xref: /petsc/src/mat/impls/aij/mpi/crl/mcrl.c (revision bcee047adeeb73090d7e36cc71e39fc287cdbb97)
1 
2 /*
3   Defines a matrix-vector product for the MATMPIAIJCRL matrix class.
4   This class is derived from the MATMPIAIJ 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.
8 
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    See src/mat/impls/aij/seq/crl/crl.c for the sequential version
13 */
14 
15 #include <../src/mat/impls/aij/mpi/mpiaij.h>
16 #include <../src/mat/impls/aij/seq/crl/crl.h>
17 
18 PetscErrorCode MatDestroy_MPIAIJCRL(Mat A)
19 {
20   Mat_AIJCRL *aijcrl = (Mat_AIJCRL *)A->spptr;
21 
22   PetscFunctionBegin;
23   if (aijcrl) {
24     PetscCall(PetscFree2(aijcrl->acols, aijcrl->icols));
25     PetscCall(VecDestroy(&aijcrl->fwork));
26     PetscCall(VecDestroy(&aijcrl->xwork));
27     PetscCall(PetscFree(aijcrl->array));
28   }
29   PetscCall(PetscFree(A->spptr));
30 
31   PetscCall(PetscObjectChangeTypeName((PetscObject)A, MATMPIAIJ));
32   PetscCall(MatDestroy_MPIAIJ(A));
33   PetscFunctionReturn(PETSC_SUCCESS);
34 }
35 
36 PetscErrorCode MatMPIAIJCRL_create_aijcrl(Mat A)
37 {
38   Mat_MPIAIJ  *a   = (Mat_MPIAIJ *)(A)->data;
39   Mat_SeqAIJ  *Aij = (Mat_SeqAIJ *)(a->A->data), *Bij = (Mat_SeqAIJ *)(a->B->data);
40   Mat_AIJCRL  *aijcrl = (Mat_AIJCRL *)A->spptr;
41   PetscInt     m      = A->rmap->n;       /* Number of rows in the matrix. */
42   PetscInt     nd     = a->A->cmap->n;    /* number of columns in diagonal portion */
43   PetscInt    *aj = Aij->j, *bj = Bij->j; /* From the CSR representation; points to the beginning  of each row. */
44   PetscInt     i, j, rmax = 0, *icols, *ailen = Aij->ilen, *bilen = Bij->ilen;
45   PetscScalar *aa = Aij->a, *ba = Bij->a, *acols, *array;
46 
47   PetscFunctionBegin;
48   /* determine the row with the most columns */
49   for (i = 0; i < m; i++) rmax = PetscMax(rmax, ailen[i] + bilen[i]);
50   aijcrl->nz   = Aij->nz + Bij->nz;
51   aijcrl->m    = A->rmap->n;
52   aijcrl->rmax = rmax;
53 
54   PetscCall(PetscFree2(aijcrl->acols, aijcrl->icols));
55   PetscCall(PetscMalloc2(rmax * m, &aijcrl->acols, rmax * m, &aijcrl->icols));
56   acols = aijcrl->acols;
57   icols = aijcrl->icols;
58   for (i = 0; i < m; i++) {
59     for (j = 0; j < ailen[i]; j++) {
60       acols[j * m + i] = *aa++;
61       icols[j * m + i] = *aj++;
62     }
63     for (; j < ailen[i] + bilen[i]; j++) {
64       acols[j * m + i] = *ba++;
65       icols[j * m + i] = nd + *bj++;
66     }
67     for (; j < rmax; j++) { /* empty column entries */
68       acols[j * m + i] = 0.0;
69       icols[j * m + i] = (j) ? icols[(j - 1) * m + i] : 0; /* handle case where row is EMPTY */
70     }
71   }
72   PetscCall(PetscInfo(A, "Percentage of 0's introduced for vectorized multiply %g\n", 1.0 - ((double)(aijcrl->nz)) / ((double)(rmax * m))));
73 
74   PetscCall(PetscFree(aijcrl->array));
75   PetscCall(PetscMalloc1(a->B->cmap->n + nd, &array));
76   /* xwork array is actually B->n+nd long, but we define xwork this length so can copy into it */
77   PetscCall(VecDestroy(&aijcrl->xwork));
78   PetscCall(VecCreateMPIWithArray(PetscObjectComm((PetscObject)A), 1, nd, PETSC_DECIDE, array, &aijcrl->xwork));
79   PetscCall(VecDestroy(&aijcrl->fwork));
80   PetscCall(VecCreateSeqWithArray(PETSC_COMM_SELF, 1, a->B->cmap->n, array + nd, &aijcrl->fwork));
81 
82   aijcrl->array = array;
83   aijcrl->xscat = a->Mvctx;
84   PetscFunctionReturn(PETSC_SUCCESS);
85 }
86 
87 PetscErrorCode MatAssemblyEnd_MPIAIJCRL(Mat A, MatAssemblyType mode)
88 {
89   Mat_MPIAIJ *a   = (Mat_MPIAIJ *)A->data;
90   Mat_SeqAIJ *Aij = (Mat_SeqAIJ *)(a->A->data), *Bij = (Mat_SeqAIJ *)(a->A->data);
91 
92   PetscFunctionBegin;
93   Aij->inode.use = PETSC_FALSE;
94   Bij->inode.use = PETSC_FALSE;
95 
96   PetscCall(MatAssemblyEnd_MPIAIJ(A, mode));
97   if (mode == MAT_FLUSH_ASSEMBLY) PetscFunctionReturn(PETSC_SUCCESS);
98 
99   /* Now calculate the permutation and grouping information. */
100   PetscCall(MatMPIAIJCRL_create_aijcrl(A));
101   PetscFunctionReturn(PETSC_SUCCESS);
102 }
103 
104 extern PetscErrorCode MatMult_AIJCRL(Mat, Vec, Vec);
105 extern PetscErrorCode MatDuplicate_AIJCRL(Mat, MatDuplicateOption, Mat *);
106 
107 /* MatConvert_MPIAIJ_MPIAIJCRL converts a MPIAIJ matrix into a
108  * MPIAIJCRL matrix.  This routine is called by the MatCreate_MPIAIJCRL()
109  * routine, but can also be used to convert an assembled MPIAIJ matrix
110  * into a MPIAIJCRL one. */
111 
112 PETSC_INTERN PetscErrorCode MatConvert_MPIAIJ_MPIAIJCRL(Mat A, MatType type, MatReuse reuse, Mat *newmat)
113 {
114   Mat         B = *newmat;
115   Mat_AIJCRL *aijcrl;
116 
117   PetscFunctionBegin;
118   if (reuse == MAT_INITIAL_MATRIX) PetscCall(MatDuplicate(A, MAT_COPY_VALUES, &B));
119 
120   PetscCall(PetscNew(&aijcrl));
121   B->spptr = (void *)aijcrl;
122 
123   /* Set function pointers for methods that we inherit from AIJ but override. */
124   B->ops->duplicate   = MatDuplicate_AIJCRL;
125   B->ops->assemblyend = MatAssemblyEnd_MPIAIJCRL;
126   B->ops->destroy     = MatDestroy_MPIAIJCRL;
127   B->ops->mult        = MatMult_AIJCRL;
128 
129   /* If A has already been assembled, compute the permutation. */
130   if (A->assembled) PetscCall(MatMPIAIJCRL_create_aijcrl(B));
131   PetscCall(PetscObjectChangeTypeName((PetscObject)B, MATMPIAIJCRL));
132   *newmat = B;
133   PetscFunctionReturn(PETSC_SUCCESS);
134 }
135 
136 /*@C
137    MatCreateMPIAIJCRL - Creates a sparse matrix of type `MATMPIAIJCRL`.
138    This type inherits from `MATAIJ`, but stores some additional
139    information that is used to allow better vectorization of
140    the matrix-vector product. At the cost of increased storage, the AIJ formatted
141    matrix can be copied to a format in which pieces of the matrix are
142    stored in ELLPACK format, allowing the vectorized matrix multiply
143    routine to use stride-1 memory accesses.
144 
145    Collective
146 
147    Input Parameters:
148 +  comm - MPI communicator, set to `PETSC_COMM_SELF`
149 .  m - number of rows
150 .  n - number of columns
151 .  nz - number of nonzeros per row (same for all rows), for the "diagonal" submatrix
152 .  nnz - array containing the number of nonzeros in the various rows (possibly different for each row) or `NULL`, for the "diagonal" submatrix
153 .  onz - number of nonzeros per row (same for all rows), for the "off-diagonal" submatrix
154 -  onnz - array containing the number of nonzeros in the various rows (possibly different for each row) or `NULL`, for the "off-diagonal" submatrix
155 
156    Output Parameter:
157 .  A - the matrix
158 
159    Level: intermediate
160 
161    Note:
162    If `nnz` is given then `nz` is ignored
163 
164 .seealso: [](ch_matrices), `Mat`, [Sparse Matrix Creation](sec_matsparse), `MATAIJ`, `MATAIJSELL`, `MATAIJPERM`, `MATAIJMKL`, `MatCreate()`, `MatCreateMPIAIJPERM()`, `MatSetValues()`
165 @*/
166 PetscErrorCode MatCreateMPIAIJCRL(MPI_Comm comm, PetscInt m, PetscInt n, PetscInt nz, const PetscInt nnz[], PetscInt onz, const PetscInt onnz[], Mat *A)
167 {
168   PetscFunctionBegin;
169   PetscCall(MatCreate(comm, A));
170   PetscCall(MatSetSizes(*A, m, n, m, n));
171   PetscCall(MatSetType(*A, MATMPIAIJCRL));
172   PetscCall(MatMPIAIJSetPreallocation_MPIAIJ(*A, nz, (PetscInt *)nnz, onz, (PetscInt *)onnz));
173   PetscFunctionReturn(PETSC_SUCCESS);
174 }
175 
176 PETSC_EXTERN PetscErrorCode MatCreate_MPIAIJCRL(Mat A)
177 {
178   PetscFunctionBegin;
179   PetscCall(MatSetType(A, MATMPIAIJ));
180   PetscCall(MatConvert_MPIAIJ_MPIAIJCRL(A, MATMPIAIJCRL, MAT_INPLACE_MATRIX, &A));
181   PetscFunctionReturn(PETSC_SUCCESS);
182 }
183