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