xref: /petsc/src/mat/impls/aij/mpi/crl/mcrl.c (revision d0e6bf2ad94dcc89b258ce16c7987200a4714786)
1 /*
2   Defines a matrix-vector product for the MATMPIAIJCRL matrix class.
3   This class is derived from the MATMPIAIJ 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.
7 
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    See src/mat/impls/aij/seq/crl/crl.c for the sequential version
12 */
13 
14 #include <../src/mat/impls/aij/mpi/mpiaij.h>
15 #include <../src/mat/impls/aij/seq/crl/crl.h>
16 
MatDestroy_MPIAIJCRL(Mat A)17 static PetscErrorCode MatDestroy_MPIAIJCRL(Mat A)
18 {
19   Mat_AIJCRL *aijcrl = (Mat_AIJCRL *)A->spptr;
20 
21   PetscFunctionBegin;
22   if (aijcrl) {
23     PetscCall(PetscFree2(aijcrl->acols, aijcrl->icols));
24     PetscCall(VecDestroy(&aijcrl->fwork));
25     PetscCall(VecDestroy(&aijcrl->xwork));
26     PetscCall(PetscFree(aijcrl->array));
27   }
28   PetscCall(PetscFree(A->spptr));
29 
30   PetscCall(PetscObjectChangeTypeName((PetscObject)A, MATMPIAIJ));
31   PetscCall(MatDestroy_MPIAIJ(A));
32   PetscFunctionReturn(PETSC_SUCCESS);
33 }
34 
MatMPIAIJCRL_create_aijcrl(Mat A)35 static PetscErrorCode MatMPIAIJCRL_create_aijcrl(Mat A)
36 {
37   Mat_MPIAIJ  *a   = (Mat_MPIAIJ *)A->data;
38   Mat_SeqAIJ  *Aij = (Mat_SeqAIJ *)a->A->data, *Bij = (Mat_SeqAIJ *)a->B->data;
39   Mat_AIJCRL  *aijcrl = (Mat_AIJCRL *)A->spptr;
40   PetscInt     m      = A->rmap->n;       /* Number of rows in the matrix. */
41   PetscInt     nd     = a->A->cmap->n;    /* number of columns in diagonal portion */
42   PetscInt    *aj = Aij->j, *bj = Bij->j; /* From the CSR representation; points to the beginning  of each row. */
43   PetscInt     i, j, rmax = 0, *icols, *ailen = Aij->ilen, *bilen = Bij->ilen;
44   PetscScalar *aa = Aij->a, *ba = Bij->a, *acols, *array;
45 
46   PetscFunctionBegin;
47   /* determine the row with the most columns */
48   for (i = 0; i < m; i++) rmax = PetscMax(rmax, ailen[i] + bilen[i]);
49   aijcrl->nz   = Aij->nz + Bij->nz;
50   aijcrl->m    = A->rmap->n;
51   aijcrl->rmax = rmax;
52 
53   PetscCall(PetscFree2(aijcrl->acols, aijcrl->icols));
54   PetscCall(PetscMalloc2(rmax * m, &aijcrl->acols, rmax * m, &aijcrl->icols));
55   acols = aijcrl->acols;
56   icols = aijcrl->icols;
57   for (i = 0; i < m; i++) {
58     for (j = 0; j < ailen[i]; j++) {
59       acols[j * m + i] = *aa++;
60       icols[j * m + i] = *aj++;
61     }
62     for (; j < ailen[i] + bilen[i]; j++) {
63       acols[j * m + i] = *ba++;
64       icols[j * m + i] = nd + *bj++;
65     }
66     for (; j < rmax; j++) { /* empty column entries */
67       acols[j * m + i] = 0.0;
68       icols[j * m + i] = (j) ? icols[(j - 1) * m + i] : 0; /* handle case where row is EMPTY */
69     }
70   }
71   PetscCall(PetscInfo(A, "Percentage of 0's introduced for vectorized multiply %g\n", 1.0 - ((double)aijcrl->nz) / PetscMax((double)rmax * m, 1)));
72 
73   PetscCall(PetscFree(aijcrl->array));
74   PetscCall(PetscMalloc1(a->B->cmap->n + nd, &array));
75   /* xwork array is actually B->n+nd long, but we define xwork this length so can copy into it */
76   PetscCall(VecDestroy(&aijcrl->xwork));
77   PetscCall(VecCreateMPIWithArray(PetscObjectComm((PetscObject)A), 1, nd, PETSC_DECIDE, array, &aijcrl->xwork));
78   PetscCall(VecDestroy(&aijcrl->fwork));
79   PetscCall(VecCreateSeqWithArray(PETSC_COMM_SELF, 1, a->B->cmap->n, array + nd, &aijcrl->fwork));
80 
81   aijcrl->array = array;
82   aijcrl->xscat = a->Mvctx;
83   PetscFunctionReturn(PETSC_SUCCESS);
84 }
85 
MatAssemblyEnd_MPIAIJCRL(Mat A,MatAssemblyType mode)86 static PetscErrorCode MatAssemblyEnd_MPIAIJCRL(Mat A, MatAssemblyType mode)
87 {
88   Mat_MPIAIJ *a   = (Mat_MPIAIJ *)A->data;
89   Mat_SeqAIJ *Aij = (Mat_SeqAIJ *)a->A->data, *Bij = (Mat_SeqAIJ *)a->A->data;
90 
91   PetscFunctionBegin;
92   Aij->inode.use = PETSC_FALSE;
93   Bij->inode.use = PETSC_FALSE;
94 
95   PetscCall(MatAssemblyEnd_MPIAIJ(A, mode));
96   if (mode == MAT_FLUSH_ASSEMBLY) PetscFunctionReturn(PETSC_SUCCESS);
97 
98   /* Now calculate the permutation and grouping information. */
99   PetscCall(MatMPIAIJCRL_create_aijcrl(A));
100   PetscFunctionReturn(PETSC_SUCCESS);
101 }
102 
103 extern PetscErrorCode MatMult_AIJCRL(Mat, Vec, Vec);
104 extern PetscErrorCode MatDuplicate_AIJCRL(Mat, MatDuplicateOption, Mat *);
105 
106 /* MatConvert_MPIAIJ_MPIAIJCRL converts a MPIAIJ matrix into a
107  * MPIAIJCRL matrix.  This routine is called by the MatCreate_MPIAIJCRL()
108  * routine, but can also be used to convert an assembled MPIAIJ matrix
109  * into a MPIAIJCRL one. */
110 
MatConvert_MPIAIJ_MPIAIJCRL(Mat A,MatType type,MatReuse reuse,Mat * newmat)111 PETSC_INTERN PetscErrorCode MatConvert_MPIAIJ_MPIAIJCRL(Mat A, MatType type, MatReuse reuse, Mat *newmat)
112 {
113   Mat         B = *newmat;
114   Mat_AIJCRL *aijcrl;
115 
116   PetscFunctionBegin;
117   if (reuse == MAT_INITIAL_MATRIX) PetscCall(MatDuplicate(A, MAT_COPY_VALUES, &B));
118 
119   PetscCall(PetscNew(&aijcrl));
120   B->spptr = (void *)aijcrl;
121 
122   /* Set function pointers for methods that we inherit from AIJ but override. */
123   B->ops->duplicate   = MatDuplicate_AIJCRL;
124   B->ops->assemblyend = MatAssemblyEnd_MPIAIJCRL;
125   B->ops->destroy     = MatDestroy_MPIAIJCRL;
126   B->ops->mult        = MatMult_AIJCRL;
127 
128   /* If A has already been assembled, compute the permutation. */
129   if (A->assembled) PetscCall(MatMPIAIJCRL_create_aijcrl(B));
130   PetscCall(PetscObjectChangeTypeName((PetscObject)B, MATMPIAIJCRL));
131   *newmat = B;
132   PetscFunctionReturn(PETSC_SUCCESS);
133 }
134 
135 /*@C
136   MatCreateMPIAIJCRL - Creates a sparse matrix of type `MATMPIAIJCRL`.
137 
138   Collective
139 
140   Input Parameters:
141 + comm - MPI communicator, set to `PETSC_COMM_SELF`
142 . m    - number of rows
143 . n    - number of columns
144 . nz   - number of nonzeros per row (same for all rows), for the "diagonal" submatrix
145 . nnz  - array containing the number of nonzeros in the various rows (possibly different for each row) or `NULL`, for the "diagonal" submatrix
146 . onz  - number of nonzeros per row (same for all rows), for the "off-diagonal" submatrix
147 - onnz - array containing the number of nonzeros in the various rows (possibly different for each row) or `NULL`, for the "off-diagonal" submatrix
148 
149   Output Parameter:
150 . A - the matrix
151 
152   Level: intermediate
153 
154   Notes:
155   This type inherits from `MATAIJ`, but stores some additional information that is used to
156   allow better vectorization of the matrix-vector product. At the cost of increased storage,
157   the AIJ formatted matrix can be copied to a format in which pieces of the matrix are stored
158   in ELLPACK format, allowing the vectorized matrix multiply routine to use stride-1 memory
159   accesses.
160 
161   If `nnz` is given then `nz` is ignored
162 
163 .seealso: [](ch_matrices), `Mat`, [Sparse Matrix Creation](sec_matsparse), `MATAIJ`, `MATAIJSELL`, `MATAIJPERM`, `MATAIJMKL`, `MatCreate()`, `MatCreateMPIAIJPERM()`, `MatSetValues()`
164 @*/
MatCreateMPIAIJCRL(MPI_Comm comm,PetscInt m,PetscInt n,PetscInt nz,const PetscInt nnz[],PetscInt onz,const PetscInt onnz[],Mat * A)165 PetscErrorCode MatCreateMPIAIJCRL(MPI_Comm comm, PetscInt m, PetscInt n, PetscInt nz, const PetscInt nnz[], PetscInt onz, const PetscInt onnz[], Mat *A)
166 {
167   PetscFunctionBegin;
168   PetscCall(MatCreate(comm, A));
169   PetscCall(MatSetSizes(*A, m, n, m, n));
170   PetscCall(MatSetType(*A, MATMPIAIJCRL));
171   PetscCall(MatMPIAIJSetPreallocation_MPIAIJ(*A, nz, (PetscInt *)nnz, onz, (PetscInt *)onnz));
172   PetscFunctionReturn(PETSC_SUCCESS);
173 }
174 
MatCreate_MPIAIJCRL(Mat A)175 PETSC_EXTERN PetscErrorCode MatCreate_MPIAIJCRL(Mat A)
176 {
177   PetscFunctionBegin;
178   PetscCall(MatSetType(A, MATMPIAIJ));
179   PetscCall(MatConvert_MPIAIJ_MPIAIJCRL(A, MATMPIAIJCRL, MAT_INPLACE_MATRIX, &A));
180   PetscFunctionReturn(PETSC_SUCCESS);
181 }
182