1 #include <../src/mat/impls/baij/seq/baij.h> 2 #include <petsc/private/kernels/blockinvert.h> 3 4 PetscErrorCode MatSolveTranspose_SeqBAIJ_1(Mat A,Vec bb,Vec xx) 5 { 6 Mat_SeqBAIJ *a = (Mat_SeqBAIJ*)A->data; 7 IS iscol = a->col,isrow = a->row; 8 PetscErrorCode ierr; 9 const PetscInt *rout,*cout,*r,*c,*adiag = a->diag,*ai = a->i,*aj = a->j,*vi; 10 PetscInt i,n = a->mbs,j; 11 PetscInt nz; 12 PetscScalar *x,*tmp,s1; 13 const MatScalar *aa = a->a,*v; 14 const PetscScalar *b; 15 16 PetscFunctionBegin; 17 ierr = VecGetArrayRead(bb,&b);CHKERRQ(ierr); 18 ierr = VecGetArray(xx,&x);CHKERRQ(ierr); 19 tmp = a->solve_work; 20 21 ierr = ISGetIndices(isrow,&rout);CHKERRQ(ierr); r = rout; 22 ierr = ISGetIndices(iscol,&cout);CHKERRQ(ierr); c = cout; 23 24 /* copy the b into temp work space according to permutation */ 25 for (i=0; i<n; i++) tmp[i] = b[c[i]]; 26 27 /* forward solve the U^T */ 28 for (i=0; i<n; i++) { 29 v = aa + adiag[i+1] + 1; 30 vi = aj + adiag[i+1] + 1; 31 nz = adiag[i] - adiag[i+1] - 1; 32 s1 = tmp[i]; 33 s1 *= v[nz]; /* multiply by inverse of diagonal entry */ 34 for (j=0; j<nz; j++) tmp[vi[j]] -= s1*v[j]; 35 tmp[i] = s1; 36 } 37 38 /* backward solve the L^T */ 39 for (i=n-1; i>=0; i--) { 40 v = aa + ai[i]; 41 vi = aj + ai[i]; 42 nz = ai[i+1] - ai[i]; 43 s1 = tmp[i]; 44 for (j=0; j<nz; j++) tmp[vi[j]] -= s1*v[j]; 45 } 46 47 /* copy tmp into x according to permutation */ 48 for (i=0; i<n; i++) x[r[i]] = tmp[i]; 49 50 ierr = ISRestoreIndices(isrow,&rout);CHKERRQ(ierr); 51 ierr = ISRestoreIndices(iscol,&cout);CHKERRQ(ierr); 52 ierr = VecRestoreArrayRead(bb,&b);CHKERRQ(ierr); 53 ierr = VecRestoreArray(xx,&x);CHKERRQ(ierr); 54 55 ierr = PetscLogFlops(2.0*a->nz-A->cmap->n);CHKERRQ(ierr); 56 PetscFunctionReturn(0); 57 } 58 59 PetscErrorCode MatSolveTranspose_SeqBAIJ_1_inplace(Mat A,Vec bb,Vec xx) 60 { 61 Mat_SeqBAIJ *a =(Mat_SeqBAIJ*)A->data; 62 IS iscol=a->col,isrow=a->row; 63 PetscErrorCode ierr; 64 const PetscInt *r,*c,*rout,*cout; 65 const PetscInt *diag=a->diag,n=a->mbs,*vi,*ai=a->i,*aj=a->j; 66 PetscInt i,nz; 67 const MatScalar *aa=a->a,*v; 68 PetscScalar s1,*x,*t; 69 const PetscScalar *b; 70 71 PetscFunctionBegin; 72 ierr = VecGetArrayRead(bb,&b);CHKERRQ(ierr); 73 ierr = VecGetArray(xx,&x);CHKERRQ(ierr); 74 t = a->solve_work; 75 76 ierr = ISGetIndices(isrow,&rout);CHKERRQ(ierr); r = rout; 77 ierr = ISGetIndices(iscol,&cout);CHKERRQ(ierr); c = cout; 78 79 /* copy the b into temp work space according to permutation */ 80 for (i=0; i<n; i++) t[i] = b[c[i]]; 81 82 /* forward solve the U^T */ 83 for (i=0; i<n; i++) { 84 85 v = aa + diag[i]; 86 /* multiply by the inverse of the block diagonal */ 87 s1 = (*v++)*t[i]; 88 vi = aj + diag[i] + 1; 89 nz = ai[i+1] - diag[i] - 1; 90 while (nz--) { 91 t[*vi++] -= (*v++)*s1; 92 } 93 t[i] = s1; 94 } 95 /* backward solve the L^T */ 96 for (i=n-1; i>=0; i--) { 97 v = aa + diag[i] - 1; 98 vi = aj + diag[i] - 1; 99 nz = diag[i] - ai[i]; 100 s1 = t[i]; 101 while (nz--) { 102 t[*vi--] -= (*v--)*s1; 103 } 104 } 105 106 /* copy t into x according to permutation */ 107 for (i=0; i<n; i++) x[r[i]] = t[i]; 108 109 ierr = ISRestoreIndices(isrow,&rout);CHKERRQ(ierr); 110 ierr = ISRestoreIndices(iscol,&cout);CHKERRQ(ierr); 111 ierr = VecRestoreArrayRead(bb,&b);CHKERRQ(ierr); 112 ierr = VecRestoreArray(xx,&x);CHKERRQ(ierr); 113 ierr = PetscLogFlops(2.0*(a->nz) - A->cmap->n);CHKERRQ(ierr); 114 PetscFunctionReturn(0); 115 } 116