xref: /petsc/src/mat/impls/baij/seq/baijfact.c (revision ebcf1981e4b18312f7d47235aee1f2bd3ce7569e)
1 #ifndef lint
2 static char vcid[] = "$Id: baijfact.c,v 1.23 1996/05/03 19:27:07 bsmith Exp bsmith $";
3 #endif
4 /*
5     Factorization code for BAIJ format.
6 */
7 
8 #include "baij.h"
9 #include "src/inline/ilu.h"
10 
11 /*
12     The symbolic factorization code is identical to that for AIJ format,
13   except for very small changes since this is now a SeqBAIJ datastructure.
14   NOT good code reuse.
15 */
16 int MatLUFactorSymbolic_SeqBAIJ(Mat A,IS isrow,IS iscol,double f,Mat *B)
17 {
18   Mat_SeqBAIJ *a = (Mat_SeqBAIJ *) A->data, *b;
19   IS          isicol;
20   int         *r,*ic, ierr, i, n = a->mbs, *ai = a->i, *aj = a->j;
21   int         *ainew,*ajnew, jmax,*fill, *ajtmp, nz, bs = a->bs, bs2=a->bs2;
22   int         *idnew, idx, row,m,fm, nnz, nzi,len, realloc = 0,nzbd,*im;
23 
24   if (a->m != a->n) SETERRQ(1,"MatLUFactorSymbolic_SeqBAIJ:Must be square");
25   if (!isrow) SETERRQ(1,"MatLUFactorSymbolic_SeqBAIJ:Must have row permutation");
26   if (!iscol) SETERRQ(1,"MatLUFactorSymbolic_SeqBAIJ:Must have col. permutation");
27 
28   ierr = ISInvertPermutation(iscol,&isicol); CHKERRQ(ierr);
29   ISGetIndices(isrow,&r); ISGetIndices(isicol,&ic);
30 
31   /* get new row pointers */
32   ainew = (int *) PetscMalloc( (n+1)*sizeof(int) ); CHKPTRQ(ainew);
33   ainew[0] = 0;
34   /* don't know how many column pointers are needed so estimate */
35   jmax = (int) (f*ai[n] + 1);
36   ajnew = (int *) PetscMalloc( (jmax)*sizeof(int) ); CHKPTRQ(ajnew);
37   /* fill is a linked list of nonzeros in active row */
38   fill = (int *) PetscMalloc( (2*n+1)*sizeof(int)); CHKPTRQ(fill);
39   im = fill + n + 1;
40   /* idnew is location of diagonal in factor */
41   idnew = (int *) PetscMalloc( (n+1)*sizeof(int)); CHKPTRQ(idnew);
42   idnew[0] = 0;
43 
44   for ( i=0; i<n; i++ ) {
45     /* first copy previous fill into linked list */
46     nnz     = nz    = ai[r[i]+1] - ai[r[i]];
47     ajtmp   = aj + ai[r[i]];
48     fill[n] = n;
49     while (nz--) {
50       fm  = n;
51       idx = ic[*ajtmp++];
52       do {
53         m  = fm;
54         fm = fill[m];
55       } while (fm < idx);
56       fill[m]   = idx;
57       fill[idx] = fm;
58     }
59     row = fill[n];
60     while ( row < i ) {
61       ajtmp = ajnew + idnew[row] + 1;
62       nzbd  = 1 + idnew[row] - ainew[row];
63       nz    = im[row] - nzbd;
64       fm    = row;
65       while (nz-- > 0) {
66         idx = *ajtmp++;
67         nzbd++;
68         if (idx == i) im[row] = nzbd;
69         do {
70           m  = fm;
71           fm = fill[m];
72         } while (fm < idx);
73         if (fm != idx) {
74           fill[m]   = idx;
75           fill[idx] = fm;
76           fm        = idx;
77           nnz++;
78         }
79       }
80       row = fill[row];
81     }
82     /* copy new filled row into permanent storage */
83     ainew[i+1] = ainew[i] + nnz;
84     if (ainew[i+1] > jmax) {
85       /* allocate a longer ajnew */
86       int maxadd;
87       maxadd = (int) ((f*(ai[n]+1)*(n-i+5))/n);
88       if (maxadd < nnz) maxadd = (n-i)*(nnz+1);
89       jmax += maxadd;
90       ajtmp = (int *) PetscMalloc( jmax*sizeof(int) );CHKPTRQ(ajtmp);
91       PetscMemcpy(ajtmp,ajnew,ainew[i]*sizeof(int));
92       PetscFree(ajnew);
93       ajnew = ajtmp;
94       realloc++; /* count how many times we realloc */
95     }
96     ajtmp = ajnew + ainew[i];
97     fm    = fill[n];
98     nzi   = 0;
99     im[i] = nnz;
100     while (nnz--) {
101       if (fm < i) nzi++;
102       *ajtmp++ = fm;
103       fm       = fill[fm];
104     }
105     idnew[i] = ainew[i] + nzi;
106   }
107 
108   PLogInfo(A,
109     "Info:MatLUFactorSymbolic_SeqBAIJ:Reallocs %d Fill ratio:given %g needed %g\n",
110                              realloc,f,((double)ainew[n])/((double)ai[i]));
111 
112   ierr = ISRestoreIndices(isrow,&r); CHKERRQ(ierr);
113   ierr = ISRestoreIndices(isicol,&ic); CHKERRQ(ierr);
114 
115   PetscFree(fill);
116 
117   /* put together the new matrix */
118   ierr = MatCreateSeqBAIJ(A->comm,bs,bs*n,bs*n,0,PETSC_NULL,B); CHKERRQ(ierr);
119   PLogObjectParent(*B,isicol);
120   ierr = ISDestroy(isicol); CHKERRQ(ierr);
121   b = (Mat_SeqBAIJ *) (*B)->data;
122   PetscFree(b->imax);
123   b->singlemalloc = 0;
124   len             = ainew[n]*sizeof(Scalar);
125   /* the next line frees the default space generated by the Create() */
126   PetscFree(b->a); PetscFree(b->ilen);
127   b->a          = (Scalar *) PetscMalloc( len*bs2 ); CHKPTRQ(b->a);
128   b->j          = ajnew;
129   b->i          = ainew;
130   b->diag       = idnew;
131   b->ilen       = 0;
132   b->imax       = 0;
133   b->row        = isrow;
134   b->col        = iscol;
135   b->solve_work = (Scalar *) PetscMalloc( (bs*n+bs)*sizeof(Scalar));
136   CHKPTRQ(b->solve_work);
137   /* In b structure:  Free imax, ilen, old a, old j.
138      Allocate idnew, solve_work, new a, new j */
139   PLogObjectMemory(*B,(ainew[n]-n)*(sizeof(int)+sizeof(Scalar)));
140   b->maxnz = b->nz = ainew[n];
141 
142   return 0;
143 }
144 
145 /* ----------------------------------------------------------- */
146 int MatLUFactorNumeric_SeqBAIJ_N(Mat A,Mat *B)
147 {
148   Mat             C = *B;
149   Mat_SeqBAIJ     *a = (Mat_SeqBAIJ *) A->data,*b = (Mat_SeqBAIJ *)C->data;
150   IS              iscol = b->col, isrow = b->row, isicol;
151   int             *r,*ic, ierr, i, j, n = a->mbs, *bi = b->i, *bj = b->j;
152   int             *ajtmpold, *ajtmp, nz, row, bslog,*ai=a->i,*aj=a->j;
153   int             *diag_offset=b->diag,diag,bs=a->bs,bs2 = bs*bs,*v_pivots;
154   Scalar          *ba = b->a,*aa = a->a;
155   register Scalar *pv,*v,*rtmp,*multiplier,*v_work,*pc,*w;
156   register int    *pj;
157 
158   ierr  = ISInvertPermutation(iscol,&isicol); CHKERRQ(ierr);
159   PLogObjectParent(*B,isicol);
160   ierr  = ISGetIndices(isrow,&r); CHKERRQ(ierr);
161   ierr  = ISGetIndices(isicol,&ic); CHKERRQ(ierr);
162   rtmp  = (Scalar *) PetscMalloc(bs2*(n+1)*sizeof(Scalar));CHKPTRQ(rtmp);
163   PetscMemzero(rtmp,bs2*(n+1)*sizeof(Scalar));
164   /* generate work space needed by dense LU factorization */
165   v_work     = (Scalar *) PetscMalloc(bs*sizeof(int) + (bs+bs2)*sizeof(Scalar));
166                CHKPTRQ(v_work);
167   multiplier = v_work + bs;
168   v_pivots   = (int *) (multiplier + bs2);
169 
170   /* flops in while loop */
171   bslog = 2*bs*bs2;
172 
173   for ( i=0; i<n; i++ ) {
174     nz    = bi[i+1] - bi[i];
175     ajtmp = bj + bi[i];
176     for  ( j=0; j<nz; j++ ) {
177       PetscMemzero(rtmp+bs2*ajtmp[j],bs2*sizeof(Scalar));
178     }
179     /* load in initial (unfactored row) */
180     nz       = ai[r[i]+1] - ai[r[i]];
181     ajtmpold = aj + ai[r[i]];
182     v        = aa + bs2*ai[r[i]];
183     for ( j=0; j<nz; j++ ) {
184       PetscMemcpy(rtmp+bs2*ic[ajtmpold[j]],v+bs2*j,bs2*sizeof(Scalar));
185     }
186     row = *ajtmp++;
187     while (row < i) {
188       pc = rtmp + bs2*row;
189 /*      if (*pc) { */
190         pv = ba + bs2*diag_offset[row];
191         pj = bj + diag_offset[row] + 1;
192         Kernel_A_gets_A_times_B(bs,pc,pv,multiplier);
193         nz = bi[row+1] - diag_offset[row] - 1;
194         pv += bs2;
195         for (j=0; j<nz; j++) {
196           Kernel_A_gets_A_minus_B_times_C(bs,rtmp+bs2*pj[j],pc,pv+bs2*j);
197         }
198         PLogFlops(bslog*(nz+1)-bs);
199 /*      } */
200         row = *ajtmp++;
201     }
202     /* finished row so stick it into b->a */
203     pv = ba + bs2*bi[i];
204     pj = bj + bi[i];
205     nz = bi[i+1] - bi[i];
206     for ( j=0; j<nz; j++ ) {
207       PetscMemcpy(pv+bs2*j,rtmp+bs2*pj[j],bs2*sizeof(Scalar));
208     }
209     diag = diag_offset[i] - bi[i];
210     /* invert diagonal block */
211     w = pv + bs2*diag;
212     Kernel_A_gets_inverse_A(bs,w,v_pivots,v_work);
213   }
214 
215   PetscFree(rtmp); PetscFree(v_work);
216   ierr = ISRestoreIndices(isicol,&ic); CHKERRQ(ierr);
217   ierr = ISRestoreIndices(isrow,&r); CHKERRQ(ierr);
218   ierr = ISDestroy(isicol); CHKERRQ(ierr);
219   C->factor = FACTOR_LU;
220   C->assembled = PETSC_TRUE;
221   PLogFlops(1.3333*bs*bs2*b->mbs); /* from inverting diagonal blocks */
222   return 0;
223 }
224 /* ------------------------------------------------------------*/
225 /*
226       Version for when blocks are 5 by 5
227 */
228 int MatLUFactorNumeric_SeqBAIJ_5(Mat A,Mat *B)
229 {
230   Mat             C = *B;
231   Mat_SeqBAIJ     *a = (Mat_SeqBAIJ *) A->data,*b = (Mat_SeqBAIJ *)C->data;
232   IS              iscol = b->col, isrow = b->row, isicol;
233   int             *r,*ic, ierr, i, j, n = a->mbs, *bi = b->i, *bj = b->j;
234   int             *ajtmpold, *ajtmp, nz, row, v_pivots[5];
235   int             *diag_offset = b->diag,bs = 5,idx,*ai=a->i,*aj=a->j;
236   register Scalar *pv,*v,*rtmp,*pc,*w,*x;
237   Scalar          p1,p2,p3,p4,v_work[5],m1,m2,m3,m4,m5,m6,m7,m8,m9,x1,x2,x3,x4;
238   Scalar          p5,p6,p7,p8,p9,x5,x6,x7,x8,x9,x10,x11,x12,x13,x14,x15,x16;
239   Scalar          x17,x18,x19,x20,x21,x22,x23,x24,x25,p10,p11,p12,p13,p14;
240   Scalar          p15,p16,p17,p18,p19,p20,p21,p22,p23,p24,p25,m10,m11,m12;
241   Scalar          m13,m14,m15,m16,m17,m18,m19,m20,m21,m22,m23,m24,m25;
242   Scalar          *ba = b->a,*aa = a->a;
243   register int    *pj;
244 
245   ierr  = ISInvertPermutation(iscol,&isicol); CHKERRQ(ierr);
246   PLogObjectParent(*B,isicol);
247   ierr  = ISGetIndices(isrow,&r); CHKERRQ(ierr);
248   ierr  = ISGetIndices(isicol,&ic); CHKERRQ(ierr);
249   rtmp  = (Scalar *) PetscMalloc(25*(n+1)*sizeof(Scalar));CHKPTRQ(rtmp);
250 
251   for ( i=0; i<n; i++ ) {
252     nz    = bi[i+1] - bi[i];
253     ajtmp = bj + bi[i];
254     for  ( j=0; j<nz; j++ ) {
255       x = rtmp+25*ajtmp[j];
256       x[0] = x[1] = x[2] = x[3] = x[4] = x[5] = x[6] = x[7] = x[8] = x[9] = 0.0;
257       x[10] = x[11] = x[12] = x[13] = x[14] = x[15] = x[16] = x[17] = 0.0;
258       x[18] = x[19] = x[20] = x[21] = x[22] = x[23] = x[24] = 0.0;
259     }
260     /* load in initial (unfactored row) */
261     idx      = r[i];
262     nz       = ai[idx+1] - ai[idx];
263     ajtmpold = aj + ai[idx];
264     v        = aa + 25*ai[idx];
265     for ( j=0; j<nz; j++ ) {
266       x    = rtmp+25*ic[ajtmpold[j]];
267       x[0] = v[0]; x[1] = v[1]; x[2] = v[2]; x[3] = v[3];
268       x[4] = v[4]; x[5] = v[5]; x[6] = v[6]; x[7] = v[7]; x[8] = v[8];
269       x[9] = v[9]; x[10] = v[10]; x[11] = v[11]; x[12] = v[12]; x[13] = v[13];
270       x[14] = v[14]; x[15] = v[15]; x[16] = v[16]; x[17] = v[17];
271       x[18] = v[18]; x[19] = v[19]; x[20] = v[20]; x[21] = v[21];
272       x[22] = v[22]; x[23] = v[23]; x[24] = v[24];
273       v    += 25;
274     }
275     row = *ajtmp++;
276     while (row < i) {
277       pc = rtmp + 25*row;
278       p1 = pc[0]; p2 = pc[1]; p3 = pc[2]; p4 = pc[3];
279       p5 = pc[4]; p6 = pc[5]; p7 = pc[6]; p8 = pc[7]; p9 = pc[8];
280       p10 = pc[9]; p11 = pc[10]; p12 = pc[11]; p13 = pc[12]; p14 = pc[13];
281       p15 = pc[14]; p16 = pc[15]; p17 = pc[16]; p18 = pc[17]; p19 = pc[18];
282       p20 = pc[19]; p21 = pc[20]; p22 = pc[21]; p23 = pc[22]; p24 = pc[23];
283       p25 = pc[24];
284       if (p1 != 0.0 || p2 != 0.0 || p3 != 0.0 || p4 != 0.0 || p5 != 0.0 ||
285           p6 != 0.0 || p7 != 0.0 || p8 != 0.0 || p9 != 0.0 || p10 != 0.0 ||
286           p11 != 0.0 || p12 != 0.0 || p13 != 0.0 || p14 != 0.0 || p15 != 0.0
287           || p16 != 0.0 || p17 != 0.0 || p18 != 0.0 || p19 != 0.0 ||
288           p20 != 0.0 || p21 != 0.0 || p22 != 0.0 || p23 != 0.0 ||
289           p24 != 0.0 || p25 != 0.0) {
290         pv = ba + 25*diag_offset[row];
291         pj = bj + diag_offset[row] + 1;
292         x1 = pv[0]; x2 = pv[1]; x3 = pv[2]; x4 = pv[3];
293         x5 = pv[4]; x6 = pv[5]; x7 = pv[6]; x8 = pv[7]; x9 = pv[8];
294         x10 = pv[9]; x11 = pv[10]; x12 = pv[11]; x13 = pv[12]; x14 = pv[13];
295         x15 = pv[14]; x16 = pv[15]; x17 = pv[16]; x18 = pv[17];
296         x19 = pv[18]; x20 = pv[19]; x21 = pv[20]; x22 = pv[21];
297         x23 = pv[22]; x24 = pv[23]; x25 = pv[24];
298         pc[0] = m1 = p1*x1 + p6*x2  + p11*x3 + p16*x4 + p21*x5;
299         pc[1] = m2 = p2*x1 + p7*x2  + p12*x3 + p17*x4 + p22*x5;
300         pc[2] = m3 = p3*x1 + p8*x2  + p13*x3 + p18*x4 + p23*x5;
301         pc[3] = m4 = p4*x1 + p9*x2  + p14*x3 + p19*x4 + p24*x5;
302         pc[4] = m5 = p5*x1 + p10*x2 + p15*x3 + p20*x4 + p25*x5;
303 
304         pc[5] = m6 = p1*x6 + p6*x7  + p11*x8 + p16*x9 + p21*x10;
305         pc[6] = m7 = p2*x6 + p7*x7  + p12*x8 + p17*x9 + p22*x10;
306         pc[7] = m8 = p3*x6 + p8*x7  + p13*x8 + p18*x9 + p23*x10;
307         pc[8] = m9 = p4*x6 + p9*x7  + p14*x8 + p19*x9 + p24*x10;
308         pc[9] = m10 = p5*x6 + p10*x7 + p15*x8 + p20*x9 + p25*x10;
309 
310         pc[10] = m11 = p1*x11 + p6*x12  + p11*x13 + p16*x14 + p21*x15;
311         pc[11] = m12 = p2*x11 + p7*x12  + p12*x13 + p17*x14 + p22*x15;
312         pc[12] = m13 = p3*x11 + p8*x12  + p13*x13 + p18*x14 + p23*x15;
313         pc[13] = m14 = p4*x11 + p9*x12  + p14*x13 + p19*x14 + p24*x15;
314         pc[14] = m15 = p5*x11 + p10*x12 + p15*x13 + p20*x14 + p25*x15;
315 
316         pc[15] = m16 = p1*x16 + p6*x17  + p11*x18 + p16*x19 + p21*x20;
317         pc[16] = m17 = p2*x16 + p7*x17  + p12*x18 + p17*x19 + p22*x20;
318         pc[17] = m18 = p3*x16 + p8*x17  + p13*x18 + p18*x19 + p23*x20;
319         pc[18] = m19 = p4*x16 + p9*x17  + p14*x18 + p19*x19 + p24*x20;
320         pc[19] = m20 = p5*x16 + p10*x17 + p15*x18 + p20*x19 + p25*x20;
321 
322         pc[20] = m21 = p1*x21 + p6*x22  + p11*x23 + p16*x24 + p21*x25;
323         pc[21] = m22 = p2*x21 + p7*x22  + p12*x23 + p17*x24 + p22*x25;
324         pc[22] = m23 = p3*x21 + p8*x22  + p13*x23 + p18*x24 + p23*x25;
325         pc[23] = m24 = p4*x21 + p9*x22  + p14*x23 + p19*x24 + p24*x25;
326         pc[24] = m25 = p5*x21 + p10*x22 + p15*x23 + p20*x24 + p25*x25;
327 
328         nz = bi[row+1] - diag_offset[row] - 1;
329         pv += 25;
330         for (j=0; j<nz; j++) {
331           x1   = pv[0];  x2 = pv[1];   x3  = pv[2];  x4  = pv[3];
332           x5   = pv[4];  x6 = pv[5];   x7  = pv[6];  x8  = pv[7]; x9 = pv[8];
333           x10  = pv[9];  x11 = pv[10]; x12 = pv[11]; x13 = pv[12];
334           x14  = pv[13]; x15 = pv[14]; x16 = pv[15]; x17 = pv[16];
335           x18  = pv[17]; x19 = pv[18]; x20 = pv[19]; x21 = pv[20];
336           x22  = pv[21]; x23 = pv[22]; x24 = pv[23]; x25 = pv[24];
337           x    = rtmp + 25*pj[j];
338           x[0] -= m1*x1 + m6*x2  + m11*x3 + m16*x4 + m21*x5;
339           x[1] -= m2*x1 + m7*x2  + m12*x3 + m17*x4 + m22*x5;
340           x[2] -= m3*x1 + m8*x2  + m13*x3 + m18*x4 + m23*x5;
341           x[3] -= m4*x1 + m9*x2  + m14*x3 + m19*x4 + m24*x5;
342           x[4] -= m5*x1 + m10*x2 + m15*x3 + m20*x4 + m25*x5;
343 
344           x[5] -= m1*x6 + m6*x7  + m11*x8 + m16*x9 + m21*x10;
345           x[6] -= m2*x6 + m7*x7  + m12*x8 + m17*x9 + m22*x10;
346           x[7] -= m3*x6 + m8*x7  + m13*x8 + m18*x9 + m23*x10;
347           x[8] -= m4*x6 + m9*x7  + m14*x8 + m19*x9 + m24*x10;
348           x[9] -= m5*x6 + m10*x7 + m15*x8 + m20*x9 + m25*x10;
349 
350           x[10] -= m1*x11 + m6*x12  + m11*x13 + m16*x14 + m21*x15;
351           x[11] -= m2*x11 + m7*x12  + m12*x13 + m17*x14 + m22*x15;
352           x[12] -= m3*x11 + m8*x12  + m13*x13 + m18*x14 + m23*x15;
353           x[13] -= m4*x11 + m9*x12  + m14*x13 + m19*x14 + m24*x15;
354           x[14] -= m5*x11 + m10*x12 + m15*x13 + m20*x14 + m25*x15;
355 
356           x[15] -= m1*x16 + m6*x17  + m11*x18 + m16*x19 + m21*x20;
357           x[16] -= m2*x16 + m7*x17  + m12*x18 + m17*x19 + m22*x20;
358           x[17] -= m3*x16 + m8*x17  + m13*x18 + m18*x19 + m23*x20;
359           x[18] -= m4*x16 + m9*x17  + m14*x18 + m19*x19 + m24*x20;
360           x[19] -= m5*x16 + m10*x17 + m15*x18 + m20*x19 + m25*x20;
361 
362           x[20] -= m1*x21 + m6*x22  + m11*x23 + m16*x24 + m21*x25;
363           x[21] -= m2*x21 + m7*x22  + m12*x23 + m17*x24 + m22*x25;
364           x[22] -= m3*x21 + m8*x22  + m13*x23 + m18*x24 + m23*x25;
365           x[23] -= m4*x21 + m9*x22  + m14*x23 + m19*x24 + m24*x25;
366           x[24] -= m5*x21 + m10*x22 + m15*x23 + m20*x24 + m25*x25;
367 
368           pv   += 25;
369         }
370         PLogFlops(250*nz+225);
371       }
372       row = *ajtmp++;
373     }
374     /* finished row so stick it into b->a */
375     pv = ba + 25*bi[i];
376     pj = bj + bi[i];
377     nz = bi[i+1] - bi[i];
378     for ( j=0; j<nz; j++ ) {
379       x     = rtmp+25*pj[j];
380       pv[0] = x[0]; pv[1] = x[1]; pv[2] = x[2]; pv[3] = x[3];
381       pv[4] = x[4]; pv[5] = x[5]; pv[6] = x[6]; pv[7] = x[7]; pv[8] = x[8];
382       pv[9] = x[9]; pv[10] = x[10]; pv[11] = x[11]; pv[12] = x[12];
383       pv[13] = x[13]; pv[14] = x[14]; pv[15] = x[15]; pv[16] = x[16];
384       pv[17] = x[17]; pv[18] = x[18]; pv[19] = x[19]; pv[20] = x[20];
385       pv[21] = x[21]; pv[22] = x[22]; pv[23] = x[23]; pv[24] = x[24];
386       pv   += 25;
387     }
388     /* invert diagonal block */
389     w = ba + 25*diag_offset[i];
390     Kernel_A_gets_inverse_A(bs,w,v_pivots,v_work);
391   }
392 
393   PetscFree(rtmp);
394   ierr = ISRestoreIndices(isicol,&ic); CHKERRQ(ierr);
395   ierr = ISRestoreIndices(isrow,&r); CHKERRQ(ierr);
396   ierr = ISDestroy(isicol); CHKERRQ(ierr);
397   C->factor = FACTOR_LU;
398   C->assembled = PETSC_TRUE;
399   PLogFlops(1.3333*125*b->mbs); /* from inverting diagonal blocks */
400   return 0;
401 }
402 
403 /* ------------------------------------------------------------*/
404 /*
405       Version for when blocks are 4 by 4
406 */
407 int MatLUFactorNumeric_SeqBAIJ_4(Mat A,Mat *B)
408 {
409   Mat             C = *B;
410   Mat_SeqBAIJ     *a = (Mat_SeqBAIJ *) A->data,*b = (Mat_SeqBAIJ *)C->data;
411   IS              iscol = b->col, isrow = b->row, isicol;
412   int             *r,*ic, ierr, i, j, n = a->mbs, *bi = b->i, *bj = b->j;
413   int             *ajtmpold, *ajtmp, nz, row, v_pivots[4];
414   int             *diag_offset = b->diag,bs = 4,idx,*ai=a->i,*aj=a->j;
415   register Scalar *pv,*v,*rtmp,*pc,*w,*x;
416   Scalar          p1,p2,p3,p4,v_work[4],m1,m2,m3,m4,m5,m6,m7,m8,m9,x1,x2,x3,x4;
417   Scalar          p5,p6,p7,p8,p9,x5,x6,x7,x8,x9,x10,x11,x12,x13,x14,x15,x16;
418   Scalar          p10,p11,p12,p13,p14,p15,p16,m10,m11,m12;
419   Scalar          m13,m14,m15,m16;
420   Scalar          *ba = b->a,*aa = a->a;
421   register int    *pj;
422 
423   ierr  = ISInvertPermutation(iscol,&isicol); CHKERRQ(ierr);
424   PLogObjectParent(*B,isicol);
425   ierr  = ISGetIndices(isrow,&r); CHKERRQ(ierr);
426   ierr  = ISGetIndices(isicol,&ic); CHKERRQ(ierr);
427   rtmp  = (Scalar *) PetscMalloc(16*(n+1)*sizeof(Scalar));CHKPTRQ(rtmp);
428 
429   for ( i=0; i<n; i++ ) {
430     nz    = bi[i+1] - bi[i];
431     ajtmp = bj + bi[i];
432     for  ( j=0; j<nz; j++ ) {
433       x = rtmp+16*ajtmp[j];
434       x[0] = x[1] = x[2] = x[3] = x[4] = x[5] = x[6] = x[7] = x[8] = x[9] = 0.0;
435       x[10] = x[11] = x[12] = x[13] = x[14] = x[15] = 0.0;
436     }
437     /* load in initial (unfactored row) */
438     idx      = r[i];
439     nz       = ai[idx+1] - ai[idx];
440     ajtmpold = aj + ai[idx];
441     v        = aa + 16*ai[idx];
442     for ( j=0; j<nz; j++ ) {
443       x    = rtmp+16*ic[ajtmpold[j]];
444       x[0] = v[0]; x[1] = v[1]; x[2] = v[2]; x[3] = v[3];
445       x[4] = v[4]; x[5] = v[5]; x[6] = v[6]; x[7] = v[7]; x[8] = v[8];
446       x[9] = v[9]; x[10] = v[10]; x[11] = v[11]; x[12] = v[12]; x[13] = v[13];
447       x[14] = v[14]; x[15] = v[15];
448       v    += 16;
449     }
450     row = *ajtmp++;
451     while (row < i) {
452       pc = rtmp + 16*row;
453       p1 = pc[0]; p2 = pc[1]; p3 = pc[2]; p4 = pc[3];
454       p5 = pc[4]; p6 = pc[5]; p7 = pc[6]; p8 = pc[7]; p9 = pc[8];
455       p10 = pc[9]; p11 = pc[10]; p12 = pc[11]; p13 = pc[12]; p14 = pc[13];
456       p15 = pc[14]; p16 = pc[15];
457       if (p1 != 0.0 || p2 != 0.0 || p3 != 0.0 || p4 != 0.0 || p5 != 0.0 ||
458           p6 != 0.0 || p7 != 0.0 || p8 != 0.0 || p9 != 0.0 || p10 != 0.0 ||
459           p11 != 0.0 || p12 != 0.0 || p13 != 0.0 || p14 != 0.0 || p15 != 0.0
460           || p16 != 0.0) {
461         pv = ba + 16*diag_offset[row];
462         pj = bj + diag_offset[row] + 1;
463         x1 = pv[0]; x2 = pv[1]; x3 = pv[2]; x4 = pv[3];
464         x5 = pv[4]; x6 = pv[5]; x7 = pv[6]; x8 = pv[7]; x9 = pv[8];
465         x10 = pv[9]; x11 = pv[10]; x12 = pv[11]; x13 = pv[12]; x14 = pv[13];
466         x15 = pv[14]; x16 = pv[15];
467         pc[0] = m1 = p1*x1 + p5*x2  + p9*x3  + p13*x4;
468         pc[1] = m2 = p2*x1 + p6*x2  + p10*x3 + p14*x4;
469         pc[2] = m3 = p3*x1 + p7*x2  + p11*x3 + p15*x4;
470         pc[3] = m4 = p4*x1 + p8*x2  + p12*x3 + p16*x4;
471 
472         pc[4] = m5 = p1*x5 + p5*x6  + p9*x7  + p13*x8;
473         pc[5] = m6 = p2*x5 + p6*x6  + p10*x7 + p14*x8;
474         pc[6] = m7 = p3*x5 + p7*x6  + p11*x7 + p15*x8;
475         pc[7] = m8 = p4*x5 + p8*x6  + p12*x7 + p16*x8;
476 
477         pc[8]  = m9  = p1*x9 + p5*x10  + p9*x11  + p13*x12;
478         pc[9]  = m10 = p2*x9 + p6*x10  + p10*x11 + p14*x12;
479         pc[10] = m11 = p3*x9 + p7*x10  + p11*x11 + p15*x12;
480         pc[11] = m12 = p4*x9 + p8*x10  + p12*x11 + p16*x12;
481 
482         pc[12] = m13 = p1*x13 + p5*x14  + p9*x15  + p13*x16;
483         pc[13] = m14 = p2*x13 + p6*x14  + p10*x15 + p14*x16;
484         pc[14] = m15 = p3*x13 + p7*x14  + p11*x15 + p15*x16;
485         pc[15] = m16 = p4*x13 + p8*x14  + p12*x15 + p16*x16;
486 
487         nz = bi[row+1] - diag_offset[row] - 1;
488         pv += 16;
489         for (j=0; j<nz; j++) {
490           x1   = pv[0];  x2 = pv[1];   x3  = pv[2];  x4  = pv[3];
491           x5   = pv[4];  x6 = pv[5];   x7  = pv[6];  x8  = pv[7]; x9 = pv[8];
492           x10  = pv[9];  x11 = pv[10]; x12 = pv[11]; x13 = pv[12];
493           x14  = pv[13]; x15 = pv[14]; x16 = pv[15];
494           x    = rtmp + 16*pj[j];
495           x[0] -= m1*x1 + m5*x2  + m9*x3 + m13*x4;
496           x[1] -= m2*x1 + m6*x2  + m10*x3 + m14*x4;
497           x[2] -= m3*x1 + m7*x2  + m11*x3 + m15*x4;
498           x[3] -= m4*x1 + m8*x2  + m12*x3 + m16*x4;
499 
500           x[4] -= m1*x5 + m5*x6  + m9*x7  + m13*x8;
501           x[5] -= m2*x5 + m6*x6  + m10*x7 + m14*x8;
502           x[6] -= m3*x5 + m7*x6  + m11*x7 + m15*x8;
503           x[7] -= m4*x5 + m8*x6  + m12*x7 + m16*x8;
504 
505           x[8] -= m1*x9  + m5*x10  + m9*x11 + m13*x12;
506           x[9] -= m2*x9  + m6*x10  + m10*x11 + m14*x12;
507           x[10] -= m3*x9 + m7*x10  + m11*x11 + m15*x12;
508           x[11] -= m4*x9 + m8*x10  + m12*x11 + m16*x12;
509 
510           x[12] -= m1*x13 + m5*x14  + m9*x15 + m13*x16;
511           x[13] -= m2*x13 + m6*x14  + m10*x15 + m14*x16;
512           x[14] -= m3*x13 + m7*x14  + m11*x15 + m15*x16;
513           x[15] -= m4*x13 + m8*x14  + m12*x15 + m16*x16;
514 
515           pv   += 16;
516         }
517         PLogFlops(128*nz+112);
518       }
519       row = *ajtmp++;
520     }
521     /* finished row so stick it into b->a */
522     pv = ba + 16*bi[i];
523     pj = bj + bi[i];
524     nz = bi[i+1] - bi[i];
525     for ( j=0; j<nz; j++ ) {
526       x     = rtmp+16*pj[j];
527       pv[0] = x[0]; pv[1] = x[1]; pv[2] = x[2]; pv[3] = x[3];
528       pv[4] = x[4]; pv[5] = x[5]; pv[6] = x[6]; pv[7] = x[7]; pv[8] = x[8];
529       pv[9] = x[9]; pv[10] = x[10]; pv[11] = x[11]; pv[12] = x[12];
530       pv[13] = x[13]; pv[14] = x[14]; pv[15] = x[15];
531       pv   += 16;
532     }
533     /* invert diagonal block */
534     w = ba + 16*diag_offset[i];
535     Kernel_A_gets_inverse_A(bs,w,v_pivots,v_work);
536   }
537 
538   PetscFree(rtmp);
539   ierr = ISRestoreIndices(isicol,&ic); CHKERRQ(ierr);
540   ierr = ISRestoreIndices(isrow,&r); CHKERRQ(ierr);
541   ierr = ISDestroy(isicol); CHKERRQ(ierr);
542   C->factor = FACTOR_LU;
543   C->assembled = PETSC_TRUE;
544   PLogFlops(1.3333*64*b->mbs); /* from inverting diagonal blocks */
545   return 0;
546 }
547 /* ------------------------------------------------------------*/
548 /*
549       Version for when blocks are 3 by 3
550 */
551 int MatLUFactorNumeric_SeqBAIJ_3(Mat A,Mat *B)
552 {
553   Mat             C = *B;
554   Mat_SeqBAIJ     *a = (Mat_SeqBAIJ *) A->data,*b = (Mat_SeqBAIJ *)C->data;
555   IS              iscol = b->col, isrow = b->row, isicol;
556   int             *r,*ic, ierr, i, j, n = a->mbs, *bi = b->i, *bj = b->j;
557   int             *ajtmpold, *ajtmp, nz, row, *ai=a->i,*aj=a->j;
558   int             *diag_offset = b->diag,idx;
559   register Scalar *pv,*v,*rtmp,*pc,*w,*x;
560   Scalar          p1,p2,p3,p4,m1,m2,m3,m4,m5,m6,m7,m8,m9,x1,x2,x3,x4;
561   Scalar          p5,p6,p7,p8,p9,x5,x6,x7,x8,x9;
562   Scalar          *ba = b->a,*aa = a->a;
563   register int    *pj;
564 
565   ierr  = ISInvertPermutation(iscol,&isicol); CHKERRQ(ierr);
566   PLogObjectParent(*B,isicol);
567   ierr  = ISGetIndices(isrow,&r); CHKERRQ(ierr);
568   ierr  = ISGetIndices(isicol,&ic); CHKERRQ(ierr);
569   rtmp  = (Scalar *) PetscMalloc(9*(n+1)*sizeof(Scalar));CHKPTRQ(rtmp);
570 
571   for ( i=0; i<n; i++ ) {
572     nz    = bi[i+1] - bi[i];
573     ajtmp = bj + bi[i];
574     for  ( j=0; j<nz; j++ ) {
575       x = rtmp + 9*ajtmp[j];
576       x[0] = x[1] = x[2] = x[3] = x[4] = x[5] = x[6] = x[7] = x[8] = x[9] = 0.0;
577     }
578     /* load in initial (unfactored row) */
579     idx      = r[i];
580     nz       = ai[idx+1] - ai[idx];
581     ajtmpold = aj + ai[idx];
582     v        = aa + 9*ai[idx];
583     for ( j=0; j<nz; j++ ) {
584       x    = rtmp + 9*ic[ajtmpold[j]];
585       x[0] = v[0]; x[1] = v[1]; x[2] = v[2]; x[3] = v[3];
586       x[4] = v[4]; x[5] = v[5]; x[6] = v[6]; x[7] = v[7]; x[8] = v[8];
587       v    += 9;
588     }
589     row = *ajtmp++;
590     while (row < i) {
591       pc = rtmp + 9*row;
592       p1 = pc[0]; p2 = pc[1]; p3 = pc[2]; p4 = pc[3];
593       p5 = pc[4]; p6 = pc[5]; p7 = pc[6]; p8 = pc[7]; p9 = pc[8];
594       if (p1 != 0.0 || p2 != 0.0 || p3 != 0.0 || p4 != 0.0 || p5 != 0.0 ||
595           p6 != 0.0 || p7 != 0.0 || p8 != 0.0 || p9 != 0.0) {
596         pv = ba + 9*diag_offset[row];
597         pj = bj + diag_offset[row] + 1;
598         x1 = pv[0]; x2 = pv[1]; x3 = pv[2]; x4 = pv[3];
599         x5 = pv[4]; x6 = pv[5]; x7 = pv[6]; x8 = pv[7]; x9 = pv[8];
600         pc[0] = m1 = p1*x1 + p4*x2 + p7*x3;
601         pc[1] = m2 = p2*x1 + p5*x2 + p8*x3;
602         pc[2] = m3 = p3*x1 + p6*x2 + p9*x3;
603 
604         pc[3] = m4 = p1*x4 + p4*x5 + p7*x6;
605         pc[4] = m5 = p2*x4 + p5*x5 + p8*x6;
606         pc[5] = m6 = p3*x4 + p6*x5 + p9*x6;
607 
608         pc[6] = m7 = p1*x7 + p4*x8 + p7*x9;
609         pc[7] = m8 = p2*x7 + p5*x8 + p8*x9;
610         pc[8] = m9 = p3*x7 + p6*x8 + p9*x9;
611         nz = bi[row+1] - diag_offset[row] - 1;
612         pv += 9;
613         for (j=0; j<nz; j++) {
614           x1   = pv[0]; x2 = pv[1]; x3 = pv[2]; x4 = pv[3];
615           x5   = pv[4]; x6 = pv[5]; x7 = pv[6]; x8 = pv[7]; x9 = pv[8];
616           x    = rtmp + 9*pj[j];
617           x[0] -= m1*x1 + m4*x2 + m7*x3;
618           x[1] -= m2*x1 + m5*x2 + m8*x3;
619           x[2] -= m3*x1 + m6*x2 + m9*x3;
620 
621           x[3] -= m1*x4 + m4*x5 + m7*x6;
622           x[4] -= m2*x4 + m5*x5 + m8*x6;
623           x[5] -= m3*x4 + m6*x5 + m9*x6;
624 
625           x[6] -= m1*x7 + m4*x8 + m7*x9;
626           x[7] -= m2*x7 + m5*x8 + m8*x9;
627           x[8] -= m3*x7 + m6*x8 + m9*x9;
628           pv   += 9;
629         }
630         PLogFlops(54*nz+36);
631       }
632       row = *ajtmp++;
633     }
634     /* finished row so stick it into b->a */
635     pv = ba + 9*bi[i];
636     pj = bj + bi[i];
637     nz = bi[i+1] - bi[i];
638     for ( j=0; j<nz; j++ ) {
639       x     = rtmp + 9*pj[j];
640       pv[0] = x[0]; pv[1] = x[1]; pv[2] = x[2]; pv[3] = x[3];
641       pv[4] = x[4]; pv[5] = x[5]; pv[6] = x[6]; pv[7] = x[7]; pv[8] = x[8];
642       pv   += 9;
643     }
644     /* invert diagonal block */
645     w = ba + 9*diag_offset[i];
646     ierr = Kernel_A_gets_inverse_A_3(w); CHKERRQ(ierr);
647   }
648 
649   PetscFree(rtmp);
650   ierr = ISRestoreIndices(isicol,&ic); CHKERRQ(ierr);
651   ierr = ISRestoreIndices(isrow,&r); CHKERRQ(ierr);
652   ierr = ISDestroy(isicol); CHKERRQ(ierr);
653   C->factor = FACTOR_LU;
654   C->assembled = PETSC_TRUE;
655   PLogFlops(1.3333*27*b->mbs); /* from inverting diagonal blocks */
656   return 0;
657 }
658 
659 /* ------------------------------------------------------------*/
660 /*
661       Version for when blocks are 2 by 2
662 */
663 int MatLUFactorNumeric_SeqBAIJ_2(Mat A,Mat *B)
664 {
665   Mat             C = *B;
666   Mat_SeqBAIJ     *a = (Mat_SeqBAIJ *) A->data,*b = (Mat_SeqBAIJ *)C->data;
667   IS              iscol = b->col, isrow = b->row, isicol;
668   int             *r,*ic, ierr, i, j, n = a->mbs, *bi = b->i, *bj = b->j;
669   int             *ajtmpold, *ajtmp, nz, row, v_pivots[2];
670   int             *diag_offset=b->diag,bs = 2,idx,*ai=a->i,*aj=a->j;
671   register Scalar *pv,*v,*rtmp,m1,m2,m3,m4,*pc,*w,*x,x1,x2,x3,x4;
672   Scalar          p1,p2,p3,p4,v_work[2];
673   Scalar          *ba = b->a,*aa = a->a;
674   register int    *pj;
675 
676   ierr  = ISInvertPermutation(iscol,&isicol); CHKERRQ(ierr);
677   PLogObjectParent(*B,isicol);
678   ierr  = ISGetIndices(isrow,&r); CHKERRQ(ierr);
679   ierr  = ISGetIndices(isicol,&ic); CHKERRQ(ierr);
680   rtmp  = (Scalar *) PetscMalloc(4*(n+1)*sizeof(Scalar));CHKPTRQ(rtmp);
681 
682   for ( i=0; i<n; i++ ) {
683     nz    = bi[i+1] - bi[i];
684     ajtmp = bj + bi[i];
685     for  ( j=0; j<nz; j++ ) {
686       x = rtmp+4*ajtmp[j]; x[0] = x[1] = x[2] = x[3] = 0.0;
687     }
688     /* load in initial (unfactored row) */
689     idx      = r[i];
690     nz       = ai[idx+1] - ai[idx];
691     ajtmpold = aj + ai[idx];
692     v        = aa + 4*ai[idx];
693     for ( j=0; j<nz; j++ ) {
694       x    = rtmp+4*ic[ajtmpold[j]];
695       x[0] = v[0]; x[1] = v[1]; x[2] = v[2]; x[3] = v[3];
696       v    += 4;
697     }
698     row = *ajtmp++;
699     while (row < i) {
700       pc = rtmp + 4*row;
701       p1 = pc[0]; p2 = pc[1]; p3 = pc[2]; p4 = pc[3];
702       if (p1 != 0.0 || p2 != 0.0 || p3 != 0.0 || p4 != 0.0) {
703         pv = ba + 4*diag_offset[row];
704         pj = bj + diag_offset[row] + 1;
705         x1 = pv[0]; x2 = pv[1]; x3 = pv[2]; x4 = pv[3];
706         pc[0] = m1 = p1*x1 + p3*x2;
707         pc[1] = m2 = p2*x1 + p4*x2;
708         pc[2] = m3 = p1*x3 + p3*x4;
709         pc[3] = m4 = p2*x3 + p4*x4;
710         nz = bi[row+1] - diag_offset[row] - 1;
711         pv += 4;
712         for (j=0; j<nz; j++) {
713           x1   = pv[0]; x2 = pv[1]; x3 = pv[2]; x4 = pv[3];
714           x    = rtmp + 4*pj[j];
715           x[0] -= m1*x1 + m3*x2;
716           x[1] -= m2*x1 + m4*x2;
717           x[2] -= m1*x3 + m3*x4;
718           x[3] -= m2*x3 + m4*x4;
719           pv   += 4;
720         }
721         PLogFlops(16*nz+12);
722       }
723       row = *ajtmp++;
724     }
725     /* finished row so stick it into b->a */
726     pv = ba + 4*bi[i];
727     pj = bj + bi[i];
728     nz = bi[i+1] - bi[i];
729     for ( j=0; j<nz; j++ ) {
730       x     = rtmp+4*pj[j];
731       pv[0] = x[0]; pv[1] = x[1]; pv[2] = x[2]; pv[3] = x[3];
732       pv   += 4;
733     }
734     /* invert diagonal block */
735     w = ba + 4*diag_offset[i];
736     Kernel_A_gets_inverse_A(bs,w,v_pivots,v_work);
737   }
738 
739   PetscFree(rtmp);
740   ierr = ISRestoreIndices(isicol,&ic); CHKERRQ(ierr);
741   ierr = ISRestoreIndices(isrow,&r); CHKERRQ(ierr);
742   ierr = ISDestroy(isicol); CHKERRQ(ierr);
743   C->factor = FACTOR_LU;
744   C->assembled = PETSC_TRUE;
745   PLogFlops(1.3333*8*b->mbs); /* from inverting diagonal blocks */
746   return 0;
747 }
748 
749 /* ----------------------------------------------------------- */
750 /*
751      Version for when blocks are 1 by 1.
752 */
753 int MatLUFactorNumeric_SeqBAIJ_1(Mat A,Mat *B)
754 {
755   Mat             C = *B;
756   Mat_SeqBAIJ     *a = (Mat_SeqBAIJ *) A->data, *b = (Mat_SeqBAIJ *)C->data;
757   IS              iscol = b->col, isrow = b->row, isicol;
758   int             *r,*ic, ierr, i, j, n = a->mbs, *bi = b->i, *bj = b->j;
759   int             *ajtmpold, *ajtmp, nz, row,*ai = a->i,*aj = a->j;
760   int             *diag_offset = b->diag,diag;
761   register Scalar *pv,*v,*rtmp,multiplier,*pc;
762   Scalar          *ba = b->a,*aa = a->a;
763   register int    *pj;
764 
765   ierr  = ISInvertPermutation(iscol,&isicol); CHKERRQ(ierr);
766   PLogObjectParent(*B,isicol);
767   ierr  = ISGetIndices(isrow,&r); CHKERRQ(ierr);
768   ierr  = ISGetIndices(isicol,&ic); CHKERRQ(ierr);
769   rtmp  = (Scalar *) PetscMalloc((n+1)*sizeof(Scalar));CHKPTRQ(rtmp);
770 
771   for ( i=0; i<n; i++ ) {
772     nz    = bi[i+1] - bi[i];
773     ajtmp = bj + bi[i];
774     for  ( j=0; j<nz; j++ ) rtmp[ajtmp[j]] = 0.0;
775 
776     /* load in initial (unfactored row) */
777     nz       = ai[r[i]+1] - ai[r[i]];
778     ajtmpold = aj + ai[r[i]];
779     v        = aa + ai[r[i]];
780     for ( j=0; j<nz; j++ ) rtmp[ic[ajtmpold[j]]] =  v[j];
781 
782     row = *ajtmp++;
783     while (row < i) {
784       pc = rtmp + row;
785       if (*pc != 0.0) {
786         pv         = ba + diag_offset[row];
787         pj         = bj + diag_offset[row] + 1;
788         multiplier = *pc * *pv++;
789         *pc        = multiplier;
790         nz         = bi[row+1] - diag_offset[row] - 1;
791         for (j=0; j<nz; j++) rtmp[pj[j]] -= multiplier * pv[j];
792         PLogFlops(1+2*nz);
793       }
794       row = *ajtmp++;
795     }
796     /* finished row so stick it into b->a */
797     pv = ba + bi[i];
798     pj = bj + bi[i];
799     nz = bi[i+1] - bi[i];
800     for ( j=0; j<nz; j++ ) {pv[j] = rtmp[pj[j]];}
801     diag = diag_offset[i] - bi[i];
802     /* check pivot entry for current row */
803     if (pv[diag] == 0.0) {
804       SETERRQ(1,"MatLUFactorNumeric_SeqAIJ:Zero pivot");
805     }
806     pv[diag] = 1.0/pv[diag];
807   }
808 
809   PetscFree(rtmp);
810   ierr = ISRestoreIndices(isicol,&ic); CHKERRQ(ierr);
811   ierr = ISRestoreIndices(isrow,&r); CHKERRQ(ierr);
812   ierr = ISDestroy(isicol); CHKERRQ(ierr);
813   C->factor    = FACTOR_LU;
814   C->assembled = PETSC_TRUE;
815   PLogFlops(b->n);
816   return 0;
817 }
818 
819 /* ----------------------------------------------------------- */
820 int MatLUFactor_SeqBAIJ(Mat A,IS row,IS col,double f)
821 {
822   Mat_SeqBAIJ *mat = (Mat_SeqBAIJ *) A->data;
823   int         ierr;
824   Mat         C;
825 
826   ierr = MatLUFactorSymbolic_SeqBAIJ(A,row,col,f,&C); CHKERRQ(ierr);
827   ierr = MatLUFactorNumeric(A,&C); CHKERRQ(ierr);
828 
829   /* free all the data structures from mat */
830   PetscFree(mat->a);
831   if (!mat->singlemalloc) {PetscFree(mat->i); PetscFree(mat->j);}
832   if (mat->diag) PetscFree(mat->diag);
833   if (mat->ilen) PetscFree(mat->ilen);
834   if (mat->imax) PetscFree(mat->imax);
835   if (mat->solve_work) PetscFree(mat->solve_work);
836   if (mat->mult_work) PetscFree(mat->mult_work);
837   PetscFree(mat);
838 
839   PetscMemcpy(A,C,sizeof(struct _Mat));
840   PetscHeaderDestroy(C);
841   return 0;
842 }
843 /* ----------------------------------------------------------- */
844 int MatSolve_SeqBAIJ_N(Mat A,Vec bb,Vec xx)
845 {
846   Mat_SeqBAIJ     *a=(Mat_SeqBAIJ *)A->data;
847   IS              iscol=a->col,isrow=a->row;
848   int             *r,*c,ierr,i,n=a->mbs,*vi,*ai=a->i,*aj=a->j;
849   int             nz,bs=a->bs,bs2=a->bs2;
850   Scalar          *xa,*ba,*aa=a->a,*sum;
851   register Scalar *x,*b,*lsum,*tmp,*v;
852 
853   ierr = VecGetArray(bb,&ba); CHKERRQ(ierr); b = ba;
854   ierr = VecGetArray(xx,&xa); CHKERRQ(ierr); x = xa;
855   tmp  = a->solve_work;
856 
857   ierr = ISGetIndices(isrow,&r);CHKERRQ(ierr);
858   ierr = ISGetIndices(iscol,&c);CHKERRQ(ierr); c = c + (n-1);
859 
860   /* forward solve the lower triangular */
861   PetscMemcpy(tmp,b + bs*(*r++), bs*sizeof(Scalar));
862   for ( i=1; i<n; i++ ) {
863     v   = aa + bs2*ai[i];
864     vi  = aj + ai[i];
865     nz  = a->diag[i] - ai[i];
866     sum = tmp + bs*i;
867     PetscMemcpy(sum,b+bs*(*r++),bs*sizeof(Scalar));
868     while (nz--) {
869       Kernel_v_gets_v_minus_A_times_w(bs,sum,v,tmp+bs*(*vi++));
870       v += bs2;
871     }
872   }
873   /* backward solve the upper triangular */
874   lsum = a->solve_work + a->n;
875   for ( i=n-1; i>=0; i-- ){
876     v   = aa + bs2*(a->diag[i] + 1);
877     vi  = aj + a->diag[i] + 1;
878     nz  = ai[i+1] - a->diag[i] - 1;
879     PetscMemcpy(lsum,tmp+i*bs,bs*sizeof(Scalar));
880     while (nz--) {
881       Kernel_v_gets_v_minus_A_times_w(bs,lsum,v,tmp+bs*(*vi++));
882       v += bs2;
883     }
884     Kernel_w_gets_A_times_v(bs,lsum,aa+bs2*a->diag[i],tmp+i*bs);
885     PetscMemcpy(x + bs*(*c--),tmp+i*bs,bs*sizeof(Scalar));
886   }
887 
888   ierr = ISRestoreIndices(isrow,&r); CHKERRQ(ierr);
889   ierr = ISRestoreIndices(iscol,&c); CHKERRQ(ierr);
890   PLogFlops(2*(a->bs2)*(a->nz) - a->n);
891   return 0;
892 }
893 
894 int MatSolve_SeqBAIJ_5(Mat A,Vec bb,Vec xx)
895 {
896   Mat_SeqBAIJ     *a=(Mat_SeqBAIJ *)A->data;
897   IS              iscol=a->col,isrow=a->row;
898   int             *r,*c,ierr,i,n=a->mbs,*vi,*ai=a->i,*aj=a->j,nz,idx,idt,idc;
899   Scalar          *xa,*ba,*aa=a->a,sum1,sum2,sum3,sum4,sum5,x1,x2,x3,x4,x5;
900   register Scalar *x,*b,*tmp,*v;
901 
902   ierr = VecGetArray(bb,&ba); CHKERRQ(ierr); b = ba;
903   ierr = VecGetArray(xx,&xa); CHKERRQ(ierr); x = xa;
904   tmp  = a->solve_work;
905 
906   ierr = ISGetIndices(isrow,&r);CHKERRQ(ierr);
907   ierr = ISGetIndices(iscol,&c);CHKERRQ(ierr); c = c + (n-1);
908 
909   /* forward solve the lower triangular */
910   idx    = 5*(*r++);
911   tmp[0] = b[idx];   tmp[1] = b[1+idx];
912   tmp[2] = b[2+idx]; tmp[3] = b[3+idx]; tmp[4] = b[4+idx];
913   for ( i=1; i<n; i++ ) {
914     v     = aa + 25*ai[i];
915     vi    = aj + ai[i];
916     nz    = a->diag[i] - ai[i];
917     idx   = 5*(*r++);
918     sum1  = b[idx];sum2 = b[1+idx];sum3 = b[2+idx];sum4 = b[3+idx];
919     sum5  = b[4+idx];
920     while (nz--) {
921       idx   = 5*(*vi++);
922       x1    = tmp[idx];  x2 = tmp[1+idx];x3 = tmp[2+idx];
923       x4    = tmp[3+idx];x5 = tmp[4+idx];
924       sum1 -= v[0]*x1 + v[5]*x2 + v[10]*x3 + v[15]*x4 + v[20]*x5;
925       sum2 -= v[1]*x1 + v[6]*x2 + v[11]*x3 + v[16]*x4 + v[21]*x5;
926       sum3 -= v[2]*x1 + v[7]*x2 + v[12]*x3 + v[17]*x4 + v[22]*x5;
927       sum4 -= v[3]*x1 + v[8]*x2 + v[13]*x3 + v[18]*x4 + v[23]*x5;
928       sum5 -= v[4]*x1 + v[9]*x2 + v[14]*x3 + v[19]*x4 + v[24]*x5;
929       v += 25;
930     }
931     idx = 5*i;
932     tmp[idx]   = sum1;tmp[1+idx] = sum2;
933     tmp[2+idx] = sum3;tmp[3+idx] = sum4; tmp[4+idx] = sum5;
934   }
935   /* backward solve the upper triangular */
936   for ( i=n-1; i>=0; i-- ){
937     v    = aa + 25*a->diag[i] + 25;
938     vi   = aj + a->diag[i] + 1;
939     nz   = ai[i+1] - a->diag[i] - 1;
940     idt  = 5*i;
941     sum1 = tmp[idt];  sum2 = tmp[1+idt];
942     sum3 = tmp[2+idt];sum4 = tmp[3+idt]; sum5 = tmp[4+idt];
943     while (nz--) {
944       idx   = 5*(*vi++);
945       x1    = tmp[idx];   x2 = tmp[1+idx];
946       x3    = tmp[2+idx]; x4 = tmp[3+idx]; x5 = tmp[4+idx];
947       sum1 -= v[0]*x1 + v[5]*x2 + v[10]*x3 + v[15]*x4 + v[20]*x5;
948       sum2 -= v[1]*x1 + v[6]*x2 + v[11]*x3 + v[16]*x4 + v[21]*x5;
949       sum3 -= v[2]*x1 + v[7]*x2 + v[12]*x3 + v[17]*x4 + v[22]*x5;
950       sum4 -= v[3]*x1 + v[8]*x2 + v[13]*x3 + v[18]*x4 + v[23]*x5;
951       sum5 -= v[4]*x1 + v[9]*x2 + v[14]*x3 + v[19]*x4 + v[24]*x5;
952       v += 25;
953     }
954     idc = 5*(*c--);
955     v   = aa + 25*a->diag[i];
956     x[idc]   = tmp[idt]   = v[0]*sum1+v[5]*sum2+v[10]*sum3+
957                                  v[15]*sum4+v[20]*sum5;
958     x[1+idc] = tmp[1+idt] = v[1]*sum1+v[6]*sum2+v[11]*sum3+
959                                  v[16]*sum4+v[21]*sum5;
960     x[2+idc] = tmp[2+idt] = v[2]*sum1+v[7]*sum2+v[12]*sum3+
961                                  v[17]*sum4+v[22]*sum5;
962     x[3+idc] = tmp[3+idt] = v[3]*sum1+v[8]*sum2+v[13]*sum3+
963                                  v[18]*sum4+v[23]*sum5;
964     x[4+idc] = tmp[4+idt] = v[4]*sum1+v[9]*sum2+v[14]*sum3+
965                                  v[19]*sum4+v[24]*sum5;
966   }
967 
968   ierr = ISRestoreIndices(isrow,&r); CHKERRQ(ierr);
969   ierr = ISRestoreIndices(iscol,&c); CHKERRQ(ierr);
970   PLogFlops(2*25*(a->nz) - a->n);
971   return 0;
972 }
973 
974 int MatSolve_SeqBAIJ_4(Mat A,Vec bb,Vec xx)
975 {
976   Mat_SeqBAIJ     *a=(Mat_SeqBAIJ *)A->data;
977   IS              iscol=a->col,isrow=a->row;
978   int             *r,*c,ierr,i,n=a->mbs,*vi,*ai=a->i,*aj=a->j,nz,idx,idt,idc;
979   Scalar          *xa,*ba,*aa=a->a,sum1,sum2,sum3,sum4,x1,x2,x3,x4;
980   register Scalar *x,*b,*tmp,*v;
981 
982   ierr = VecGetArray(bb,&ba); CHKERRQ(ierr); b = ba;
983   ierr = VecGetArray(xx,&xa); CHKERRQ(ierr); x = xa;
984   tmp  = a->solve_work;
985 
986   ierr = ISGetIndices(isrow,&r);CHKERRQ(ierr);
987   ierr = ISGetIndices(iscol,&c);CHKERRQ(ierr); c = c + (n-1);
988 
989   /* forward solve the lower triangular */
990   idx    = 4*(*r++);
991   tmp[0] = b[idx];   tmp[1] = b[1+idx];
992   tmp[2] = b[2+idx]; tmp[3] = b[3+idx];
993   for ( i=1; i<n; i++ ) {
994     v     = aa + 16*ai[i];
995     vi    = aj + ai[i];
996     nz    = a->diag[i] - ai[i];
997     idx   = 4*(*r++);
998     sum1  = b[idx];sum2 = b[1+idx];sum3 = b[2+idx];sum4 = b[3+idx];
999     while (nz--) {
1000       idx   = 4*(*vi++);
1001       x1    = tmp[idx];x2 = tmp[1+idx];x3 = tmp[2+idx];x4 = tmp[3+idx];
1002       sum1 -= v[0]*x1 + v[4]*x2 + v[8]*x3  + v[12]*x4;
1003       sum2 -= v[1]*x1 + v[5]*x2 + v[9]*x3  + v[13]*x4;
1004       sum3 -= v[2]*x1 + v[6]*x2 + v[10]*x3 + v[14]*x4;
1005       sum4 -= v[3]*x1 + v[7]*x2 + v[11]*x3 + v[15]*x4;
1006       v += 16;
1007     }
1008     idx = 4*i;
1009     tmp[idx]   = sum1;tmp[1+idx] = sum2;
1010     tmp[2+idx] = sum3;tmp[3+idx] = sum4;
1011   }
1012   /* backward solve the upper triangular */
1013   for ( i=n-1; i>=0; i-- ){
1014     v    = aa + 16*a->diag[i] + 16;
1015     vi   = aj + a->diag[i] + 1;
1016     nz   = ai[i+1] - a->diag[i] - 1;
1017     idt  = 4*i;
1018     sum1 = tmp[idt];  sum2 = tmp[1+idt];
1019     sum3 = tmp[2+idt];sum4 = tmp[3+idt];
1020     while (nz--) {
1021       idx   = 4*(*vi++);
1022       x1    = tmp[idx];   x2 = tmp[1+idx];
1023       x3    = tmp[2+idx]; x4 = tmp[3+idx];
1024       sum1 -= v[0]*x1 + v[4]*x2 + v[8]*x3   + v[12]*x4;
1025       sum2 -= v[1]*x1 + v[5]*x2 + v[9]*x3   + v[13]*x4;
1026       sum3 -= v[2]*x1 + v[6]*x2 + v[10]*x3  + v[14]*x4;
1027       sum4 -= v[3]*x1 + v[7]*x2 + v[11]*x3  + v[15]*x4;
1028       v += 16;
1029     }
1030     idc = 4*(*c--);
1031     v   = aa + 16*a->diag[i];
1032     x[idc]   = tmp[idt]   = v[0]*sum1+v[4]*sum2+v[8]*sum3+v[12]*sum4;
1033     x[1+idc] = tmp[1+idt] = v[1]*sum1+v[5]*sum2+v[9]*sum3+v[13]*sum4;
1034     x[2+idc] = tmp[2+idt] = v[2]*sum1+v[6]*sum2+v[10]*sum3+v[14]*sum4;
1035     x[3+idc] = tmp[3+idt] = v[3]*sum1+v[7]*sum2+v[11]*sum3+v[15]*sum4;
1036   }
1037 
1038   ierr = ISRestoreIndices(isrow,&r); CHKERRQ(ierr);
1039   ierr = ISRestoreIndices(iscol,&c); CHKERRQ(ierr);
1040   PLogFlops(2*16*(a->nz) - a->n);
1041   return 0;
1042 }
1043 
1044 
1045 int MatSolve_SeqBAIJ_3(Mat A,Vec bb,Vec xx)
1046 {
1047   Mat_SeqBAIJ     *a=(Mat_SeqBAIJ *)A->data;
1048   IS              iscol=a->col,isrow=a->row;
1049   int             *r,*c,ierr,i,n=a->mbs,*vi,*ai=a->i,*aj=a->j,nz,idx,idt,idc;
1050   Scalar          *xa,*ba,*aa=a->a,sum1,sum2,sum3,x1,x2,x3;
1051   register Scalar *x,*b,*tmp,*v;
1052 
1053   ierr = VecGetArray(bb,&ba); CHKERRQ(ierr); b = ba;
1054   ierr = VecGetArray(xx,&xa); CHKERRQ(ierr); x = xa;
1055   tmp  = a->solve_work;
1056 
1057   ierr = ISGetIndices(isrow,&r);CHKERRQ(ierr);
1058   ierr = ISGetIndices(iscol,&c);CHKERRQ(ierr); c = c + (n-1);
1059 
1060   /* forward solve the lower triangular */
1061   idx    = 3*(*r++);
1062   tmp[0] = b[idx]; tmp[1] = b[1+idx]; tmp[2] = b[2+idx];
1063   for ( i=1; i<n; i++ ) {
1064     v     = aa + 9*ai[i];
1065     vi    = aj + ai[i];
1066     nz    = a->diag[i] - ai[i];
1067     idx   = 3*(*r++);
1068     sum1  = b[idx]; sum2 = b[1+idx]; sum3 = b[2+idx];
1069     while (nz--) {
1070       idx   = 3*(*vi++);
1071       x1    = tmp[idx]; x2 = tmp[1+idx]; x3 = tmp[2+idx];
1072       sum1 -= v[0]*x1 + v[3]*x2 + v[6]*x3;
1073       sum2 -= v[1]*x1 + v[4]*x2 + v[7]*x3;
1074       sum3 -= v[2]*x1 + v[5]*x2 + v[8]*x3;
1075       v += 9;
1076     }
1077     idx = 3*i;
1078     tmp[idx] = sum1; tmp[1+idx] = sum2; tmp[2+idx] = sum3;
1079   }
1080   /* backward solve the upper triangular */
1081   for ( i=n-1; i>=0; i-- ){
1082     v    = aa + 9*a->diag[i] + 9;
1083     vi   = aj + a->diag[i] + 1;
1084     nz   = ai[i+1] - a->diag[i] - 1;
1085     idt  = 3*i;
1086     sum1 = tmp[idt]; sum2 = tmp[1+idt]; sum3 = tmp[2+idt];
1087     while (nz--) {
1088       idx   = 3*(*vi++);
1089       x1    = tmp[idx]; x2 = tmp[1+idx]; x3 = tmp[2+idx];
1090       sum1 -= v[0]*x1 + v[3]*x2 + v[6]*x3;
1091       sum2 -= v[1]*x1 + v[4]*x2 + v[7]*x3;
1092       sum3 -= v[2]*x1 + v[5]*x2 + v[8]*x3;
1093       v += 9;
1094     }
1095     idc = 3*(*c--);
1096     v   = aa + 9*a->diag[i];
1097     x[idc]   = tmp[idt]   = v[0]*sum1 + v[3]*sum2 + v[6]*sum3;
1098     x[1+idc] = tmp[1+idt] = v[1]*sum1 + v[4]*sum2 + v[7]*sum3;
1099     x[2+idc] = tmp[2+idt] = v[2]*sum1 + v[5]*sum2 + v[8]*sum3;
1100   }
1101   ierr = ISRestoreIndices(isrow,&r); CHKERRQ(ierr);
1102   ierr = ISRestoreIndices(iscol,&c); CHKERRQ(ierr);
1103   PLogFlops(2*9*(a->nz) - a->n);
1104   return 0;
1105 }
1106 
1107 int MatSolve_SeqBAIJ_2(Mat A,Vec bb,Vec xx)
1108 {
1109   Mat_SeqBAIJ     *a=(Mat_SeqBAIJ *)A->data;
1110   IS              iscol=a->col,isrow=a->row;
1111   int             *r,*c,ierr,i,n=a->mbs,*vi,*ai=a->i,*aj=a->j,nz,idx,idt,idc;
1112   Scalar          *xa,*ba,*aa=a->a,sum1,sum2,x1,x2;
1113   register Scalar *x,*b,*tmp,*v;
1114 
1115   ierr = VecGetArray(bb,&ba); CHKERRQ(ierr); b = ba;
1116   ierr = VecGetArray(xx,&xa); CHKERRQ(ierr); x = xa;
1117   tmp  = a->solve_work;
1118 
1119   ierr = ISGetIndices(isrow,&r);CHKERRQ(ierr);
1120   ierr = ISGetIndices(iscol,&c);CHKERRQ(ierr); c = c + (n-1);
1121 
1122   /* forward solve the lower triangular */
1123   idx    = 2*(*r++);
1124   tmp[0] = b[idx]; tmp[1] = b[1+idx];
1125   for ( i=1; i<n; i++ ) {
1126     v     = aa + 4*ai[i];
1127     vi    = aj + ai[i];
1128     nz    = a->diag[i] - ai[i];
1129     idx   = 2*(*r++);
1130     sum1  = b[idx]; sum2 = b[1+idx];
1131     while (nz--) {
1132       idx   = 2*(*vi++);
1133       x1    = tmp[idx]; x2 = tmp[1+idx];
1134       sum1 -= v[0]*x1 + v[2]*x2;
1135       sum2 -= v[1]*x1 + v[3]*x2;
1136       v += 4;
1137     }
1138     idx = 2*i;
1139     tmp[idx] = sum1; tmp[1+idx] = sum2;
1140   }
1141   /* backward solve the upper triangular */
1142   for ( i=n-1; i>=0; i-- ){
1143     v    = aa + 4*a->diag[i] + 4;
1144     vi   = aj + a->diag[i] + 1;
1145     nz   = ai[i+1] - a->diag[i] - 1;
1146     idt  = 2*i;
1147     sum1 = tmp[idt]; sum2 = tmp[1+idt];
1148     while (nz--) {
1149       idx   = 2*(*vi++);
1150       x1    = tmp[idx]; x2 = tmp[1+idx];
1151       sum1 -= v[0]*x1 + v[2]*x2;
1152       sum2 -= v[1]*x1 + v[3]*x2;
1153       v += 4;
1154     }
1155     idc = 2*(*c--);
1156     v   = aa + 4*a->diag[i];
1157     x[idc]   = tmp[idt]   = v[0]*sum1 + v[2]*sum2;
1158     x[1+idc] = tmp[1+idt] = v[1]*sum1 + v[3]*sum2;
1159   }
1160   ierr = ISRestoreIndices(isrow,&r); CHKERRQ(ierr);
1161   ierr = ISRestoreIndices(iscol,&c); CHKERRQ(ierr);
1162   PLogFlops(2*4*(a->nz) - a->n);
1163   return 0;
1164 }
1165 
1166 
1167 int MatSolve_SeqBAIJ_1(Mat A,Vec bb,Vec xx)
1168 {
1169   Mat_SeqBAIJ     *a=(Mat_SeqBAIJ *)A->data;
1170   IS              iscol=a->col,isrow=a->row;
1171   int             *r,*c,ierr,i,n=a->mbs,*vi,*ai=a->i,*aj=a->j,nz;
1172   Scalar          *xa,*ba,*aa=a->a,sum1;
1173   register Scalar *x,*b,*tmp,*v;
1174 
1175   ierr = VecGetArray(bb,&ba); CHKERRQ(ierr); b = ba;
1176   ierr = VecGetArray(xx,&xa); CHKERRQ(ierr); x = xa;
1177   tmp  = a->solve_work;
1178 
1179   ierr = ISGetIndices(isrow,&r);CHKERRQ(ierr);
1180   ierr = ISGetIndices(iscol,&c);CHKERRQ(ierr); c = c + (n-1);
1181 
1182   /* forward solve the lower triangular */
1183   tmp[0] = b[*r++];
1184   for ( i=1; i<n; i++ ) {
1185     v     = aa + ai[i];
1186     vi    = aj + ai[i];
1187     nz    = a->diag[i] - ai[i];
1188     sum1  = b[*r++];
1189     while (nz--) {
1190       sum1 -= (*v++)*tmp[*vi++];
1191     }
1192     tmp[i] = sum1;
1193   }
1194   /* backward solve the upper triangular */
1195   for ( i=n-1; i>=0; i-- ){
1196     v    = aa + a->diag[i] + 1;
1197     vi   = aj + a->diag[i] + 1;
1198     nz   = ai[i+1] - a->diag[i] - 1;
1199     sum1 = tmp[i];
1200     while (nz--) {
1201       sum1 -= (*v++)*tmp[*vi++];
1202     }
1203     x[*c--] = tmp[i] = aa[a->diag[i]]*sum1;
1204   }
1205 
1206   ierr = ISRestoreIndices(isrow,&r); CHKERRQ(ierr);
1207   ierr = ISRestoreIndices(iscol,&c); CHKERRQ(ierr);
1208   PLogFlops(2*1*(a->nz) - a->n);
1209   return 0;
1210 }
1211 
1212 /* ----------------------------------------------------------------*/
1213 /*
1214      This code is virtually identical to MatILUFactorSymbolic_SeqAIJ
1215    except that the data structure of Mat_SeqAIJ is slightly different.
1216    Not a good example of code reuse.
1217 */
1218 int MatILUFactorSymbolic_SeqBAIJ(Mat A,IS isrow,IS iscol,double f,int levels,
1219                                  Mat *fact)
1220 {
1221   Mat_SeqBAIJ *a = (Mat_SeqBAIJ *) A->data, *b;
1222   IS          isicol;
1223   int         *r,*ic, ierr, prow, n = a->mbs, *ai = a->i, *aj = a->j;
1224   int         *ainew,*ajnew, jmax,*fill, *xi, nz, *im,*ajfill,*flev;
1225   int         *dloc, idx, row,m,fm, nzf, nzi,len,  realloc = 0;
1226   int         incrlev,nnz,i,bs = a->bs,bs2 = a->bs2;
1227   PetscTruth  col_identity, row_identity;
1228 
1229   if (a->m != a->n) SETERRQ(1,"MatILUFactorSymbolic_SeqBAIJ:Matrix must be square");
1230   if (!isrow) SETERRQ(1,"MatILUFactorSymbolic_SeqBAIJ:Must have row permutation");
1231   if (!iscol) SETERRQ(1,"MatILUFactorSymbolic_SeqBAIJ:Must have column permutation");
1232 
1233   /* special case that simply copies fill pattern */
1234   ISIdentity(isrow,&row_identity); ISIdentity(iscol,&col_identity);
1235   if (levels == 0 && row_identity && col_identity) {
1236     ierr = MatConvertSameType_SeqBAIJ(A,fact,DO_NOT_COPY_VALUES); CHKERRQ(ierr);
1237     (*fact)->factor = FACTOR_LU;
1238     b               = (Mat_SeqBAIJ *) (*fact)->data;
1239     if (!b->diag) {
1240       ierr = MatMarkDiag_SeqBAIJ(*fact); CHKERRQ(ierr);
1241     }
1242     b->row        = isrow;
1243     b->col        = iscol;
1244     b->solve_work = (Scalar *) PetscMalloc((b->m+1+b->bs)*sizeof(Scalar));CHKPTRQ(b->solve_work);
1245     return 0;
1246   }
1247 
1248   ierr = ISInvertPermutation(iscol,&isicol); CHKERRQ(ierr);
1249   ierr = ISGetIndices(isrow,&r); CHKERRQ(ierr);
1250   ierr = ISGetIndices(isicol,&ic); CHKERRQ(ierr);
1251 
1252   /* get new row pointers */
1253   ainew = (int *) PetscMalloc( (n+1)*sizeof(int) ); CHKPTRQ(ainew);
1254   ainew[0] = 0;
1255   /* don't know how many column pointers are needed so estimate */
1256   jmax = (int) (f*ai[n] + 1);
1257   ajnew = (int *) PetscMalloc( (jmax)*sizeof(int) ); CHKPTRQ(ajnew);
1258   /* ajfill is level of fill for each fill entry */
1259   ajfill = (int *) PetscMalloc( (jmax)*sizeof(int) ); CHKPTRQ(ajfill);
1260   /* fill is a linked list of nonzeros in active row */
1261   fill = (int *) PetscMalloc( (n+1)*sizeof(int)); CHKPTRQ(fill);
1262   /* im is level for each filled value */
1263   im = (int *) PetscMalloc( (n+1)*sizeof(int)); CHKPTRQ(im);
1264   /* dloc is location of diagonal in factor */
1265   dloc = (int *) PetscMalloc( (n+1)*sizeof(int)); CHKPTRQ(dloc);
1266   dloc[0]  = 0;
1267   for ( prow=0; prow<n; prow++ ) {
1268     /* first copy previous fill into linked list */
1269     nzf     = nz  = ai[r[prow]+1] - ai[r[prow]];
1270     xi      = aj + ai[r[prow]];
1271     fill[n] = n;
1272     while (nz--) {
1273       fm  = n;
1274       idx = ic[*xi++];
1275       do {
1276         m  = fm;
1277         fm = fill[m];
1278       } while (fm < idx);
1279       fill[m]   = idx;
1280       fill[idx] = fm;
1281       im[idx]   = 0;
1282     }
1283     nzi = 0;
1284     row = fill[n];
1285     while ( row < prow ) {
1286       incrlev = im[row] + 1;
1287       nz      = dloc[row];
1288       xi      = ajnew  + ainew[row] + nz;
1289       flev    = ajfill + ainew[row] + nz + 1;
1290       nnz     = ainew[row+1] - ainew[row] - nz - 1;
1291       if (*xi++ != row) {
1292         SETERRQ(1,"MatILUFactorSymbolic_SeqBAIJ:zero pivot");
1293       }
1294       fm      = row;
1295       while (nnz-- > 0) {
1296         idx = *xi++;
1297         if (*flev + incrlev > levels) {
1298           flev++;
1299           continue;
1300         }
1301         do {
1302           m  = fm;
1303           fm = fill[m];
1304         } while (fm < idx);
1305         if (fm != idx) {
1306           im[idx]   = *flev + incrlev;
1307           fill[m]   = idx;
1308           fill[idx] = fm;
1309           fm        = idx;
1310           nzf++;
1311         }
1312         else {
1313           if (im[idx] > *flev + incrlev) im[idx] = *flev+incrlev;
1314         }
1315         flev++;
1316       }
1317       row = fill[row];
1318       nzi++;
1319     }
1320     /* copy new filled row into permanent storage */
1321     ainew[prow+1] = ainew[prow] + nzf;
1322     if (ainew[prow+1] > jmax) {
1323       /* allocate a longer ajnew */
1324       int maxadd;
1325       maxadd = (int) (((f*ai[n]+1)*(n-prow+5))/n);
1326       if (maxadd < nzf) maxadd = (n-prow)*(nzf+1);
1327       jmax += maxadd;
1328       xi = (int *) PetscMalloc( jmax*sizeof(int) );CHKPTRQ(xi);
1329       PetscMemcpy(xi,ajnew,ainew[prow]*sizeof(int));
1330       PetscFree(ajnew);
1331       ajnew = xi;
1332       /* allocate a longer ajfill */
1333       xi = (int *) PetscMalloc( jmax*sizeof(int) );CHKPTRQ(xi);
1334       PetscMemcpy(xi,ajfill,ainew[prow]*sizeof(int));
1335       PetscFree(ajfill);
1336       ajfill = xi;
1337       realloc++;
1338     }
1339     xi          = ajnew + ainew[prow];
1340     flev        = ajfill + ainew[prow];
1341     dloc[prow]  = nzi;
1342     fm          = fill[n];
1343     while (nzf--) {
1344       *xi++   = fm;
1345       *flev++ = im[fm];
1346       fm      = fill[fm];
1347     }
1348   }
1349   PetscFree(ajfill);
1350   ierr = ISRestoreIndices(isrow,&r); CHKERRQ(ierr);
1351   ierr = ISRestoreIndices(isicol,&ic); CHKERRQ(ierr);
1352   ierr = ISDestroy(isicol); CHKERRQ(ierr);
1353   PetscFree(fill); PetscFree(im);
1354 
1355   PLogInfo(A,
1356     "Info:MatILUFactorSymbolic_SeqBAIJ:Realloc %d Fill ratio:given %g needed %g\n",
1357                              realloc,f,((double)ainew[n])/((double)ai[prow]));
1358 
1359   /* put together the new matrix */
1360   ierr = MatCreateSeqBAIJ(A->comm,bs,bs*n,bs*n,0,PETSC_NULL,fact);CHKERRQ(ierr);
1361   b = (Mat_SeqBAIJ *) (*fact)->data;
1362   PetscFree(b->imax);
1363   b->singlemalloc = 0;
1364   len = bs2*ainew[n]*sizeof(Scalar);
1365   /* the next line frees the default space generated by the Create() */
1366   PetscFree(b->a); PetscFree(b->ilen);
1367   b->a          = (Scalar *) PetscMalloc( len ); CHKPTRQ(b->a);
1368   b->j          = ajnew;
1369   b->i          = ainew;
1370   for ( i=0; i<n; i++ ) dloc[i] += ainew[i];
1371   b->diag       = dloc;
1372   b->ilen       = 0;
1373   b->imax       = 0;
1374   b->row        = isrow;
1375   b->col        = iscol;
1376   b->solve_work = (Scalar *) PetscMalloc( (bs*n+bs)*sizeof(Scalar));
1377   CHKPTRQ(b->solve_work);
1378   /* In b structure:  Free imax, ilen, old a, old j.
1379      Allocate dloc, solve_work, new a, new j */
1380   PLogObjectMemory(*fact,(ainew[n]-n)*(sizeof(int))+bs2*ainew[n]*sizeof(Scalar));
1381   b->maxnz          = b->nz = ainew[n];
1382   (*fact)->factor   = FACTOR_LU;
1383   return 0;
1384 }
1385 
1386 
1387 
1388 
1389