Date: 2025-03-29T05:58:39+00:00

Actual source code: gcreate.c

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

      3: #include <../src/mat/impls/aij/seq/aij.h>
      4: #include <../src/mat/impls/aij/mpi/mpiaij.h>

      6: PetscErrorCode MatSetBlockSizes_Default(Mat mat, PetscInt rbs, PetscInt cbs)
      7: {
      8:   PetscFunctionBegin;
      9:   if (!mat->preallocated) PetscFunctionReturn(PETSC_SUCCESS);
     10:   PetscCheck(mat->rmap->bs <= 0 || mat->rmap->bs == rbs, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Cannot change row block size %" PetscInt_FMT " to %" PetscInt_FMT, mat->rmap->bs, rbs);
     11:   PetscCheck(mat->cmap->bs <= 0 || mat->cmap->bs == cbs, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Cannot change column block size %" PetscInt_FMT " to %" PetscInt_FMT, mat->cmap->bs, cbs);
     12:   PetscFunctionReturn(PETSC_SUCCESS);
     13: }

     15: PetscErrorCode MatShift_Basic(Mat Y, PetscScalar a)
     16: {
     17:   PetscInt    i, start, end, oldValA = 0, oldValB = 0;
     18:   PetscScalar alpha = a;
     19:   PetscBool   prevoption;
     20:   PetscBool   isSeqAIJDerived, isMPIAIJDerived; // all classes sharing SEQAIJHEADER or MPIAIJHEADER
     21:   Mat         A = NULL, B = NULL;

     23:   PetscFunctionBegin;
     24:   PetscCall(MatGetOption(Y, MAT_NO_OFF_PROC_ENTRIES, &prevoption));
     25:   PetscCall(MatSetOption(Y, MAT_NO_OFF_PROC_ENTRIES, PETSC_TRUE));
     26:   PetscCall(PetscObjectBaseTypeCompareAny((PetscObject)Y, &isSeqAIJDerived, MATSEQAIJ, MATSEQBAIJ, MATSEQSBAIJ, ""));
     27:   PetscCall(PetscObjectBaseTypeCompareAny((PetscObject)Y, &isMPIAIJDerived, MATMPIAIJ, MATMPIBAIJ, MATMPISBAIJ, ""));

     29:   if (isSeqAIJDerived) A = Y;
     30:   else if (isMPIAIJDerived) {
     31:     Mat_MPIAIJ *mpiaij = (Mat_MPIAIJ *)Y->data;
     32:     A                  = mpiaij->A;
     33:     B                  = mpiaij->B;
     34:   }

     36:   if (A) {
     37:     oldValA                        = ((Mat_SeqAIJ *)A->data)->nonew;
     38:     ((Mat_SeqAIJ *)A->data)->nonew = 0; // so that new nonzero locations are allowed
     39:   }
     40:   if (B) {
     41:     oldValB                        = ((Mat_SeqAIJ *)B->data)->nonew;
     42:     ((Mat_SeqAIJ *)B->data)->nonew = 0;
     43:   }

     45:   PetscCall(MatGetOwnershipRange(Y, &start, &end));
     46:   for (i = start; i < end; i++) {
     47:     if (i < Y->cmap->N) PetscCall(MatSetValues(Y, 1, &i, 1, &i, &alpha, ADD_VALUES));
     48:   }
     49:   PetscCall(MatAssemblyBegin(Y, MAT_FINAL_ASSEMBLY));
     50:   PetscCall(MatAssemblyEnd(Y, MAT_FINAL_ASSEMBLY));
     51:   PetscCall(MatSetOption(Y, MAT_NO_OFF_PROC_ENTRIES, prevoption));
     52:   if (A) ((Mat_SeqAIJ *)A->data)->nonew = oldValA;
     53:   if (B) ((Mat_SeqAIJ *)B->data)->nonew = oldValB;
     54:   PetscFunctionReturn(PETSC_SUCCESS);
     55: }

     57: /*@
     58:   MatCreate - Creates a matrix where the type is determined
     59:   from either a call to `MatSetType()` or from the options database
     60:   with a call to `MatSetFromOptions()`.

     62:   Collective

     64:   Input Parameter:
     65: . comm - MPI communicator

     67:   Output Parameter:
     68: . A - the matrix

     70:   Options Database Keys:
     71: + -mat_type seqaij   - `MATSEQAIJ` type, uses `MatCreateSeqAIJ()`
     72: . -mat_type mpiaij   - `MATMPIAIJ` type, uses `MatCreateAIJ()`
     73: . -mat_type seqdense - `MATSEQDENSE`, uses `MatCreateSeqDense()`
     74: . -mat_type mpidense - `MATMPIDENSE` type, uses `MatCreateDense()`
     75: . -mat_type seqbaij  - `MATSEQBAIJ` type, uses `MatCreateSeqBAIJ()`
     76: - -mat_type mpibaij  - `MATMPIBAIJ` type, uses `MatCreateBAIJ()`

     78:    See the manpages for particular formats (e.g., `MATSEQAIJ`)
     79:    for additional format-specific options.

     81:   Level: beginner

     83:   Notes:
     84:   The default matrix type is `MATAIJ`, using the routines `MatCreateSeqAIJ()` or
     85:   `MatCreateAIJ()` if you do not set a type in the options database. If you never call
     86:   `MatSetType()` or `MatSetFromOptions()` it will generate an error when you try to use the
     87:   matrix.

     89: .seealso: [](ch_matrices), `Mat`, `MatCreateSeqAIJ()`, `MatCreateAIJ()`,
     90:           `MatCreateSeqDense()`, `MatCreateDense()`,
     91:           `MatCreateSeqBAIJ()`, `MatCreateBAIJ()`,
     92:           `MatCreateSeqSBAIJ()`, `MatCreateSBAIJ()`,
     93:           `MatConvert()`
     94: @*/
     95: PetscErrorCode MatCreate(MPI_Comm comm, Mat *A)
     96: {
     97:   Mat B;

     99:   PetscFunctionBegin;
    100:   PetscAssertPointer(A, 2);
    101:   PetscCall(MatInitializePackage());

    103:   PetscCall(PetscHeaderCreate(B, MAT_CLASSID, "Mat", "Matrix", "Mat", comm, MatDestroy, MatView));
    104:   PetscCall(PetscLayoutCreate(comm, &B->rmap));
    105:   PetscCall(PetscLayoutCreate(comm, &B->cmap));
    106:   PetscCall(PetscStrallocpy(VECSTANDARD, &B->defaultvectype));
    107:   PetscCall(PetscStrallocpy(PETSCRANDER48, &B->defaultrandtype));

    109:   B->symmetric                   = PETSC_BOOL3_UNKNOWN;
    110:   B->hermitian                   = PETSC_BOOL3_UNKNOWN;
    111:   B->structurally_symmetric      = PETSC_BOOL3_UNKNOWN;
    112:   B->spd                         = PETSC_BOOL3_UNKNOWN;
    113:   B->symmetry_eternal            = PETSC_FALSE;
    114:   B->structural_symmetry_eternal = PETSC_FALSE;

    116:   B->congruentlayouts = PETSC_DECIDE;
    117:   B->preallocated     = PETSC_FALSE;
    118: #if defined(PETSC_HAVE_DEVICE)
    119:   B->boundtocpu = PETSC_TRUE;
    120: #endif
    121:   *A = B;
    122:   PetscFunctionReturn(PETSC_SUCCESS);
    123: }

    125: /*@
    126:   MatCreateFromOptions - Creates a matrix whose type is set from the options database

    128:   Collective

    130:   Input Parameters:
    131: + comm   - MPI communicator
    132: . prefix - [optional] prefix for the options database
    133: . bs     - the blocksize (commonly 1)
    134: . m      - the local number of rows (or `PETSC_DECIDE`)
    135: . n      - the local number of columns (or `PETSC_DECIDE` or `PETSC_DETERMINE`)
    136: . M      - the global number of rows (or `PETSC_DETERMINE`)
    137: - N      - the global number of columns (or `PETSC_DETERMINE`)

    139:   Output Parameter:
    140: . A - the matrix

    142:   Options Database Key:
    143: . -mat_type - see `MatType`, for example `aij`, `aijcusparse`, `baij`, `sbaij`, dense, defaults to `aij`

    145:   Level: beginner

    147: .seealso: [](ch_matrices), `Mat`, `MatCreateSeqAIJ()`, `MatCreateAIJ()`,
    148:           `MatCreateSeqDense()`, `MatCreateDense()`,
    149:           `MatCreateSeqBAIJ()`, `MatCreateBAIJ()`,
    150:           `MatCreateSeqSBAIJ()`, `MatCreateSBAIJ()`,
    151:           `MatConvert()`, `MatCreate()`
    152: @*/
    153: PetscErrorCode MatCreateFromOptions(MPI_Comm comm, const char *prefix, PetscInt bs, PetscInt m, PetscInt n, PetscInt M, PetscInt N, Mat *A)
    154: {
    155:   PetscFunctionBegin;
    156:   PetscAssertPointer(A, 8);
    157:   PetscCall(MatCreate(comm, A));
    158:   if (prefix) PetscCall(MatSetOptionsPrefix(*A, prefix));
    159:   PetscCall(MatSetBlockSize(*A, bs));
    160:   PetscCall(MatSetSizes(*A, m, n, M, N));
    161:   PetscCall(MatSetFromOptions(*A));
    162:   PetscFunctionReturn(PETSC_SUCCESS);
    163: }

    165: /*@
    166:   MatSetErrorIfFailure - Causes `Mat` to generate an immediate error, for example a zero pivot, is detected.

    168:   Logically Collective

    170:   Input Parameters:
    171: + mat - matrix obtained from `MatCreate()`
    172: - flg - `PETSC_TRUE` indicates you want the error generated

    174:   Level: advanced

    176:   Note:
    177:   If this flag is not set then the matrix operation will note the error and continue. The error may cause a later `PC` or `KSP` error
    178:   or result in a `KSPConvergedReason` indicating the method did not converge.

    180: .seealso: [](ch_matrices), `Mat`, `PCSetErrorIfFailure()`, `KSPConvergedReason`, `SNESConvergedReason`
    181: @*/
    182: PetscErrorCode MatSetErrorIfFailure(Mat mat, PetscBool flg)
    183: {
    184:   PetscFunctionBegin;
    187:   mat->erroriffailure = flg;
    188:   PetscFunctionReturn(PETSC_SUCCESS);
    189: }

    191: /*@
    192:   MatSetSizes - Sets the local and global sizes, and checks to determine compatibility

    194:   Collective

    196:   Input Parameters:
    197: + A - the matrix
    198: . m - number of local rows (or `PETSC_DECIDE`)
    199: . n - number of local columns (or `PETSC_DECIDE`)
    200: . M - number of global rows (or `PETSC_DETERMINE`)
    201: - N - number of global columns (or `PETSC_DETERMINE`)

    203:   Level: beginner

    205:   Notes:
    206:   `m` (`n`) and `M` (`N`) cannot be both `PETSC_DECIDE`
    207:   If one processor calls this with `M` (`N`) of `PETSC_DECIDE` then all processors must, otherwise the program will hang.

    209:   If `PETSC_DECIDE` is not used for the arguments 'm' and 'n', then the
    210:   user must ensure that they are chosen to be compatible with the
    211:   vectors. To do this, one first considers the matrix-vector product
    212:   'y = A x'. The `m` that is used in the above routine must match the
    213:   local size of 'y'. Likewise, the `n` used must match the local size of 'x'.

    215:   If `m` and `n` are not `PETSC_DECIDE`, then the values determine the `PetscLayout` of the matrix and the ranges returned by
    216:   `MatGetOwnershipRange()`,  `MatGetOwnershipRanges()`, `MatGetOwnershipRangeColumn()`, and `MatGetOwnershipRangesColumn()`.

    218:   You cannot change the sizes once they have been set.

    220:   The sizes must be set before `MatSetUp()` or MatXXXSetPreallocation() is called.

    222: .seealso: [](ch_matrices), `Mat`, `MatGetSize()`, `PetscSplitOwnership()`, `MatGetOwnershipRange()`, `MatGetOwnershipRanges()`,
    223:           `MatGetOwnershipRangeColumn()`, `MatGetOwnershipRangesColumn()`, `PetscLayout`, `VecSetSizes()`
    224: @*/
    225: PetscErrorCode MatSetSizes(Mat A, PetscInt m, PetscInt n, PetscInt M, PetscInt N)
    226: {
    227:   PetscFunctionBegin;
    231:   PetscCheck(M <= 0 || m <= M, PETSC_COMM_SELF, PETSC_ERR_ARG_INCOMP, "Local row size %" PetscInt_FMT " cannot be larger than global row size %" PetscInt_FMT, m, M);
    232:   PetscCheck(N <= 0 || n <= N, PETSC_COMM_SELF, PETSC_ERR_ARG_INCOMP, "Local column size %" PetscInt_FMT " cannot be larger than global column size %" PetscInt_FMT, n, N);
    233:   PetscCheck((A->rmap->n < 0 || A->rmap->N < 0) || (A->rmap->n == m && (M <= 0 || A->rmap->N == M)), PETSC_COMM_SELF, PETSC_ERR_SUP, "Cannot change/reset row sizes to %" PetscInt_FMT " local %" PetscInt_FMT " global after previously setting them to %" PetscInt_FMT " local %" PetscInt_FMT " global", m, M,
    234:              A->rmap->n, A->rmap->N);
    235:   PetscCheck((A->cmap->n < 0 || A->cmap->N < 0) || (A->cmap->n == n && (N <= 0 || A->cmap->N == N)), PETSC_COMM_SELF, PETSC_ERR_SUP, "Cannot change/reset column sizes to %" PetscInt_FMT " local %" PetscInt_FMT " global after previously setting them to %" PetscInt_FMT " local %" PetscInt_FMT " global", n, N,
    236:              A->cmap->n, A->cmap->N);
    237:   A->rmap->n = m;
    238:   A->cmap->n = n;
    239:   A->rmap->N = M > -1 ? M : A->rmap->N;
    240:   A->cmap->N = N > -1 ? N : A->cmap->N;
    241:   PetscFunctionReturn(PETSC_SUCCESS);
    242: }

    244: /*@
    245:   MatSetFromOptions - Creates a matrix where the type is determined
    246:   from the options database.

    248:   Collective

    250:   Input Parameter:
    251: . B - the matrix

    253:   Options Database Keys:
    254: + -mat_type seqaij   - `MATSEQAIJ` type, uses `MatCreateSeqAIJ()`
    255: . -mat_type mpiaij   - `MATMPIAIJ` type, uses `MatCreateAIJ()`
    256: . -mat_type seqdense - `MATSEQDENSE` type, uses `MatCreateSeqDense()`
    257: . -mat_type mpidense - `MATMPIDENSE`, uses `MatCreateDense()`
    258: . -mat_type seqbaij  - `MATSEQBAIJ`, uses `MatCreateSeqBAIJ()`
    259: - -mat_type mpibaij  - `MATMPIBAIJ`, uses `MatCreateBAIJ()`

    261:    See the manpages for particular formats (e.g., `MATSEQAIJ`)
    262:    for additional format-specific options.

    264:   Level: beginner

    266:   Notes:
    267:   Generates a parallel MPI matrix if the communicator has more than one processor.  The default
    268:   matrix type is `MATAIJ`, using the routines `MatCreateSeqAIJ()` and `MatCreateAIJ()` if you
    269:   do not select a type in the options database.

    271: .seealso: [](ch_matrices), `Mat`, `MatCreateSeqAIJ()`, `MatCreateAIJ()`,
    272:           `MatCreateSeqDense()`, `MatCreateDense()`,
    273:           `MatCreateSeqBAIJ()`, `MatCreateBAIJ()`,
    274:           `MatCreateSeqSBAIJ()`, `MatCreateSBAIJ()`,
    275:           `MatConvert()`
    276: @*/
    277: PetscErrorCode MatSetFromOptions(Mat B)
    278: {
    279:   const char *deft = MATAIJ;
    280:   char        type[256];
    281:   PetscBool   flg, set;
    282:   PetscInt    bind_below = 0, newbs = -1;

    284:   PetscFunctionBegin;

    287:   PetscObjectOptionsBegin((PetscObject)B);

    289:   PetscCall(PetscOptionsInt("-mat_block_size", "Set the blocksize used to store the matrix", "MatSetBlockSize", newbs, &newbs, &flg));
    290:   if (flg) {
    291:     PetscCall(PetscLayoutSetBlockSize(B->rmap, newbs));
    292:     PetscCall(PetscLayoutSetBlockSize(B->cmap, newbs));
    293:   }

    295:   PetscCall(PetscOptionsFList("-mat_type", "Matrix type", "MatSetType", MatList, deft, type, 256, &flg));
    296:   if (flg) {
    297:     PetscCall(MatSetType(B, type));
    298:   } else if (!((PetscObject)B)->type_name) {
    299:     PetscCall(MatSetType(B, deft));
    300:   }

    302:   PetscCall(PetscOptionsName("-mat_is_symmetric", "Checks if mat is symmetric on MatAssemblyEnd()", "MatIsSymmetric", &B->checksymmetryonassembly));
    303:   PetscCall(PetscOptionsReal("-mat_is_symmetric", "Checks if mat is symmetric on MatAssemblyEnd()", "MatIsSymmetric", B->checksymmetrytol, &B->checksymmetrytol, NULL));
    304:   PetscCall(PetscOptionsBool("-mat_null_space_test", "Checks if provided null space is correct in MatAssemblyEnd()", "MatSetNullSpaceTest", B->checknullspaceonassembly, &B->checknullspaceonassembly, NULL));
    305:   PetscCall(PetscOptionsBool("-mat_error_if_failure", "Generate an error if an error occurs when factoring the matrix", "MatSetErrorIfFailure", B->erroriffailure, &B->erroriffailure, NULL));

    307:   PetscTryTypeMethod(B, setfromoptions, PetscOptionsObject);

    309:   flg = PETSC_FALSE;
    310:   PetscCall(PetscOptionsBool("-mat_new_nonzero_location_err", "Generate an error if new nonzeros are created in the matrix nonzero structure (useful to test preallocation)", "MatSetOption", flg, &flg, &set));
    311:   if (set) PetscCall(MatSetOption(B, MAT_NEW_NONZERO_LOCATION_ERR, flg));
    312:   flg = PETSC_FALSE;
    313:   PetscCall(PetscOptionsBool("-mat_new_nonzero_allocation_err", "Generate an error if new nonzeros are allocated in the matrix nonzero structure (useful to test preallocation)", "MatSetOption", flg, &flg, &set));
    314:   if (set) PetscCall(MatSetOption(B, MAT_NEW_NONZERO_ALLOCATION_ERR, flg));
    315:   flg = PETSC_FALSE;
    316:   PetscCall(PetscOptionsBool("-mat_ignore_zero_entries", "For AIJ/IS matrices this will stop zero values from creating a zero location in the matrix", "MatSetOption", flg, &flg, &set));
    317:   if (set) PetscCall(MatSetOption(B, MAT_IGNORE_ZERO_ENTRIES, flg));

    319:   flg = PETSC_FALSE;
    320:   PetscCall(PetscOptionsBool("-mat_form_explicit_transpose", "Hint to form an explicit transpose for operations like MatMultTranspose", "MatSetOption", flg, &flg, &set));
    321:   if (set) PetscCall(MatSetOption(B, MAT_FORM_EXPLICIT_TRANSPOSE, flg));

    323:   /* Bind to CPU if below a user-specified size threshold.
    324:    * This perhaps belongs in the options for the GPU Mat types, but MatBindToCPU() does nothing when called on non-GPU types,
    325:    * and putting it here makes is more maintainable than duplicating this for all. */
    326:   PetscCall(PetscOptionsInt("-mat_bind_below", "Set the size threshold (in local rows) below which the Mat is bound to the CPU", "MatBindToCPU", bind_below, &bind_below, &flg));
    327:   if (flg && B->rmap->n < bind_below) PetscCall(MatBindToCPU(B, PETSC_TRUE));

    329:   /* process any options handlers added with PetscObjectAddOptionsHandler() */
    330:   PetscCall(PetscObjectProcessOptionsHandlers((PetscObject)B, PetscOptionsObject));
    331:   PetscOptionsEnd();
    332:   PetscFunctionReturn(PETSC_SUCCESS);
    333: }

    335: /*@
    336:   MatXAIJSetPreallocation - set preallocation for serial and parallel `MATAIJ`, `MATBAIJ`, and `MATSBAIJ` matrices and their unassembled versions.

    338:   Collective

    340:   Input Parameters:
    341: + A     - matrix being preallocated
    342: . bs    - block size
    343: . dnnz  - number of nonzero column blocks per block row of diagonal part of parallel matrix
    344: . onnz  - number of nonzero column blocks per block row of off-diagonal part of parallel matrix
    345: . dnnzu - number of nonzero column blocks per block row of upper-triangular part of diagonal part of parallel matrix
    346: - onnzu - number of nonzero column blocks per block row of upper-triangular part of off-diagonal part of parallel matrix

    348:   Level: beginner

    350: .seealso: [](ch_matrices), `Mat`, `MatSeqAIJSetPreallocation()`, `MatMPIAIJSetPreallocation()`, `MatSeqBAIJSetPreallocation()`, `MatMPIBAIJSetPreallocation()`,
    351:           `MatSeqSBAIJSetPreallocation()`, `MatMPISBAIJSetPreallocation()`,
    352:           `PetscSplitOwnership()`
    353: @*/
    354: PetscErrorCode MatXAIJSetPreallocation(Mat A, PetscInt bs, const PetscInt dnnz[], const PetscInt onnz[], const PetscInt dnnzu[], const PetscInt onnzu[])
    355: {
    356:   PetscInt  cbs;
    357:   PetscBool aij, is, hyp;

    359:   PetscFunctionBegin;
    360:   if (bs != PETSC_DECIDE) { /* don't mess with an already set block size */
    361:     PetscCall(MatSetBlockSize(A, bs));
    362:   }
    363:   PetscCall(PetscLayoutSetUp(A->rmap));
    364:   PetscCall(PetscLayoutSetUp(A->cmap));
    365:   PetscCall(MatGetBlockSizes(A, &bs, &cbs));
    366:   /* these routines assumes bs == cbs, this should be checked somehow */
    367:   PetscCall(MatSeqBAIJSetPreallocation(A, bs, 0, dnnz));
    368:   PetscCall(MatMPIBAIJSetPreallocation(A, bs, 0, dnnz, 0, onnz));
    369:   PetscCall(MatSeqSBAIJSetPreallocation(A, bs, 0, dnnzu));
    370:   PetscCall(MatMPISBAIJSetPreallocation(A, bs, 0, dnnzu, 0, onnzu));
    371:   /*
    372:     In general, we have to do extra work to preallocate for scalar (AIJ) or unassembled (IS) matrices so we check whether it will do any
    373:     good before going on with it.
    374:   */
    375:   PetscCall(PetscObjectHasFunction((PetscObject)A, "MatMPIAIJSetPreallocation_C", &aij));
    376:   PetscCall(PetscObjectHasFunction((PetscObject)A, "MatISSetPreallocation_C", &is));
    377:   PetscCall(PetscObjectHasFunction((PetscObject)A, "MatHYPRESetPreallocation_C", &hyp));
    378:   if (!aij && !is && !hyp) PetscCall(PetscObjectHasFunction((PetscObject)A, "MatSeqAIJSetPreallocation_C", &aij));
    379:   if (aij || is || hyp) {
    380:     if (bs == cbs && bs == 1) {
    381:       PetscCall(MatSeqAIJSetPreallocation(A, 0, dnnz));
    382:       PetscCall(MatMPIAIJSetPreallocation(A, 0, dnnz, 0, onnz));
    383:       PetscCall(MatISSetPreallocation(A, 0, dnnz, 0, onnz));
    384: #if defined(PETSC_HAVE_HYPRE)
    385:       PetscCall(MatHYPRESetPreallocation(A, 0, dnnz, 0, onnz));
    386: #endif
    387:     } else { /* Convert block-row precallocation to scalar-row */
    388:       PetscInt i, m, *sdnnz, *sonnz;
    389:       PetscCall(MatGetLocalSize(A, &m, NULL));
    390:       PetscCall(PetscMalloc2((!!dnnz) * m, &sdnnz, (!!onnz) * m, &sonnz));
    391:       for (i = 0; i < m; i++) {
    392:         if (dnnz) sdnnz[i] = dnnz[i / bs] * cbs;
    393:         if (onnz) sonnz[i] = onnz[i / bs] * cbs;
    394:       }
    395:       PetscCall(MatSeqAIJSetPreallocation(A, 0, dnnz ? sdnnz : NULL));
    396:       PetscCall(MatMPIAIJSetPreallocation(A, 0, dnnz ? sdnnz : NULL, 0, onnz ? sonnz : NULL));
    397:       PetscCall(MatISSetPreallocation(A, 0, dnnz ? sdnnz : NULL, 0, onnz ? sonnz : NULL));
    398: #if defined(PETSC_HAVE_HYPRE)
    399:       PetscCall(MatHYPRESetPreallocation(A, 0, dnnz ? sdnnz : NULL, 0, onnz ? sonnz : NULL));
    400: #endif
    401:       PetscCall(PetscFree2(sdnnz, sonnz));
    402:     }
    403:   }
    404:   PetscFunctionReturn(PETSC_SUCCESS);
    405: }

    407: /*@C
    408:   MatHeaderMerge - Merges some information from the header of `C` to `A`; the `C` object is then destroyed

    410:   Collective, No Fortran Support

    412:   Input Parameters:
    413: + A - a `Mat` being merged into
    414: - C - the `Mat` providing the merge information

    416:   Level: developer

    418:   Notes:
    419:   `A` and `C` must be of the same type.
    420:   The object list and query function list in `A` are retained, as well as the object name, and prefix.
    421:   The object state of `A` is increased by 1.

    423:   Developer Note:
    424:   This is somewhat different from `MatHeaderReplace()`, it would be nice to merge the code

    426: .seealso: `Mat`, `MatHeaderReplace()`
    427:  @*/
    428: PetscErrorCode MatHeaderMerge(Mat A, Mat *C)
    429: {
    430:   PetscInt          refct;
    431:   PetscOps          Abops;
    432:   struct _MatOps    Aops;
    433:   char             *mtype, *mname, *mprefix;
    434:   Mat_Product      *product;
    435:   Mat_Redundant    *redundant;
    436:   PetscObjectState  state;
    437:   PetscObjectList   olist;
    438:   PetscFunctionList qlist;

    440:   PetscFunctionBegin;
    443:   if (A == *C) PetscFunctionReturn(PETSC_SUCCESS);
    444:   PetscCheckSameTypeAndComm(A, 1, *C, 2);
    445:   /* save the parts of A we need */
    446:   Abops     = ((PetscObject)A)->bops[0];
    447:   Aops      = A->ops[0];
    448:   refct     = ((PetscObject)A)->refct;
    449:   mtype     = ((PetscObject)A)->type_name;
    450:   mname     = ((PetscObject)A)->name;
    451:   state     = ((PetscObject)A)->state;
    452:   mprefix   = ((PetscObject)A)->prefix;
    453:   product   = A->product;
    454:   redundant = A->redundant;
    455:   qlist     = ((PetscObject)A)->qlist;
    456:   olist     = ((PetscObject)A)->olist;

    458:   /* zero these so the destroy below does not free them */
    459:   ((PetscObject)A)->type_name = NULL;
    460:   ((PetscObject)A)->name      = NULL;
    461:   ((PetscObject)A)->qlist     = NULL;
    462:   ((PetscObject)A)->olist     = NULL;

    464:   /*
    465:      free all the interior data structures from mat
    466:      cannot use PetscUseTypeMethod(A,destroy); because compiler
    467:      thinks it may print NULL type_name and name
    468:   */
    469:   PetscTryTypeMethod(A, destroy);

    471:   PetscCall(PetscFree(A->defaultvectype));
    472:   PetscCall(PetscFree(A->defaultrandtype));
    473:   PetscCall(PetscLayoutDestroy(&A->rmap));
    474:   PetscCall(PetscLayoutDestroy(&A->cmap));
    475:   PetscCall(PetscComposedQuantitiesDestroy((PetscObject)A));

    477:   /* copy C over to A */
    478:   PetscCall(PetscFree(A->factorprefix));
    479:   PetscCall(PetscMemcpy(A, *C, sizeof(struct _p_Mat)));

    481:   /* return the parts of A we saved */
    482:   ((PetscObject)A)->bops[0]   = Abops;
    483:   A->ops[0]                   = Aops;
    484:   ((PetscObject)A)->refct     = refct;
    485:   ((PetscObject)A)->type_name = mtype;
    486:   ((PetscObject)A)->name      = mname;
    487:   ((PetscObject)A)->prefix    = mprefix;
    488:   ((PetscObject)A)->state     = state + 1;
    489:   A->product                  = product;
    490:   A->redundant                = redundant;

    492:   /* Append the saved lists */
    493:   PetscCall(PetscFunctionListDuplicate(qlist, &((PetscObject)A)->qlist));
    494:   PetscCall(PetscObjectListDuplicate(olist, &((PetscObject)A)->olist));
    495:   PetscCall(PetscFunctionListDestroy(&qlist));
    496:   PetscCall(PetscObjectListDestroy(&olist));

    498:   /* since these two are copied into A we do not want them destroyed in C */
    499:   ((PetscObject)*C)->qlist = NULL;
    500:   ((PetscObject)*C)->olist = NULL;
    501:   PetscCall(PetscHeaderDestroy(C));
    502:   PetscFunctionReturn(PETSC_SUCCESS);
    503: }

    505: /*@
    506:   MatHeaderReplace - Replaces the internal data of matrix `A` by the internal data of matrix `C` while deleting the outer wrapper of `C`

    508:   Input Parameters:
    509: + A - a `Mat` whose internal data is to be replaced
    510: - C - the `Mat` providing new internal data for `A`

    512:   Level: advanced

    514:   Example Usage\:
    515: .vb
    516:   Mat C;
    517:   MatCreateSeqAIJWithArrays(..., &C);
    518:   MatHeaderReplace(A, &C);
    519:   // C has been destroyed and A contains the matrix entries of C
    520: .ve

    522:   Note:
    523:   This can be used inside a function provided to `SNESSetJacobian()`, `TSSetRHSJacobian()`, or `TSSetIJacobian()` in cases where the user code
    524:   computes an entirely new sparse matrix  (generally with a different matrix nonzero structure/pattern) for each Newton update.
    525:   It is usually better to reuse the matrix nonzero structure of `A` instead of constructing an entirely new one.

    527:   Developer Note:
    528:   This is somewhat different from `MatHeaderMerge()` it would be nice to merge the code

    530: .seealso: `Mat`, `MatHeaderMerge()`
    531:  @*/
    532: PetscErrorCode MatHeaderReplace(Mat A, Mat *C)
    533: {
    534:   PetscInt         refct;
    535:   PetscObjectState state;
    536:   struct _p_Mat    buffer;
    537:   MatStencilInfo   stencil;

    539:   PetscFunctionBegin;
    542:   if (A == *C) PetscFunctionReturn(PETSC_SUCCESS);
    543:   PetscCheckSameComm(A, 1, *C, 2);
    544:   PetscCheck(((PetscObject)*C)->refct == 1, PetscObjectComm((PetscObject)C), PETSC_ERR_ARG_WRONGSTATE, "Object C has refct %" PetscInt_FMT " > 1, would leave hanging reference", ((PetscObject)*C)->refct);

    546:   /* swap C and A */
    547:   refct   = ((PetscObject)A)->refct;
    548:   state   = ((PetscObject)A)->state;
    549:   stencil = A->stencil;
    550:   PetscCall(PetscMemcpy(&buffer, A, sizeof(struct _p_Mat)));
    551:   PetscCall(PetscMemcpy(A, *C, sizeof(struct _p_Mat)));
    552:   PetscCall(PetscMemcpy(*C, &buffer, sizeof(struct _p_Mat)));
    553:   ((PetscObject)A)->refct = refct;
    554:   ((PetscObject)A)->state = state + 1;
    555:   A->stencil              = stencil;

    557:   ((PetscObject)*C)->refct = 1;
    558:   PetscCall(MatDestroy(C));
    559:   PetscFunctionReturn(PETSC_SUCCESS);
    560: }

    562: /*@
    563:   MatBindToCPU - marks a matrix to temporarily stay on the CPU and perform computations on the CPU

    565:   Logically Collective

    567:   Input Parameters:
    568: + A   - the matrix
    569: - flg - bind to the CPU if value of `PETSC_TRUE`

    571:   Level: intermediate

    573: .seealso: [](ch_matrices), `Mat`, `MatBoundToCPU()`
    574: @*/
    575: PetscErrorCode MatBindToCPU(Mat A, PetscBool flg)
    576: {
    577:   PetscFunctionBegin;
    580: #if defined(PETSC_HAVE_DEVICE)
    581:   if (A->boundtocpu == flg) PetscFunctionReturn(PETSC_SUCCESS);
    582:   A->boundtocpu = flg;
    583:   PetscTryTypeMethod(A, bindtocpu, flg);
    584: #endif
    585:   PetscFunctionReturn(PETSC_SUCCESS);
    586: }

    588: /*@
    589:   MatBoundToCPU - query if a matrix is bound to the CPU

    591:   Input Parameter:
    592: . A - the matrix

    594:   Output Parameter:
    595: . flg - the logical flag

    597:   Level: intermediate

    599: .seealso: [](ch_matrices), `Mat`, `MatBindToCPU()`
    600: @*/
    601: PetscErrorCode MatBoundToCPU(Mat A, PetscBool *flg)
    602: {
    603:   PetscFunctionBegin;
    605:   PetscAssertPointer(flg, 2);
    606: #if defined(PETSC_HAVE_DEVICE)
    607:   *flg = A->boundtocpu;
    608: #else
    609:   *flg = PETSC_TRUE;
    610: #endif
    611:   PetscFunctionReturn(PETSC_SUCCESS);
    612: }

    614: PetscErrorCode MatSetValuesCOO_Basic(Mat A, const PetscScalar coo_v[], InsertMode imode)
    615: {
    616:   IS              is_coo_i, is_coo_j;
    617:   const PetscInt *coo_i, *coo_j;
    618:   PetscInt        n, n_i, n_j;
    619:   PetscScalar     zero = 0.;

    621:   PetscFunctionBegin;
    622:   PetscCall(PetscObjectQuery((PetscObject)A, "__PETSc_coo_i", (PetscObject *)&is_coo_i));
    623:   PetscCall(PetscObjectQuery((PetscObject)A, "__PETSc_coo_j", (PetscObject *)&is_coo_j));
    624:   PetscCheck(is_coo_i, PetscObjectComm((PetscObject)A), PETSC_ERR_COR, "Missing coo_i IS");
    625:   PetscCheck(is_coo_j, PetscObjectComm((PetscObject)A), PETSC_ERR_COR, "Missing coo_j IS");
    626:   PetscCall(ISGetLocalSize(is_coo_i, &n_i));
    627:   PetscCall(ISGetLocalSize(is_coo_j, &n_j));
    628:   PetscCheck(n_i == n_j, PETSC_COMM_SELF, PETSC_ERR_COR, "Wrong local size %" PetscInt_FMT " != %" PetscInt_FMT, n_i, n_j);
    629:   PetscCall(ISGetIndices(is_coo_i, &coo_i));
    630:   PetscCall(ISGetIndices(is_coo_j, &coo_j));
    631:   if (imode != ADD_VALUES) PetscCall(MatZeroEntries(A));
    632:   for (n = 0; n < n_i; n++) PetscCall(MatSetValue(A, coo_i[n], coo_j[n], coo_v ? coo_v[n] : zero, ADD_VALUES));
    633:   PetscCall(ISRestoreIndices(is_coo_i, &coo_i));
    634:   PetscCall(ISRestoreIndices(is_coo_j, &coo_j));
    635:   PetscFunctionReturn(PETSC_SUCCESS);
    636: }

    638: PetscErrorCode MatSetPreallocationCOO_Basic(Mat A, PetscCount ncoo, PetscInt coo_i[], PetscInt coo_j[])
    639: {
    640:   Mat         preallocator;
    641:   IS          is_coo_i, is_coo_j;
    642:   PetscInt    ncoo_i;
    643:   PetscScalar zero = 0.0;

    645:   PetscFunctionBegin;
    646:   PetscCall(PetscIntCast(ncoo, &ncoo_i));
    647:   PetscCall(PetscLayoutSetUp(A->rmap));
    648:   PetscCall(PetscLayoutSetUp(A->cmap));
    649:   PetscCall(MatCreate(PetscObjectComm((PetscObject)A), &preallocator));
    650:   PetscCall(MatSetType(preallocator, MATPREALLOCATOR));
    651:   PetscCall(MatSetSizes(preallocator, A->rmap->n, A->cmap->n, A->rmap->N, A->cmap->N));
    652:   PetscCall(MatSetLayouts(preallocator, A->rmap, A->cmap));
    653:   PetscCall(MatSetUp(preallocator));
    654:   for (PetscCount n = 0; n < ncoo; n++) PetscCall(MatSetValue(preallocator, coo_i[n], coo_j[n], zero, INSERT_VALUES));
    655:   PetscCall(MatAssemblyBegin(preallocator, MAT_FINAL_ASSEMBLY));
    656:   PetscCall(MatAssemblyEnd(preallocator, MAT_FINAL_ASSEMBLY));
    657:   PetscCall(MatPreallocatorPreallocate(preallocator, PETSC_TRUE, A));
    658:   PetscCall(MatDestroy(&preallocator));
    659:   PetscCall(ISCreateGeneral(PETSC_COMM_SELF, ncoo_i, coo_i, PETSC_COPY_VALUES, &is_coo_i));
    660:   PetscCall(ISCreateGeneral(PETSC_COMM_SELF, ncoo_i, coo_j, PETSC_COPY_VALUES, &is_coo_j));
    661:   PetscCall(PetscObjectCompose((PetscObject)A, "__PETSc_coo_i", (PetscObject)is_coo_i));
    662:   PetscCall(PetscObjectCompose((PetscObject)A, "__PETSc_coo_j", (PetscObject)is_coo_j));
    663:   PetscCall(ISDestroy(&is_coo_i));
    664:   PetscCall(ISDestroy(&is_coo_j));
    665:   PetscFunctionReturn(PETSC_SUCCESS);
    666: }

    668: /*@C
    669:   MatSetPreallocationCOO - set preallocation for matrices using a coordinate format of the entries with global indices

    671:   Collective

    673:   Input Parameters:
    674: + A     - matrix being preallocated
    675: . ncoo  - number of entries
    676: . coo_i - row indices
    677: - coo_j - column indices

    679:   Level: beginner

    681:   Notes:
    682:   The indices within `coo_i` and `coo_j` may be modified within this function. The caller should not rely on them
    683:   having any specific value after this function returns. The arrays can be freed or reused immediately
    684:   after this function returns.

    686:   Entries can be repeated, see `MatSetValuesCOO()`. Entries with negative row or column indices are allowed
    687:   but will be ignored. The corresponding entries in `MatSetValuesCOO()` will be ignored too. Remote entries
    688:   are allowed and will be properly added or inserted to the matrix, unless the matrix option `MAT_IGNORE_OFF_PROC_ENTRIES`
    689:   is set, in which case remote entries are ignored, or `MAT_NO_OFF_PROC_ENTRIES` is set, in which case an error will be generated.

    691:   If you just want to create a sequential AIJ matrix (`MATSEQAIJ`), and your matrix entries in COO format are unique, you can also use
    692:   `MatCreateSeqAIJFromTriple()`. But that is not recommended for iterative applications.

    694: .seealso: [](ch_matrices), `Mat`, `MatSetValuesCOO()`, `MatSeqAIJSetPreallocation()`, `MatMPIAIJSetPreallocation()`, `MatSeqBAIJSetPreallocation()`,
    695:           `MatMPIBAIJSetPreallocation()`, `MatSeqSBAIJSetPreallocation()`, `MatMPISBAIJSetPreallocation()`, `MatSetPreallocationCOOLocal()`,
    696:           `DMSetMatrixPreallocateSkip()`, `MatCreateSeqAIJFromTriple()`
    697: @*/
    698: PetscErrorCode MatSetPreallocationCOO(Mat A, PetscCount ncoo, PetscInt coo_i[], PetscInt coo_j[])
    699: {
    700:   PetscErrorCode (*f)(Mat, PetscCount, PetscInt[], PetscInt[]) = NULL;

    702:   PetscFunctionBegin;
    705:   if (ncoo) PetscAssertPointer(coo_i, 3);
    706:   if (ncoo) PetscAssertPointer(coo_j, 4);
    707:   PetscCall(PetscLayoutSetUp(A->rmap));
    708:   PetscCall(PetscLayoutSetUp(A->cmap));
    709:   PetscCall(PetscObjectQueryFunction((PetscObject)A, "MatSetPreallocationCOO_C", &f));

    711:   PetscCall(PetscLogEventBegin(MAT_PreallCOO, A, 0, 0, 0));
    712:   if (f) {
    713:     PetscCall((*f)(A, ncoo, coo_i, coo_j));
    714:   } else { /* allow fallback, very slow */
    715:     PetscCall(MatSetPreallocationCOO_Basic(A, ncoo, coo_i, coo_j));
    716:   }
    717:   PetscCall(PetscLogEventEnd(MAT_PreallCOO, A, 0, 0, 0));
    718:   A->preallocated = PETSC_TRUE;
    719:   A->nonzerostate++;
    720:   PetscFunctionReturn(PETSC_SUCCESS);
    721: }

    723: /*@C
    724:   MatSetPreallocationCOOLocal - set preallocation for matrices using a coordinate format of the entries with local indices

    726:   Collective

    728:   Input Parameters:
    729: + A     - matrix being preallocated
    730: . ncoo  - number of entries
    731: . coo_i - row indices (local numbering; may be modified)
    732: - coo_j - column indices (local numbering; may be modified)

    734:   Level: beginner

    736:   Notes:
    737:   The local indices are translated using the local to global mapping, thus `MatSetLocalToGlobalMapping()` must have been
    738:   called prior to this function. For matrices created with `DMCreateMatrix()` the local to global mapping is often already provided.

    740:   The indices `coo_i` and `coo_j` may be modified within this function. They might be translated to corresponding global
    741:   indices, but the caller should not rely on them having any specific value after this function returns. The arrays
    742:   can be freed or reused immediately after this function returns.

    744:   Entries can be repeated, see `MatSetValuesCOO()`. Entries with negative row or column indices are allowed
    745:   but will be ignored. The corresponding entries in `MatSetValuesCOO()` will be ignored too. Remote entries
    746:   are allowed and will be properly added or inserted to the matrix.

    748: .seealso: [](ch_matrices), `Mat`, `MatSetValuesCOO()`, `MatSeqAIJSetPreallocation()`, `MatMPIAIJSetPreallocation()`, `MatSeqBAIJSetPreallocation()`,
    749:           `MatMPIBAIJSetPreallocation()`, `MatSeqSBAIJSetPreallocation()`, `MatMPISBAIJSetPreallocation()`, `MatSetPreallocationCOO()`,
    750:           `DMSetMatrixPreallocateSkip()`
    751: @*/
    752: PetscErrorCode MatSetPreallocationCOOLocal(Mat A, PetscCount ncoo, PetscInt coo_i[], PetscInt coo_j[])
    753: {
    754:   PetscErrorCode (*f)(Mat, PetscCount, PetscInt[], PetscInt[]) = NULL;

    756:   PetscFunctionBegin;
    759:   if (ncoo) PetscAssertPointer(coo_i, 3);
    760:   if (ncoo) PetscAssertPointer(coo_j, 4);
    761:   PetscCall(PetscLayoutSetUp(A->rmap));
    762:   PetscCall(PetscLayoutSetUp(A->cmap));

    764:   PetscCall(PetscObjectQueryFunction((PetscObject)A, "MatSetPreallocationCOOLocal_C", &f));
    765:   if (f) {
    766:     PetscCall((*f)(A, ncoo, coo_i, coo_j));
    767:     A->nonzerostate++;
    768:   } else {
    769:     PetscInt               ncoo_i;
    770:     ISLocalToGlobalMapping ltog_row, ltog_col;

    772:     PetscCall(MatGetLocalToGlobalMapping(A, &ltog_row, &ltog_col));
    773:     if (ltog_row) {
    774:       PetscCall(PetscIntCast(ncoo, &ncoo_i));
    775:       PetscCall(ISLocalToGlobalMappingApply(ltog_row, ncoo_i, coo_i, coo_i));
    776:     }
    777:     if (ltog_col) {
    778:       PetscCall(PetscIntCast(ncoo, &ncoo_i));
    779:       PetscCall(ISLocalToGlobalMappingApply(ltog_col, ncoo_i, coo_j, coo_j));
    780:     }
    781:     PetscCall(MatSetPreallocationCOO(A, ncoo, coo_i, coo_j));
    782:   }
    783:   A->preallocated = PETSC_TRUE;
    784:   PetscFunctionReturn(PETSC_SUCCESS);
    785: }

    787: /*@
    788:   MatSetValuesCOO - set values at once in a matrix preallocated using `MatSetPreallocationCOO()`

    790:   Collective

    792:   Input Parameters:
    793: + A     - matrix being preallocated
    794: . coo_v - the matrix values (can be `NULL`)
    795: - imode - the insert mode

    797:   Level: beginner

    799:   Notes:
    800:   The values must follow the order of the indices prescribed with `MatSetPreallocationCOO()` or `MatSetPreallocationCOOLocal()`.

    802:   When repeated entries are specified in the COO indices the `coo_v` values are first properly summed, regardless of the value of imode.
    803:   The imode flag indicates if coo_v must be added to the current values of the matrix (`ADD_VALUES`) or overwritten (`INSERT_VALUES`).

    805:   `MatAssemblyBegin()` and `MatAssemblyEnd()` do not need to be called after this routine. It automatically handles the assembly process.

    807: .seealso: [](ch_matrices), `Mat`, `MatSetPreallocationCOO()`, `MatSetPreallocationCOOLocal()`, `InsertMode`, `INSERT_VALUES`, `ADD_VALUES`
    808: @*/
    809: PetscErrorCode MatSetValuesCOO(Mat A, const PetscScalar coo_v[], InsertMode imode)
    810: {
    811:   PetscErrorCode (*f)(Mat, const PetscScalar[], InsertMode) = NULL;
    812:   PetscBool oldFlg;

    814:   PetscFunctionBegin;
    817:   MatCheckPreallocated(A, 1);
    819:   PetscCall(PetscObjectQueryFunction((PetscObject)A, "MatSetValuesCOO_C", &f));
    820:   PetscCall(PetscLogEventBegin(MAT_SetVCOO, A, 0, 0, 0));
    821:   if (f) {
    822:     PetscCall((*f)(A, coo_v, imode)); // all known COO implementations do not use MatStash. They do their own off-proc communication
    823:     PetscCall(MatGetOption(A, MAT_NO_OFF_PROC_ENTRIES, &oldFlg));
    824:     PetscCall(MatSetOption(A, MAT_NO_OFF_PROC_ENTRIES, PETSC_TRUE)); // set A->nooffprocentries to avoid costly MatStash scatter in MatAssembly
    825:   } else {
    826:     PetscCall(MatSetValuesCOO_Basic(A, coo_v, imode)); // fall back to MatSetValues, which might use MatStash
    827:   }
    828:   PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
    829:   PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
    830:   if (f) PetscCall(MatSetOption(A, MAT_NO_OFF_PROC_ENTRIES, oldFlg));
    831:   PetscCall(PetscLogEventEnd(MAT_SetVCOO, A, 0, 0, 0));
    832:   PetscFunctionReturn(PETSC_SUCCESS);
    833: }

    835: /*@
    836:   MatSetBindingPropagates - Sets whether the state of being bound to the CPU for a GPU matrix type propagates to child and some other associated objects

    838:   Input Parameters:
    839: + A   - the matrix
    840: - flg - flag indicating whether the boundtocpu flag should be propagated

    842:   Level: developer

    844:   Notes:
    845:   If the value of flg is set to true, the following will occur
    846: +   `MatCreateSubMatrices()` and `MatCreateRedundantMatrix()` - bind created matrices to CPU if the input matrix is bound to the CPU.
    847: -   `MatCreateVecs()` - bind created vectors to CPU if the input matrix is bound to the CPU.

    849:   The bindingpropagates flag itself is also propagated by the above routines.

    851:   Developer Notes:
    852:   If the fine-scale `DMDA` has the `-dm_bind_below` option set to true, then `DMCreateInterpolationScale()` calls `MatSetBindingPropagates()`
    853:   on the restriction/interpolation operator to set the bindingpropagates flag to true.

    855: .seealso: [](ch_matrices), `Mat`, `VecSetBindingPropagates()`, `MatGetBindingPropagates()`
    856: @*/
    857: PetscErrorCode MatSetBindingPropagates(Mat A, PetscBool flg)
    858: {
    859:   PetscFunctionBegin;
    861: #if defined(PETSC_HAVE_VIENNACL) || defined(PETSC_HAVE_CUDA) || defined(PETSC_HAVE_HIP)
    862:   A->bindingpropagates = flg;
    863: #endif
    864:   PetscFunctionReturn(PETSC_SUCCESS);
    865: }

    867: /*@
    868:   MatGetBindingPropagates - Gets whether the state of being bound to the CPU for a GPU matrix type propagates to child and some other associated objects

    870:   Input Parameter:
    871: . A - the matrix

    873:   Output Parameter:
    874: . flg - flag indicating whether the boundtocpu flag will be propagated

    876:   Level: developer

    878: .seealso: [](ch_matrices), `Mat`, `MatSetBindingPropagates()`
    879: @*/
    880: PetscErrorCode MatGetBindingPropagates(Mat A, PetscBool *flg)
    881: {
    882:   PetscFunctionBegin;
    884:   PetscAssertPointer(flg, 2);
    885: #if defined(PETSC_HAVE_VIENNACL) || defined(PETSC_HAVE_CUDA) || defined(PETSC_HAVE_HIP)
    886:   *flg = A->bindingpropagates;
    887: #else
    888:   *flg = PETSC_FALSE;
    889: #endif
    890:   PetscFunctionReturn(PETSC_SUCCESS);
    891: }