1 /* 2 Factorization code for BAIJ format. 3 */ 4 #include <../src/mat/impls/baij/seq/baij.h> 5 #include <petsc/private/kernels/blockinvert.h> 6 7 PetscErrorCode MatLUFactorNumeric_SeqBAIJ_N_inplace(Mat C, Mat A, const MatFactorInfo *info) 8 { 9 Mat_SeqBAIJ *a = (Mat_SeqBAIJ *)A->data, *b = (Mat_SeqBAIJ *)C->data; 10 IS isrow = b->row, isicol = b->icol; 11 const PetscInt *r, *ic; 12 PetscInt i, j, n = a->mbs, *bi = b->i, *bj = b->j; 13 PetscInt *ajtmpold, *ajtmp, nz, row, *ai = a->i, *aj = a->j, k, flg; 14 PetscInt *diag_offset = b->diag, diag, bs = A->rmap->bs, bs2 = a->bs2, *pj, *v_pivots; 15 MatScalar *ba = b->a, *aa = a->a, *pv, *v, *rtmp, *multiplier, *v_work, *pc, *w; 16 PetscBool allowzeropivot, zeropivotdetected; 17 18 PetscFunctionBegin; 19 PetscCall(ISGetIndices(isrow, &r)); 20 PetscCall(ISGetIndices(isicol, &ic)); 21 allowzeropivot = PetscNot(A->erroriffailure); 22 23 PetscCall(PetscCalloc1(bs2 * (n + 1), &rtmp)); 24 /* generate work space needed by dense LU factorization */ 25 PetscCall(PetscMalloc3(bs, &v_work, bs2, &multiplier, bs, &v_pivots)); 26 27 for (i = 0; i < n; i++) { 28 nz = bi[i + 1] - bi[i]; 29 ajtmp = bj + bi[i]; 30 for (j = 0; j < nz; j++) PetscCall(PetscArrayzero(rtmp + bs2 * ajtmp[j], bs2)); 31 /* load in initial (unfactored row) */ 32 nz = ai[r[i] + 1] - ai[r[i]]; 33 ajtmpold = aj + ai[r[i]]; 34 v = aa + bs2 * ai[r[i]]; 35 for (j = 0; j < nz; j++) PetscCall(PetscArraycpy(rtmp + bs2 * ic[ajtmpold[j]], v + bs2 * j, bs2)); 36 row = *ajtmp++; 37 while (row < i) { 38 pc = rtmp + bs2 * row; 39 /* if (*pc) { */ 40 for (flg = 0, k = 0; k < bs2; k++) { 41 if (pc[k] != 0.0) { 42 flg = 1; 43 break; 44 } 45 } 46 if (flg) { 47 pv = ba + bs2 * diag_offset[row]; 48 pj = bj + diag_offset[row] + 1; 49 PetscKernel_A_gets_A_times_B(bs, pc, pv, multiplier); 50 nz = bi[row + 1] - diag_offset[row] - 1; 51 pv += bs2; 52 for (j = 0; j < nz; j++) PetscKernel_A_gets_A_minus_B_times_C(bs, rtmp + bs2 * pj[j], pc, pv + bs2 * j); 53 PetscCall(PetscLogFlops(2.0 * bs * bs2 * (nz + 1.0) - bs)); 54 } 55 row = *ajtmp++; 56 } 57 /* finished row so stick it into b->a */ 58 pv = ba + bs2 * bi[i]; 59 pj = bj + bi[i]; 60 nz = bi[i + 1] - bi[i]; 61 for (j = 0; j < nz; j++) PetscCall(PetscArraycpy(pv + bs2 * j, rtmp + bs2 * pj[j], bs2)); 62 diag = diag_offset[i] - bi[i]; 63 /* invert diagonal block */ 64 w = pv + bs2 * diag; 65 66 PetscCall(PetscKernel_A_gets_inverse_A(bs, w, v_pivots, v_work, allowzeropivot, &zeropivotdetected)); 67 if (zeropivotdetected) C->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT; 68 } 69 70 PetscCall(PetscFree(rtmp)); 71 PetscCall(PetscFree3(v_work, multiplier, v_pivots)); 72 PetscCall(ISRestoreIndices(isicol, &ic)); 73 PetscCall(ISRestoreIndices(isrow, &r)); 74 75 C->ops->solve = MatSolve_SeqBAIJ_N_inplace; 76 C->ops->solvetranspose = MatSolveTranspose_SeqBAIJ_N_inplace; 77 C->assembled = PETSC_TRUE; 78 79 PetscCall(PetscLogFlops(1.333333333333 * bs * bs2 * b->mbs)); /* from inverting diagonal blocks */ 80 PetscFunctionReturn(PETSC_SUCCESS); 81 } 82