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

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

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

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

 47:   PetscCall(PetscFree2(aijcrl->acols, aijcrl->icols));
 48:   PetscCall(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:   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));
 62:   PetscFunctionReturn(PETSC_SUCCESS);
 63: }

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

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

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

 75:   /* Now calculate the permutation and grouping information. */
 76:   PetscCall(MatSeqAIJCRL_create_aijcrl(A));
 77:   PetscFunctionReturn(PETSC_SUCCESS);
 78: }

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

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

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

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

103:   PetscFunctionBegin;
104:   if (aijcrl->xscat) {
105:     PetscCall(VecCopy(xx, aijcrl->xwork));
106:     /* get remote values needed for local part of multiply */
107:     PetscCall(VecScatterBegin(aijcrl->xscat, xx, aijcrl->fwork, INSERT_VALUES, SCATTER_FORWARD));
108:     PetscCall(VecScatterEnd(aijcrl->xscat, xx, aijcrl->fwork, INSERT_VALUES, SCATTER_FORWARD));
109:     xx = aijcrl->xwork;
110:   }

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

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

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

122:     /* other columns */
123:   #if defined(PETSC_HAVE_CRAY_VECTOR)
124:     #pragma _CRI preferstream
125:   #endif
126:   for (i = 1; i < rmax; i++) {
127:     ii = i * m;
128:   #if defined(PETSC_HAVE_CRAY_VECTOR)
129:     #pragma _CRI prefervector
130:   #endif
131:     for (j = 0; j < m; j++) y[j] = y[j] + acols[ii + j] * x[icols[ii + j]];
132:   }
133: #endif
134:   PetscCall(PetscLogFlops(2.0 * aijcrl->nz - m));
135:   PetscCall(VecRestoreArrayRead(xx, &x));
136:   PetscCall(VecRestoreArray(yy, &y));
137:   PetscFunctionReturn(PETSC_SUCCESS);
138: }

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

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

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

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

164:   /* If A has already been assembled, compute the permutation. */
165:   if (A->assembled) PetscCall(MatSeqAIJCRL_create_aijcrl(B));
166:   PetscCall(PetscObjectChangeTypeName((PetscObject)B, MATSEQAIJCRL));
167:   *newmat = B;
168:   PetscFunctionReturn(PETSC_SUCCESS);
169: }

171: /*@C
172:    MatCreateSeqAIJCRL - Creates a sparse matrix of type `MATSEQAIJCRL`.
173:    This type inherits from `MATSEQAIJ`, but stores some additional
174:    information that is used to allow better vectorization of
175:    the matrix-vector product. At the cost of increased storage, the `MATSEQAIJ` formatted
176:    matrix can be copied to a format in which pieces of the matrix are
177:    stored in ELLPACK format, allowing the vectorized matrix multiply
178:    routine to use stride-1 memory accesses.

180:    Collective

182:    Input Parameters:
183: +  comm - MPI communicator, set to `PETSC_COMM_SELF`
184: .  m - number of rows
185: .  n - number of columns
186: .  nz - number of nonzeros per row (same for all rows), ignored if `nnz` is given
187: -  nnz - array containing the number of nonzeros in the various rows
188:          (possibly different for each row) or `NULL`

190:    Output Parameter:
191: .  A - the matrix

193:    Level: intermediate

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: }