Date: 2015-10-02T22:06:19+00:00

Actual source code: crl.c
petsc-3.6.2 2015-10-02
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      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>

     16: PetscErrorCode MatDestroy_SeqAIJCRL(Mat A)
     17: {
     19:   Mat_AIJCRL     *aijcrl = (Mat_AIJCRL*) A->spptr;

     21:   /* Free everything in the Mat_AIJCRL data structure. */
     22:   if (aijcrl) {
     23:     PetscFree2(aijcrl->acols,aijcrl->icols);
     24:   }
     25:   PetscFree(A->spptr);
     26:   PetscObjectChangeTypeName((PetscObject)A, MATSEQAIJ);
     27:   MatDestroy_SeqAIJ(A);
     28:   return(0);
     29: }

     31: PetscErrorCode MatDuplicate_AIJCRL(Mat A, MatDuplicateOption op, Mat *M)
     32: {
     34:   SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"Cannot duplicate AIJCRL matrices yet");
     35:   return(0);
     36: }

     40: PetscErrorCode MatSeqAIJCRL_create_aijcrl(Mat A)
     41: {
     42:   Mat_SeqAIJ     *a      = (Mat_SeqAIJ*)(A)->data;
     43:   Mat_AIJCRL     *aijcrl = (Mat_AIJCRL*) A->spptr;
     44:   PetscInt       m       = A->rmap->n; /* Number of rows in the matrix. */
     45:   PetscInt       *aj     = a->j; /* From the CSR representation; points to the beginning  of each row. */
     46:   PetscInt       i, j,rmax = a->rmax,*icols, *ilen = a->ilen;
     47:   MatScalar      *aa = a->a;
     48:   PetscScalar    *acols;

     52:   aijcrl->nz   = a->nz;
     53:   aijcrl->m    = A->rmap->n;
     54:   aijcrl->rmax = rmax;

     56:   PetscFree2(aijcrl->acols,aijcrl->icols);
     57:   PetscMalloc2(rmax*m,&aijcrl->acols,rmax*m,&aijcrl->icols);
     58:   acols = aijcrl->acols;
     59:   icols = aijcrl->icols;
     60:   for (i=0; i<m; i++) {
     61:     for (j=0; j<ilen[i]; j++) {
     62:       acols[j*m+i] = *aa++;
     63:       icols[j*m+i] = *aj++;
     64:     }
     65:     for (; j<rmax; j++) { /* empty column entries */
     66:       acols[j*m+i] = 0.0;
     67:       icols[j*m+i] = (j) ? icols[(j-1)*m+i] : 0;  /* handle case where row is EMPTY */
     68:     }
     69:   }
     70:   PetscInfo2(A,"Percentage of 0's introduced for vectorized multiply %g. Rmax= %D\n",1.0-((double)a->nz)/((double)(rmax*m)),rmax);
     71:   return(0);
     72: }

     74: extern PetscErrorCode MatAssemblyEnd_SeqAIJ(Mat,MatAssemblyType);

     78: PetscErrorCode MatAssemblyEnd_SeqAIJCRL(Mat A, MatAssemblyType mode)
     79: {
     81:   Mat_SeqAIJ     *a = (Mat_SeqAIJ*)A->data;

     84:   a->inode.use = PETSC_FALSE;

     86:   MatAssemblyEnd_SeqAIJ(A,mode);
     87:   if (mode == MAT_FLUSH_ASSEMBLY) return(0);

     89:   /* Now calculate the permutation and grouping information. */
     90:   MatSeqAIJCRL_create_aijcrl(A);
     91:   return(0);
     92: }

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

     98: /*
     99:     Shared by both sequential and parallel versions of CRL matrix: MATMPIAIJCRL and MATSEQAIJCRL
    100:     - the scatter is used only in the parallel version

    102: */
    103: PetscErrorCode MatMult_AIJCRL(Mat A,Vec xx,Vec yy)
    104: {
    105:   Mat_AIJCRL        *aijcrl = (Mat_AIJCRL*) A->spptr;
    106:   PetscInt          m       = aijcrl->m; /* Number of rows in the matrix. */
    107:   PetscInt          rmax    = aijcrl->rmax,*icols = aijcrl->icols;
    108:   PetscScalar       *acols  = aijcrl->acols;
    109:   PetscErrorCode    ierr;
    110:   PetscScalar       *y;
    111:   const PetscScalar *x;
    112: #if !defined(PETSC_USE_FORTRAN_KERNEL_MULTCRL)
    113:   PetscInt          i,j,ii;
    114: #endif

    116: #if defined(PETSC_HAVE_PRAGMA_DISJOINT)
    117: #pragma disjoint(*x,*y,*aa)
    118: #endif

    121:   if (aijcrl->xscat) {
    122:     VecCopy(xx,aijcrl->xwork);
    123:     /* get remote values needed for local part of multiply */
    124:     VecScatterBegin(aijcrl->xscat,xx,aijcrl->fwork,INSERT_VALUES,SCATTER_FORWARD);
    125:     VecScatterEnd(aijcrl->xscat,xx,aijcrl->fwork,INSERT_VALUES,SCATTER_FORWARD);
    126:     xx   = aijcrl->xwork;
    127:   }

    129:   VecGetArrayRead(xx,&x);
    130:   VecGetArray(yy,&y);

    132: #if defined(PETSC_USE_FORTRAN_KERNEL_MULTCRL)
    133:   fortranmultcrl_(&m,&rmax,x,y,icols,acols);
    134: #else

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

    139:   /* other columns */
    140: #if defined(PETSC_HAVE_CRAY_VECTOR)
    141: #pragma _CRI preferstream
    142: #endif
    143:   for (i=1; i<rmax; i++) {
    144:     ii = i*m;
    145: #if defined(PETSC_HAVE_CRAY_VECTOR)
    146: #pragma _CRI prefervector
    147: #endif
    148:     for (j=0; j<m; j++) y[j] = y[j] + acols[ii+j]*x[icols[ii+j]];
    149:   }
    150: #if defined(PETSC_HAVE_CRAY_VECTOR)
    151: #pragma _CRI ivdep
    152: #endif

    154: #endif
    155:   PetscLogFlops(2.0*aijcrl->nz - m);
    156:   VecRestoreArrayRead(xx,&x);
    157:   VecRestoreArray(yy,&y);
    158:   return(0);
    159: }

    162: /* MatConvert_SeqAIJ_SeqAIJCRL converts a SeqAIJ matrix into a
    163:  * SeqAIJCRL matrix.  This routine is called by the MatCreate_SeqAIJCRL()
    164:  * routine, but can also be used to convert an assembled SeqAIJ matrix
    165:  * into a SeqAIJCRL one. */
    168: PETSC_EXTERN PetscErrorCode MatConvert_SeqAIJ_SeqAIJCRL(Mat A,MatType type,MatReuse reuse,Mat *newmat)
    169: {
    171:   Mat            B = *newmat;
    172:   Mat_AIJCRL     *aijcrl;

    175:   if (reuse == MAT_INITIAL_MATRIX) {
    176:     MatDuplicate(A,MAT_COPY_VALUES,&B);
    177:   }

    179:   PetscNewLog(B,&aijcrl);
    180:   B->spptr = (void*) aijcrl;

    182:   /* Set function pointers for methods that we inherit from AIJ but override. */
    183:   B->ops->duplicate   = MatDuplicate_AIJCRL;
    184:   B->ops->assemblyend = MatAssemblyEnd_SeqAIJCRL;
    185:   B->ops->destroy     = MatDestroy_SeqAIJCRL;
    186:   B->ops->mult        = MatMult_AIJCRL;

    188:   /* If A has already been assembled, compute the permutation. */
    189:   if (A->assembled) {
    190:     MatSeqAIJCRL_create_aijcrl(B);
    191:   }
    192:   PetscObjectChangeTypeName((PetscObject)B,MATSEQAIJCRL);
    193:   *newmat = B;
    194:   return(0);
    195: }

    199: /*@C
    200:    MatCreateSeqAIJCRL - Creates a sparse matrix of type SEQAIJCRL.
    201:    This type inherits from AIJ, but stores some additional
    202:    information that is used to allow better vectorization of
    203:    the matrix-vector product. At the cost of increased storage, the AIJ formatted
    204:    matrix can be copied to a format in which pieces of the matrix are
    205:    stored in ELLPACK format, allowing the vectorized matrix multiply
    206:    routine to use stride-1 memory accesses.  As with the AIJ type, it is
    207:    important to preallocate matrix storage in order to get good assembly
    208:    performance.

    210:    Collective on MPI_Comm

    212:    Input Parameters:
    213: +  comm - MPI communicator, set to PETSC_COMM_SELF
    214: .  m - number of rows
    215: .  n - number of columns
    216: .  nz - number of nonzeros per row (same for all rows)
    217: -  nnz - array containing the number of nonzeros in the various rows
    218:          (possibly different for each row) or NULL

    220:    Output Parameter:
    221: .  A - the matrix

    223:    Notes:
    224:    If nnz is given then nz is ignored

    226:    Level: intermediate

    228: .keywords: matrix, cray, sparse, parallel

    230: .seealso: MatCreate(), MatCreateMPIAIJPERM(), MatSetValues()
    231: @*/
    232: PetscErrorCode  MatCreateSeqAIJCRL(MPI_Comm comm,PetscInt m,PetscInt n,PetscInt nz,const PetscInt nnz[],Mat *A)
    233: {

    237:   MatCreate(comm,A);
    238:   MatSetSizes(*A,m,n,m,n);
    239:   MatSetType(*A,MATSEQAIJCRL);
    240:   MatSeqAIJSetPreallocation_SeqAIJ(*A,nz,nnz);
    241:   return(0);
    242: }

    246: PETSC_EXTERN PetscErrorCode MatCreate_SeqAIJCRL(Mat A)
    247: {

    251:   MatSetType(A,MATSEQAIJ);
    252:   MatConvert_SeqAIJ_SeqAIJCRL(A,MATSEQAIJCRL,MAT_REUSE_MATRIX,&A);
    253:   return(0);
    254: }