Date: 2022-03-31T04:46:46+00:00

Actual source code: crl.c

      2: /*
      3:   Defines a matrix-vector product for the MATSEQAIJCRL matrix class.
      4:   This class is derived from the MATSEQAIJ class and retains the
      5:   compressed row storage (aka Yale sparse matrix format) but augments
      6:   it with a column oriented storage that is more efficient for
      7:   matrix vector products on Vector machines.

      9:   CRL stands for constant row length (that is the same number of columns
     10:   is kept (padded with zeros) for each row of the sparse matrix.
     11: */
     12: #include <../src/mat/impls/aij/seq/crl/crl.h>

     14: PetscErrorCode MatDestroy_SeqAIJCRL(Mat A)
     15: {
     16:   Mat_AIJCRL     *aijcrl = (Mat_AIJCRL*) A->spptr;

     18:   /* Free everything in the Mat_AIJCRL data structure. */
     19:   if (aijcrl) {
     20:     PetscFree2(aijcrl->acols,aijcrl->icols);
     21:   }
     22:   PetscFree(A->spptr);
     23:   PetscObjectChangeTypeName((PetscObject)A, MATSEQAIJ);
     24:   MatDestroy_SeqAIJ(A);
     25:   return 0;
     26: }

     28: PetscErrorCode MatDuplicate_AIJCRL(Mat A, MatDuplicateOption op, Mat *M)
     29: {
     30:   SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"Cannot duplicate AIJCRL matrices yet");
     31: }

     33: PetscErrorCode MatSeqAIJCRL_create_aijcrl(Mat A)
     34: {
     35:   Mat_SeqAIJ     *a      = (Mat_SeqAIJ*)(A)->data;
     36:   Mat_AIJCRL     *aijcrl = (Mat_AIJCRL*) A->spptr;
     37:   PetscInt       m       = A->rmap->n; /* Number of rows in the matrix. */
     38:   PetscInt       *aj     = a->j; /* From the CSR representation; points to the beginning  of each row. */
     39:   PetscInt       i, j,rmax = a->rmax,*icols, *ilen = a->ilen;
     40:   MatScalar      *aa = a->a;
     41:   PetscScalar    *acols;

     43:   aijcrl->nz   = a->nz;
     44:   aijcrl->m    = A->rmap->n;
     45:   aijcrl->rmax = rmax;

     47:   PetscFree2(aijcrl->acols,aijcrl->icols);
     48:   PetscMalloc2(rmax*m,&aijcrl->acols,rmax*m,&aijcrl->icols);
     49:   acols = aijcrl->acols;
     50:   icols = aijcrl->icols;
     51:   for (i=0; i<m; i++) {
     52:     for (j=0; j<ilen[i]; j++) {
     53:       acols[j*m+i] = *aa++;
     54:       icols[j*m+i] = *aj++;
     55:     }
     56:     for (; j<rmax; j++) { /* empty column entries */
     57:       acols[j*m+i] = 0.0;
     58:       icols[j*m+i] = (j) ? icols[(j-1)*m+i] : 0;  /* handle case where row is EMPTY */
     59:     }
     60:   }
     61:   PetscInfo(A,"Percentage of 0's introduced for vectorized multiply %g. Rmax= %" PetscInt_FMT "\n",1.0-((double)a->nz)/((double)(rmax*m)),rmax);
     62:   return 0;
     63: }

     65: PetscErrorCode MatAssemblyEnd_SeqAIJCRL(Mat A, MatAssemblyType mode)
     66: {
     67:   Mat_SeqAIJ     *a = (Mat_SeqAIJ*)A->data;

     69:   a->inode.use = PETSC_FALSE;

     71:   MatAssemblyEnd_SeqAIJ(A,mode);
     72:   if (mode == MAT_FLUSH_ASSEMBLY) return 0;

     74:   /* Now calculate the permutation and grouping information. */
     75:   MatSeqAIJCRL_create_aijcrl(A);
     76:   return 0;
     77: }

     79: #include <../src/mat/impls/aij/seq/crl/ftn-kernels/fmultcrl.h>

     81: /*
     82:     Shared by both sequential and parallel versions of CRL matrix: MATMPIAIJCRL and MATSEQAIJCRL
     83:     - the scatter is used only in the parallel version

     85: */
     86: PetscErrorCode MatMult_AIJCRL(Mat A,Vec xx,Vec yy)
     87: {
     88:   Mat_AIJCRL        *aijcrl = (Mat_AIJCRL*) A->spptr;
     89:   PetscInt          m       = aijcrl->m; /* Number of rows in the matrix. */
     90:   PetscInt          rmax    = aijcrl->rmax,*icols = aijcrl->icols;
     91:   PetscScalar       *acols  = aijcrl->acols;
     92:   PetscScalar       *y;
     93:   const PetscScalar *x;
     94: #if !defined(PETSC_USE_FORTRAN_KERNEL_MULTCRL)
     95:   PetscInt          i,j,ii;
     96: #endif

     98: #if defined(PETSC_HAVE_PRAGMA_DISJOINT)
     99: #pragma disjoint(*x,*y,*aa)
    100: #endif

    102:   if (aijcrl->xscat) {
    103:     VecCopy(xx,aijcrl->xwork);
    104:     /* get remote values needed for local part of multiply */
    105:     VecScatterBegin(aijcrl->xscat,xx,aijcrl->fwork,INSERT_VALUES,SCATTER_FORWARD);
    106:     VecScatterEnd(aijcrl->xscat,xx,aijcrl->fwork,INSERT_VALUES,SCATTER_FORWARD);
    107:     xx   = aijcrl->xwork;
    108:   }

    110:   VecGetArrayRead(xx,&x);
    111:   VecGetArray(yy,&y);

    113: #if defined(PETSC_USE_FORTRAN_KERNEL_MULTCRL)
    114:   fortranmultcrl_(&m,&rmax,x,y,icols,acols);
    115: #else

    117:   /* first column */
    118:   for (j=0; j<m; j++) y[j] = acols[j]*x[icols[j]];

    120:   /* other columns */
    121: #if defined(PETSC_HAVE_CRAY_VECTOR)
    122: #pragma _CRI preferstream
    123: #endif
    124:   for (i=1; i<rmax; i++) {
    125:     ii = i*m;
    126: #if defined(PETSC_HAVE_CRAY_VECTOR)
    127: #pragma _CRI prefervector
    128: #endif
    129:     for (j=0; j<m; j++) y[j] = y[j] + acols[ii+j]*x[icols[ii+j]];
    130:   }
    131: #if defined(PETSC_HAVE_CRAY_VECTOR)
    132: #pragma _CRI ivdep
    133: #endif

    135: #endif
    136:   PetscLogFlops(2.0*aijcrl->nz - m);
    137:   VecRestoreArrayRead(xx,&x);
    138:   VecRestoreArray(yy,&y);
    139:   return 0;
    140: }

    142: /* MatConvert_SeqAIJ_SeqAIJCRL converts a SeqAIJ matrix into a
    143:  * SeqAIJCRL matrix.  This routine is called by the MatCreate_SeqAIJCRL()
    144:  * routine, but can also be used to convert an assembled SeqAIJ matrix
    145:  * into a SeqAIJCRL one. */
    146: PETSC_INTERN PetscErrorCode MatConvert_SeqAIJ_SeqAIJCRL(Mat A,MatType type,MatReuse reuse,Mat *newmat)
    147: {
    148:   Mat            B = *newmat;
    149:   Mat_AIJCRL     *aijcrl;
    150:   PetscBool      sametype;

    152:   if (reuse == MAT_INITIAL_MATRIX) {
    153:     MatDuplicate(A,MAT_COPY_VALUES,&B);
    154:   }
    155:   PetscObjectTypeCompare((PetscObject)A,type,&sametype);
    156:   if (sametype) return 0;

    158:   PetscNewLog(B,&aijcrl);
    159:   B->spptr = (void*) aijcrl;

    161:   /* Set function pointers for methods that we inherit from AIJ but override. */
    162:   B->ops->duplicate   = MatDuplicate_AIJCRL;
    163:   B->ops->assemblyend = MatAssemblyEnd_SeqAIJCRL;
    164:   B->ops->destroy     = MatDestroy_SeqAIJCRL;
    165:   B->ops->mult        = MatMult_AIJCRL;

    167:   /* If A has already been assembled, compute the permutation. */
    168:   if (A->assembled) {
    169:     MatSeqAIJCRL_create_aijcrl(B);
    170:   }
    171:   PetscObjectChangeTypeName((PetscObject)B,MATSEQAIJCRL);
    172:   *newmat = B;
    173:   return 0;
    174: }

    176: /*@C
    177:    MatCreateSeqAIJCRL - Creates a sparse matrix of type SEQAIJCRL.
    178:    This type inherits from AIJ, but stores some additional
    179:    information that is used to allow better vectorization of
    180:    the matrix-vector product. At the cost of increased storage, the AIJ formatted
    181:    matrix can be copied to a format in which pieces of the matrix are
    182:    stored in ELLPACK format, allowing the vectorized matrix multiply
    183:    routine to use stride-1 memory accesses.  As with the AIJ type, it is
    184:    important to preallocate matrix storage in order to get good assembly
    185:    performance.

    187:    Collective

    189:    Input Parameters:
    190: +  comm - MPI communicator, set to PETSC_COMM_SELF
    191: .  m - number of rows
    192: .  n - number of columns
    193: .  nz - number of nonzeros per row (same for all rows)
    194: -  nnz - array containing the number of nonzeros in the various rows
    195:          (possibly different for each row) or NULL

    197:    Output Parameter:
    198: .  A - the matrix

    200:    Notes:
    201:    If nnz is given then nz is ignored

    203:    Level: intermediate

    205: .seealso: MatCreate(), MatCreateMPIAIJPERM(), MatSetValues()
    206: @*/
    207: PetscErrorCode  MatCreateSeqAIJCRL(MPI_Comm comm,PetscInt m,PetscInt n,PetscInt nz,const PetscInt nnz[],Mat *A)
    208: {
    209:   MatCreate(comm,A);
    210:   MatSetSizes(*A,m,n,m,n);
    211:   MatSetType(*A,MATSEQAIJCRL);
    212:   MatSeqAIJSetPreallocation_SeqAIJ(*A,nz,nnz);
    213:   return 0;
    214: }

    216: PETSC_EXTERN PetscErrorCode MatCreate_SeqAIJCRL(Mat A)
    217: {
    218:   MatSetType(A,MATSEQAIJ);
    219:   MatConvert_SeqAIJ_SeqAIJCRL(A,MATSEQAIJCRL,MAT_INPLACE_MATRIX,&A);
    220:   return 0;
    221: }