);CHKSTRINGERROR("Message to short");
    141:   /* Sizes */
    142:   PetscSNPrintfCount(string_tail, end_of_buffer - string_tail,
    143: "  const int dim    = %d;                           // The spatial dimension\n"
    144: "  const int N_bl   = %d;                           // The number of concurrent blocks\n"
    145: "  const int N_b    = %d;                           // The number of basis functions\n"
    146: "  const int N_comp = %d;                           // The number of basis function components\n"
    147: "  const int N_bt   = N_b*N_comp;                    // The total number of scalar basis functions\n"
    148: "  const int N_q    = %d;                           // The number of quadrature points\n"
    149: "  const int N_bst  = N_bt*N_q;                      // The block size, LCM(N_b*N_comp, N_q), Notice that a block is not processed simultaneously\n"
    150: "  const int N_t    = N_bst*N_bl;                    // The number of threads, N_bst * N_bl\n"
    151: "  const int N_bc   = N_t/N_comp;                    // The number of cells per batch (N_b*N_q*N_bl)\n"
    152: "  const int N_sbc  = N_bst / (N_q * N_comp);\n"
    153: "  const int N_sqc  = N_bst / N_bt;\n"
    154: "  /*const int N_c    = N_cb * N_bc;*/\n"
    155: "\n"
    156: "  /* Calculated indices */\n"
    157: "  /*const int tidx    = get_local_id(0) + get_local_size(0)*get_local_id(1);*/\n"
    158: "  const int tidx    = get_local_id(0);\n"
    159: "  const int blidx   = tidx / N_bst;                  // Block number for this thread\n"
    160: "  const int bidx    = tidx %% N_bt;                   // Basis function mapped to this thread\n"
    161: "  const int cidx    = tidx %% N_comp;                 // Basis component mapped to this thread\n"
    162: "  const int qidx    = tidx %% N_q;                    // Quadrature point mapped to this thread\n"
    163: "  const int blbidx  = tidx %% N_q + blidx*N_q;        // Cell mapped to this thread in the basis phase\n"
    164: "  const int blqidx  = tidx %% N_b + blidx*N_b;        // Cell mapped to this thread in the quadrature phase\n"
    165: "  const int gidx    = get_group_id(1)*get_num_groups(0) + get_group_id(0);\n"
    166: "  const int Goffset = gidx*N_cb*N_bc;\n",
    167:                             &count, dim, N_bl, N_b, N_c, N_q);CHKSTRINGERROR("Message to short");
    168:   /* Local memory */
    169:   PetscSNPrintfCount(string_tail, end_of_buffer - string_tail,
    170: "\n"
    171: "  /* Quadrature data */\n"
    172: "  %s                w;                   // $w_q$, Quadrature weight at $x_q$\n"
    173: "  __local %s         phi_i[%d];    //[N_bt*N_q];  // $\\phi_i(x_q)$, Value of the basis function $i$ at $x_q$\n"
    174: "  __local %s%d       phiDer_i[%d]; //[N_bt*N_q];  // $\\frac{\\partial\\phi_i(x_q)}{\\partial x_d}$, Value of the derivative of basis function $i$ in direction $x_d$ at $x_q$\n"
    175: "  /* Geometric data */\n"
    176: "  __local %s        detJ[%d]; //[N_t];           // $|J(x_q)|$, Jacobian determinant at $x_q$\n"
    177: "  __local %s        invJ[%d];//[N_t*dim*dim];   // $J^{-1}(x_q)$, Jacobian inverse at $x_q$\n",
    178:                             &count, numeric_str, numeric_str, N_b*N_c*N_q, numeric_str, dim, N_b*N_c*N_q, numeric_str, N_t,
    179:                             numeric_str, N_t*dim*dim, numeric_str, N_t*N_b*N_c);CHKSTRINGERROR("Message to short");
    180:   PetscSNPrintfCount(string_tail, end_of_buffer - string_tail,
    181: "  /* FEM data */\n"
    182: "  __local %s        u_i[%d]; //[N_t*N_bt];       // Coefficients $u_i$ of the field $u|_{\\mathcal{T}} = \\sum_i u_i \\phi_i$\n",
    183:                             &count, numeric_str, N_t*N_b*N_c);CHKSTRINGERROR("Message to short");
    184:   if (useAux) {
    185:     PetscSNPrintfCount(string_tail, end_of_buffer - string_tail,
    186: "  __local %s        a_i[%d]; //[N_t];            // Coefficients $a_i$ of the auxiliary field $a|_{\\mathcal{T}} = \\sum_i a_i \\phi^R_i$\n",
    187:                             &count, numeric_str, N_t);CHKSTRINGERROR("Message to short");
    188:   }
    189:   if (useF0) {
    190:     PetscSNPrintfCount(string_tail, end_of_buffer - string_tail,
    191: "  /* Intermediate calculations */\n"
    192: "  __local %s         f_0[%d]; //[N_t*N_sqc];      // $f_0(u(x_q), \\nabla u(x_q)) |J(x_q)| w_q$\n",
    193:                               &count, numeric_str, N_t*N_q);CHKSTRINGERROR("Message to short");
    194:   }
    195:   if (useF1) {
    196:     PetscSNPrintfCount(string_tail, end_of_buffer - string_tail,
    197: "  __local %s%d       f_1[%d]; //[N_t*N_sqc];      // $f_1(u(x_q), \\nabla u(x_q)) |J(x_q)| w_q$\n",
    198:                               &count, numeric_str, dim, N_t*N_q);CHKSTRINGERROR("Message to short");
    199:   }
    200:   /* TODO: If using elasticity, put in mu/lambda coefficients */
    201:   PetscSNPrintfCount(string_tail, end_of_buffer - string_tail,
    202: "  /* Output data */\n"
    203: "  %s                e_i;                 // Coefficient $e_i$ of the residual\n\n",
    204:                             &count, numeric_str);CHKSTRINGERROR("Message to short");
    205:   /* One-time loads */
    206:   PetscSNPrintfCount(string_tail, end_of_buffer - string_tail,
    207: "  /* These should be generated inline */\n"
    208: "  /* Load quadrature weights */\n"
    209: "  w = weights[qidx];\n"
    210: "  /* Load basis tabulation \\phi_i for this cell */\n"
    211: "  if (tidx < N_bt*N_q) {\n"
    212: "    phi_i[tidx]    = Basis[tidx];\n"
    213: "    phiDer_i[tidx] = BasisDerivatives[tidx];\n"
    214: "  }\n\n",
    215:                        &count);CHKSTRINGERROR("Message to short");
    216:   /* Batch loads */
    217:   PetscSNPrintfCount(string_tail, end_of_buffer - string_tail,
    218: "  for (int batch = 0; batch < N_cb; ++batch) {\n"
    219: "    /* Load geometry */\n"
    220: "    detJ[tidx] = jacobianDeterminants[Goffset+batch*N_bc+tidx];\n"
    221: "    for (int n = 0; n < dim*dim; ++n) {\n"
    222: "      const int offset = n*N_t;\n"
    223: "      invJ[offset+tidx] = jacobianInverses[(Goffset+batch*N_bc)*dim*dim+offset+tidx];\n"
    224: "    }\n"
    225: "    /* Load coefficients u_i for this cell */\n"
    226: "    for (int n = 0; n < N_bt; ++n) {\n"
    227: "      const int offset = n*N_t;\n"
    228: "      u_i[offset+tidx] = coefficients[(Goffset*N_bt)+batch*N_t*N_b+offset+tidx];\n"
    229: "    }\n",
    230:                        &count);CHKSTRINGERROR("Message to short");
    231:   if (useAux) {
    232:   PetscSNPrintfCount(string_tail, end_of_buffer - string_tail,
    233: "    /* Load coefficients a_i for this cell */\n"
    234: "    /* TODO: This should not be N_t here, it should be N_bc*N_comp_aux */\n"
    235: "    a_i[tidx] = coefficientsAux[Goffset+batch*N_t+tidx];\n",
    236:                             &count);CHKSTRINGERROR("Message to short");
    237:   }
    238:   /* Quadrature phase */
    239:   PetscSNPrintfCount(string_tail, end_of_buffer - string_tail,
    240: "    barrier(CLK_LOCAL_MEM_FENCE);\n"
    241: "\n"
    242: "    /* Map coefficients to values at quadrature points */\n"
    243: "    for (int c = 0; c < N_sqc; ++c) {\n"
    244: "      const int cell          = c*N_bl*N_b + blqidx;\n"
    245: "      const int fidx          = (cell*N_q + qidx)*N_comp + cidx;\n",
    246:                        &count);CHKSTRINGERROR("Message to short");
    247:   if (useField) {
    248:     PetscSNPrintfCount(string_tail, end_of_buffer - string_tail,
    249: "      %s  u[%d]; //[N_comp];     // $u(x_q)$, Value of the field at $x_q$\n",
    250:                               &count, numeric_str, N_c);CHKSTRINGERROR("Message to short");
    251:   }
    252:   if (useFieldDer) {
    253:     PetscSNPrintfCount(string_tail, end_of_buffer - string_tail,
    254: "      %s%d   gradU[%d]; //[N_comp]; // $\\nabla u(x_q)$, Value of the field gradient at $x_q$\n",
    255:                               &count, numeric_str, dim, N_c);CHKSTRINGERROR("Message to short");
    256:   }
    257:   if (useFieldAux) {
    258:     PetscSNPrintfCount(string_tail, end_of_buffer - string_tail,
    259: "      %s  a[%d]; //[1];     // $a(x_q)$, Value of the auxiliary fields at $x_q$\n",
    260:                               &count, numeric_str, 1);CHKSTRINGERROR("Message to short");
    261:   }
    262:   if (useFieldDerAux) {
    263:     PetscSNPrintfCount(string_tail, end_of_buffer - string_tail,
    264: "      %s%d   gradA[%d]; //[1]; // $\\nabla a(x_q)$, Value of the auxiliary field gradient at $x_q$\n",
    265:                               &count, numeric_str, dim, 1);CHKSTRINGERROR("Message to short");
    266:   }
    267:   PetscSNPrintfCount(string_tail, end_of_buffer - string_tail,
    268: "\n"
    269: "      for (int comp = 0; comp < N_comp; ++comp) {\n",
    270:                             &count);CHKSTRINGERROR("Message to short");
    271:   if (useField) {PetscSNPrintfCount(string_tail, end_of_buffer - string_tail, "        u[comp] = 0.0;\n", &count);CHKSTRINGERROR("Message to short");}
    272:   if (useFieldDer) {
    273:     switch (dim) {
    274:     case 1:
    275:       PetscSNPrintfCount(string_tail, end_of_buffer - string_tail, "        gradU[comp].x = 0.0;\n", &count);CHKSTRINGERROR("Message to short");break;
    276:     case 2:
    277:       PetscSNPrintfCount(string_tail, end_of_buffer - string_tail, "        gradU[comp].x = 0.0; gradU[comp].y = 0.0;\n", &count);CHKSTRINGERROR("Message to short");break;
    278:     case 3:
    279:       PetscSNPrintfCount(string_tail, end_of_buffer - string_tail, "        gradU[comp].x = 0.0; gradU[comp].y = 0.0; gradU[comp].z = 0.0;\n", &count);CHKSTRINGERROR("Message to short");break;
    280:     }
    281:   }
    282:   PetscSNPrintfCount(string_tail, end_of_buffer - string_tail,
    283: "      }\n",
    284:                             &count);CHKSTRINGERROR("Message to short");
    285:   if (useFieldAux) {
    286:     PetscSNPrintfCount(string_tail, end_of_buffer - string_tail, "      a[0] = 0.0;\n", &count);CHKSTRINGERROR("Message to short");
    287:   }
    288:   if (useFieldDerAux) {
    289:     switch (dim) {
    290:     case 1:
    291:       PetscSNPrintfCount(string_tail, end_of_buffer - string_tail, "      gradA[0].x = 0.0;\n", &count);CHKSTRINGERROR("Message to short");break;
    292:     case 2:
    293:       PetscSNPrintfCount(string_tail, end_of_buffer - string_tail, "      gradA[0].x = 0.0; gradA[0].y = 0.0;\n", &count);CHKSTRINGERROR("Message to short");break;
    294:     case 3:
    295:       PetscSNPrintfCount(string_tail, end_of_buffer - string_tail, "      gradA[0].x = 0.0; gradA[0].y = 0.0; gradA[0].z = 0.0;\n", &count);CHKSTRINGERROR("Message to short");break;
    296:     }
    297:   }
    298:   PetscSNPrintfCount(string_tail, end_of_buffer - string_tail,
    299: "      /* Get field and derivatives at this quadrature point */\n"
    300: "      for (int i = 0; i < N_b; ++i) {\n"
    301: "        for (int comp = 0; comp < N_comp; ++comp) {\n"
    302: "          const int b    = i*N_comp+comp;\n"
    303: "          const int pidx = qidx*N_bt + b;\n"
    304: "          const int uidx = cell*N_bt + b;\n"
    305: "          %s%d   realSpaceDer;\n\n",
    306:                             &count, numeric_str, dim);CHKSTRINGERROR("Message to short");
    307:   if (useField) {PetscSNPrintfCount(string_tail, end_of_buffer - string_tail,"          u[comp] += u_i[uidx]*phi_i[pidx];\n", &count);CHKSTRINGERROR("Message to short");}
    308:   if (useFieldDer) {
    309:     switch (dim) {
    310:     case 2:
    311:       PetscSNPrintfCount(string_tail, end_of_buffer - string_tail,
    312: "          realSpaceDer.x = invJ[cell*dim*dim+0*dim+0]*phiDer_i[pidx].x + invJ[cell*dim*dim+1*dim+0]*phiDer_i[pidx].y;\n"
    313: "          gradU[comp].x += u_i[uidx]*realSpaceDer.x;\n"
    314: "          realSpaceDer.y = invJ[cell*dim*dim+0*dim+1]*phiDer_i[pidx].x + invJ[cell*dim*dim+1*dim+1]*phiDer_i[pidx].y;\n"
    315: "          gradU[comp].y += u_i[uidx]*realSpaceDer.y;\n",
    316:                            &count);CHKSTRINGERROR("Message to short");break;
    317:     case 3:
    318:       PetscSNPrintfCount(string_tail, end_of_buffer - string_tail,
    319: "          realSpaceDer.x = invJ[cell*dim*dim+0*dim+0]*phiDer_i[pidx].x + invJ[cell*dim*dim+1*dim+0]*phiDer_i[pidx].y + invJ[cell*dim*dim+2*dim+0]*phiDer_i[pidx].z;\n"
    320: "          gradU[comp].x += u_i[uidx]*realSpaceDer.x;\n"
    321: "          realSpaceDer.y = invJ[cell*dim*dim+0*dim+1]*phiDer_i[pidx].x + invJ[cell*dim*dim+1*dim+1]*phiDer_i[pidx].y + invJ[cell*dim*dim+2*dim+1]*phiDer_i[pidx].z;\n"
    322: "          gradU[comp].y += u_i[uidx]*realSpaceDer.y;\n"
    323: "          realSpaceDer.z = invJ[cell*dim*dim+0*dim+2]*phiDer_i[pidx].x + invJ[cell*dim*dim+1*dim+2]*phiDer_i[pidx].y + invJ[cell*dim*dim+2*dim+2]*phiDer_i[pidx].z;\n"
    324: "          gradU[comp].z += u_i[uidx]*realSpaceDer.z;\n",
    325:                            &count);CHKSTRINGERROR("Message to short");break;
    326:     }
    327:   }
    328:   PetscSNPrintfCount(string_tail, end_of_buffer - string_tail,
    329: "        }\n"
    330: "      }\n",
    331:                             &count);CHKSTRINGERROR("Message to short");
    332:   if (useFieldAux) {
    333:     PetscSNPrintfCount(string_tail, end_of_buffer - string_tail,"          a[0] += a_i[cell];\n", &count);CHKSTRINGERROR("Message to short");
    334:   }
    335:   /* Calculate residual at quadrature points: Should be generated by an weak form egine */
    336:   PetscSNPrintfCount(string_tail, end_of_buffer - string_tail,
    337: "      /* Process values at quadrature points */\n",
    338:                             &count);CHKSTRINGERROR("Message to short");
    339:   switch (op) {
    340:   case LAPLACIAN:
    341:     if (useF0) {PetscSNPrintfCount(string_tail, end_of_buffer - string_tail, "      f_0[fidx] = 4.0;\n", &count);CHKSTRINGERROR("Message to short");}
    342:     if (useF1) {
    343:       if (useAux) {PetscSNPrintfCount(string_tail, end_of_buffer - string_tail, "      f_1[fidx] = a[0]*gradU[cidx];\n", &count);CHKSTRINGERROR("Message to short");}
    344:       else        {PetscSNPrintfCount(string_tail, end_of_buffer - string_tail, "      f_1[fidx] = gradU[cidx];\n", &count);CHKSTRINGERROR("Message to short");}
    345:     }
    346:     break;
    347:   case ELASTICITY:
    348:     if (useF0) {PetscSNPrintfCount(string_tail, end_of_buffer - string_tail, "      f_0[fidx] = 4.0;\n", &count);CHKSTRINGERROR("Message to short");}
    349:     if (useF1) {
    350:     switch (dim) {
    351:     case 2:
    352:       PetscSNPrintfCount(string_tail, end_of_buffer - string_tail,
    353: "      switch (cidx) {\n"
    354: "      case 0:\n"
    355: "        f_1[fidx].x = lambda*(gradU[0].x + gradU[1].y) + mu*(gradU[0].x + gradU[0].x);\n"
    356: "        f_1[fidx].y = lambda*(gradU[0].x + gradU[1].y) + mu*(gradU[0].y + gradU[1].x);\n"
    357: "        break;\n"
    358: "      case 1:\n"
    359: "        f_1[fidx].x = lambda*(gradU[0].x + gradU[1].y) + mu*(gradU[1].x + gradU[0].y);\n"
    360: "        f_1[fidx].y = lambda*(gradU[0].x + gradU[1].y) + mu*(gradU[1].y + gradU[1].y);\n"
    361: "      }\n",
    362:                            &count);CHKSTRINGERROR("Message to short");break;
    363:     case 3:
    364:       PetscSNPrintfCount(string_tail, end_of_buffer - string_tail,
    365: "      switch (cidx) {\n"
    366: "      case 0:\n"
    367: "        f_1[fidx].x = lambda*(gradU[0].x + gradU[1].y + gradU[2].z) + mu*(gradU[0].x + gradU[0].x);\n"
    368: "        f_1[fidx].y = lambda*(gradU[0].x + gradU[1].y + gradU[2].z) + mu*(gradU[0].y + gradU[1].x);\n"
    369: "        f_1[fidx].z = lambda*(gradU[0].x + gradU[1].y + gradU[2].z) + mu*(gradU[0].z + gradU[2].x);\n"
    370: "        break;\n"
    371: "      case 1:\n"
    372: "        f_1[fidx].x = lambda*(gradU[0].x + gradU[1].y + gradU[2].z) + mu*(gradU[1].x + gradU[0].y);\n"
    373: "        f_1[fidx].y = lambda*(gradU[0].x + gradU[1].y + gradU[2].z) + mu*(gradU[1].y + gradU[1].y);\n"
    374: "        f_1[fidx].z = lambda*(gradU[0].x + gradU[1].y + gradU[2].z) + mu*(gradU[1].y + gradU[2].y);\n"
    375: "        break;\n"
    376: "      case 2:\n"
    377: "        f_1[fidx].x = lambda*(gradU[0].x + gradU[1].y + gradU[2].z) + mu*(gradU[2].x + gradU[0].z);\n"
    378: "        f_1[fidx].y = lambda*(gradU[0].x + gradU[1].y + gradU[2].z) + mu*(gradU[2].y + gradU[1].z);\n"
    379: "        f_1[fidx].z = lambda*(gradU[0].x + gradU[1].y + gradU[2].z) + mu*(gradU[2].y + gradU[2].z);\n"
    380: "      }\n",
    381:                            &count);CHKSTRINGERROR("Message to short");break;
    382:     }}
    383:     break;
    384:   default:
    385:     SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_SUP, "PDE operator %d is not supported", op);
    386:   }
    387:   if (useF0) {PetscSNPrintfCount(string_tail, end_of_buffer - string_tail,"      f_0[fidx] *= detJ[cell]*w;\n", &count);CHKSTRINGERROR("Message to short");}
    388:   if (useF1) {
    389:     switch (dim) {
    390:     case 1:
    391:       PetscSNPrintfCount(string_tail, end_of_buffer - string_tail,"      f_1[fidx].x *= detJ[cell]*w;\n", &count);CHKSTRINGERROR("Message to short");break;
    392:     case 2:
    393:       PetscSNPrintfCount(string_tail, end_of_buffer - string_tail,"      f_1[fidx].x *= detJ[cell]*w; f_1[fidx].y *= detJ[cell]*w;\n", &count);CHKSTRINGERROR("Message to short");break;
    394:     case 3:
    395:       PetscSNPrintfCount(string_tail, end_of_buffer - string_tail,"      f_1[fidx].x *= detJ[cell]*w; f_1[fidx].y *= detJ[cell]*w; f_1[fidx].z *= detJ[cell]*w;\n", &count);CHKSTRINGERROR("Message to short");break;
    396:     }
    397:   }
    398:   /* Thread transpose */
    399:   PetscSNPrintfCount(string_tail, end_of_buffer - string_tail,
    400: "    }\n\n"
    401: "    /* ==== TRANSPOSE THREADS ==== */\n"
    402: "    barrier(CLK_LOCAL_MEM_FENCE);\n\n",
    403:                        &count);CHKSTRINGERROR("Message to short");
    404:   /* Basis phase */
    405:   PetscSNPrintfCount(string_tail, end_of_buffer - string_tail,
    406: "    /* Map values at quadrature points to coefficients */\n"
    407: "    for (int c = 0; c < N_sbc; ++c) {\n"
    408: "      const int cell = c*N_bl*N_q + blbidx; /* Cell number in batch */\n"
    409: "\n"
    410: "      e_i = 0.0;\n"
    411: "      for (int q = 0; q < N_q; ++q) {\n"
    412: "        const int pidx = q*N_bt + bidx;\n"
    413: "        const int fidx = (cell*N_q + q)*N_comp + cidx;\n"
    414: "        %s%d   realSpaceDer;\n\n",
    415:                        &count, numeric_str, dim);CHKSTRINGERROR("Message to short");

    417:   if (useF0) {PetscSNPrintfCount(string_tail, end_of_buffer - string_tail,"        e_i += phi_i[pidx]*f_0[fidx];\n", &count);CHKSTRINGERROR("Message to short");}
    418:   if (useF1) {
    419:     switch (dim) {
    420:     case 2:
    421:       PetscSNPrintfCount(string_tail, end_of_buffer - string_tail,
    422: "        realSpaceDer.x = invJ[cell*dim*dim+0*dim+0]*phiDer_i[pidx].x + invJ[cell*dim*dim+1*dim+0]*phiDer_i[pidx].y;\n"
    423: "        e_i           += realSpaceDer.x*f_1[fidx].x;\n"
    424: "        realSpaceDer.y = invJ[cell*dim*dim+0*dim+1]*phiDer_i[pidx].x + invJ[cell*dim*dim+1*dim+1]*phiDer_i[pidx].y;\n"
    425: "        e_i           += realSpaceDer.y*f_1[fidx].y;\n",
    426:                            &count);CHKSTRINGERROR("Message to short");break;
    427:     case 3:
    428:       PetscSNPrintfCount(string_tail, end_of_buffer - string_tail,
    429: "        realSpaceDer.x = invJ[cell*dim*dim+0*dim+0]*phiDer_i[pidx].x + invJ[cell*dim*dim+1*dim+0]*phiDer_i[pidx].y + invJ[cell*dim*dim+2*dim+0]*phiDer_i[pidx].z;\n"
    430: "        e_i           += realSpaceDer.x*f_1[fidx].x;\n"
    431: "        realSpaceDer.y = invJ[cell*dim*dim+0*dim+1]*phiDer_i[pidx].x + invJ[cell*dim*dim+1*dim+1]*phiDer_i[pidx].y + invJ[cell*dim*dim+2*dim+1]*phiDer_i[pidx].z;\n"
    432: "        e_i           += realSpaceDer.y*f_1[fidx].y;\n"
    433: "        realSpaceDer.z = invJ[cell*dim*dim+0*dim+2]*phiDer_i[pidx].x + invJ[cell*dim*dim+1*dim+2]*phiDer_i[pidx].y + invJ[cell*dim*dim+2*dim+2]*phiDer_i[pidx].z;\n"
    434: "        e_i           += realSpaceDer.z*f_1[fidx].z;\n",
    435:                            &count);CHKSTRINGERROR("Message to short");break;
    436:     }
    437:   }
    438:   PetscSNPrintfCount(string_tail, end_of_buffer - string_tail,
    439: "      }\n"
    440: "      /* Write element vector for N_{cbc} cells at a time */\n"
    441: "      elemVec[(Goffset + batch*N_bc + c*N_bl*N_q)*N_bt + tidx] = e_i;\n"
    442: "    }\n"
    443: "    /* ==== Could do one write per batch ==== */\n"
    444: "  }\n"
    445: "  return;\n"
    446: "}\n",
    447:                        &count);CHKSTRINGERROR("Message to short");
    448:   return(0);
    449: }

    451: static PetscErrorCode PetscFEOpenCLGetIntegrationKernel(PetscFE fem, PetscBool useAux, cl_program *ocl_prog, cl_kernel *ocl_kernel)
    452: {
    453:   PetscFE_OpenCL *ocl = (PetscFE_OpenCL *) fem->data;
    454:   PetscInt        dim, N_bl;
    455:   PetscBool       flg;
    456:   char           *buffer;
    457:   size_t          len;
    458:   char            errMsg[8192];
    459:   cl_int          err;
    460:   PetscErrorCode  ierr;

    463:   PetscFEGetSpatialDimension(fem, &dim);
    464:   PetscMalloc1(8192, &buffer);
    465:   PetscFEGetTileSizes(fem, NULL, &N_bl, NULL, NULL);
    466:   PetscFEOpenCLGenerateIntegrationCode(fem, &buffer, 8192, useAux, N_bl);
    467:   PetscOptionsHasName(((PetscObject)fem)->options,((PetscObject)fem)->prefix, "-petscfe_opencl_kernel_print", &flg);
    468:   if (flg) {PetscPrintf(PetscObjectComm((PetscObject) fem), "OpenCL FE Integration Kernel:\n%s\n", buffer);}
    469:   PetscStrlen(buffer,&len);
    470:   *ocl_prog = clCreateProgramWithSource(ocl->ctx_id, 1, (const char **) &buffer, &len, &err);CHKERRQ(err);
    471:   err = clBuildProgram(*ocl_prog, 0, NULL, NULL, NULL, NULL);
    472:   if (err != CL_SUCCESS) {
    473:     err = clGetProgramBuildInfo(*ocl_prog, ocl->dev_id, CL_PROGRAM_BUILD_LOG, 8192*sizeof(char), &errMsg, NULL);
    474:     SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_PLIB, "Build failed! Log:\n %s", errMsg);
    475:   }
    476:   PetscFree(buffer);
    477:   *ocl_kernel = clCreateKernel(*ocl_prog, "integrateElementQuadrature", &ierr);
    478:   return(0);
    479: }

    481: static PetscErrorCode PetscFEOpenCLCalculateGrid(PetscFE fem, PetscInt N, PetscInt blockSize, size_t *x, size_t *y, size_t *z)
    482: {
    483:   const PetscInt Nblocks = N/blockSize;

    486:   if (N % blockSize) SETERRQ2(PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Invalid block size %d for %d elements", blockSize, N);
    487:   *z = 1;
    488:   *y = 1;
    489:   for (*x = (size_t) (PetscSqrtReal(Nblocks) + 0.5); *x > 0; --*x) {
    490:     *y = Nblocks / *x;
    491:     if (*x * *y == (size_t)Nblocks) break;
    492:   }
    493:   if (*x * *y != (size_t)Nblocks) SETERRQ2(PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Could not find partition for %D with block size %D", N, blockSize);
    494:   return(0);
    495: }

    497: static PetscErrorCode PetscFEOpenCLLogResidual(PetscFE fem, PetscLogDouble time, PetscLogDouble flops)
    498: {
    499:   PetscFE_OpenCL   *ocl = (PetscFE_OpenCL *) fem->data;
    500:   PetscStageLog     stageLog;
    501:   PetscEventPerfLog eventLog = NULL;
    502:   int               stage;
    503:   PetscErrorCode    ierr;

    506:   PetscLogGetStageLog(&stageLog);
    507:   PetscStageLogGetCurrent(stageLog, &stage);
    508:   PetscStageLogGetEventPerfLog(stageLog, stage, &eventLog);
    509:     /* Log performance info */
    510:   eventLog->eventInfo[ocl->residualEvent].count++;
    511:   eventLog->eventInfo[ocl->residualEvent].time  += time;
    512:   eventLog->eventInfo[ocl->residualEvent].flops += flops;
    513:   return(0);
    514: }

    516: static PetscErrorCode PetscFEIntegrateResidual_OpenCL(PetscDS prob, PetscHashFormKey key, PetscInt Ne, PetscFEGeom *cgeom,
    517:                                                       const PetscScalar coefficients[], const PetscScalar coefficients_t[], PetscDS probAux, const PetscScalar coefficientsAux[], PetscReal t, PetscScalar elemVec[])
    518: {
    519:   /* Nbc = batchSize */
    520:   PetscFE           fem;
    521:   PetscFE_OpenCL   *ocl;
    522:   PetscPointFunc    f0_func;
    523:   PetscPointFunc    f1_func;
    524:   PetscQuadrature   q;
    525:   PetscInt          dim, qNc;
    526:   PetscInt          N_b;    /* The number of basis functions */
    527:   PetscInt          N_comp; /* The number of basis function components */
    528:   PetscInt          N_bt;   /* The total number of scalar basis functions */
    529:   PetscInt          N_q;    /* The number of quadrature points */
    530:   PetscInt          N_bst;  /* The block size, LCM(N_bt, N_q), Notice that a block is not process simultaneously */
    531:   PetscInt          N_t;    /* The number of threads, N_bst * N_bl */
    532:   PetscInt          N_bl;   /* The number of blocks */
    533:   PetscInt          N_bc;   /* The batch size, N_bl*N_q*N_b */
    534:   PetscInt          N_cb;   /* The number of batches */
    535:   const PetscInt    field = key.field;
    536:   PetscInt          numFlops, f0Flops = 0, f1Flops = 0;
    537:   PetscBool         useAux      = probAux ? PETSC_TRUE : PETSC_FALSE;
    538:   PetscBool         useField    = PETSC_FALSE;
    539:   PetscBool         useFieldDer = PETSC_TRUE;
    540:   PetscBool         useF0       = PETSC_TRUE;
    541:   PetscBool         useF1       = PETSC_TRUE;
    542:   /* OpenCL variables */
    543:   cl_program        ocl_prog;
    544:   cl_kernel         ocl_kernel;
    545:   cl_event          ocl_ev;         /* The event for tracking kernel execution */
    546:   cl_ulong          ns_start;       /* Nanoseconds counter on GPU at kernel start */
    547:   cl_ulong          ns_end;         /* Nanoseconds counter on GPU at kernel stop */
    548:   cl_mem            o_jacobianInverses, o_jacobianDeterminants;
    549:   cl_mem            o_coefficients, o_coefficientsAux, o_elemVec;
    550:   float            *f_coeff = NULL, *f_coeffAux = NULL, *f_invJ = NULL, *f_detJ = NULL;
    551:   double           *d_coeff = NULL, *d_coeffAux = NULL, *d_invJ = NULL, *d_detJ = NULL;
    552:   PetscReal        *r_invJ = NULL, *r_detJ = NULL;
    553:   void             *oclCoeff, *oclCoeffAux, *oclInvJ, *oclDetJ;
    554:   size_t            local_work_size[3], global_work_size[3];
    555:   size_t            realSize, x, y, z;
    556:   const PetscReal   *points, *weights;
    557:   PetscErrorCode    ierr;

    560:   PetscDSGetDiscretization(prob, field, (PetscObject *) &fem);
    561:   ocl  = (PetscFE_OpenCL *) fem->data;
    562:   if (!Ne) {PetscFEOpenCLLogResidual(fem, 0.0, 0.0); return(0);}
    563:   PetscFEGetSpatialDimension(fem, &dim);
    564:   PetscFEGetQuadrature(fem, &q);
    565:   PetscQuadratureGetData(q, NULL, &qNc, &N_q, &points, &weights);
    566:   if (qNc != 1) SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_SUP, "Only supports scalar quadrature, not %D components\n", qNc);
    567:   PetscFEGetDimension(fem, &N_b);
    568:   PetscFEGetNumComponents(fem, &N_comp);
    569:   PetscDSGetResidual(prob, field, &f0_func, &f1_func);
    570:   PetscFEGetTileSizes(fem, NULL, &N_bl, &N_bc, &N_cb);
    571:   N_bt  = N_b*N_comp;
    572:   N_bst = N_bt*N_q;
    573:   N_t   = N_bst*N_bl;
    574:   if (N_bc*N_comp != N_t) SETERRQ3(PETSC_COMM_SELF, PETSC_ERR_PLIB, "Number of threads %d should be %d * %d", N_t, N_bc, N_comp);
    575:   /* Calculate layout */
    576:   if (Ne % (N_cb*N_bc)) { /* Remainder cells */
    577:     PetscFEIntegrateResidual_Basic(prob, key, Ne, cgeom, coefficients, coefficients_t, probAux, coefficientsAux, t, elemVec);
    578:     return(0);
    579:   }
    580:   PetscFEOpenCLCalculateGrid(fem, Ne, N_cb*N_bc, &x, &y, &z);
    581:   local_work_size[0]  = N_bc*N_comp;
    582:   local_work_size[1]  = 1;
    583:   local_work_size[2]  = 1;
    584:   global_work_size[0] = x * local_work_size[0];
    585:   global_work_size[1] = y * local_work_size[1];
    586:   global_work_size[2] = z * local_work_size[2];
    587:   PetscInfo7(fem, "GPU layout grid(%d,%d,%d) block(%d,%d,%d) with %d batches\n", x, y, z, local_work_size[0], local_work_size[1], local_work_size[2], N_cb);
    588:   PetscInfo2(fem, " N_t: %d, N_cb: %d\n", N_t, N_cb);
    589:   /* Generate code */
    590:   if (probAux) {
    591:     PetscSpace P;
    592:     PetscInt   NfAux, order, f;

    594:     PetscDSGetNumFields(probAux, &NfAux);
    595:     for (f = 0; f < NfAux; ++f) {
    596:       PetscFE feAux;

    598:       PetscDSGetDiscretization(probAux, f, (PetscObject *) &feAux);
    599:       PetscFEGetBasisSpace(feAux, &P);
    600:       PetscSpaceGetDegree(P, &order, NULL);
    601:       if (order > 0) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Can only handle P0 coefficient fields");
    602:     }
    603:   }
    604:   PetscFEOpenCLGetIntegrationKernel(fem, useAux, &ocl_prog, &ocl_kernel);
    605:   /* Create buffers on the device and send data over */
    606:   PetscDataTypeGetSize(ocl->realType, &realSize);
    607:   if (cgeom->numPoints > 1) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP, "Only support affine geometry for OpenCL integration right now");
    608:   if (sizeof(PetscReal) != realSize) {
    609:     switch (ocl->realType) {
    610:     case PETSC_FLOAT:
    611:     {
    612:       PetscInt c, b, d;

    614:       PetscMalloc4(Ne*N_bt,&f_coeff,Ne,&f_coeffAux,Ne*dim*dim,&f_invJ,Ne,&f_detJ);
    615:       for (c = 0; c < Ne; ++c) {
    616:         f_detJ[c] = (float) cgeom->detJ[c];
    617:         for (d = 0; d < dim*dim; ++d) {
    618:           f_invJ[c*dim*dim+d] = (float) cgeom->invJ[c * dim * dim + d];
    619:         }
    620:         for (b = 0; b < N_bt; ++b) {
    621:           f_coeff[c*N_bt+b] = (float) coefficients[c*N_bt+b];
    622:         }
    623:       }
    624:       if (coefficientsAux) { /* Assume P0 */
    625:         for (c = 0; c < Ne; ++c) {
    626:           f_coeffAux[c] = (float) coefficientsAux[c];
    627:         }
    628:       }
    629:       oclCoeff      = (void *) f_coeff;
    630:       if (coefficientsAux) {
    631:         oclCoeffAux = (void *) f_coeffAux;
    632:       } else {
    633:         oclCoeffAux = NULL;
    634:       }
    635:       oclInvJ       = (void *) f_invJ;
    636:       oclDetJ       = (void *) f_detJ;
    637:     }
    638:     break;
    639:     case PETSC_DOUBLE:
    640:     {
    641:       PetscInt c, b, d;

    643:       PetscMalloc4(Ne*N_bt,&d_coeff,Ne,&d_coeffAux,Ne*dim*dim,&d_invJ,Ne,&d_detJ);
    644:       for (c = 0; c < Ne; ++c) {
    645:         d_detJ[c] = (double) cgeom->detJ[c];
    646:         for (d = 0; d < dim*dim; ++d) {
    647:           d_invJ[c*dim*dim+d] = (double) cgeom->invJ[c * dim * dim + d];
    648:         }
    649:         for (b = 0; b < N_bt; ++b) {
    650:           d_coeff[c*N_bt+b] = (double) coefficients[c*N_bt+b];
    651:         }
    652:       }
    653:       if (coefficientsAux) { /* Assume P0 */
    654:         for (c = 0; c < Ne; ++c) {
    655:           d_coeffAux[c] = (double) coefficientsAux[c];
    656:         }
    657:       }
    658:       oclCoeff      = (void *) d_coeff;
    659:       if (coefficientsAux) {
    660:         oclCoeffAux = (void *) d_coeffAux;
    661:       } else {
    662:         oclCoeffAux = NULL;
    663:       }
    664:       oclInvJ       = (void *) d_invJ;
    665:       oclDetJ       = (void *) d_detJ;
    666:     }
    667:     break;
    668:     default:
    669:       SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Unsupported PETSc type %d", ocl->realType);
    670:     }
    671:   } else {
    672:     PetscInt c, d;

    674:     PetscMalloc2(Ne*dim*dim,&r_invJ,Ne,&r_detJ);
    675:     for (c = 0; c < Ne; ++c) {
    676:       r_detJ[c] = cgeom->detJ[c];
    677:       for (d = 0; d < dim*dim; ++d) {
    678:         r_invJ[c*dim*dim+d] = cgeom->invJ[c * dim * dim + d];
    679:       }
    680:     }
    681:     oclCoeff    = (void *) coefficients;
    682:     oclCoeffAux = (void *) coefficientsAux;
    683:     oclInvJ     = (void *) r_invJ;
    684:     oclDetJ     = (void *) r_detJ;
    685:   }
    686:   o_coefficients         = clCreateBuffer(ocl->ctx_id, CL_MEM_READ_ONLY | CL_MEM_COPY_HOST_PTR, Ne*N_bt    * realSize, oclCoeff,    &ierr);
    687:   if (coefficientsAux) {
    688:     o_coefficientsAux    = clCreateBuffer(ocl->ctx_id, CL_MEM_READ_ONLY | CL_MEM_COPY_HOST_PTR, Ne         * realSize, oclCoeffAux, &ierr);
    689:   } else {
    690:     o_coefficientsAux    = clCreateBuffer(ocl->ctx_id, CL_MEM_READ_ONLY,                        Ne         * realSize, oclCoeffAux, &ierr);
    691:   }
    692:   o_jacobianInverses     = clCreateBuffer(ocl->ctx_id, CL_MEM_READ_ONLY | CL_MEM_COPY_HOST_PTR, Ne*dim*dim * realSize, oclInvJ,     &ierr);
    693:   o_jacobianDeterminants = clCreateBuffer(ocl->ctx_id, CL_MEM_READ_ONLY | CL_MEM_COPY_HOST_PTR, Ne         * realSize, oclDetJ,     &ierr);
    694:   o_elemVec              = clCreateBuffer(ocl->ctx_id, CL_MEM_WRITE_ONLY,                       Ne*N_bt    * realSize, NULL,        &ierr);
    695:   /* Kernel launch */
    696:   clSetKernelArg(ocl_kernel, 0, sizeof(cl_int), (void*) &N_cb);
    697:   clSetKernelArg(ocl_kernel, 1, sizeof(cl_mem), (void*) &o_coefficients);
    698:   clSetKernelArg(ocl_kernel, 2, sizeof(cl_mem), (void*) &o_coefficientsAux);
    699:   clSetKernelArg(ocl_kernel, 3, sizeof(cl_mem), (void*) &o_jacobianInverses);
    700:   clSetKernelArg(ocl_kernel, 4, sizeof(cl_mem), (void*) &o_jacobianDeterminants);
    701:   clSetKernelArg(ocl_kernel, 5, sizeof(cl_mem), (void*) &o_elemVec);
    702:   clEnqueueNDRangeKernel(ocl->queue_id, ocl_kernel, 3, NULL, global_work_size, local_work_size, 0, NULL, &ocl_ev);
    703:   /* Read data back from device */
    704:   if (sizeof(PetscReal) != realSize) {
    705:     switch (ocl->realType) {
    706:     case PETSC_FLOAT:
    707:     {
    708:       float   *elem;
    709:       PetscInt c, b;

    711:       PetscFree4(f_coeff,f_coeffAux,f_invJ,f_detJ);
    712:       PetscMalloc1(Ne*N_bt, &elem);
    713:       clEnqueueReadBuffer(ocl->queue_id, o_elemVec, CL_TRUE, 0, Ne*N_bt * realSize, elem, 0, NULL, NULL);
    714:       for (c = 0; c < Ne; ++c) {
    715:         for (b = 0; b < N_bt; ++b) {
    716:           elemVec[c*N_bt+b] = (PetscScalar) elem[c*N_bt+b];
    717:         }
    718:       }
    719:       PetscFree(elem);
    720:     }
    721:     break;
    722:     case PETSC_DOUBLE:
    723:     {
    724:       double  *elem;
    725:       PetscInt c, b;

    727:       PetscFree4(d_coeff,d_coeffAux,d_invJ,d_detJ);
    728:       PetscMalloc1(Ne*N_bt, &elem);
    729:       clEnqueueReadBuffer(ocl->queue_id, o_elemVec, CL_TRUE, 0, Ne*N_bt * realSize, elem, 0, NULL, NULL);
    730:       for (c = 0; c < Ne; ++c) {
    731:         for (b = 0; b < N_bt; ++b) {
    732:           elemVec[c*N_bt+b] = (PetscScalar) elem[c*N_bt+b];
    733:         }
    734:       }
    735:       PetscFree(elem);
    736:     }
    737:     break;
    738:     default:
    739:       SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Unsupported PETSc type %d", ocl->realType);
    740:     }
    741:   } else {
    742:     PetscFree2(r_invJ,r_detJ);
    743:     clEnqueueReadBuffer(ocl->queue_id, o_elemVec, CL_TRUE, 0, Ne*N_bt * realSize, elemVec, 0, NULL, NULL);
    744:   }
    745:   /* Log performance */
    746:   clGetEventProfilingInfo(ocl_ev, CL_PROFILING_COMMAND_START, sizeof(cl_ulong), &ns_start, NULL);
    747:   clGetEventProfilingInfo(ocl_ev, CL_PROFILING_COMMAND_END,   sizeof(cl_ulong), &ns_end,   NULL);
    748:   f0Flops = 0;
    749:   switch (ocl->op) {
    750:   case LAPLACIAN:
    751:     f1Flops = useAux ? dim : 0;break;
    752:   case ELASTICITY:
    753:     f1Flops = 2*dim*dim;break;
    754:   }
    755:   numFlops = Ne*(
    756:     N_q*(
    757:       N_b*N_comp*((useField ? 2 : 0) + (useFieldDer ? 2*dim*(dim + 1) : 0))
    758:       /*+
    759:        N_ba*N_compa*((useFieldAux ? 2 : 0) + (useFieldDerAux ? 2*dim*(dim + 1) : 0))*/
    760:       +
    761:       N_comp*((useF0 ? f0Flops + 2 : 0) + (useF1 ? f1Flops + 2*dim : 0)))
    762:     +
    763:     N_b*((useF0 ? 2 : 0) + (useF1 ? 2*dim*(dim + 1) : 0)));
    764:   PetscFEOpenCLLogResidual(fem, (ns_end - ns_start)*1.0e-9, numFlops);
    765:   /* Cleanup */
    766:   clReleaseMemObject(o_coefficients);
    767:   clReleaseMemObject(o_coefficientsAux);
    768:   clReleaseMemObject(o_jacobianInverses);
    769:   clReleaseMemObject(o_jacobianDeterminants);
    770:   clReleaseMemObject(o_elemVec);
    771:   clReleaseKernel(ocl_kernel);
    772:   clReleaseProgram(ocl_prog);
    773:   return(0);
    774: }

    776: PETSC_INTERN PetscErrorCode PetscFESetUp_Basic(PetscFE);
    777: PETSC_INTERN PetscErrorCode PetscFECreateTabulation_Basic(PetscFE, PetscInt, const PetscReal [], PetscInt, PetscTabulation);

    779: static PetscErrorCode PetscFEInitialize_OpenCL(PetscFE fem)
    780: {
    782:   fem->ops->setfromoptions          = NULL;
    783:   fem->ops->setup                   = PetscFESetUp_Basic;
    784:   fem->ops->view                    = NULL;
    785:   fem->ops->destroy                 = PetscFEDestroy_OpenCL;
    786:   fem->ops->getdimension            = PetscFEGetDimension_Basic;
    787:   fem->ops->createtabulation        = PetscFECreateTabulation_Basic;
    788:   fem->ops->integrateresidual       = PetscFEIntegrateResidual_OpenCL;
    789:   fem->ops->integratebdresidual     = NULL/* PetscFEIntegrateBdResidual_OpenCL */;
    790:   fem->ops->integratejacobianaction = NULL/* PetscFEIntegrateJacobianAction_OpenCL */;
    791:   fem->ops->integratejacobian       = PetscFEIntegrateJacobian_Basic;
    792:   return(0);
    793: }

    795: /*MC
    796:   PETSCFEOPENCL = "opencl" - A PetscFE object that integrates using a vectorized OpenCL implementation

    798:   Level: intermediate

    800: .seealso: PetscFEType, PetscFECreate(), PetscFESetType()
    801: M*/

    803: PETSC_EXTERN PetscErrorCode PetscFECreate_OpenCL(PetscFE fem)
    804: {
    805:   PetscFE_OpenCL *ocl;
    806:   cl_uint         num_platforms;
    807:   cl_platform_id  platform_ids[42];
    808:   cl_uint         num_devices;
    809:   cl_device_id    device_ids[42];
    810:   cl_int          err;
    811:   PetscErrorCode  ierr;

    815:   PetscNewLog(fem,&ocl);
    816:   fem->data = ocl;

    818:   /* Init Platform */
    819:   clGetPlatformIDs(42, platform_ids, &num_platforms);
    820:   if (!num_platforms) SETERRQ(PetscObjectComm((PetscObject) fem), PETSC_ERR_SUP, "No OpenCL platform found.");
    821:   ocl->pf_id = platform_ids[0];
    822:   /* Init Device */
    823:   clGetDeviceIDs(ocl->pf_id, CL_DEVICE_TYPE_ALL, 42, device_ids, &num_devices);
    824:   if (!num_devices) SETERRQ(PetscObjectComm((PetscObject) fem), PETSC_ERR_SUP, "No OpenCL device found.");
    825:   ocl->dev_id = device_ids[0];
    826:   /* Create context with one command queue */
    827:   ocl->ctx_id   = clCreateContext(0, 1, &(ocl->dev_id), NULL, NULL, &err);CHKERRQ(err);
    828:   ocl->queue_id = clCreateCommandQueue(ocl->ctx_id, ocl->dev_id, CL_QUEUE_PROFILING_ENABLE, &err);CHKERRQ(err);
    829:   /* Types */
    830:   ocl->realType = PETSC_FLOAT;
    831:   /* Register events */
    832:   PetscLogEventRegister("OpenCL FEResidual", PETSCFE_CLASSID, &ocl->residualEvent);
    833:   /* Equation handling */
    834:   ocl->op = LAPLACIAN;

    836:   PetscFEInitialize_OpenCL(fem);
    837:   return(0);
    838: }

    840: /*@
    841:   PetscFEOpenCLSetRealType - Set the scalar type for running on the accelerator

    843:   Input Parameters:
    844: + fem      - The PetscFE
    845: - realType - The scalar type

    847:   Level: developer

    849: .seealso: PetscFEOpenCLGetRealType()
    850: @*/
    851: PetscErrorCode PetscFEOpenCLSetRealType(PetscFE fem, PetscDataType realType)
    852: {
    853:   PetscFE_OpenCL *ocl = (PetscFE_OpenCL *) fem->data;

    857:   ocl->realType = realType;
    858:   return(0);
    859: }

    861: /*@
    862:   PetscFEOpenCLGetRealType - Get the scalar type for running on the accelerator

    864:   Input Parameter:
    865: . fem      - The PetscFE

    867:   Output Parameter:
    868: . realType - The scalar type

    870:   Level: developer

    872: .seealso: PetscFEOpenCLSetRealType()
    873: @*/
    874: PetscErrorCode PetscFEOpenCLGetRealType(PetscFE fem, PetscDataType *realType)
    875: {
    876:   PetscFE_OpenCL *ocl = (PetscFE_OpenCL *) fem->data;

    881:   *realType = ocl->realType;
    882:   return(0);
    883: }

    885: #endif /* PETSC_HAVE_OPENCL */