1 #include <../src/mat/impls/baij/seq/baij.h> 2 3 PetscErrorCode MatSolveTranspose_SeqBAIJ_3_NaturalOrdering_inplace(Mat A,Vec bb,Vec xx) 4 { 5 Mat_SeqBAIJ *a=(Mat_SeqBAIJ*)A->data; 6 PetscErrorCode ierr; 7 const PetscInt n=a->mbs,*vi,*ai=a->i,*aj=a->j,*diag=a->diag; 8 PetscInt i,nz,idx,idt,oidx; 9 const MatScalar *aa=a->a,*v; 10 PetscScalar s1,s2,s3,x1,x2,x3,*x; 11 12 PetscFunctionBegin; 13 ierr = VecCopy(bb,xx);CHKERRQ(ierr); 14 ierr = VecGetArray(xx,&x);CHKERRQ(ierr); 15 16 /* forward solve the U^T */ 17 idx = 0; 18 for (i=0; i<n; i++) { 19 20 v = aa + 9*diag[i]; 21 /* multiply by the inverse of the block diagonal */ 22 x1 = x[idx]; x2 = x[1+idx]; x3 = x[2+idx]; 23 s1 = v[0]*x1 + v[1]*x2 + v[2]*x3; 24 s2 = v[3]*x1 + v[4]*x2 + v[5]*x3; 25 s3 = v[6]*x1 + v[7]*x2 + v[8]*x3; 26 v += 9; 27 28 vi = aj + diag[i] + 1; 29 nz = ai[i+1] - diag[i] - 1; 30 while (nz--) { 31 oidx = 3*(*vi++); 32 x[oidx] -= v[0]*s1 + v[1]*s2 + v[2]*s3; 33 x[oidx+1] -= v[3]*s1 + v[4]*s2 + v[5]*s3; 34 x[oidx+2] -= v[6]*s1 + v[7]*s2 + v[8]*s3; 35 v += 9; 36 } 37 x[idx] = s1;x[1+idx] = s2; x[2+idx] = s3; 38 idx += 3; 39 } 40 /* backward solve the L^T */ 41 for (i=n-1; i>=0; i--) { 42 v = aa + 9*diag[i] - 9; 43 vi = aj + diag[i] - 1; 44 nz = diag[i] - ai[i]; 45 idt = 3*i; 46 s1 = x[idt]; s2 = x[1+idt]; s3 = x[2+idt]; 47 while (nz--) { 48 idx = 3*(*vi--); 49 x[idx] -= v[0]*s1 + v[1]*s2 + v[2]*s3; 50 x[idx+1] -= v[3]*s1 + v[4]*s2 + v[5]*s3; 51 x[idx+2] -= v[6]*s1 + v[7]*s2 + v[8]*s3; 52 v -= 9; 53 } 54 } 55 ierr = VecRestoreArray(xx,&x);CHKERRQ(ierr); 56 ierr = PetscLogFlops(2.0*9.0*(a->nz) - 3.0*A->cmap->n);CHKERRQ(ierr); 57 PetscFunctionReturn(0); 58 } 59 60 PetscErrorCode MatSolveTranspose_SeqBAIJ_3_NaturalOrdering(Mat A,Vec bb,Vec xx) 61 { 62 Mat_SeqBAIJ *a=(Mat_SeqBAIJ*)A->data; 63 PetscErrorCode ierr; 64 const PetscInt n=a->mbs,*vi,*ai=a->i,*aj=a->j,*diag=a->diag; 65 PetscInt nz,idx,idt,j,i,oidx; 66 const PetscInt bs =A->rmap->bs,bs2=a->bs2; 67 const MatScalar *aa=a->a,*v; 68 PetscScalar s1,s2,s3,x1,x2,x3,*x; 69 70 PetscFunctionBegin; 71 ierr = VecCopy(bb,xx);CHKERRQ(ierr); 72 ierr = VecGetArray(xx,&x);CHKERRQ(ierr); 73 74 /* forward solve the U^T */ 75 idx = 0; 76 for (i=0; i<n; i++) { 77 v = aa + bs2*diag[i]; 78 /* multiply by the inverse of the block diagonal */ 79 x1 = x[idx]; x2 = x[1+idx]; x3 = x[2+idx]; 80 s1 = v[0]*x1 + v[1]*x2 + v[2]*x3; 81 s2 = v[3]*x1 + v[4]*x2 + v[5]*x3; 82 s3 = v[6]*x1 + v[7]*x2 + v[8]*x3; 83 v -= bs2; 84 85 vi = aj + diag[i] - 1; 86 nz = diag[i] - diag[i+1] - 1; 87 for (j=0; j>-nz; j--) { 88 oidx = bs*vi[j]; 89 x[oidx] -= v[0]*s1 + v[1]*s2 + v[2]*s3; 90 x[oidx+1] -= v[3]*s1 + v[4]*s2 + v[5]*s3; 91 x[oidx+2] -= v[6]*s1 + v[7]*s2 + v[8]*s3; 92 v -= bs2; 93 } 94 x[idx] = s1;x[1+idx] = s2; x[2+idx] = s3; 95 idx += bs; 96 } 97 /* backward solve the L^T */ 98 for (i=n-1; i>=0; i--) { 99 v = aa + bs2*ai[i]; 100 vi = aj + ai[i]; 101 nz = ai[i+1] - ai[i]; 102 idt = bs*i; 103 s1 = x[idt]; s2 = x[1+idt]; s3 = x[2+idt]; 104 for (j=0; j<nz; j++) { 105 idx = bs*vi[j]; 106 x[idx] -= v[0]*s1 + v[1]*s2 + v[2]*s3; 107 x[idx+1] -= v[3]*s1 + v[4]*s2 + v[5]*s3; 108 x[idx+2] -= v[6]*s1 + v[7]*s2 + v[8]*s3; 109 v += bs2; 110 } 111 } 112 ierr = VecRestoreArray(xx,&x);CHKERRQ(ierr); 113 ierr = PetscLogFlops(2.0*bs2*(a->nz) - bs*A->cmap->n);CHKERRQ(ierr); 114 PetscFunctionReturn(0); 115 } 116