xref: /petsc/src/mat/impls/aij/seq/crl/crl.c (revision 2d30e087755efd99e28fdfe792ffbeb2ee1ea928)
1 
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.
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 #include <../src/mat/impls/aij/seq/crl/crl.h>
13 
14 PetscErrorCode MatDestroy_SeqAIJCRL(Mat A) {
15   Mat_AIJCRL *aijcrl = (Mat_AIJCRL *)A->spptr;
16 
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(0);
24 }
25 
26 PetscErrorCode MatDuplicate_AIJCRL(Mat A, MatDuplicateOption op, Mat *M) {
27   SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP, "Cannot duplicate AIJCRL matrices yet");
28 }
29 
30 PetscErrorCode MatSeqAIJCRL_create_aijcrl(Mat A) {
31   Mat_SeqAIJ  *a      = (Mat_SeqAIJ *)(A)->data;
32   Mat_AIJCRL  *aijcrl = (Mat_AIJCRL *)A->spptr;
33   PetscInt     m      = A->rmap->n; /* Number of rows in the matrix. */
34   PetscInt    *aj     = a->j;       /* From the CSR representation; points to the beginning  of each row. */
35   PetscInt     i, j, rmax = a->rmax, *icols, *ilen = a->ilen;
36   MatScalar   *aa = a->a;
37   PetscScalar *acols;
38 
39   PetscFunctionBegin;
40   aijcrl->nz   = a->nz;
41   aijcrl->m    = A->rmap->n;
42   aijcrl->rmax = rmax;
43 
44   PetscCall(PetscFree2(aijcrl->acols, aijcrl->icols));
45   PetscCall(PetscMalloc2(rmax * m, &aijcrl->acols, rmax * m, &aijcrl->icols));
46   acols = aijcrl->acols;
47   icols = aijcrl->icols;
48   for (i = 0; i < m; i++) {
49     for (j = 0; j < ilen[i]; j++) {
50       acols[j * m + i] = *aa++;
51       icols[j * m + i] = *aj++;
52     }
53     for (; j < rmax; j++) { /* empty column entries */
54       acols[j * m + i] = 0.0;
55       icols[j * m + i] = (j) ? icols[(j - 1) * m + i] : 0; /* handle case where row is EMPTY */
56     }
57   }
58   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));
59   PetscFunctionReturn(0);
60 }
61 
62 PetscErrorCode MatAssemblyEnd_SeqAIJCRL(Mat A, MatAssemblyType mode) {
63   Mat_SeqAIJ *a = (Mat_SeqAIJ *)A->data;
64 
65   PetscFunctionBegin;
66   a->inode.use = PETSC_FALSE;
67 
68   PetscCall(MatAssemblyEnd_SeqAIJ(A, mode));
69   if (mode == MAT_FLUSH_ASSEMBLY) PetscFunctionReturn(0);
70 
71   /* Now calculate the permutation and grouping information. */
72   PetscCall(MatSeqAIJCRL_create_aijcrl(A));
73   PetscFunctionReturn(0);
74 }
75 
76 #include <../src/mat/impls/aij/seq/crl/ftn-kernels/fmultcrl.h>
77 
78 /*
79     Shared by both sequential and parallel versions of CRL matrix: MATMPIAIJCRL and MATSEQAIJCRL
80     - the scatter is used only in the parallel version
81 
82 */
83 PetscErrorCode MatMult_AIJCRL(Mat A, Vec xx, Vec yy) {
84   Mat_AIJCRL        *aijcrl = (Mat_AIJCRL *)A->spptr;
85   PetscInt           m      = aijcrl->m; /* Number of rows in the matrix. */
86   PetscInt           rmax = aijcrl->rmax, *icols = aijcrl->icols;
87   PetscScalar       *acols = aijcrl->acols;
88   PetscScalar       *y;
89   const PetscScalar *x;
90 #if !defined(PETSC_USE_FORTRAN_KERNEL_MULTCRL)
91   PetscInt i, j, ii;
92 #endif
93 
94 #if defined(PETSC_HAVE_PRAGMA_DISJOINT)
95 #pragma disjoint(*x, *y, *aa)
96 #endif
97 
98   PetscFunctionBegin;
99   if (aijcrl->xscat) {
100     PetscCall(VecCopy(xx, aijcrl->xwork));
101     /* get remote values needed for local part of multiply */
102     PetscCall(VecScatterBegin(aijcrl->xscat, xx, aijcrl->fwork, INSERT_VALUES, SCATTER_FORWARD));
103     PetscCall(VecScatterEnd(aijcrl->xscat, xx, aijcrl->fwork, INSERT_VALUES, SCATTER_FORWARD));
104     xx = aijcrl->xwork;
105   }
106 
107   PetscCall(VecGetArrayRead(xx, &x));
108   PetscCall(VecGetArray(yy, &y));
109 
110 #if defined(PETSC_USE_FORTRAN_KERNEL_MULTCRL)
111   fortranmultcrl_(&m, &rmax, x, y, icols, acols);
112 #else
113 
114   /* first column */
115   for (j = 0; j < m; j++) y[j] = acols[j] * x[icols[j]];
116 
117     /* other columns */
118 #if defined(PETSC_HAVE_CRAY_VECTOR)
119 #pragma _CRI preferstream
120 #endif
121   for (i = 1; i < rmax; i++) {
122     ii = i * m;
123 #if defined(PETSC_HAVE_CRAY_VECTOR)
124 #pragma _CRI prefervector
125 #endif
126     for (j = 0; j < m; j++) y[j] = y[j] + acols[ii + j] * x[icols[ii + j]];
127   }
128 #if defined(PETSC_HAVE_CRAY_VECTOR)
129 #pragma _CRI ivdep
130 #endif
131 
132 #endif
133   PetscCall(PetscLogFlops(2.0 * aijcrl->nz - m));
134   PetscCall(VecRestoreArrayRead(xx, &x));
135   PetscCall(VecRestoreArray(yy, &y));
136   PetscFunctionReturn(0);
137 }
138 
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   Mat         B = *newmat;
145   Mat_AIJCRL *aijcrl;
146   PetscBool   sametype;
147 
148   PetscFunctionBegin;
149   if (reuse == MAT_INITIAL_MATRIX) PetscCall(MatDuplicate(A, MAT_COPY_VALUES, &B));
150   PetscCall(PetscObjectTypeCompare((PetscObject)A, type, &sametype));
151   if (sametype) PetscFunctionReturn(0);
152 
153   PetscCall(PetscNewLog(B, &aijcrl));
154   B->spptr = (void *)aijcrl;
155 
156   /* Set function pointers for methods that we inherit from AIJ but override. */
157   B->ops->duplicate   = MatDuplicate_AIJCRL;
158   B->ops->assemblyend = MatAssemblyEnd_SeqAIJCRL;
159   B->ops->destroy     = MatDestroy_SeqAIJCRL;
160   B->ops->mult        = MatMult_AIJCRL;
161 
162   /* If A has already been assembled, compute the permutation. */
163   if (A->assembled) PetscCall(MatSeqAIJCRL_create_aijcrl(B));
164   PetscCall(PetscObjectChangeTypeName((PetscObject)B, MATSEQAIJCRL));
165   *newmat = B;
166   PetscFunctionReturn(0);
167 }
168 
169 /*@C
170    MatCreateSeqAIJCRL - Creates a sparse matrix of type `MATSEQAIJCRL`.
171    This type inherits from `MATSEQAIJ`, but stores some additional
172    information that is used to allow better vectorization of
173    the matrix-vector product. At the cost of increased storage, the `MATSEQAIJ` formatted
174    matrix can be copied to a format in which pieces of the matrix are
175    stored in ELLPACK format, allowing the vectorized matrix multiply
176    routine to use stride-1 memory accesses.  As with the `MATSEQAIJ` type, it is
177    important to preallocate matrix storage in order to get good assembly
178    performance.
179 
180    Collective
181 
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)
187 -  nnz - array containing the number of nonzeros in the various rows
188          (possibly different for each row) or NULL
189 
190    Output Parameter:
191 .  A - the matrix
192 
193    Note:
194    If nnz is given then nz is ignored
195 
196    Level: intermediate
197 
198 .seealso: `MatCreate()`, `MatCreateMPIAIJPERM()`, `MatSetValues()`
199 @*/
200 PetscErrorCode MatCreateSeqAIJCRL(MPI_Comm comm, PetscInt m, PetscInt n, PetscInt nz, const PetscInt nnz[], Mat *A) {
201   PetscFunctionBegin;
202   PetscCall(MatCreate(comm, A));
203   PetscCall(MatSetSizes(*A, m, n, m, n));
204   PetscCall(MatSetType(*A, MATSEQAIJCRL));
205   PetscCall(MatSeqAIJSetPreallocation_SeqAIJ(*A, nz, nnz));
206   PetscFunctionReturn(0);
207 }
208 
209 PETSC_EXTERN PetscErrorCode MatCreate_SeqAIJCRL(Mat A) {
210   PetscFunctionBegin;
211   PetscCall(MatSetType(A, MATSEQAIJ));
212   PetscCall(MatConvert_SeqAIJ_SeqAIJCRL(A, MATSEQAIJCRL, MAT_INPLACE_MATRIX, &A));
213   PetscFunctionReturn(0);
214 }
215