xref: /petsc/src/mat/impls/aij/mpi/mpimattransposematmult.c (revision 967582eba84cc53dc1fbf6b54d6aa49b7d83bae6)
1 
2 /*
3   Defines matrix-matrix product routines for pairs of MPIAIJ matrices
4           C = A^T * B
5   The routines are slightly modified from MatTransposeMatMultxxx_SeqAIJ_SeqDense().
6 */
7 #include <../src/mat/impls/aij/seq/aij.h> /*I "petscmat.h" I*/
8 #include <../src/mat/impls/aij/mpi/mpiaij.h>
9 #include <../src/mat/impls/dense/mpi/mpidense.h>
10 
11 PetscErrorCode MatDestroy_MPIDense_MatTransMatMult(Mat A)
12 {
13   PetscErrorCode      ierr;
14   Mat_MPIDense        *a = (Mat_MPIDense*)A->data;
15   Mat_MatTransMatMult *atb = a->atb;
16 
17   PetscFunctionBegin;
18   ierr = MatDestroy(&atb->mA);CHKERRQ(ierr);
19   ierr = VecDestroy(&atb->bt);CHKERRQ(ierr);
20   ierr = VecDestroy(&atb->ct);CHKERRQ(ierr);
21   ierr = (atb->destroy)(A);CHKERRQ(ierr);
22   ierr = PetscFree(atb);CHKERRQ(ierr);
23   PetscFunctionReturn(0);
24 }
25 
26 PetscErrorCode MatTransposeMatMultSymbolic_MPIAIJ_MPIDense(Mat A,Mat B,PetscReal fill,Mat C)
27 {
28   PetscErrorCode      ierr;
29   PetscInt            m=A->rmap->n,n=A->cmap->n,BN=B->cmap->N;
30   Mat_MatTransMatMult *atb;
31   Vec                 bt,ct;
32   Mat_MPIDense        *c;
33 
34   PetscFunctionBegin;
35   ierr = PetscNew(&atb);CHKERRQ(ierr);
36 
37   /* create output dense matrix C = A^T*B */
38   ierr = MatSetSizes(C,n,B->cmap->n,A->cmap->N,BN);CHKERRQ(ierr);
39   ierr = MatSetType(C,MATMPIDENSE);CHKERRQ(ierr);
40   ierr = MatSetUp(C);CHKERRQ(ierr);
41 
42   /* create vectors bt and ct to hold locally transposed arrays of B and C */
43   ierr = VecCreate(PetscObjectComm((PetscObject)A),&bt);CHKERRQ(ierr);
44   ierr = VecSetSizes(bt,m*BN,PETSC_DECIDE);CHKERRQ(ierr);
45   ierr = VecSetType(bt,VECSTANDARD);CHKERRQ(ierr);
46   ierr = VecCreate(PetscObjectComm((PetscObject)A),&ct);CHKERRQ(ierr);
47   ierr = VecSetSizes(ct,n*BN,PETSC_DECIDE);CHKERRQ(ierr);
48   ierr = VecSetType(ct,VECSTANDARD);CHKERRQ(ierr);
49   atb->bt = bt;
50   atb->ct = ct;
51 
52   c                               = (Mat_MPIDense*)C->data;
53   c->atb                          = atb;
54   atb->destroy                    = C->ops->destroy;
55   C->ops->destroy                 = MatDestroy_MPIDense_MatTransMatMult;
56   C->ops->transposematmultnumeric = MatTransposeMatMultNumeric_MPIAIJ_MPIDense;
57   PetscFunctionReturn(0);
58 }
59 
60 PetscErrorCode MatTransposeMatMultNumeric_MPIAIJ_MPIDense(Mat A,Mat B,Mat C)
61 {
62   PetscErrorCode      ierr;
63   const PetscScalar   *Barray,*ctarray;
64   PetscScalar         *Carray,*btarray;
65   Mat_MPIDense        *b=(Mat_MPIDense*)B->data,*c=(Mat_MPIDense*)C->data;
66   Mat_SeqDense        *bseq=(Mat_SeqDense*)(b->A)->data,*cseq=(Mat_SeqDense*)(c->A)->data;
67   PetscInt            i,j,m=A->rmap->n,n=A->cmap->n,ldb=bseq->lda,BN=B->cmap->N,ldc=cseq->lda;
68   Mat_MatTransMatMult *atb=c->atb;
69   Vec                 bt=atb->bt,ct=atb->ct;
70 
71   PetscFunctionBegin;
72   /* create MAIJ matrix mA from A -- should be done in symbolic phase */
73   ierr = MatDestroy(&atb->mA);CHKERRQ(ierr);
74   ierr = MatCreateMAIJ(A,BN,&atb->mA);CHKERRQ(ierr);
75 
76   /* transpose local arry of B, then copy it to vector bt */
77   ierr = MatDenseGetArrayRead(B,&Barray);CHKERRQ(ierr);
78   ierr = VecGetArray(bt,&btarray);CHKERRQ(ierr);
79 
80   for (j=0; j<BN; j++) {
81     for (i=0; i<m; i++) btarray[i*BN + j] = Barray[j*ldb + i];
82   }
83   ierr = VecRestoreArray(bt,&btarray);CHKERRQ(ierr);
84   ierr = MatDenseRestoreArrayRead(B,&Barray);CHKERRQ(ierr);
85 
86   /* compute ct = mA^T * cb */
87   ierr = MatMultTranspose(atb->mA,bt,ct);CHKERRQ(ierr);
88 
89   /* transpose local array of ct to matrix C */
90   ierr = MatDenseGetArray(C,&Carray);CHKERRQ(ierr);
91   ierr = VecGetArrayRead(ct,&ctarray);CHKERRQ(ierr);
92 
93   for (j=0; j<BN; j++) {
94     for (i=0; i<n; i++) Carray[j*ldc + i] = ctarray[i*BN + j];
95   }
96   ierr = VecRestoreArrayRead(ct,&ctarray);CHKERRQ(ierr);
97   ierr = MatDenseRestoreArray(C,&Carray);CHKERRQ(ierr);
98   ierr = MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
99   ierr = MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
100   PetscFunctionReturn(0);
101 }
102