Actual source code: crl.c

  1: /*
  2:   Defines a matrix-vector product for the MATSEQAIJCRL matrix class.
  3:   This class is derived from the MATSEQAIJ class and retains the
  4:   compressed row storage (aka Yale sparse matrix format) but augments
  5:   it with a column oriented storage that is more efficient for
  6:   matrix vector products on Vector machines.

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

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

 17:   PetscFunctionBegin;
 18:   /* Free everything in the Mat_AIJCRL data structure. */
 19:   if (aijcrl) PetscCall(PetscFree2(aijcrl->acols, aijcrl->icols));
 20:   PetscCall(PetscFree(A->spptr));
 21:   PetscCall(PetscObjectChangeTypeName((PetscObject)A, MATSEQAIJ));
 22:   PetscCall(MatDestroy_SeqAIJ(A));
 23:   PetscFunctionReturn(PETSC_SUCCESS);
 24: }

 26: PetscErrorCode MatDuplicate_AIJCRL(Mat A, MatDuplicateOption op, Mat *M)
 27: {
 28:   SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP, "Cannot duplicate AIJCRL matrices yet");
 29: }

 31: static PetscErrorCode MatSeqAIJCRL_create_aijcrl(Mat A)
 32: {
 33:   Mat_SeqAIJ  *a      = (Mat_SeqAIJ *)(A)->data;
 34:   Mat_AIJCRL  *aijcrl = (Mat_AIJCRL *)A->spptr;
 35:   PetscInt     m      = A->rmap->n; /* Number of rows in the matrix. */
 36:   PetscInt    *aj     = a->j;       /* From the CSR representation; points to the beginning  of each row. */
 37:   PetscInt     i, j, rmax = a->rmax, *icols, *ilen = a->ilen;
 38:   MatScalar   *aa = a->a;
 39:   PetscScalar *acols;

 41:   PetscFunctionBegin;
 42:   aijcrl->nz   = a->nz;
 43:   aijcrl->m    = A->rmap->n;
 44:   aijcrl->rmax = rmax;

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

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

 68:   PetscFunctionBegin;
 69:   a->inode.use = PETSC_FALSE;

 71:   PetscCall(MatAssemblyEnd_SeqAIJ(A, mode));
 72:   if (mode == MAT_FLUSH_ASSEMBLY) PetscFunctionReturn(PETSC_SUCCESS);

 74:   /* Now calculate the permutation and grouping information. */
 75:   PetscCall(MatSeqAIJCRL_create_aijcrl(A));
 76:   PetscFunctionReturn(PETSC_SUCCESS);
 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:   PetscFunctionBegin;
103:   if (aijcrl->xscat) {
104:     PetscCall(VecCopy(xx, aijcrl->xwork));
105:     /* get remote values needed for local part of multiply */
106:     PetscCall(VecScatterBegin(aijcrl->xscat, xx, aijcrl->fwork, INSERT_VALUES, SCATTER_FORWARD));
107:     PetscCall(VecScatterEnd(aijcrl->xscat, xx, aijcrl->fwork, INSERT_VALUES, SCATTER_FORWARD));
108:     xx = aijcrl->xwork;
109:   }

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

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

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

121:     /* other columns */
122:   #if defined(PETSC_HAVE_CRAY_VECTOR)
123:     #pragma _CRI preferstream
124:   #endif
125:   for (i = 1; i < rmax; i++) {
126:     ii = i * m;
127:   #if defined(PETSC_HAVE_CRAY_VECTOR)
128:     #pragma _CRI prefervector
129:   #endif
130:     for (j = 0; j < m; j++) y[j] = y[j] + acols[ii + j] * x[icols[ii + j]];
131:   }
132: #endif
133:   PetscCall(PetscLogFlops(2.0 * aijcrl->nz - m));
134:   PetscCall(VecRestoreArrayRead(xx, &x));
135:   PetscCall(VecRestoreArray(yy, &y));
136:   PetscFunctionReturn(PETSC_SUCCESS);
137: }

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

149:   PetscFunctionBegin;
150:   if (reuse == MAT_INITIAL_MATRIX) PetscCall(MatDuplicate(A, MAT_COPY_VALUES, &B));
151:   PetscCall(PetscObjectTypeCompare((PetscObject)A, type, &sametype));
152:   if (sametype) PetscFunctionReturn(PETSC_SUCCESS);

154:   PetscCall(PetscNew(&aijcrl));
155:   B->spptr = (void *)aijcrl;

157:   /* Set function pointers for methods that we inherit from AIJ but override. */
158:   B->ops->duplicate   = MatDuplicate_AIJCRL;
159:   B->ops->assemblyend = MatAssemblyEnd_SeqAIJCRL;
160:   B->ops->destroy     = MatDestroy_SeqAIJCRL;
161:   B->ops->mult        = MatMult_AIJCRL;

163:   /* If A has already been assembled, compute the permutation. */
164:   if (A->assembled) PetscCall(MatSeqAIJCRL_create_aijcrl(B));
165:   PetscCall(PetscObjectChangeTypeName((PetscObject)B, MATSEQAIJCRL));
166:   *newmat = B;
167:   PetscFunctionReturn(PETSC_SUCCESS);
168: }

170: /*@C
171:   MatCreateSeqAIJCRL - Creates a sparse matrix of type `MATSEQAIJCRL`.

173:   Collective

175:   Input Parameters:
176: + comm - MPI communicator, set to `PETSC_COMM_SELF`
177: . m    - number of rows
178: . n    - number of columns
179: . nz   - number of nonzeros per row (same for all rows), ignored if `nnz` is given
180: - nnz  - array containing the number of nonzeros in the various rows
181:          (possibly different for each row) or `NULL`

183:   Output Parameter:
184: . A - the matrix

186:   Level: intermediate

188:   Notes:
189:   This type inherits from `MATSEQAIJ`, but stores some additional information that is used to
190:   allow better vectorization of the matrix-vector product. At the cost of increased storage,
191:   the `MATSEQAIJ` formatted matrix can be copied to a format in which pieces of the matrix are
192:   stored in ELLPACK format, allowing the vectorized matrix multiply routine to use stride-1
193:   memory accesses.

195: .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `MatCreateMPIAIJPERM()`, `MatSetValues()`
196: @*/
197: PetscErrorCode MatCreateSeqAIJCRL(MPI_Comm comm, PetscInt m, PetscInt n, PetscInt nz, const PetscInt nnz[], Mat *A)
198: {
199:   PetscFunctionBegin;
200:   PetscCall(MatCreate(comm, A));
201:   PetscCall(MatSetSizes(*A, m, n, m, n));
202:   PetscCall(MatSetType(*A, MATSEQAIJCRL));
203:   PetscCall(MatSeqAIJSetPreallocation_SeqAIJ(*A, nz, nnz));
204:   PetscFunctionReturn(PETSC_SUCCESS);
205: }

207: PETSC_EXTERN PetscErrorCode MatCreate_SeqAIJCRL(Mat A)
208: {
209:   PetscFunctionBegin;
210:   PetscCall(MatSetType(A, MATSEQAIJ));
211:   PetscCall(MatConvert_SeqAIJ_SeqAIJCRL(A, MATSEQAIJCRL, MAT_INPLACE_MATRIX, &A));
212:   PetscFunctionReturn(PETSC_SUCCESS);
213: }