Date: 2022-08-02T03:13:47+00:00

Actual source code: aijsell.c

      1: /*
      2:   Defines basic operations for the MATSEQAIJSELL matrix class.
      3:   This class is derived from the MATAIJCLASS, but maintains a "shadow" copy
      4:   of the matrix stored in MATSEQSELL format, which is used as appropriate for
      5:   performing operations for which this format is more suitable.
      6: */

      8: #include <../src/mat/impls/aij/seq/aij.h>
      9: #include <../src/mat/impls/sell/seq/sell.h>

     11: typedef struct {
     12:   Mat              S; /* The SELL formatted "shadow" matrix. */
     13:   PetscBool        eager_shadow;
     14:   PetscObjectState state; /* State of the matrix when shadow matrix was last constructed. */
     15: } Mat_SeqAIJSELL;

     17: PETSC_INTERN PetscErrorCode MatConvert_SeqAIJSELL_SeqAIJ(Mat A,MatType type,MatReuse reuse,Mat *newmat)
     18: {
     19:   /* This routine is only called to convert a MATAIJSELL to its base PETSc type, */
     20:   /* so we will ignore 'MatType type'. */
     21:   Mat            B        = *newmat;
     22:   Mat_SeqAIJSELL *aijsell = (Mat_SeqAIJSELL*) A->spptr;

     24:   if (reuse == MAT_INITIAL_MATRIX) {
     25:     MatDuplicate(A,MAT_COPY_VALUES,&B);
     26:   }

     28:   /* Reset the original function pointers. */
     29:   B->ops->duplicate        = MatDuplicate_SeqAIJ;
     30:   B->ops->assemblyend      = MatAssemblyEnd_SeqAIJ;
     31:   B->ops->destroy          = MatDestroy_SeqAIJ;
     32:   B->ops->mult             = MatMult_SeqAIJ;
     33:   B->ops->multtranspose    = MatMultTranspose_SeqAIJ;
     34:   B->ops->multadd          = MatMultAdd_SeqAIJ;
     35:   B->ops->multtransposeadd = MatMultTransposeAdd_SeqAIJ;
     36:   B->ops->sor              = MatSOR_SeqAIJ;

     38:   PetscObjectComposeFunction((PetscObject)B,"MatConvert_seqaijsell_seqaij_C",NULL);

     40:   if (reuse == MAT_INITIAL_MATRIX) aijsell = (Mat_SeqAIJSELL*)B->spptr;

     42:   /* Clean up the Mat_SeqAIJSELL data structure.
     43:    * Note that MatDestroy() simply returns if passed a NULL value, so it's OK to call even if the shadow matrix was never constructed. */
     44:   MatDestroy(&aijsell->S);
     45:   PetscFree(B->spptr);

     47:   /* Change the type of B to MATSEQAIJ. */
     48:   PetscObjectChangeTypeName((PetscObject)B, MATSEQAIJ);

     50:   *newmat = B;
     51:   return 0;
     52: }

     54: PetscErrorCode MatDestroy_SeqAIJSELL(Mat A)
     55: {
     56:   Mat_SeqAIJSELL  *aijsell = (Mat_SeqAIJSELL*) A->spptr;

     59:   /* If MatHeaderMerge() was used, then this SeqAIJSELL matrix will not have an
     60:    * spptr pointer. */
     61:   if (aijsell) {
     62:     /* Clean up everything in the Mat_SeqAIJSELL data structure, then free A->spptr. */
     63:     MatDestroy(&aijsell->S);
     64:     PetscFree(A->spptr);
     65:   }

     67:   /* Change the type of A back to SEQAIJ and use MatDestroy_SeqAIJ()
     68:    * to destroy everything that remains. */
     69:   PetscObjectChangeTypeName((PetscObject)A, MATSEQAIJ);
     70:   /* Note that I don't call MatSetType().  I believe this is because that
     71:    * is only to be called when *building* a matrix.  I could be wrong, but
     72:    * that is how things work for the SuperLU matrix class. */
     73:   MatDestroy_SeqAIJ(A);
     74:   return 0;
     75: }

     77: /* Build or update the shadow matrix if and only if needed.
     78:  * We track the ObjectState to determine when this needs to be done. */
     79: PETSC_INTERN PetscErrorCode MatSeqAIJSELL_build_shadow(Mat A)
     80: {
     81:   Mat_SeqAIJSELL   *aijsell = (Mat_SeqAIJSELL*) A->spptr;
     82:   PetscObjectState state;

     84:   PetscObjectStateGet((PetscObject)A,&state);
     85:   if (aijsell->S && aijsell->state == state) {
     86:     /* The existing shadow matrix is up-to-date, so simply exit. */
     87:     return 0;
     88:   }

     90:   PetscLogEventBegin(MAT_Convert,A,0,0,0);
     91:   if (aijsell->S) {
     92:     MatConvert_SeqAIJ_SeqSELL(A,MATSEQSELL,MAT_REUSE_MATRIX,&aijsell->S);
     93:   } else {
     94:     MatConvert_SeqAIJ_SeqSELL(A,MATSEQSELL,MAT_INITIAL_MATRIX,&aijsell->S);
     95:   }
     96:   PetscLogEventEnd(MAT_Convert,A,0,0,0);

     98:   /* Record the ObjectState so that we can tell when the shadow matrix needs updating */
     99:   PetscObjectStateGet((PetscObject)A,&aijsell->state);

    101:   return 0;
    102: }

    104: PetscErrorCode MatDuplicate_SeqAIJSELL(Mat A, MatDuplicateOption op, Mat *M)
    105: {
    106:   Mat_SeqAIJSELL *aijsell;
    107:   Mat_SeqAIJSELL *aijsell_dest;

    109:   MatDuplicate_SeqAIJ(A,op,M);
    110:   aijsell      = (Mat_SeqAIJSELL*) A->spptr;
    111:   aijsell_dest = (Mat_SeqAIJSELL*) (*M)->spptr;
    112:   PetscArraycpy(aijsell_dest,aijsell,1);
    113:   /* We don't duplicate the shadow matrix -- that will be constructed as needed. */
    114:   aijsell_dest->S = NULL;
    115:   if (aijsell->eager_shadow) {
    116:     MatSeqAIJSELL_build_shadow(A);
    117:   }
    118:   return 0;
    119: }

    121: PetscErrorCode MatAssemblyEnd_SeqAIJSELL(Mat A, MatAssemblyType mode)
    122: {
    123:   Mat_SeqAIJ      *a = (Mat_SeqAIJ*)A->data;
    124:   Mat_SeqAIJSELL  *aijsell = (Mat_SeqAIJSELL*)A->spptr;

    126:   if (mode == MAT_FLUSH_ASSEMBLY) return 0;

    128:   /* I disable the use of the inode routines so that the AIJSELL ones will be
    129:    * used instead, but I wonder if it might make sense (and is feasible) to
    130:    * use some of them. */
    131:   a->inode.use = PETSC_FALSE;

    133:   /* Since a MATSEQAIJSELL matrix is really just a MATSEQAIJ with some
    134:    * extra information and some different methods, call the AssemblyEnd
    135:    * routine for a MATSEQAIJ.
    136:    * I'm not sure if this is the best way to do this, but it avoids
    137:    * a lot of code duplication. */

    139:   MatAssemblyEnd_SeqAIJ(A, mode);

    141:   /* If the user has requested "eager" shadowing, create the SELL shadow matrix (if needed; the function checks).
    142:    * (The default is to take a "lazy" approach, deferring this until something like MatMult() is called.) */
    143:   if (aijsell->eager_shadow) {
    144:     MatSeqAIJSELL_build_shadow(A);
    145:   }

    147:   return 0;
    148: }

    150: PetscErrorCode MatMult_SeqAIJSELL(Mat A,Vec xx,Vec yy)
    151: {
    152:   Mat_SeqAIJSELL    *aijsell = (Mat_SeqAIJSELL*)A->spptr;

    154:   MatSeqAIJSELL_build_shadow(A);
    155:   MatMult_SeqSELL(aijsell->S,xx,yy);
    156:   return 0;
    157: }

    159: PetscErrorCode MatMultTranspose_SeqAIJSELL(Mat A,Vec xx,Vec yy)
    160: {
    161:   Mat_SeqAIJSELL    *aijsell=(Mat_SeqAIJSELL*)A->spptr;

    163:   MatSeqAIJSELL_build_shadow(A);
    164:   MatMultTranspose_SeqSELL(aijsell->S,xx,yy);
    165:   return 0;
    166: }

    168: PetscErrorCode MatMultAdd_SeqAIJSELL(Mat A,Vec xx,Vec yy,Vec zz)
    169: {
    170:   Mat_SeqAIJSELL    *aijsell=(Mat_SeqAIJSELL*)A->spptr;

    172:   MatSeqAIJSELL_build_shadow(A);
    173:   MatMultAdd_SeqSELL(aijsell->S,xx,yy,zz);
    174:   return 0;
    175: }

    177: PetscErrorCode MatMultTransposeAdd_SeqAIJSELL(Mat A,Vec xx,Vec yy,Vec zz)
    178: {
    179:   Mat_SeqAIJSELL    *aijsell=(Mat_SeqAIJSELL*)A->spptr;

    181:   MatSeqAIJSELL_build_shadow(A);
    182:   MatMultTransposeAdd_SeqSELL(aijsell->S,xx,yy,zz);
    183:   return 0;
    184: }

    186: PetscErrorCode MatSOR_SeqAIJSELL(Mat A,Vec bb,PetscReal omega,MatSORType flag,PetscReal fshift,PetscInt its,PetscInt lits,Vec xx)
    187: {
    188:   Mat_SeqAIJSELL    *aijsell=(Mat_SeqAIJSELL*)A->spptr;

    190:   MatSeqAIJSELL_build_shadow(A);
    191:   MatSOR_SeqSELL(aijsell->S,bb,omega,flag,fshift,its,lits,xx);
    192:   return 0;
    193: }

    195: /* MatConvert_SeqAIJ_SeqAIJSELL converts a SeqAIJ matrix into a
    196:  * SeqAIJSELL matrix.  This routine is called by the MatCreate_SeqAIJSELL()
    197:  * routine, but can also be used to convert an assembled SeqAIJ matrix
    198:  * into a SeqAIJSELL one. */
    199: PETSC_INTERN PetscErrorCode MatConvert_SeqAIJ_SeqAIJSELL(Mat A,MatType type,MatReuse reuse,Mat *newmat)
    200: {
    202:   Mat            B = *newmat;
    203:   Mat_SeqAIJ     *b;
    204:   Mat_SeqAIJSELL *aijsell;
    205:   PetscBool      set;
    206:   PetscBool      sametype;

    208:   if (reuse == MAT_INITIAL_MATRIX) {
    209:     MatDuplicate(A,MAT_COPY_VALUES,&B);
    210:   }

    212:   PetscObjectTypeCompare((PetscObject)A,type,&sametype);
    213:   if (sametype) return 0;

    215:   PetscNewLog(B,&aijsell);
    216:   b        = (Mat_SeqAIJ*) B->data;
    217:   B->spptr = (void*) aijsell;

    219:   /* Disable use of the inode routines so that the AIJSELL ones will be used instead.
    220:    * This happens in MatAssemblyEnd_SeqAIJSELL as well, but the assembly end may not be called, so set it here, too.
    221:    * As noted elsewhere, I wonder if it might make sense and be feasible to use some of the inode routines. */
    222:   b->inode.use = PETSC_FALSE;

    224:   /* Set function pointers for methods that we inherit from AIJ but override.
    225:    * We also parse some command line options below, since those determine some of the methods we point to. */
    226:   B->ops->duplicate        = MatDuplicate_SeqAIJSELL;
    227:   B->ops->assemblyend      = MatAssemblyEnd_SeqAIJSELL;
    228:   B->ops->destroy          = MatDestroy_SeqAIJSELL;

    230:   aijsell->S = NULL;
    231:   aijsell->eager_shadow = PETSC_FALSE;

    233:   /* Parse command line options. */
    234:   PetscOptionsBegin(PetscObjectComm((PetscObject)A),((PetscObject)A)->prefix,"AIJSELL Options","Mat");
    235:   PetscOptionsBool("-mat_aijsell_eager_shadow","Eager Shadowing","None",(PetscBool)aijsell->eager_shadow,(PetscBool*)&aijsell->eager_shadow,&set);
    236:   PetscOptionsEnd();

    238:   /* If A has already been assembled and eager shadowing is specified, build the shadow matrix. */
    239:   if (A->assembled && aijsell->eager_shadow) {
    240:     MatSeqAIJSELL_build_shadow(A);
    241:   }

    243:   B->ops->mult             = MatMult_SeqAIJSELL;
    244:   B->ops->multtranspose    = MatMultTranspose_SeqAIJSELL;
    245:   B->ops->multadd          = MatMultAdd_SeqAIJSELL;
    246:   B->ops->multtransposeadd = MatMultTransposeAdd_SeqAIJSELL;
    247:   B->ops->sor              = MatSOR_SeqAIJSELL;

    249:   PetscObjectComposeFunction((PetscObject)B,"MatConvert_seqaijsell_seqaij_C",MatConvert_SeqAIJSELL_SeqAIJ);

    251:   PetscObjectChangeTypeName((PetscObject)B,MATSEQAIJSELL);
    252:   *newmat = B;
    253:   return 0;
    254: }

    256: /*@C
    257:    MatCreateSeqAIJSELL - Creates a sparse matrix of type SEQAIJSELL.
    258:    This type inherits from AIJ and is largely identical, but keeps a "shadow"
    259:    copy of the matrix in SEQSELL format, which is used when this format
    260:    may be more suitable for a requested operation. Currently, SEQSELL format
    261:    is used for MatMult, MatMultTranspose, MatMultAdd, MatMultTransposeAdd,
    262:    and MatSOR operations.
    263:    Because SEQAIJSELL is a subtype of SEQAIJ, the option "-mat_seqaij_type seqaijsell" can be used to make
    264:    sequential AIJ matrices default to being instances of MATSEQAIJSELL.

    266:    Collective

    268:    Input Parameters:
    269: +  comm - MPI communicator, set to PETSC_COMM_SELF
    270: .  m - number of rows
    271: .  n - number of columns
    272: .  nz - number of nonzeros per row (same for all rows)
    273: -  nnz - array containing the number of nonzeros in the various rows
    274:          (possibly different for each row) or NULL

    276:    Output Parameter:
    277: .  A - the matrix

    279:    Options Database Keys:
    280: .  -mat_aijsell_eager_shadow - Construct shadow matrix upon matrix assembly; default is to take a "lazy" approach, performing this step the first time the matrix is applied

    282:    Notes:
    283:    If nnz is given then nz is ignored

    285:    Level: intermediate

    287: .seealso: MatCreate(), MatCreateMPIAIJSELL(), MatSetValues()
    288: @*/
    289: PetscErrorCode  MatCreateSeqAIJSELL(MPI_Comm comm,PetscInt m,PetscInt n,PetscInt nz,const PetscInt nnz[],Mat *A)
    290: {
    291:   MatCreate(comm,A);
    292:   MatSetSizes(*A,m,n,m,n);
    293:   MatSetType(*A,MATSEQAIJSELL);
    294:   MatSeqAIJSetPreallocation_SeqAIJ(*A,nz,nnz);
    295:   return 0;
    296: }

    298: PETSC_EXTERN PetscErrorCode MatCreate_SeqAIJSELL(Mat A)
    299: {
    300:   MatSetType(A,MATSEQAIJ);
    301:   MatConvert_SeqAIJ_SeqAIJSELL(A,MATSEQAIJSELL,MAT_INPLACE_MATRIX,&A);
    302:   return 0;
    303: }