1 2 /* 3 Factorization code for BAIJ format. 4 */ 5 #include <../src/mat/impls/baij/seq/baij.h> 6 #include <petsc/private/kernels/blockinvert.h> 7 8 /* ----------------------------------------------------------- */ 9 PetscErrorCode MatLUFactorNumeric_SeqBAIJ_N_inplace(Mat C,Mat A,const MatFactorInfo *info) 10 { 11 Mat_SeqBAIJ *a = (Mat_SeqBAIJ*)A->data,*b = (Mat_SeqBAIJ*)C->data; 12 IS isrow = b->row,isicol = b->icol; 13 PetscErrorCode ierr; 14 const PetscInt *r,*ic; 15 PetscInt i,j,n = a->mbs,*bi = b->i,*bj = b->j; 16 PetscInt *ajtmpold,*ajtmp,nz,row,*ai=a->i,*aj=a->j,k,flg; 17 PetscInt *diag_offset=b->diag,diag,bs=A->rmap->bs,bs2 = a->bs2,*pj,*v_pivots; 18 MatScalar *ba = b->a,*aa = a->a,*pv,*v,*rtmp,*multiplier,*v_work,*pc,*w; 19 PetscBool allowzeropivot,zeropivotdetected; 20 21 PetscFunctionBegin; 22 ierr = ISGetIndices(isrow,&r);CHKERRQ(ierr); 23 ierr = ISGetIndices(isicol,&ic);CHKERRQ(ierr); 24 allowzeropivot = PetscNot(A->erroriffailure); 25 26 ierr = PetscMalloc1(bs2*(n+1),&rtmp);CHKERRQ(ierr); 27 ierr = PetscMemzero(rtmp,(bs2*n+1)*sizeof(MatScalar));CHKERRQ(ierr); 28 /* generate work space needed by dense LU factorization */ 29 ierr = PetscMalloc3(bs,&v_work,bs2,&multiplier,bs,&v_pivots);CHKERRQ(ierr); 30 31 for (i=0; i<n; i++) { 32 nz = bi[i+1] - bi[i]; 33 ajtmp = bj + bi[i]; 34 for (j=0; j<nz; j++) { 35 ierr = PetscMemzero(rtmp+bs2*ajtmp[j],bs2*sizeof(MatScalar));CHKERRQ(ierr); 36 } 37 /* load in initial (unfactored row) */ 38 nz = ai[r[i]+1] - ai[r[i]]; 39 ajtmpold = aj + ai[r[i]]; 40 v = aa + bs2*ai[r[i]]; 41 for (j=0; j<nz; j++) { 42 ierr = PetscMemcpy(rtmp+bs2*ic[ajtmpold[j]],v+bs2*j,bs2*sizeof(MatScalar));CHKERRQ(ierr); 43 } 44 row = *ajtmp++; 45 while (row < i) { 46 pc = rtmp + bs2*row; 47 /* if (*pc) { */ 48 for (flg=0,k=0; k<bs2; k++) { 49 if (pc[k]!=0.0) { 50 flg = 1; 51 break; 52 } 53 } 54 if (flg) { 55 pv = ba + bs2*diag_offset[row]; 56 pj = bj + diag_offset[row] + 1; 57 PetscKernel_A_gets_A_times_B(bs,pc,pv,multiplier); 58 nz = bi[row+1] - diag_offset[row] - 1; 59 pv += bs2; 60 for (j=0; j<nz; j++) { 61 PetscKernel_A_gets_A_minus_B_times_C(bs,rtmp+bs2*pj[j],pc,pv+bs2*j); 62 } 63 ierr = PetscLogFlops(2.0*bs*bs2*(nz+1.0)-bs);CHKERRQ(ierr); 64 } 65 row = *ajtmp++; 66 } 67 /* finished row so stick it into b->a */ 68 pv = ba + bs2*bi[i]; 69 pj = bj + bi[i]; 70 nz = bi[i+1] - bi[i]; 71 for (j=0; j<nz; j++) { 72 ierr = PetscMemcpy(pv+bs2*j,rtmp+bs2*pj[j],bs2*sizeof(MatScalar));CHKERRQ(ierr); 73 } 74 diag = diag_offset[i] - bi[i]; 75 /* invert diagonal block */ 76 w = pv + bs2*diag; 77 78 ierr = PetscKernel_A_gets_inverse_A(bs,w,v_pivots,v_work,allowzeropivot,&zeropivotdetected);CHKERRQ(ierr); 79 if (zeropivotdetected) C->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT; 80 } 81 82 ierr = PetscFree(rtmp);CHKERRQ(ierr); 83 ierr = PetscFree3(v_work,multiplier,v_pivots);CHKERRQ(ierr); 84 ierr = ISRestoreIndices(isicol,&ic);CHKERRQ(ierr); 85 ierr = ISRestoreIndices(isrow,&r);CHKERRQ(ierr); 86 87 C->ops->solve = MatSolve_SeqBAIJ_N_inplace; 88 C->ops->solvetranspose = MatSolveTranspose_SeqBAIJ_N_inplace; 89 C->assembled = PETSC_TRUE; 90 91 ierr = PetscLogFlops(1.333333333333*bs*bs2*b->mbs);CHKERRQ(ierr); /* from inverting diagonal blocks */ 92 PetscFunctionReturn(0); 93 } 94