xref: /petsc/src/mat/impls/aij/mpi/crl/mcrl.c (revision 3ff96bc97e95df46fbdbdf211ddbac0ba3669e66)
1 #define PETSCMAT_DLL
2 
3 /*
4   Defines a matrix-vector product for the MATMPIAIJCRL matrix class.
5   This class is derived from the MATMPIAIJ class and retains the
6   compressed row storage (aka Yale sparse matrix format) but augments
7   it with a column oriented storage that is more efficient for
8   matrix vector products on Vector machines.
9 
10   CRL stands for constant row length (that is the same number of columns
11   is kept (padded with zeros) for each row of the sparse matrix.
12 
13    See src/mat/impls/aij/seq/crl/crl.c for the sequential version
14 */
15 
16 #include "../src/mat/impls/aij/mpi/mpiaij.h"
17 #include "../src/mat/impls/aij/seq/crl/crl.h"
18 
19 extern PetscErrorCode MatDestroy_MPIAIJ(Mat);
20 
21 #undef __FUNCT__
22 #define __FUNCT__ "MatDestroy_MPICRL"
23 PetscErrorCode MatDestroy_MPICRL(Mat A)
24 {
25   PetscErrorCode ierr;
26   Mat_CRL        *crl = (Mat_CRL *) A->spptr;
27 
28   /* Free everything in the Mat_CRL data structure. */
29   ierr = PetscFree2(crl->acols,crl->icols);CHKERRQ(ierr);
30   if (crl->fwork) {
31     ierr = VecDestroy(crl->fwork);CHKERRQ(ierr);
32   }
33   if (crl->xwork) {
34     ierr = VecDestroy(crl->xwork);CHKERRQ(ierr);
35   }
36   ierr = PetscFree(crl->array);CHKERRQ(ierr);
37   ierr = PetscFree(crl);CHKERRQ(ierr);
38   A->spptr = 0;
39 
40   ierr = PetscObjectChangeTypeName( (PetscObject)A, MATMPIAIJ);CHKERRQ(ierr);
41   ierr = MatDestroy_MPIAIJ(A);CHKERRQ(ierr);
42   PetscFunctionReturn(0);
43 }
44 
45 #undef __FUNCT__
46 #define __FUNCT__ "MPICRL_create_crl"
47 PetscErrorCode MPICRL_create_crl(Mat A)
48 {
49   Mat_MPIAIJ     *a = (Mat_MPIAIJ *)(A)->data;
50   Mat_SeqAIJ     *Aij = (Mat_SeqAIJ*)(a->A->data), *Bij = (Mat_SeqAIJ*)(a->B->data);
51   Mat_CRL        *crl = (Mat_CRL*) A->spptr;
52   PetscInt       m = A->rmap->n;  /* Number of rows in the matrix. */
53   PetscInt       nd = a->A->cmap->n; /* number of columns in diagonal portion */
54   PetscInt       *aj = Aij->j,*bj = Bij->j;  /* From the CSR representation; points to the beginning  of each row. */
55   PetscInt       i, j,rmax = 0,*icols, *ailen = Aij->ilen, *bilen = Bij->ilen;
56   PetscScalar    *aa = Aij->a,*ba = Bij->a,*acols,*array;
57   PetscErrorCode ierr;
58 
59   PetscFunctionBegin;
60   /* determine the row with the most columns */
61   for (i=0; i<m; i++) {
62     rmax = PetscMax(rmax,ailen[i]+bilen[i]);
63   }
64   crl->nz   = Aij->nz+Bij->nz;
65   crl->m    = A->rmap->n;
66   crl->rmax = rmax;
67   ierr = PetscFree2(crl->acols,crl->icols);CHKERRQ(ierr);
68   ierr = PetscMalloc2(rmax*m,PetscScalar,&crl->acols,rmax*m,PetscInt,&crl->icols);CHKERRQ(ierr);
69   acols = crl->acols;
70   icols = crl->icols;
71   for (i=0; i<m; i++) {
72     for (j=0; j<ailen[i]; j++) {
73       acols[j*m+i] = *aa++;
74       icols[j*m+i] = *aj++;
75     }
76     for (;j<ailen[i]+bilen[i]; j++) {
77       acols[j*m+i] = *ba++;
78       icols[j*m+i] = nd + *bj++;
79     }
80     for (;j<rmax; j++) { /* empty column entries */
81       acols[j*m+i] = 0.0;
82       icols[j*m+i] = (j) ? icols[(j-1)*m+i] : 0;  /* handle case where row is EMPTY */
83     }
84   }
85   ierr = PetscInfo1(A,"Percentage of 0's introduced for vectorized multiply %g\n",1.0-((double)(crl->nz))/((double)(rmax*m)));
86 
87   ierr = PetscFree(crl->array);CHKERRQ(ierr);
88   ierr = PetscMalloc((a->B->cmap->n+nd)*sizeof(PetscScalar),&array);CHKERRQ(ierr);
89   /* xwork array is actually B->n+nd long, but we define xwork this length so can copy into it */
90   if (crl->xwork) {ierr = VecDestroy(crl->xwork);CHKERRQ(ierr);}
91   ierr = VecCreateMPIWithArray(((PetscObject)A)->comm,nd,PETSC_DECIDE,array,&crl->xwork);CHKERRQ(ierr);
92   if (crl->fwork) {ierr = VecDestroy(crl->fwork);CHKERRQ(ierr);}
93   ierr = VecCreateSeqWithArray(PETSC_COMM_SELF,a->B->cmap->n,array+nd,&crl->fwork);CHKERRQ(ierr);
94   crl->array = array;
95   crl->xscat = a->Mvctx;
96   PetscFunctionReturn(0);
97 }
98 
99 extern PetscErrorCode MatAssemblyEnd_MPIAIJ(Mat,MatAssemblyType);
100 
101 #undef __FUNCT__
102 #define __FUNCT__ "MatAssemblyEnd_MPICRL"
103 PetscErrorCode MatAssemblyEnd_MPICRL(Mat A, MatAssemblyType mode)
104 {
105   PetscErrorCode ierr;
106   Mat_MPIAIJ     *a = (Mat_MPIAIJ*)A->data;
107   Mat_SeqAIJ     *Aij = (Mat_SeqAIJ*)(a->A->data), *Bij = (Mat_SeqAIJ*)(a->A->data);
108 
109   PetscFunctionBegin;
110   Aij->inode.use = PETSC_FALSE;
111   Bij->inode.use = PETSC_FALSE;
112   ierr = MatAssemblyEnd_MPIAIJ(A,mode);CHKERRQ(ierr);
113   if (mode == MAT_FLUSH_ASSEMBLY) PetscFunctionReturn(0);
114 
115   /* Now calculate the permutation and grouping information. */
116   ierr = MPICRL_create_crl(A);CHKERRQ(ierr);
117   PetscFunctionReturn(0);
118 }
119 
120 extern PetscErrorCode MatMult_CRL(Mat,Vec,Vec);
121 extern PetscErrorCode MatDuplicate_CRL(Mat,MatDuplicateOption,Mat*);
122 
123 /* MatConvert_MPIAIJ_MPICRL converts a MPIAIJ matrix into a
124  * MPICRL matrix.  This routine is called by the MatCreate_MPICRL()
125  * routine, but can also be used to convert an assembled MPIAIJ matrix
126  * into a MPICRL one. */
127 EXTERN_C_BEGIN
128 #undef __FUNCT__
129 #define __FUNCT__ "MatConvert_MPIAIJ_MPICRL"
130 PetscErrorCode PETSCMAT_DLLEXPORT MatConvert_MPIAIJ_MPICRL(Mat A,const MatType type,MatReuse reuse,Mat *newmat)
131 {
132   PetscErrorCode ierr;
133   Mat            B = *newmat;
134   Mat_CRL        *crl;
135 
136   PetscFunctionBegin;
137   if (reuse == MAT_INITIAL_MATRIX) {
138     ierr = MatDuplicate(A,MAT_COPY_VALUES,&B);CHKERRQ(ierr);
139   }
140 
141   ierr = PetscNewLog(B,Mat_CRL,&crl);CHKERRQ(ierr);
142   B->spptr = (void *) crl;
143 
144   /* Set function pointers for methods that we inherit from AIJ but override. */
145   B->ops->duplicate   = MatDuplicate_CRL;
146   B->ops->assemblyend = MatAssemblyEnd_MPICRL;
147   B->ops->destroy     = MatDestroy_MPICRL;
148   B->ops->mult        = MatMult_CRL;
149 
150   /* If A has already been assembled, compute the permutation. */
151   if (A->assembled) {
152     ierr = MPICRL_create_crl(B);CHKERRQ(ierr);
153   }
154   ierr = PetscObjectChangeTypeName((PetscObject)B,MATMPICRL);CHKERRQ(ierr);
155   *newmat = B;
156   PetscFunctionReturn(0);
157 }
158 EXTERN_C_END
159 
160 
161 #undef __FUNCT__
162 #define __FUNCT__ "MatCreateMPICRL"
163 /*@C
164    MatCreateMPICRL - Creates a sparse matrix of type MPICRL.
165    This type inherits from AIJ, but stores some additional
166    information that is used to allow better vectorization of
167    the matrix-vector product. At the cost of increased storage, the AIJ formatted
168    matrix can be copied to a format in which pieces of the matrix are
169    stored in ELLPACK format, allowing the vectorized matrix multiply
170    routine to use stride-1 memory accesses.  As with the AIJ type, it is
171    important to preallocate matrix storage in order to get good assembly
172    performance.
173 
174    Collective on MPI_Comm
175 
176    Input Parameters:
177 +  comm - MPI communicator, set to PETSC_COMM_SELF
178 .  m - number of rows
179 .  n - number of columns
180 .  nz - number of nonzeros per row (same for all rows)
181 -  nnz - array containing the number of nonzeros in the various rows
182          (possibly different for each row) or PETSC_NULL
183 
184    Output Parameter:
185 .  A - the matrix
186 
187    Notes:
188    If nnz is given then nz is ignored
189 
190    Level: intermediate
191 
192 .keywords: matrix, cray, sparse, parallel
193 
194 .seealso: MatCreate(), MatCreateMPICSRPERM(), MatSetValues()
195 @*/
196 PetscErrorCode PETSCMAT_DLLEXPORT MatCreateMPICRL(MPI_Comm comm,PetscInt m,PetscInt n,PetscInt nz,const PetscInt nnz[],PetscInt onz,const PetscInt onnz[],Mat *A)
197 {
198   PetscErrorCode ierr;
199 
200   PetscFunctionBegin;
201   ierr = MatCreate(comm,A);CHKERRQ(ierr);
202   ierr = MatSetSizes(*A,m,n,m,n);CHKERRQ(ierr);
203   ierr = MatSetType(*A,MATMPICRL);CHKERRQ(ierr);
204   ierr = MatMPIAIJSetPreallocation_MPIAIJ(*A,nz,(PetscInt*)nnz,onz,(PetscInt*)onnz);CHKERRQ(ierr);
205   PetscFunctionReturn(0);
206 }
207 
208 
209 EXTERN_C_BEGIN
210 #undef __FUNCT__
211 #define __FUNCT__ "MatCreate_MPICRL"
212 PetscErrorCode PETSCMAT_DLLEXPORT MatCreate_MPICRL(Mat A)
213 {
214   PetscErrorCode ierr;
215 
216   PetscFunctionBegin;
217   ierr = MatSetType(A,MATMPIAIJ);CHKERRQ(ierr);
218   ierr = MatConvert_MPIAIJ_MPICRL(A,MATMPICRL,MAT_REUSE_MATRIX,&A);CHKERRQ(ierr);
219   PetscFunctionReturn(0);
220 }
221 EXTERN_C_END
222 
223