Actual source code: baijfact4.c
1: /*$Id: baijfact4.c,v 1.4 2001/03/23 23:22:07 balay Exp $*/
2: /*
3: Factorization code for BAIJ format.
4: */
5: #include src/mat/impls/baij/seq/baij.h
6: #include src/vec/vecimpl.h
7: #include src/inline/ilu.h
9: /* ----------------------------------------------------------- */
10: int MatLUFactorNumeric_SeqBAIJ_N(Mat A,Mat *B)
11: {
12: Mat C = *B;
13: Mat_SeqBAIJ *a = (Mat_SeqBAIJ*)A->data,*b = (Mat_SeqBAIJ *)C->data;
14: IS isrow = b->row,isicol = b->icol;
15: int *r,*ic,ierr,i,j,n = a->mbs,*bi = b->i,*bj = b->j;
16: int *ajtmpold,*ajtmp,nz,row,bslog,*ai=a->i,*aj=a->j,k,flg;
17: int *diag_offset=b->diag,diag,bs=a->bs,bs2 = a->bs2,*v_pivots,*pj;
18: MatScalar *ba = b->a,*aa = a->a,*pv,*v,*rtmp,*multiplier,*v_work,*pc,*w;
21: ISGetIndices(isrow,&r);
22: ISGetIndices(isicol,&ic);
23: PetscMalloc(bs2*(n+1)*sizeof(MatScalar),&rtmp);
24: PetscMemzero(rtmp,bs2*(n+1)*sizeof(MatScalar));
25: /* generate work space needed by dense LU factorization */
26: ierr = PetscMalloc(bs*sizeof(int) + (bs+bs2)*sizeof(MatScalar),&v_work);
27: multiplier = v_work + bs;
28: v_pivots = (int*)(multiplier + bs2);
30: /* flops in while loop */
31: bslog = 2*bs*bs2;
33: for (i=0; i<n; i++) {
34: nz = bi[i+1] - bi[i];
35: ajtmp = bj + bi[i];
36: for (j=0; j<nz; j++) {
37: PetscMemzero(rtmp+bs2*ajtmp[j],bs2*sizeof(MatScalar));
38: }
39: /* load in initial (unfactored row) */
40: nz = ai[r[i]+1] - ai[r[i]];
41: ajtmpold = aj + ai[r[i]];
42: v = aa + bs2*ai[r[i]];
43: for (j=0; j<nz; j++) {
44: PetscMemcpy(rtmp+bs2*ic[ajtmpold[j]],v+bs2*j,bs2*sizeof(MatScalar));
45: }
46: row = *ajtmp++;
47: while (row < i) {
48: pc = rtmp + bs2*row;
49: /* if (*pc) { */
50: for (flg=0,k=0; k<bs2; k++) { if (pc[k]!=0.0) { flg = 1; break; }}
51: if (flg) {
52: pv = ba + bs2*diag_offset[row];
53: pj = bj + diag_offset[row] + 1;
54: Kernel_A_gets_A_times_B(bs,pc,pv,multiplier);
55: nz = bi[row+1] - diag_offset[row] - 1;
56: pv += bs2;
57: for (j=0; j<nz; j++) {
58: Kernel_A_gets_A_minus_B_times_C(bs,rtmp+bs2*pj[j],pc,pv+bs2*j);
59: }
60: PetscLogFlops(bslog*(nz+1)-bs);
61: }
62: row = *ajtmp++;
63: }
64: /* finished row so stick it into b->a */
65: pv = ba + bs2*bi[i];
66: pj = bj + bi[i];
67: nz = bi[i+1] - bi[i];
68: for (j=0; j<nz; j++) {
69: PetscMemcpy(pv+bs2*j,rtmp+bs2*pj[j],bs2*sizeof(MatScalar));
70: }
71: diag = diag_offset[i] - bi[i];
72: /* invert diagonal block */
73: w = pv + bs2*diag;
74: Kernel_A_gets_inverse_A(bs,w,v_pivots,v_work);
75: }
77: PetscFree(rtmp);
78: PetscFree(v_work);
79: ISRestoreIndices(isicol,&ic);
80: ISRestoreIndices(isrow,&r);
81: C->factor = FACTOR_LU;
82: C->assembled = PETSC_TRUE;
83: PetscLogFlops(1.3333*bs*bs2*b->mbs); /* from inverting diagonal blocks */
84: return(0);
85: }