Date: 2026-03-01T05:24:59+00:00

Actual source code: matelem.cxx

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

      3: const char       ElementalCitation[] = "@Article{Elemental2012,\n"
      4:                                        "  author  = {Jack Poulson and Bryan Marker and Jeff R. Hammond and Nichols A. Romero and Robert {v}an~{d}e~{G}eijn},\n"
      5:                                        "  title   = {Elemental: A New Framework for Distributed Memory Dense Matrix Computations},\n"
      6:                                        "  journal = {{ACM} Transactions on Mathematical Software},\n"
      7:                                        "  volume  = {39},\n"
      8:                                        "  number  = {2},\n"
      9:                                        "  year    = {2013}\n"
     10:                                        "}\n";
     11: static PetscBool ElementalCite       = PETSC_FALSE;

     13: /*
     14:     The variable Petsc_Elemental_keyval is used to indicate an MPI attribute that
     15:   is attached to a communicator, in this case the attribute is a Mat_Elemental_Grid
     16: */
     17: static PetscMPIInt Petsc_Elemental_keyval = MPI_KEYVAL_INVALID;

     19: static PetscErrorCode MatView_Elemental(Mat A, PetscViewer viewer)
     20: {
     21:   Mat_Elemental *a = (Mat_Elemental *)A->data;
     22:   PetscBool      isascii;

     24:   PetscFunctionBegin;
     25:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &isascii));
     26:   if (isascii) {
     27:     PetscViewerFormat format;
     28:     PetscCall(PetscViewerGetFormat(viewer, &format));
     29:     if (format == PETSC_VIEWER_ASCII_INFO) {
     30:       /* call elemental viewing function */
     31:       PetscCall(PetscViewerASCIIPrintf(viewer, "Elemental run parameters:\n"));
     32:       PetscCall(PetscViewerASCIIPrintf(viewer, "  allocated entries=%zu\n", (*a->emat).AllocatedMemory()));
     33:       PetscCall(PetscViewerASCIIPrintf(viewer, "  grid height=%d, grid width=%d\n", (*a->emat).Grid().Height(), (*a->emat).Grid().Width()));
     34:       if (format == PETSC_VIEWER_ASCII_FACTOR_INFO) {
     35:         /* call elemental viewing function */
     36:         PetscCall(PetscPrintf(PetscObjectComm((PetscObject)viewer), "test matview_elemental 2\n"));
     37:       }

     39:     } else if (format == PETSC_VIEWER_DEFAULT) {
     40:       PetscCall(PetscViewerASCIIUseTabs(viewer, PETSC_FALSE));
     41:       El::Print(*a->emat, "Elemental matrix (cyclic ordering)");
     42:       PetscCall(PetscViewerASCIIUseTabs(viewer, PETSC_TRUE));
     43:       if (A->factortype == MAT_FACTOR_NONE) {
     44:         Mat Adense;
     45:         PetscCall(MatConvert(A, MATDENSE, MAT_INITIAL_MATRIX, &Adense));
     46:         PetscCall(MatView(Adense, viewer));
     47:         PetscCall(MatDestroy(&Adense));
     48:       }
     49:     } else SETERRQ(PetscObjectComm((PetscObject)viewer), PETSC_ERR_SUP, "Format");
     50:   } else {
     51:     /* convert to dense format and call MatView() */
     52:     Mat Adense;
     53:     PetscCall(MatConvert(A, MATDENSE, MAT_INITIAL_MATRIX, &Adense));
     54:     PetscCall(MatView(Adense, viewer));
     55:     PetscCall(MatDestroy(&Adense));
     56:   }
     57:   PetscFunctionReturn(PETSC_SUCCESS);
     58: }

     60: static PetscErrorCode MatGetInfo_Elemental(Mat A, MatInfoType flag, MatInfo *info)
     61: {
     62:   Mat_Elemental *a = (Mat_Elemental *)A->data;

     64:   PetscFunctionBegin;
     65:   info->block_size = 1.0;

     67:   if (flag == MAT_LOCAL) {
     68:     info->nz_allocated = (*a->emat).AllocatedMemory(); /* locally allocated */
     69:     info->nz_used      = info->nz_allocated;
     70:   } else if (flag == MAT_GLOBAL_MAX) {
     71:     //PetscCallMPI(MPIU_Allreduce(isend,irecv,5,MPIU_REAL,MPIU_MAX,PetscObjectComm((PetscObject)matin)));
     72:     /* see MatGetInfo_MPIAIJ() for getting global info->nz_allocated! */
     73:     //SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP," MAT_GLOBAL_MAX not written yet");
     74:   } else if (flag == MAT_GLOBAL_SUM) {
     75:     //SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP," MAT_GLOBAL_SUM not written yet");
     76:     info->nz_allocated = (*a->emat).AllocatedMemory(); /* locally allocated */
     77:     info->nz_used      = info->nz_allocated;           /* assume Elemental does accurate allocation */
     78:     //PetscCallMPI(MPIU_Allreduce(isend,irecv,1,MPIU_REAL,MPIU_SUM,PetscObjectComm((PetscObject)A)));
     79:     //PetscPrintf(PETSC_COMM_SELF,"    ... [%d] locally allocated %g\n",rank,info->nz_allocated);
     80:   }

     82:   info->nz_unneeded       = 0.0;
     83:   info->assemblies        = A->num_ass;
     84:   info->mallocs           = 0;
     85:   info->memory            = 0; /* REVIEW ME */
     86:   info->fill_ratio_given  = 0; /* determined by Elemental */
     87:   info->fill_ratio_needed = 0;
     88:   info->factor_mallocs    = 0;
     89:   PetscFunctionReturn(PETSC_SUCCESS);
     90: }

     92: static PetscErrorCode MatSetOption_Elemental(Mat A, MatOption op, PetscBool flg)
     93: {
     94:   Mat_Elemental *a = (Mat_Elemental *)A->data;

     96:   PetscFunctionBegin;
     97:   switch (op) {
     98:   case MAT_ROW_ORIENTED:
     99:     a->roworiented = flg;
    100:     break;
    101:   default:
    102:     break;
    103:   }
    104:   PetscFunctionReturn(PETSC_SUCCESS);
    105: }

    107: static PetscErrorCode MatSetValues_Elemental(Mat A, PetscInt nr, const PetscInt *rows, PetscInt nc, const PetscInt *cols, const PetscScalar *vals, InsertMode imode)
    108: {
    109:   Mat_Elemental *a = (Mat_Elemental *)A->data;
    110:   PetscInt       i, j, rrank, ridx, crank, cidx, erow, ecol, numQueues = 0;

    112:   PetscFunctionBegin;
    113:   // TODO: Initialize matrix to all zeros?

    115:   // Count the number of queues from this process
    116:   if (a->roworiented) {
    117:     for (i = 0; i < nr; i++) {
    118:       if (rows[i] < 0) continue;
    119:       P2RO(A, 0, rows[i], &rrank, &ridx);
    120:       RO2E(A, 0, rrank, ridx, &erow);
    121:       PetscCheck(rrank >= 0 && ridx >= 0 && erow >= 0, PetscObjectComm((PetscObject)A), PETSC_ERR_PLIB, "Incorrect row translation");
    122:       for (j = 0; j < nc; j++) {
    123:         if (cols[j] < 0) continue;
    124:         P2RO(A, 1, cols[j], &crank, &cidx);
    125:         RO2E(A, 1, crank, cidx, &ecol);
    126:         PetscCheck(crank >= 0 && cidx >= 0 && ecol >= 0, PetscObjectComm((PetscObject)A), PETSC_ERR_PLIB, "Incorrect col translation");
    127:         if (!a->emat->IsLocal(erow, ecol)) { /* off-proc entry */
    128:           /* printf("Will later remotely update (%d,%d)\n",erow,ecol); */
    129:           PetscCheck(imode == ADD_VALUES, PETSC_COMM_SELF, PETSC_ERR_SUP, "Only ADD_VALUES to off-processor entry is supported");
    130:           ++numQueues;
    131:           continue;
    132:         }
    133:         /* printf("Locally updating (%d,%d)\n",erow,ecol); */
    134:         switch (imode) {
    135:         case INSERT_VALUES:
    136:           a->emat->Set(erow, ecol, (PetscElemScalar)vals[i * nc + j]);
    137:           break;
    138:         case ADD_VALUES:
    139:           a->emat->Update(erow, ecol, (PetscElemScalar)vals[i * nc + j]);
    140:           break;
    141:         default:
    142:           SETERRQ(PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "No support for InsertMode %d", (int)imode);
    143:         }
    144:       }
    145:     }

    147:     /* printf("numQueues=%d\n",numQueues); */
    148:     a->emat->Reserve(numQueues);
    149:     for (i = 0; i < nr; i++) {
    150:       if (rows[i] < 0) continue;
    151:       P2RO(A, 0, rows[i], &rrank, &ridx);
    152:       RO2E(A, 0, rrank, ridx, &erow);
    153:       for (j = 0; j < nc; j++) {
    154:         if (cols[j] < 0) continue;
    155:         P2RO(A, 1, cols[j], &crank, &cidx);
    156:         RO2E(A, 1, crank, cidx, &ecol);
    157:         if (!a->emat->IsLocal(erow, ecol)) { /*off-proc entry*/
    158:           /* printf("Queueing remotely update of (%d,%d)\n",erow,ecol); */
    159:           a->emat->QueueUpdate(erow, ecol, vals[i * nc + j]);
    160:         }
    161:       }
    162:     }
    163:   } else { /* column-oriented */
    164:     for (j = 0; j < nc; j++) {
    165:       if (cols[j] < 0) continue;
    166:       P2RO(A, 1, cols[j], &crank, &cidx);
    167:       RO2E(A, 1, crank, cidx, &ecol);
    168:       PetscCheck(crank >= 0 && cidx >= 0 && ecol >= 0, PetscObjectComm((PetscObject)A), PETSC_ERR_PLIB, "Incorrect col translation");
    169:       for (i = 0; i < nr; i++) {
    170:         if (rows[i] < 0) continue;
    171:         P2RO(A, 0, rows[i], &rrank, &ridx);
    172:         RO2E(A, 0, rrank, ridx, &erow);
    173:         PetscCheck(rrank >= 0 && ridx >= 0 && erow >= 0, PetscObjectComm((PetscObject)A), PETSC_ERR_PLIB, "Incorrect row translation");
    174:         if (!a->emat->IsLocal(erow, ecol)) { /* off-proc entry */
    175:           /* printf("Will later remotely update (%d,%d)\n",erow,ecol); */
    176:           PetscCheck(imode == ADD_VALUES, PETSC_COMM_SELF, PETSC_ERR_SUP, "Only ADD_VALUES to off-processor entry is supported");
    177:           ++numQueues;
    178:           continue;
    179:         }
    180:         /* printf("Locally updating (%d,%d)\n",erow,ecol); */
    181:         switch (imode) {
    182:         case INSERT_VALUES:
    183:           a->emat->Set(erow, ecol, (PetscElemScalar)vals[i + j * nr]);
    184:           break;
    185:         case ADD_VALUES:
    186:           a->emat->Update(erow, ecol, (PetscElemScalar)vals[i + j * nr]);
    187:           break;
    188:         default:
    189:           SETERRQ(PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "No support for InsertMode %d", (int)imode);
    190:         }
    191:       }
    192:     }

    194:     /* printf("numQueues=%d\n",numQueues); */
    195:     a->emat->Reserve(numQueues);
    196:     for (j = 0; j < nc; j++) {
    197:       if (cols[j] < 0) continue;
    198:       P2RO(A, 1, cols[j], &crank, &cidx);
    199:       RO2E(A, 1, crank, cidx, &ecol);

    201:       for (i = 0; i < nr; i++) {
    202:         if (rows[i] < 0) continue;
    203:         P2RO(A, 0, rows[i], &rrank, &ridx);
    204:         RO2E(A, 0, rrank, ridx, &erow);
    205:         if (!a->emat->IsLocal(erow, ecol)) { /*off-proc entry*/
    206:           /* printf("Queueing remotely update of (%d,%d)\n",erow,ecol); */
    207:           a->emat->QueueUpdate(erow, ecol, vals[i + j * nr]);
    208:         }
    209:       }
    210:     }
    211:   }
    212:   PetscFunctionReturn(PETSC_SUCCESS);
    213: }

    215: static PetscErrorCode MatMult_Elemental(Mat A, Vec X, Vec Y)
    216: {
    217:   Mat_Elemental         *a = (Mat_Elemental *)A->data;
    218:   const PetscElemScalar *x;
    219:   PetscElemScalar       *y;
    220:   PetscElemScalar        one = 1, zero = 0;

    222:   PetscFunctionBegin;
    223:   PetscCall(VecGetArrayRead(X, (const PetscScalar **)&x));
    224:   PetscCall(VecGetArray(Y, (PetscScalar **)&y));
    225:   { /* Scoping so that constructor is called before pointer is returned */
    226:     El::DistMatrix<PetscElemScalar, El::VC, El::STAR> xe, ye;
    227:     xe.LockedAttach(A->cmap->N, 1, *a->grid, 0, 0, x, A->cmap->n);
    228:     ye.Attach(A->rmap->N, 1, *a->grid, 0, 0, y, A->rmap->n);
    229:     El::Gemv(El::NORMAL, one, *a->emat, xe, zero, ye);
    230:   }
    231:   PetscCall(VecRestoreArrayRead(X, (const PetscScalar **)&x));
    232:   PetscCall(VecRestoreArray(Y, (PetscScalar **)&y));
    233:   PetscFunctionReturn(PETSC_SUCCESS);
    234: }

    236: static PetscErrorCode MatMultTranspose_Elemental(Mat A, Vec X, Vec Y)
    237: {
    238:   Mat_Elemental         *a = (Mat_Elemental *)A->data;
    239:   const PetscElemScalar *x;
    240:   PetscElemScalar       *y;
    241:   PetscElemScalar        one = 1, zero = 0;

    243:   PetscFunctionBegin;
    244:   PetscCall(VecGetArrayRead(X, (const PetscScalar **)&x));
    245:   PetscCall(VecGetArray(Y, (PetscScalar **)&y));
    246:   { /* Scoping so that constructor is called before pointer is returned */
    247:     El::DistMatrix<PetscElemScalar, El::VC, El::STAR> xe, ye;
    248:     xe.LockedAttach(A->rmap->N, 1, *a->grid, 0, 0, x, A->rmap->n);
    249:     ye.Attach(A->cmap->N, 1, *a->grid, 0, 0, y, A->cmap->n);
    250:     El::Gemv(El::TRANSPOSE, one, *a->emat, xe, zero, ye);
    251:   }
    252:   PetscCall(VecRestoreArrayRead(X, (const PetscScalar **)&x));
    253:   PetscCall(VecRestoreArray(Y, (PetscScalar **)&y));
    254:   PetscFunctionReturn(PETSC_SUCCESS);
    255: }

    257: static PetscErrorCode MatMultAdd_Elemental(Mat A, Vec X, Vec Y, Vec Z)
    258: {
    259:   Mat_Elemental         *a = (Mat_Elemental *)A->data;
    260:   const PetscElemScalar *x;
    261:   PetscElemScalar       *z;
    262:   PetscElemScalar        one = 1;

    264:   PetscFunctionBegin;
    265:   if (Y != Z) PetscCall(VecCopy(Y, Z));
    266:   PetscCall(VecGetArrayRead(X, (const PetscScalar **)&x));
    267:   PetscCall(VecGetArray(Z, (PetscScalar **)&z));
    268:   { /* Scoping so that constructor is called before pointer is returned */
    269:     El::DistMatrix<PetscElemScalar, El::VC, El::STAR> xe, ze;
    270:     xe.LockedAttach(A->cmap->N, 1, *a->grid, 0, 0, x, A->cmap->n);
    271:     ze.Attach(A->rmap->N, 1, *a->grid, 0, 0, z, A->rmap->n);
    272:     El::Gemv(El::NORMAL, one, *a->emat, xe, one, ze);
    273:   }
    274:   PetscCall(VecRestoreArrayRead(X, (const PetscScalar **)&x));
    275:   PetscCall(VecRestoreArray(Z, (PetscScalar **)&z));
    276:   PetscFunctionReturn(PETSC_SUCCESS);
    277: }

    279: static PetscErrorCode MatMultTransposeAdd_Elemental(Mat A, Vec X, Vec Y, Vec Z)
    280: {
    281:   Mat_Elemental         *a = (Mat_Elemental *)A->data;
    282:   const PetscElemScalar *x;
    283:   PetscElemScalar       *z;
    284:   PetscElemScalar        one = 1;

    286:   PetscFunctionBegin;
    287:   if (Y != Z) PetscCall(VecCopy(Y, Z));
    288:   PetscCall(VecGetArrayRead(X, (const PetscScalar **)&x));
    289:   PetscCall(VecGetArray(Z, (PetscScalar **)&z));
    290:   { /* Scoping so that constructor is called before pointer is returned */
    291:     El::DistMatrix<PetscElemScalar, El::VC, El::STAR> xe, ze;
    292:     xe.LockedAttach(A->rmap->N, 1, *a->grid, 0, 0, x, A->rmap->n);
    293:     ze.Attach(A->cmap->N, 1, *a->grid, 0, 0, z, A->cmap->n);
    294:     El::Gemv(El::TRANSPOSE, one, *a->emat, xe, one, ze);
    295:   }
    296:   PetscCall(VecRestoreArrayRead(X, (const PetscScalar **)&x));
    297:   PetscCall(VecRestoreArray(Z, (PetscScalar **)&z));
    298:   PetscFunctionReturn(PETSC_SUCCESS);
    299: }

    301: PetscErrorCode MatMatMultNumeric_Elemental(Mat A, Mat B, Mat C)
    302: {
    303:   Mat_Elemental  *a   = (Mat_Elemental *)A->data;
    304:   Mat_Elemental  *b   = (Mat_Elemental *)B->data;
    305:   Mat_Elemental  *c   = (Mat_Elemental *)C->data;
    306:   PetscElemScalar one = 1, zero = 0;

    308:   PetscFunctionBegin;
    309:   { /* Scoping so that constructor is called before pointer is returned */
    310:     El::Gemm(El::NORMAL, El::NORMAL, one, *a->emat, *b->emat, zero, *c->emat);
    311:   }
    312:   C->assembled = PETSC_TRUE;
    313:   PetscFunctionReturn(PETSC_SUCCESS);
    314: }

    316: PetscErrorCode MatMatMultSymbolic_Elemental(Mat A, Mat B, PetscReal, Mat Ce)
    317: {
    318:   PetscFunctionBegin;
    319:   PetscCall(MatSetSizes(Ce, A->rmap->n, B->cmap->n, PETSC_DECIDE, PETSC_DECIDE));
    320:   PetscCall(MatSetType(Ce, MATELEMENTAL));
    321:   PetscCall(MatSetUp(Ce));
    322:   Ce->ops->matmultnumeric = MatMatMultNumeric_Elemental;
    323:   PetscFunctionReturn(PETSC_SUCCESS);
    324: }

    326: static PetscErrorCode MatMatTransposeMultNumeric_Elemental(Mat A, Mat B, Mat C)
    327: {
    328:   Mat_Elemental  *a   = (Mat_Elemental *)A->data;
    329:   Mat_Elemental  *b   = (Mat_Elemental *)B->data;
    330:   Mat_Elemental  *c   = (Mat_Elemental *)C->data;
    331:   PetscElemScalar one = 1, zero = 0;

    333:   PetscFunctionBegin;
    334:   { /* Scoping so that constructor is called before pointer is returned */
    335:     El::Gemm(El::NORMAL, El::TRANSPOSE, one, *a->emat, *b->emat, zero, *c->emat);
    336:   }
    337:   C->assembled = PETSC_TRUE;
    338:   PetscFunctionReturn(PETSC_SUCCESS);
    339: }

    341: static PetscErrorCode MatMatTransposeMultSymbolic_Elemental(Mat A, Mat B, PetscReal, Mat C)
    342: {
    343:   PetscFunctionBegin;
    344:   PetscCall(MatSetSizes(C, A->rmap->n, B->rmap->n, PETSC_DECIDE, PETSC_DECIDE));
    345:   PetscCall(MatSetType(C, MATELEMENTAL));
    346:   PetscCall(MatSetUp(C));
    347:   PetscFunctionReturn(PETSC_SUCCESS);
    348: }

    350: static PetscErrorCode MatProductSetFromOptions_Elemental_AB(Mat C)
    351: {
    352:   PetscFunctionBegin;
    353:   C->ops->matmultsymbolic = MatMatMultSymbolic_Elemental;
    354:   C->ops->productsymbolic = MatProductSymbolic_AB;
    355:   PetscFunctionReturn(PETSC_SUCCESS);
    356: }

    358: static PetscErrorCode MatProductSetFromOptions_Elemental_ABt(Mat C)
    359: {
    360:   PetscFunctionBegin;
    361:   C->ops->mattransposemultsymbolic = MatMatTransposeMultSymbolic_Elemental;
    362:   C->ops->productsymbolic          = MatProductSymbolic_ABt;
    363:   PetscFunctionReturn(PETSC_SUCCESS);
    364: }

    366: PETSC_INTERN PetscErrorCode MatProductSetFromOptions_Elemental(Mat C)
    367: {
    368:   Mat_Product *product = C->product;

    370:   PetscFunctionBegin;
    371:   switch (product->type) {
    372:   case MATPRODUCT_AB:
    373:     PetscCall(MatProductSetFromOptions_Elemental_AB(C));
    374:     break;
    375:   case MATPRODUCT_ABt:
    376:     PetscCall(MatProductSetFromOptions_Elemental_ABt(C));
    377:     break;
    378:   default:
    379:     break;
    380:   }
    381:   PetscFunctionReturn(PETSC_SUCCESS);
    382: }

    384: static PetscErrorCode MatMatMultNumeric_Elemental_MPIDense(Mat A, Mat B, Mat C)
    385: {
    386:   Mat Be, Ce;

    388:   PetscFunctionBegin;
    389:   PetscCall(MatConvert(B, MATELEMENTAL, MAT_INITIAL_MATRIX, &Be));
    390:   PetscCall(MatMatMult(A, Be, MAT_INITIAL_MATRIX, PETSC_DETERMINE, &Ce));
    391:   PetscCall(MatConvert(Ce, MATMPIDENSE, MAT_REUSE_MATRIX, &C));
    392:   PetscCall(MatDestroy(&Be));
    393:   PetscCall(MatDestroy(&Ce));
    394:   PetscFunctionReturn(PETSC_SUCCESS);
    395: }

    397: static PetscErrorCode MatMatMultSymbolic_Elemental_MPIDense(Mat A, Mat B, PetscReal, Mat C)
    398: {
    399:   PetscFunctionBegin;
    400:   PetscCall(MatSetSizes(C, A->rmap->n, B->cmap->n, PETSC_DECIDE, PETSC_DECIDE));
    401:   PetscCall(MatSetType(C, MATMPIDENSE));
    402:   PetscCall(MatSetUp(C));
    403:   C->ops->matmultnumeric = MatMatMultNumeric_Elemental_MPIDense;
    404:   PetscFunctionReturn(PETSC_SUCCESS);
    405: }

    407: static PetscErrorCode MatProductSetFromOptions_Elemental_MPIDense_AB(Mat C)
    408: {
    409:   PetscFunctionBegin;
    410:   C->ops->matmultsymbolic = MatMatMultSymbolic_Elemental_MPIDense;
    411:   C->ops->productsymbolic = MatProductSymbolic_AB;
    412:   PetscFunctionReturn(PETSC_SUCCESS);
    413: }

    415: static PetscErrorCode MatProductSetFromOptions_Elemental_MPIDense(Mat C)
    416: {
    417:   Mat_Product *product = C->product;

    419:   PetscFunctionBegin;
    420:   if (product->type == MATPRODUCT_AB) PetscCall(MatProductSetFromOptions_Elemental_MPIDense_AB(C));
    421:   PetscFunctionReturn(PETSC_SUCCESS);
    422: }

    424: static PetscErrorCode MatGetDiagonal_Elemental(Mat A, Vec D)
    425: {
    426:   PetscInt        i, nrows, ncols, nD, rrank, ridx, crank, cidx;
    427:   Mat_Elemental  *a = (Mat_Elemental *)A->data;
    428:   PetscElemScalar v;
    429:   MPI_Comm        comm;

    431:   PetscFunctionBegin;
    432:   PetscCall(PetscObjectGetComm((PetscObject)A, &comm));
    433:   PetscCall(MatGetSize(A, &nrows, &ncols));
    434:   nD = nrows > ncols ? ncols : nrows;
    435:   for (i = 0; i < nD; i++) {
    436:     PetscInt erow, ecol;
    437:     P2RO(A, 0, i, &rrank, &ridx);
    438:     RO2E(A, 0, rrank, ridx, &erow);
    439:     PetscCheck(rrank >= 0 && ridx >= 0 && erow >= 0, comm, PETSC_ERR_PLIB, "Incorrect row translation");
    440:     P2RO(A, 1, i, &crank, &cidx);
    441:     RO2E(A, 1, crank, cidx, &ecol);
    442:     PetscCheck(crank >= 0 && cidx >= 0 && ecol >= 0, comm, PETSC_ERR_PLIB, "Incorrect col translation");
    443:     v = a->emat->Get(erow, ecol);
    444:     PetscCall(VecSetValues(D, 1, &i, (PetscScalar *)&v, INSERT_VALUES));
    445:   }
    446:   PetscCall(VecAssemblyBegin(D));
    447:   PetscCall(VecAssemblyEnd(D));
    448:   PetscFunctionReturn(PETSC_SUCCESS);
    449: }

    451: static PetscErrorCode MatDiagonalScale_Elemental(Mat X, Vec L, Vec R)
    452: {
    453:   Mat_Elemental         *x = (Mat_Elemental *)X->data;
    454:   const PetscElemScalar *d;

    456:   PetscFunctionBegin;
    457:   if (R) {
    458:     PetscCall(VecGetArrayRead(R, (const PetscScalar **)&d));
    459:     El::DistMatrix<PetscElemScalar, El::VC, El::STAR> de;
    460:     de.LockedAttach(X->cmap->N, 1, *x->grid, 0, 0, d, X->cmap->n);
    461:     El::DiagonalScale(El::RIGHT, El::NORMAL, de, *x->emat);
    462:     PetscCall(VecRestoreArrayRead(R, (const PetscScalar **)&d));
    463:   }
    464:   if (L) {
    465:     PetscCall(VecGetArrayRead(L, (const PetscScalar **)&d));
    466:     El::DistMatrix<PetscElemScalar, El::VC, El::STAR> de;
    467:     de.LockedAttach(X->rmap->N, 1, *x->grid, 0, 0, d, X->rmap->n);
    468:     El::DiagonalScale(El::LEFT, El::NORMAL, de, *x->emat);
    469:     PetscCall(VecRestoreArrayRead(L, (const PetscScalar **)&d));
    470:   }
    471:   PetscFunctionReturn(PETSC_SUCCESS);
    472: }

    474: static PetscErrorCode MatMissingDiagonal_Elemental(Mat, PetscBool *missing, PetscInt *)
    475: {
    476:   PetscFunctionBegin;
    477:   *missing = PETSC_FALSE;
    478:   PetscFunctionReturn(PETSC_SUCCESS);
    479: }

    481: static PetscErrorCode MatScale_Elemental(Mat X, PetscScalar a)
    482: {
    483:   Mat_Elemental *x = (Mat_Elemental *)X->data;

    485:   PetscFunctionBegin;
    486:   El::Scale((PetscElemScalar)a, *x->emat);
    487:   PetscFunctionReturn(PETSC_SUCCESS);
    488: }

    490: /*
    491:   MatAXPY - Computes Y = a*X + Y.
    492: */
    493: static PetscErrorCode MatAXPY_Elemental(Mat Y, PetscScalar a, Mat X, MatStructure)
    494: {
    495:   Mat_Elemental *x = (Mat_Elemental *)X->data;
    496:   Mat_Elemental *y = (Mat_Elemental *)Y->data;

    498:   PetscFunctionBegin;
    499:   El::Axpy((PetscElemScalar)a, *x->emat, *y->emat);
    500:   PetscCall(PetscObjectStateIncrease((PetscObject)Y));
    501:   PetscFunctionReturn(PETSC_SUCCESS);
    502: }

    504: static PetscErrorCode MatCopy_Elemental(Mat A, Mat B, MatStructure)
    505: {
    506:   Mat_Elemental *a = (Mat_Elemental *)A->data;
    507:   Mat_Elemental *b = (Mat_Elemental *)B->data;

    509:   PetscFunctionBegin;
    510:   El::Copy(*a->emat, *b->emat);
    511:   PetscCall(PetscObjectStateIncrease((PetscObject)B));
    512:   PetscFunctionReturn(PETSC_SUCCESS);
    513: }

    515: static PetscErrorCode MatDuplicate_Elemental(Mat A, MatDuplicateOption op, Mat *B)
    516: {
    517:   Mat            Be;
    518:   MPI_Comm       comm;
    519:   Mat_Elemental *a = (Mat_Elemental *)A->data;

    521:   PetscFunctionBegin;
    522:   PetscCall(PetscObjectGetComm((PetscObject)A, &comm));
    523:   PetscCall(MatCreate(comm, &Be));
    524:   PetscCall(MatSetSizes(Be, A->rmap->n, A->cmap->n, PETSC_DECIDE, PETSC_DECIDE));
    525:   PetscCall(MatSetType(Be, MATELEMENTAL));
    526:   PetscCall(MatSetUp(Be));
    527:   *B = Be;
    528:   if (op == MAT_COPY_VALUES) {
    529:     Mat_Elemental *b = (Mat_Elemental *)Be->data;
    530:     El::Copy(*a->emat, *b->emat);
    531:   }
    532:   Be->assembled = PETSC_TRUE;
    533:   PetscFunctionReturn(PETSC_SUCCESS);
    534: }

    536: static PetscErrorCode MatTranspose_Elemental(Mat A, MatReuse reuse, Mat *B)
    537: {
    538:   Mat            Be = *B;
    539:   MPI_Comm       comm;
    540:   Mat_Elemental *a = (Mat_Elemental *)A->data, *b;

    542:   PetscFunctionBegin;
    543:   if (reuse == MAT_REUSE_MATRIX) PetscCall(MatTransposeCheckNonzeroState_Private(A, *B));
    544:   PetscCall(PetscObjectGetComm((PetscObject)A, &comm));
    545:   /* Only out-of-place supported */
    546:   PetscCheck(reuse != MAT_INPLACE_MATRIX, comm, PETSC_ERR_SUP, "Only out-of-place supported");
    547:   if (reuse == MAT_INITIAL_MATRIX) {
    548:     PetscCall(MatCreate(comm, &Be));
    549:     PetscCall(MatSetSizes(Be, A->cmap->n, A->rmap->n, PETSC_DECIDE, PETSC_DECIDE));
    550:     PetscCall(MatSetType(Be, MATELEMENTAL));
    551:     PetscCall(MatSetUp(Be));
    552:     *B = Be;
    553:   }
    554:   b = (Mat_Elemental *)Be->data;
    555:   El::Transpose(*a->emat, *b->emat);
    556:   Be->assembled = PETSC_TRUE;
    557:   PetscFunctionReturn(PETSC_SUCCESS);
    558: }

    560: static PetscErrorCode MatConjugate_Elemental(Mat A)
    561: {
    562:   Mat_Elemental *a = (Mat_Elemental *)A->data;

    564:   PetscFunctionBegin;
    565:   El::Conjugate(*a->emat);
    566:   PetscFunctionReturn(PETSC_SUCCESS);
    567: }

    569: static PetscErrorCode MatHermitianTranspose_Elemental(Mat A, MatReuse reuse, Mat *B)
    570: {
    571:   Mat            Be = *B;
    572:   MPI_Comm       comm;
    573:   Mat_Elemental *a = (Mat_Elemental *)A->data, *b;

    575:   PetscFunctionBegin;
    576:   PetscCall(PetscObjectGetComm((PetscObject)A, &comm));
    577:   /* Only out-of-place supported */
    578:   if (reuse == MAT_INITIAL_MATRIX) {
    579:     PetscCall(MatCreate(comm, &Be));
    580:     PetscCall(MatSetSizes(Be, A->cmap->n, A->rmap->n, PETSC_DECIDE, PETSC_DECIDE));
    581:     PetscCall(MatSetType(Be, MATELEMENTAL));
    582:     PetscCall(MatSetUp(Be));
    583:     *B = Be;
    584:   }
    585:   b = (Mat_Elemental *)Be->data;
    586:   El::Adjoint(*a->emat, *b->emat);
    587:   Be->assembled = PETSC_TRUE;
    588:   PetscFunctionReturn(PETSC_SUCCESS);
    589: }

    591: static PetscErrorCode MatSolve_Elemental(Mat A, Vec B, Vec X)
    592: {
    593:   Mat_Elemental   *a = (Mat_Elemental *)A->data;
    594:   PetscElemScalar *x;
    595:   PetscInt         pivoting = a->pivoting;

    597:   PetscFunctionBegin;
    598:   PetscCall(VecCopy(B, X));
    599:   PetscCall(VecGetArray(X, (PetscScalar **)&x));

    601:   El::DistMatrix<PetscElemScalar, El::VC, El::STAR> xe;
    602:   xe.Attach(A->rmap->N, 1, *a->grid, 0, 0, x, A->rmap->n);
    603:   El::DistMatrix<PetscElemScalar, El::MC, El::MR> xer(xe);
    604:   switch (A->factortype) {
    605:   case MAT_FACTOR_LU:
    606:     if (pivoting == 0) {
    607:       El::lu::SolveAfter(El::NORMAL, *a->emat, xer);
    608:     } else if (pivoting == 1) {
    609:       El::lu::SolveAfter(El::NORMAL, *a->emat, *a->P, xer);
    610:     } else { /* pivoting == 2 */
    611:       El::lu::SolveAfter(El::NORMAL, *a->emat, *a->P, *a->Q, xer);
    612:     }
    613:     break;
    614:   case MAT_FACTOR_CHOLESKY:
    615:     El::cholesky::SolveAfter(El::UPPER, El::NORMAL, *a->emat, xer);
    616:     break;
    617:   default:
    618:     SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP, "Unfactored Matrix or Unsupported MatFactorType");
    619:     break;
    620:   }
    621:   El::Copy(xer, xe);

    623:   PetscCall(VecRestoreArray(X, (PetscScalar **)&x));
    624:   PetscFunctionReturn(PETSC_SUCCESS);
    625: }

    627: static PetscErrorCode MatSolveAdd_Elemental(Mat A, Vec B, Vec Y, Vec X)
    628: {
    629:   PetscFunctionBegin;
    630:   PetscCall(MatSolve_Elemental(A, B, X));
    631:   PetscCall(VecAXPY(X, 1, Y));
    632:   PetscFunctionReturn(PETSC_SUCCESS);
    633: }

    635: static PetscErrorCode MatMatSolve_Elemental(Mat A, Mat B, Mat X)
    636: {
    637:   Mat_Elemental *a = (Mat_Elemental *)A->data;
    638:   Mat_Elemental *x;
    639:   Mat            C;
    640:   PetscInt       pivoting = a->pivoting;
    641:   PetscBool      flg;
    642:   MatType        type;

    644:   PetscFunctionBegin;
    645:   PetscCall(MatGetType(X, &type));
    646:   PetscCall(PetscStrcmp(type, MATELEMENTAL, &flg));
    647:   if (!flg) {
    648:     PetscCall(MatConvert(B, MATELEMENTAL, MAT_INITIAL_MATRIX, &C));
    649:     x = (Mat_Elemental *)C->data;
    650:   } else {
    651:     x = (Mat_Elemental *)X->data;
    652:     El::Copy(*((Mat_Elemental *)B->data)->emat, *x->emat);
    653:   }
    654:   switch (A->factortype) {
    655:   case MAT_FACTOR_LU:
    656:     if (pivoting == 0) {
    657:       El::lu::SolveAfter(El::NORMAL, *a->emat, *x->emat);
    658:     } else if (pivoting == 1) {
    659:       El::lu::SolveAfter(El::NORMAL, *a->emat, *a->P, *x->emat);
    660:     } else {
    661:       El::lu::SolveAfter(El::NORMAL, *a->emat, *a->P, *a->Q, *x->emat);
    662:     }
    663:     break;
    664:   case MAT_FACTOR_CHOLESKY:
    665:     El::cholesky::SolveAfter(El::UPPER, El::NORMAL, *a->emat, *x->emat);
    666:     break;
    667:   default:
    668:     SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP, "Unfactored Matrix or Unsupported MatFactorType");
    669:     break;
    670:   }
    671:   if (!flg) {
    672:     PetscCall(MatConvert(C, type, MAT_REUSE_MATRIX, &X));
    673:     PetscCall(MatDestroy(&C));
    674:   }
    675:   PetscFunctionReturn(PETSC_SUCCESS);
    676: }

    678: static PetscErrorCode MatLUFactor_Elemental(Mat A, IS, IS, const MatFactorInfo *)
    679: {
    680:   Mat_Elemental *a        = (Mat_Elemental *)A->data;
    681:   PetscInt       pivoting = a->pivoting;

    683:   PetscFunctionBegin;
    684:   if (pivoting == 0) {
    685:     El::LU(*a->emat);
    686:   } else if (pivoting == 1) {
    687:     El::LU(*a->emat, *a->P);
    688:   } else {
    689:     El::LU(*a->emat, *a->P, *a->Q);
    690:   }
    691:   A->factortype = MAT_FACTOR_LU;
    692:   A->assembled  = PETSC_TRUE;

    694:   PetscCall(PetscFree(A->solvertype));
    695:   PetscCall(PetscStrallocpy(MATSOLVERELEMENTAL, &A->solvertype));
    696:   PetscFunctionReturn(PETSC_SUCCESS);
    697: }

    699: static PetscErrorCode MatLUFactorNumeric_Elemental(Mat F, Mat A, const MatFactorInfo *info)
    700: {
    701:   PetscFunctionBegin;
    702:   PetscCall(MatCopy(A, F, SAME_NONZERO_PATTERN));
    703:   PetscCall(MatLUFactor_Elemental(F, nullptr, nullptr, info));
    704:   PetscFunctionReturn(PETSC_SUCCESS);
    705: }

    707: static PetscErrorCode MatLUFactorSymbolic_Elemental(Mat, Mat, IS, IS, const MatFactorInfo *)
    708: {
    709:   PetscFunctionBegin;
    710:   /* F is created and allocated by MatGetFactor_elemental_petsc(), skip this routine. */
    711:   PetscFunctionReturn(PETSC_SUCCESS);
    712: }

    714: static PetscErrorCode MatCholeskyFactor_Elemental(Mat A, IS, const MatFactorInfo *)
    715: {
    716:   Mat_Elemental                                    *a = (Mat_Elemental *)A->data;
    717:   El::DistMatrix<PetscElemScalar, El::MC, El::STAR> d;

    719:   PetscFunctionBegin;
    720:   El::Cholesky(El::UPPER, *a->emat);
    721:   A->factortype = MAT_FACTOR_CHOLESKY;
    722:   A->assembled  = PETSC_TRUE;

    724:   PetscCall(PetscFree(A->solvertype));
    725:   PetscCall(PetscStrallocpy(MATSOLVERELEMENTAL, &A->solvertype));
    726:   PetscFunctionReturn(PETSC_SUCCESS);
    727: }

    729: static PetscErrorCode MatCholeskyFactorNumeric_Elemental(Mat F, Mat A, const MatFactorInfo *info)
    730: {
    731:   PetscFunctionBegin;
    732:   PetscCall(MatCopy(A, F, SAME_NONZERO_PATTERN));
    733:   PetscCall(MatCholeskyFactor_Elemental(F, nullptr, info));
    734:   PetscFunctionReturn(PETSC_SUCCESS);
    735: }

    737: static PetscErrorCode MatCholeskyFactorSymbolic_Elemental(Mat, Mat, IS, const MatFactorInfo *)
    738: {
    739:   PetscFunctionBegin;
    740:   /* F is created and allocated by MatGetFactor_elemental_petsc(), skip this routine. */
    741:   PetscFunctionReturn(PETSC_SUCCESS);
    742: }

    744: static PetscErrorCode MatFactorGetSolverType_elemental_elemental(Mat, MatSolverType *type)
    745: {
    746:   PetscFunctionBegin;
    747:   *type = MATSOLVERELEMENTAL;
    748:   PetscFunctionReturn(PETSC_SUCCESS);
    749: }

    751: static PetscErrorCode MatGetFactor_elemental_elemental(Mat A, MatFactorType ftype, Mat *F)
    752: {
    753:   Mat B;

    755:   PetscFunctionBegin;
    756:   /* Create the factorization matrix */
    757:   PetscCall(MatCreate(PetscObjectComm((PetscObject)A), &B));
    758:   PetscCall(MatSetSizes(B, A->rmap->n, A->cmap->n, PETSC_DECIDE, PETSC_DECIDE));
    759:   PetscCall(MatSetType(B, MATELEMENTAL));
    760:   PetscCall(MatSetUp(B));
    761:   B->factortype      = ftype;
    762:   B->trivialsymbolic = PETSC_TRUE;
    763:   PetscCall(PetscFree(B->solvertype));
    764:   PetscCall(PetscStrallocpy(MATSOLVERELEMENTAL, &B->solvertype));

    766:   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatFactorGetSolverType_C", MatFactorGetSolverType_elemental_elemental));
    767:   *F = B;
    768:   PetscFunctionReturn(PETSC_SUCCESS);
    769: }

    771: PETSC_INTERN PetscErrorCode MatSolverTypeRegister_Elemental(void)
    772: {
    773:   PetscFunctionBegin;
    774:   PetscCall(MatSolverTypeRegister(MATSOLVERELEMENTAL, MATELEMENTAL, MAT_FACTOR_LU, MatGetFactor_elemental_elemental));
    775:   PetscCall(MatSolverTypeRegister(MATSOLVERELEMENTAL, MATELEMENTAL, MAT_FACTOR_CHOLESKY, MatGetFactor_elemental_elemental));
    776:   PetscFunctionReturn(PETSC_SUCCESS);
    777: }

    779: static PetscErrorCode MatNorm_Elemental(Mat A, NormType type, PetscReal *nrm)
    780: {
    781:   Mat_Elemental *a = (Mat_Elemental *)A->data;

    783:   PetscFunctionBegin;
    784:   switch (type) {
    785:   case NORM_1:
    786:     *nrm = El::OneNorm(*a->emat);
    787:     break;
    788:   case NORM_FROBENIUS:
    789:     *nrm = El::FrobeniusNorm(*a->emat);
    790:     break;
    791:   case NORM_INFINITY:
    792:     *nrm = El::InfinityNorm(*a->emat);
    793:     break;
    794:   default:
    795:     SETERRQ(PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Unsupported norm type");
    796:   }
    797:   PetscFunctionReturn(PETSC_SUCCESS);
    798: }

    800: static PetscErrorCode MatZeroEntries_Elemental(Mat A)
    801: {
    802:   Mat_Elemental *a = (Mat_Elemental *)A->data;

    804:   PetscFunctionBegin;
    805:   El::Zero(*a->emat);
    806:   PetscFunctionReturn(PETSC_SUCCESS);
    807: }

    809: static PetscErrorCode MatGetOwnershipIS_Elemental(Mat A, IS *rows, IS *cols)
    810: {
    811:   Mat_Elemental *a = (Mat_Elemental *)A->data;
    812:   PetscInt       i, m, shift, stride, *idx;

    814:   PetscFunctionBegin;
    815:   if (rows) {
    816:     m      = a->emat->LocalHeight();
    817:     shift  = a->emat->ColShift();
    818:     stride = a->emat->ColStride();
    819:     PetscCall(PetscMalloc1(m, &idx));
    820:     for (i = 0; i < m; i++) {
    821:       PetscInt rank, offset;
    822:       E2RO(A, 0, shift + i * stride, &rank, &offset);
    823:       RO2P(A, 0, rank, offset, &idx[i]);
    824:     }
    825:     PetscCall(ISCreateGeneral(PETSC_COMM_SELF, m, idx, PETSC_OWN_POINTER, rows));
    826:   }
    827:   if (cols) {
    828:     m      = a->emat->LocalWidth();
    829:     shift  = a->emat->RowShift();
    830:     stride = a->emat->RowStride();
    831:     PetscCall(PetscMalloc1(m, &idx));
    832:     for (i = 0; i < m; i++) {
    833:       PetscInt rank, offset;
    834:       E2RO(A, 1, shift + i * stride, &rank, &offset);
    835:       RO2P(A, 1, rank, offset, &idx[i]);
    836:     }
    837:     PetscCall(ISCreateGeneral(PETSC_COMM_SELF, m, idx, PETSC_OWN_POINTER, cols));
    838:   }
    839:   PetscFunctionReturn(PETSC_SUCCESS);
    840: }

    842: static PetscErrorCode MatConvert_Elemental_Dense(Mat A, MatType, MatReuse reuse, Mat *B)
    843: {
    844:   Mat             Bmpi;
    845:   Mat_Elemental  *a = (Mat_Elemental *)A->data;
    846:   MPI_Comm        comm;
    847:   IS              isrows, iscols;
    848:   PetscInt        rrank, ridx, crank, cidx, nrows, ncols, i, j, erow, ecol, elrow, elcol;
    849:   const PetscInt *rows, *cols;
    850:   PetscElemScalar v;
    851:   const El::Grid &grid = a->emat->Grid();

    853:   PetscFunctionBegin;
    854:   PetscCall(PetscObjectGetComm((PetscObject)A, &comm));

    856:   if (reuse == MAT_REUSE_MATRIX) {
    857:     Bmpi = *B;
    858:   } else {
    859:     PetscCall(MatCreate(comm, &Bmpi));
    860:     PetscCall(MatSetSizes(Bmpi, A->rmap->n, A->cmap->n, PETSC_DECIDE, PETSC_DECIDE));
    861:     PetscCall(MatSetType(Bmpi, MATDENSE));
    862:     PetscCall(MatSetUp(Bmpi));
    863:   }

    865:   /* Get local entries of A */
    866:   PetscCall(MatGetOwnershipIS(A, &isrows, &iscols));
    867:   PetscCall(ISGetLocalSize(isrows, &nrows));
    868:   PetscCall(ISGetIndices(isrows, &rows));
    869:   PetscCall(ISGetLocalSize(iscols, &ncols));
    870:   PetscCall(ISGetIndices(iscols, &cols));

    872:   if (a->roworiented) {
    873:     for (i = 0; i < nrows; i++) {
    874:       P2RO(A, 0, rows[i], &rrank, &ridx); /* convert indices between PETSc <-> (Rank,Offset) <-> Elemental */
    875:       RO2E(A, 0, rrank, ridx, &erow);
    876:       PetscCheck(rrank >= 0 && ridx >= 0 && erow >= 0, comm, PETSC_ERR_PLIB, "Incorrect row translation");
    877:       for (j = 0; j < ncols; j++) {
    878:         P2RO(A, 1, cols[j], &crank, &cidx);
    879:         RO2E(A, 1, crank, cidx, &ecol);
    880:         PetscCheck(crank >= 0 && cidx >= 0 && ecol >= 0, comm, PETSC_ERR_PLIB, "Incorrect col translation");

    882:         elrow = erow / grid.MCSize(); /* Elemental local row index */
    883:         elcol = ecol / grid.MRSize(); /* Elemental local column index */
    884:         v     = a->emat->GetLocal(elrow, elcol);
    885:         PetscCall(MatSetValues(Bmpi, 1, &rows[i], 1, &cols[j], (PetscScalar *)&v, INSERT_VALUES));
    886:       }
    887:     }
    888:   } else { /* column-oriented */
    889:     for (j = 0; j < ncols; j++) {
    890:       P2RO(A, 1, cols[j], &crank, &cidx);
    891:       RO2E(A, 1, crank, cidx, &ecol);
    892:       PetscCheck(crank >= 0 && cidx >= 0 && ecol >= 0, comm, PETSC_ERR_PLIB, "Incorrect col translation");
    893:       for (i = 0; i < nrows; i++) {
    894:         P2RO(A, 0, rows[i], &rrank, &ridx); /* convert indices between PETSc <-> (Rank,Offset) <-> Elemental */
    895:         RO2E(A, 0, rrank, ridx, &erow);
    896:         PetscCheck(rrank >= 0 && ridx >= 0 && erow >= 0, comm, PETSC_ERR_PLIB, "Incorrect row translation");

    898:         elrow = erow / grid.MCSize(); /* Elemental local row index */
    899:         elcol = ecol / grid.MRSize(); /* Elemental local column index */
    900:         v     = a->emat->GetLocal(elrow, elcol);
    901:         PetscCall(MatSetValues(Bmpi, 1, &rows[i], 1, &cols[j], (PetscScalar *)&v, INSERT_VALUES));
    902:       }
    903:     }
    904:   }
    905:   PetscCall(MatAssemblyBegin(Bmpi, MAT_FINAL_ASSEMBLY));
    906:   PetscCall(MatAssemblyEnd(Bmpi, MAT_FINAL_ASSEMBLY));
    907:   if (reuse == MAT_INPLACE_MATRIX) {
    908:     PetscCall(MatHeaderReplace(A, &Bmpi));
    909:   } else {
    910:     *B = Bmpi;
    911:   }
    912:   PetscCall(ISDestroy(&isrows));
    913:   PetscCall(ISDestroy(&iscols));
    914:   PetscFunctionReturn(PETSC_SUCCESS);
    915: }

    917: PETSC_INTERN PetscErrorCode MatConvert_SeqAIJ_Elemental(Mat A, MatType, MatReuse reuse, Mat *newmat)
    918: {
    919:   Mat                mat_elemental;
    920:   PetscInt           M = A->rmap->N, N = A->cmap->N, row, ncols;
    921:   const PetscInt    *cols;
    922:   const PetscScalar *vals;

    924:   PetscFunctionBegin;
    925:   if (reuse == MAT_REUSE_MATRIX) {
    926:     mat_elemental = *newmat;
    927:     PetscCall(MatZeroEntries(mat_elemental));
    928:   } else {
    929:     PetscCall(MatCreate(PetscObjectComm((PetscObject)A), &mat_elemental));
    930:     PetscCall(MatSetSizes(mat_elemental, PETSC_DECIDE, PETSC_DECIDE, M, N));
    931:     PetscCall(MatSetType(mat_elemental, MATELEMENTAL));
    932:     PetscCall(MatSetUp(mat_elemental));
    933:   }
    934:   for (row = 0; row < M; row++) {
    935:     PetscCall(MatGetRow(A, row, &ncols, &cols, &vals));
    936:     /* PETSc-Elemental interface uses axpy for setting off-processor entries, only ADD_VALUES is allowed */
    937:     PetscCall(MatSetValues(mat_elemental, 1, &row, ncols, cols, vals, ADD_VALUES));
    938:     PetscCall(MatRestoreRow(A, row, &ncols, &cols, &vals));
    939:   }
    940:   PetscCall(MatAssemblyBegin(mat_elemental, MAT_FINAL_ASSEMBLY));
    941:   PetscCall(MatAssemblyEnd(mat_elemental, MAT_FINAL_ASSEMBLY));

    943:   if (reuse == MAT_INPLACE_MATRIX) {
    944:     PetscCall(MatHeaderReplace(A, &mat_elemental));
    945:   } else {
    946:     *newmat = mat_elemental;
    947:   }
    948:   PetscFunctionReturn(PETSC_SUCCESS);
    949: }

    951: PETSC_INTERN PetscErrorCode MatConvert_MPIAIJ_Elemental(Mat A, MatType, MatReuse reuse, Mat *newmat)
    952: {
    953:   Mat                mat_elemental;
    954:   PetscInt           row, ncols, rstart = A->rmap->rstart, rend = A->rmap->rend, j;
    955:   const PetscInt    *cols;
    956:   const PetscScalar *vals;

    958:   PetscFunctionBegin;
    959:   if (reuse == MAT_REUSE_MATRIX) {
    960:     mat_elemental = *newmat;
    961:     PetscCall(MatZeroEntries(mat_elemental));
    962:   } else {
    963:     PetscCall(MatCreate(PetscObjectComm((PetscObject)A), &mat_elemental));
    964:     PetscCall(MatSetSizes(mat_elemental, PETSC_DECIDE, PETSC_DECIDE, A->rmap->N, A->cmap->N));
    965:     PetscCall(MatSetType(mat_elemental, MATELEMENTAL));
    966:     PetscCall(MatSetUp(mat_elemental));
    967:   }
    968:   for (row = rstart; row < rend; row++) {
    969:     PetscCall(MatGetRow(A, row, &ncols, &cols, &vals));
    970:     for (j = 0; j < ncols; j++) {
    971:       /* PETSc-Elemental interface uses axpy for setting off-processor entries, only ADD_VALUES is allowed */
    972:       PetscCall(MatSetValues(mat_elemental, 1, &row, 1, &cols[j], &vals[j], ADD_VALUES));
    973:     }
    974:     PetscCall(MatRestoreRow(A, row, &ncols, &cols, &vals));
    975:   }
    976:   PetscCall(MatAssemblyBegin(mat_elemental, MAT_FINAL_ASSEMBLY));
    977:   PetscCall(MatAssemblyEnd(mat_elemental, MAT_FINAL_ASSEMBLY));

    979:   if (reuse == MAT_INPLACE_MATRIX) {
    980:     PetscCall(MatHeaderReplace(A, &mat_elemental));
    981:   } else {
    982:     *newmat = mat_elemental;
    983:   }
    984:   PetscFunctionReturn(PETSC_SUCCESS);
    985: }

    987: PETSC_INTERN PetscErrorCode MatConvert_SeqSBAIJ_Elemental(Mat A, MatType, MatReuse reuse, Mat *newmat)
    988: {
    989:   Mat                mat_elemental;
    990:   PetscInt           M = A->rmap->N, N = A->cmap->N, row, ncols, j;
    991:   const PetscInt    *cols;
    992:   const PetscScalar *vals;

    994:   PetscFunctionBegin;
    995:   if (reuse == MAT_REUSE_MATRIX) {
    996:     mat_elemental = *newmat;
    997:     PetscCall(MatZeroEntries(mat_elemental));
    998:   } else {
    999:     PetscCall(MatCreate(PetscObjectComm((PetscObject)A), &mat_elemental));
    1000:     PetscCall(MatSetSizes(mat_elemental, PETSC_DECIDE, PETSC_DECIDE, M, N));
    1001:     PetscCall(MatSetType(mat_elemental, MATELEMENTAL));
    1002:     PetscCall(MatSetUp(mat_elemental));
    1003:   }
    1004:   PetscCall(MatGetRowUpperTriangular(A));
    1005:   for (row = 0; row < M; row++) {
    1006:     PetscCall(MatGetRow(A, row, &ncols, &cols, &vals));
    1007:     /* PETSc-Elemental interface uses axpy for setting off-processor entries, only ADD_VALUES is allowed */
    1008:     PetscCall(MatSetValues(mat_elemental, 1, &row, ncols, cols, vals, ADD_VALUES));
    1009:     for (j = 0; j < ncols; j++) { /* lower triangular part */
    1010:       PetscScalar v;
    1011:       if (cols[j] == row) continue;
    1012:       v = A->hermitian == PETSC_BOOL3_TRUE ? PetscConj(vals[j]) : vals[j];
    1013:       PetscCall(MatSetValues(mat_elemental, 1, &cols[j], 1, &row, &v, ADD_VALUES));
    1014:     }
    1015:     PetscCall(MatRestoreRow(A, row, &ncols, &cols, &vals));
    1016:   }
    1017:   PetscCall(MatRestoreRowUpperTriangular(A));
    1018:   PetscCall(MatAssemblyBegin(mat_elemental, MAT_FINAL_ASSEMBLY));
    1019:   PetscCall(MatAssemblyEnd(mat_elemental, MAT_FINAL_ASSEMBLY));

    1021:   if (reuse == MAT_INPLACE_MATRIX) {
    1022:     PetscCall(MatHeaderReplace(A, &mat_elemental));
    1023:   } else {
    1024:     *newmat = mat_elemental;
    1025:   }
    1026:   PetscFunctionReturn(PETSC_SUCCESS);
    1027: }

    1029: PETSC_INTERN PetscErrorCode MatConvert_MPISBAIJ_Elemental(Mat A, MatType, MatReuse reuse, Mat *newmat)
    1030: {
    1031:   Mat                mat_elemental;
    1032:   PetscInt           M = A->rmap->N, N = A->cmap->N, row, ncols, j, rstart = A->rmap->rstart, rend = A->rmap->rend;
    1033:   const PetscInt    *cols;
    1034:   const PetscScalar *vals;

    1036:   PetscFunctionBegin;
    1037:   if (reuse == MAT_REUSE_MATRIX) {
    1038:     mat_elemental = *newmat;
    1039:     PetscCall(MatZeroEntries(mat_elemental));
    1040:   } else {
    1041:     PetscCall(MatCreate(PetscObjectComm((PetscObject)A), &mat_elemental));
    1042:     PetscCall(MatSetSizes(mat_elemental, PETSC_DECIDE, PETSC_DECIDE, M, N));
    1043:     PetscCall(MatSetType(mat_elemental, MATELEMENTAL));
    1044:     PetscCall(MatSetUp(mat_elemental));
    1045:   }
    1046:   PetscCall(MatGetRowUpperTriangular(A));
    1047:   for (row = rstart; row < rend; row++) {
    1048:     PetscCall(MatGetRow(A, row, &ncols, &cols, &vals));
    1049:     /* PETSc-Elemental interface uses axpy for setting off-processor entries, only ADD_VALUES is allowed */
    1050:     PetscCall(MatSetValues(mat_elemental, 1, &row, ncols, cols, vals, ADD_VALUES));
    1051:     for (j = 0; j < ncols; j++) { /* lower triangular part */
    1052:       PetscScalar v;
    1053:       if (cols[j] == row) continue;
    1054:       v = A->hermitian == PETSC_BOOL3_TRUE ? PetscConj(vals[j]) : vals[j];
    1055:       PetscCall(MatSetValues(mat_elemental, 1, &cols[j], 1, &row, &v, ADD_VALUES));
    1056:     }
    1057:     PetscCall(MatRestoreRow(A, row, &ncols, &cols, &vals));
    1058:   }
    1059:   PetscCall(MatRestoreRowUpperTriangular(A));
    1060:   PetscCall(MatAssemblyBegin(mat_elemental, MAT_FINAL_ASSEMBLY));
    1061:   PetscCall(MatAssemblyEnd(mat_elemental, MAT_FINAL_ASSEMBLY));

    1063:   if (reuse == MAT_INPLACE_MATRIX) {
    1064:     PetscCall(MatHeaderReplace(A, &mat_elemental));
    1065:   } else {
    1066:     *newmat = mat_elemental;
    1067:   }
    1068:   PetscFunctionReturn(PETSC_SUCCESS);
    1069: }

    1071: static PetscErrorCode MatDestroy_Elemental(Mat A)
    1072: {
    1073:   Mat_Elemental      *a = (Mat_Elemental *)A->data;
    1074:   Mat_Elemental_Grid *commgrid;
    1075:   PetscMPIInt         iflg;
    1076:   MPI_Comm            icomm;

    1078:   PetscFunctionBegin;
    1079:   delete a->emat;
    1080:   delete a->P;
    1081:   delete a->Q;

    1083:   El::mpi::Comm cxxcomm(PetscObjectComm((PetscObject)A));
    1084:   PetscCall(PetscCommDuplicate(cxxcomm.comm, &icomm, nullptr));
    1085:   PetscCallMPI(MPI_Comm_get_attr(icomm, Petsc_Elemental_keyval, (void **)&commgrid, &iflg));
    1086:   if (--commgrid->grid_refct == 0) {
    1087:     delete commgrid->grid;
    1088:     PetscCall(PetscFree(commgrid));
    1089:     PetscCallMPI(MPI_Comm_free_keyval(&Petsc_Elemental_keyval));
    1090:   }
    1091:   PetscCall(PetscCommDestroy(&icomm));
    1092:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatGetOwnershipIS_C", nullptr));
    1093:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatFactorGetSolverType_C", nullptr));
    1094:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatProductSetFromOptions_elemental_mpidense_C", nullptr));
    1095:   PetscCall(PetscFree(A->data));
    1096:   PetscFunctionReturn(PETSC_SUCCESS);
    1097: }

    1099: static PetscErrorCode MatSetUp_Elemental(Mat A)
    1100: {
    1101:   Mat_Elemental *a = (Mat_Elemental *)A->data;
    1102:   MPI_Comm       comm;
    1103:   PetscMPIInt    rsize, csize;
    1104:   PetscInt       n;

    1106:   PetscFunctionBegin;
    1107:   PetscCall(PetscLayoutSetUp(A->rmap));
    1108:   PetscCall(PetscLayoutSetUp(A->cmap));

    1110:   /* Check if local row and column sizes are equally distributed.
    1111:      Jed: Elemental uses "element" cyclic ordering so the sizes need to match that
    1112:      exactly.  The strategy in MatElemental is for PETSc to implicitly permute to block ordering (like would be returned by
    1113:      PetscSplitOwnership(comm,&n,&N), at which point Elemental matrices can act on PETSc vectors without redistributing the vectors. */
    1114:   PetscCall(PetscObjectGetComm((PetscObject)A, &comm));
    1115:   n = PETSC_DECIDE;
    1116:   PetscCall(PetscSplitOwnership(comm, &n, &A->rmap->N));
    1117:   PetscCheck(n == A->rmap->n, PETSC_COMM_SELF, PETSC_ERR_ARG_INCOMP, "Local row size %" PetscInt_FMT " of ELEMENTAL matrix must be equally distributed", A->rmap->n);

    1119:   n = PETSC_DECIDE;
    1120:   PetscCall(PetscSplitOwnership(comm, &n, &A->cmap->N));
    1121:   PetscCheck(n == A->cmap->n, PETSC_COMM_SELF, PETSC_ERR_ARG_INCOMP, "Local column size %" PetscInt_FMT " of ELEMENTAL matrix must be equally distributed", A->cmap->n);

    1123:   a->emat->Resize(A->rmap->N, A->cmap->N);
    1124:   El::Zero(*a->emat);

    1126:   PetscCallMPI(MPI_Comm_size(A->rmap->comm, &rsize));
    1127:   PetscCallMPI(MPI_Comm_size(A->cmap->comm, &csize));
    1128:   PetscCheck(csize == rsize, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_INCOMP, "Cannot use row and column communicators of different sizes");
    1129:   a->commsize = rsize;
    1130:   a->mr[0]    = A->rmap->N % rsize;
    1131:   if (!a->mr[0]) a->mr[0] = rsize;
    1132:   a->mr[1] = A->cmap->N % csize;
    1133:   if (!a->mr[1]) a->mr[1] = csize;
    1134:   a->m[0] = A->rmap->N / rsize + (a->mr[0] != rsize);
    1135:   a->m[1] = A->cmap->N / csize + (a->mr[1] != csize);
    1136:   PetscFunctionReturn(PETSC_SUCCESS);
    1137: }

    1139: static PetscErrorCode MatAssemblyBegin_Elemental(Mat A, MatAssemblyType)
    1140: {
    1141:   Mat_Elemental *a = (Mat_Elemental *)A->data;

    1143:   PetscFunctionBegin;
    1144:   /* printf("Calling ProcessQueues\n"); */
    1145:   a->emat->ProcessQueues();
    1146:   /* printf("Finished ProcessQueues\n"); */
    1147:   PetscFunctionReturn(PETSC_SUCCESS);
    1148: }

    1150: static PetscErrorCode MatAssemblyEnd_Elemental(Mat, MatAssemblyType)
    1151: {
    1152:   PetscFunctionBegin;
    1153:   /* Currently does nothing */
    1154:   PetscFunctionReturn(PETSC_SUCCESS);
    1155: }

    1157: static PetscErrorCode MatLoad_Elemental(Mat newMat, PetscViewer viewer)
    1158: {
    1159:   Mat      Adense, Ae;
    1160:   MPI_Comm comm;

    1162:   PetscFunctionBegin;
    1163:   PetscCall(PetscObjectGetComm((PetscObject)newMat, &comm));
    1164:   PetscCall(MatCreate(comm, &Adense));
    1165:   PetscCall(MatSetType(Adense, MATDENSE));
    1166:   PetscCall(MatLoad(Adense, viewer));
    1167:   PetscCall(MatConvert(Adense, MATELEMENTAL, MAT_INITIAL_MATRIX, &Ae));
    1168:   PetscCall(MatDestroy(&Adense));
    1169:   PetscCall(MatHeaderReplace(newMat, &Ae));
    1170:   PetscFunctionReturn(PETSC_SUCCESS);
    1171: }

    1173: static struct _MatOps MatOps_Values = {MatSetValues_Elemental,
    1174:                                        nullptr,
    1175:                                        nullptr,
    1176:                                        MatMult_Elemental,
    1177:                                        /* 4*/ MatMultAdd_Elemental,
    1178:                                        MatMultTranspose_Elemental,
    1179:                                        MatMultTransposeAdd_Elemental,
    1180:                                        MatSolve_Elemental,
    1181:                                        MatSolveAdd_Elemental,
    1182:                                        nullptr,
    1183:                                        /*10*/ nullptr,
    1184:                                        MatLUFactor_Elemental,
    1185:                                        MatCholeskyFactor_Elemental,
    1186:                                        nullptr,
    1187:                                        MatTranspose_Elemental,
    1188:                                        /*15*/ MatGetInfo_Elemental,
    1189:                                        nullptr,
    1190:                                        MatGetDiagonal_Elemental,
    1191:                                        MatDiagonalScale_Elemental,
    1192:                                        MatNorm_Elemental,
    1193:                                        /*20*/ MatAssemblyBegin_Elemental,
    1194:                                        MatAssemblyEnd_Elemental,
    1195:                                        MatSetOption_Elemental,
    1196:                                        MatZeroEntries_Elemental,
    1197:                                        /*24*/ nullptr,
    1198:                                        MatLUFactorSymbolic_Elemental,
    1199:                                        MatLUFactorNumeric_Elemental,
    1200:                                        MatCholeskyFactorSymbolic_Elemental,
    1201:                                        MatCholeskyFactorNumeric_Elemental,
    1202:                                        /*29*/ MatSetUp_Elemental,
    1203:                                        nullptr,
    1204:                                        nullptr,
    1205:                                        nullptr,
    1206:                                        nullptr,
    1207:                                        /*34*/ MatDuplicate_Elemental,
    1208:                                        nullptr,
    1209:                                        nullptr,
    1210:                                        nullptr,
    1211:                                        nullptr,
    1212:                                        /*39*/ MatAXPY_Elemental,
    1213:                                        nullptr,
    1214:                                        nullptr,
    1215:                                        nullptr,
    1216:                                        MatCopy_Elemental,
    1217:                                        /*44*/ nullptr,
    1218:                                        MatScale_Elemental,
    1219:                                        MatShift_Basic,
    1220:                                        nullptr,
    1221:                                        nullptr,
    1222:                                        /*49*/ nullptr,
    1223:                                        nullptr,
    1224:                                        nullptr,
    1225:                                        nullptr,
    1226:                                        nullptr,
    1227:                                        /*54*/ nullptr,
    1228:                                        nullptr,
    1229:                                        nullptr,
    1230:                                        nullptr,
    1231:                                        nullptr,
    1232:                                        /*59*/ nullptr,
    1233:                                        MatDestroy_Elemental,
    1234:                                        MatView_Elemental,
    1235:                                        nullptr,
    1236:                                        nullptr,
    1237:                                        /*64*/ nullptr,
    1238:                                        nullptr,
    1239:                                        nullptr,
    1240:                                        nullptr,
    1241:                                        nullptr,
    1242:                                        /*69*/ nullptr,
    1243:                                        MatConvert_Elemental_Dense,
    1244:                                        nullptr,
    1245:                                        nullptr,
    1246:                                        nullptr,
    1247:                                        /*74*/ nullptr,
    1248:                                        nullptr,
    1249:                                        nullptr,
    1250:                                        nullptr,
    1251:                                        MatLoad_Elemental,
    1252:                                        /*79*/ nullptr,
    1253:                                        nullptr,
    1254:                                        nullptr,
    1255:                                        nullptr,
    1256:                                        nullptr,
    1257:                                        /*84*/ nullptr,
    1258:                                        MatMatMultNumeric_Elemental,
    1259:                                        nullptr,
    1260:                                        nullptr,
    1261:                                        MatMatTransposeMultNumeric_Elemental,
    1262:                                        /*89*/ nullptr,
    1263:                                        MatProductSetFromOptions_Elemental,
    1264:                                        nullptr,
    1265:                                        nullptr,
    1266:                                        MatConjugate_Elemental,
    1267:                                        /*94*/ nullptr,
    1268:                                        nullptr,
    1269:                                        nullptr,
    1270:                                        nullptr,
    1271:                                        nullptr,
    1272:                                        /*99*/ nullptr,
    1273:                                        MatMatSolve_Elemental,
    1274:                                        nullptr,
    1275:                                        nullptr,
    1276:                                        nullptr,
    1277:                                        /*104*/ MatMissingDiagonal_Elemental,
    1278:                                        nullptr,
    1279:                                        nullptr,
    1280:                                        nullptr,
    1281:                                        nullptr,
    1282:                                        /*109*/ nullptr,
    1283:                                        nullptr,
    1284:                                        MatHermitianTranspose_Elemental,
    1285:                                        nullptr,
    1286:                                        nullptr,
    1287:                                        /*114*/ nullptr,
    1288:                                        nullptr,
    1289:                                        nullptr,
    1290:                                        nullptr,
    1291:                                        nullptr,
    1292:                                        /*119*/ nullptr,
    1293:                                        nullptr,
    1294:                                        nullptr,
    1295:                                        nullptr,
    1296:                                        nullptr,
    1297:                                        /*124*/ nullptr,
    1298:                                        nullptr,
    1299:                                        nullptr,
    1300:                                        nullptr,
    1301:                                        nullptr,
    1302:                                        /*129*/ nullptr,
    1303:                                        nullptr,
    1304:                                        nullptr,
    1305:                                        nullptr,
    1306:                                        nullptr,
    1307:                                        /*134*/ nullptr,
    1308:                                        nullptr,
    1309:                                        nullptr,
    1310:                                        nullptr,
    1311:                                        nullptr,
    1312:                                        nullptr,
    1313:                                        /*140*/ nullptr,
    1314:                                        nullptr,
    1315:                                        nullptr,
    1316:                                        nullptr,
    1317:                                        nullptr};

    1319: /*MC
    1320:    MATELEMENTAL = "elemental" - A matrix type for dense matrices using the Elemental package

    1322:   Use ./configure --download-elemental to install PETSc to use Elemental

    1324:    Options Database Keys:
    1325: + -mat_type elemental - sets the matrix type to "elemental" during a call to MatSetFromOptions()
    1326: . -pc_factor_mat_solver_type elemental - to use this direct solver with the option -pc_type lu
    1327: - -mat_elemental_grid_height - sets Grid Height for 2D cyclic ordering of internal matrix

    1329:   Level: beginner

    1331:   Note:
    1332:    Note unlike most matrix formats, this format does not store all the matrix entries for a contiguous
    1333:    range of rows on an MPI rank. Use `MatGetOwnershipIS()` to determine what values are stored on
    1334:    the given rank.

    1336: .seealso: `MATDENSE`, `MATSCALAPACK`, `MatGetOwnershipIS()`
    1337: M*/
    1338: #if defined(__clang__)
    1339:   #pragma clang diagnostic push
    1340:   #pragma clang diagnostic ignored "-Wzero-as-null-pointer-constant"
    1341: #endif
    1342: PETSC_EXTERN PetscErrorCode MatCreate_Elemental(Mat A)
    1343: {
    1344:   Mat_Elemental      *a;
    1345:   PetscBool           flg;
    1346:   PetscMPIInt         iflg;
    1347:   Mat_Elemental_Grid *commgrid;
    1348:   MPI_Comm            icomm;
    1349:   PetscInt            optv1;

    1351:   PetscFunctionBegin;
    1352:   A->ops[0]     = MatOps_Values;
    1353:   A->insertmode = NOT_SET_VALUES;

    1355:   PetscCall(PetscNew(&a));
    1356:   A->data = (void *)a;

    1358:   /* Set up the elemental matrix */
    1359:   El::mpi::Comm cxxcomm(PetscObjectComm((PetscObject)A));

    1361:   /* Grid needs to be shared between multiple Mats on the same communicator, implement by attribute caching on the MPI_Comm */
    1362:   if (Petsc_Elemental_keyval == MPI_KEYVAL_INVALID) {
    1363:     PetscCallMPI(MPI_Comm_create_keyval(MPI_COMM_NULL_COPY_FN, MPI_COMM_NULL_DELETE_FN, &Petsc_Elemental_keyval, nullptr));
    1364:     PetscCall(PetscCitationsRegister(ElementalCitation, &ElementalCite));
    1365:   }
    1366:   PetscCall(PetscCommDuplicate(cxxcomm.comm, &icomm, NULL));
    1367:   PetscCallMPI(MPI_Comm_get_attr(icomm, Petsc_Elemental_keyval, (void **)&commgrid, &iflg));
    1368:   if (!iflg) {
    1369:     PetscCall(PetscNew(&commgrid));

    1371:     PetscOptionsBegin(PetscObjectComm((PetscObject)A), ((PetscObject)A)->prefix, "Elemental Options", "Mat");
    1372:     /* displayed default grid sizes (CommSize,1) are set by us arbitrarily until El::Grid() is called */
    1373:     PetscCall(PetscOptionsInt("-mat_elemental_grid_height", "Grid Height", "None", El::mpi::Size(cxxcomm), &optv1, &flg));
    1374:     if (flg) {
    1375:       PetscCheck((El::mpi::Size(cxxcomm) % optv1) == 0, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_INCOMP, "Grid Height %" PetscInt_FMT " must evenly divide CommSize %" PetscInt_FMT, optv1, (PetscInt)El::mpi::Size(cxxcomm));
    1376:       commgrid->grid = new El::Grid(cxxcomm, optv1); /* use user-provided grid height */
    1377:     } else {
    1378:       commgrid->grid = new El::Grid(cxxcomm); /* use Elemental default grid sizes */
    1379:       /* printf("new commgrid->grid = %p\n",commgrid->grid);  -- memory leak revealed by valgrind? */
    1380:     }
    1381:     commgrid->grid_refct = 1;
    1382:     PetscCallMPI(MPI_Comm_set_attr(icomm, Petsc_Elemental_keyval, (void *)commgrid));

    1384:     a->pivoting = 1;
    1385:     PetscCall(PetscOptionsInt("-mat_elemental_pivoting", "Pivoting", "None", a->pivoting, &a->pivoting, NULL));

    1387:     PetscOptionsEnd();
    1388:   } else {
    1389:     commgrid->grid_refct++;
    1390:   }
    1391:   PetscCall(PetscCommDestroy(&icomm));
    1392:   a->grid        = commgrid->grid;
    1393:   a->emat        = new El::DistMatrix<PetscElemScalar>(*a->grid);
    1394:   a->roworiented = PETSC_TRUE;

    1396:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatGetOwnershipIS_C", MatGetOwnershipIS_Elemental));
    1397:   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatProductSetFromOptions_elemental_mpidense_C", MatProductSetFromOptions_Elemental_MPIDense));
    1398:   PetscCall(PetscObjectChangeTypeName((PetscObject)A, MATELEMENTAL));
    1399:   PetscFunctionReturn(PETSC_SUCCESS);
    1400: }
    1401: #if defined(__clang__)
    1402:   #pragma clang diagnostic pop
    1403: #endif