xref: /petsc/src/mat/impls/baij/mpi/mpiaijbaij.c (revision 503c0ea9b45bcfbcebbb1ea5341243bbc69f0bea)
1 
2 #include <../src/mat/impls/baij/mpi/mpibaij.h> /*I "petscmat.h" I*/
3 #include <../src/mat/impls/aij/mpi/mpiaij.h>
4 #include <petsc/private/matimpl.h>
5 #include <petscmat.h>
6 
7 PETSC_INTERN PetscErrorCode MatConvert_MPIAIJ_MPIBAIJ(Mat A, MatType newtype,MatReuse reuse,Mat *newmat)
8 {
9   Mat               M;
10   Mat_MPIAIJ        *mpimat = (Mat_MPIAIJ*)A->data;
11   Mat_SeqAIJ        *Aa     = (Mat_SeqAIJ*)mpimat->A->data,*Ba = (Mat_SeqAIJ*)mpimat->B->data;
12   PetscInt          *d_nnz,*o_nnz;
13   PetscInt          i,m,n,lm,ln,bs=PetscAbs(A->rmap->bs);
14 
15   PetscFunctionBegin;
16   if (reuse != MAT_REUSE_MATRIX) {
17     PetscCall(MatGetSize(A,&m,&n));
18     PetscCall(MatGetLocalSize(A,&lm,&ln));
19     PetscCall(PetscMalloc2(lm/bs,&d_nnz,lm/bs,&o_nnz));
20 
21     for (i=0; i<lm/bs; i++) {
22       d_nnz[i] = (Aa->i[i*bs+1] - Aa->i[i*bs])/bs;
23       o_nnz[i] = (Ba->i[i*bs+1] - Ba->i[i*bs])/bs;
24     }
25 
26     PetscCall(MatCreate(PetscObjectComm((PetscObject)A),&M));
27     PetscCall(MatSetSizes(M,lm,ln,m,n));
28     PetscCall(MatSetType(M,MATMPIBAIJ));
29     PetscCall(MatSeqBAIJSetPreallocation(M,bs,0,d_nnz));
30     PetscCall(MatMPIBAIJSetPreallocation(M,bs,0,d_nnz,0,o_nnz));
31     PetscCall(PetscFree2(d_nnz,o_nnz));
32   } else M = *newmat;
33 
34   /* reuse may not be equal to MAT_REUSE_MATRIX, but the basic converter will reallocate or replace newmat if this value is not used */
35   /* if reuse is equal to MAT_INITIAL_MATRIX, it has been appropriately preallocated before                                          */
36   /*                      MAT_INPLACE_MATRIX, it will be replaced with MatHeaderReplace below                                        */
37   PetscCall(MatConvert_Basic(A,newtype,MAT_REUSE_MATRIX,&M));
38 
39   if (reuse == MAT_INPLACE_MATRIX) {
40     PetscCall(MatHeaderReplace(A,&M));
41   } else *newmat = M;
42   PetscFunctionReturn(0);
43 }
44