xref: /petsc/src/mat/impls/baij/seq/baijfact2.c (revision bfd962fb1dfc9cddccc27313f52c303bf516c8ae)
1 #ifdef PETSC_RCS_HEADER
2 static char vcid[] = "$Id: baijfact2.c,v 1.16 1998/10/28 16:06:02 bsmith Exp bsmith $";
3 #endif
4 /*
5     Factorization code for BAIJ format.
6 */
7 
8 #include "src/mat/impls/baij/seq/baij.h"
9 #include "src/vec/vecimpl.h"
10 #include "src/inline/ilu.h"
11 #include "src/inline/dot.h"
12 
13 /* ----------------------------------------------------------- */
14 #undef __FUNC__
15 #define __FUNC__ "MatSolve_SeqBAIJ_N"
16 int MatSolve_SeqBAIJ_N(Mat A,Vec bb,Vec xx)
17 {
18   Mat_SeqBAIJ     *a=(Mat_SeqBAIJ *)A->data;
19   IS              iscol=a->col,isrow=a->row;
20   int             *r,*c,ierr,i,n=a->mbs,*vi,*ai=a->i,*aj=a->j;
21   int             nz,bs=a->bs,bs2=a->bs2,*rout,*cout;
22   Scalar          *aa=a->a,*sum;
23   Scalar *x,*b,*lsum,*tmp,*v;
24 
25   PetscFunctionBegin;
26   ierr = VecGetArray(bb,&b);CHKERRQ(ierr);
27   ierr = VecGetArray(xx,&x); CHKERRQ(ierr);
28   tmp  = a->solve_work;
29 
30   ierr = ISGetIndices(isrow,&rout);CHKERRQ(ierr); r = rout;
31   ierr = ISGetIndices(iscol,&cout);CHKERRQ(ierr); c = cout + (n-1);
32 
33   /* forward solve the lower triangular */
34   PetscMemcpy(tmp,b + bs*(*r++), bs*sizeof(Scalar));
35   for ( i=1; i<n; i++ ) {
36     v   = aa + bs2*ai[i];
37     vi  = aj + ai[i];
38     nz  = a->diag[i] - ai[i];
39     sum = tmp + bs*i;
40     PetscMemcpy(sum,b+bs*(*r++),bs*sizeof(Scalar));
41     while (nz--) {
42       Kernel_v_gets_v_minus_A_times_w(bs,sum,v,tmp+bs*(*vi++));
43       v += bs2;
44     }
45   }
46   /* backward solve the upper triangular */
47   lsum = a->solve_work + a->n;
48   for ( i=n-1; i>=0; i-- ){
49     v   = aa + bs2*(a->diag[i] + 1);
50     vi  = aj + a->diag[i] + 1;
51     nz  = ai[i+1] - a->diag[i] - 1;
52     PetscMemcpy(lsum,tmp+i*bs,bs*sizeof(Scalar));
53     while (nz--) {
54       Kernel_v_gets_v_minus_A_times_w(bs,lsum,v,tmp+bs*(*vi++));
55       v += bs2;
56     }
57     Kernel_w_gets_A_times_v(bs,lsum,aa+bs2*a->diag[i],tmp+i*bs);
58     PetscMemcpy(x + bs*(*c--),tmp+i*bs,bs*sizeof(Scalar));
59   }
60 
61   ierr = ISRestoreIndices(isrow,&rout); CHKERRQ(ierr);
62   ierr = ISRestoreIndices(iscol,&cout); CHKERRQ(ierr);
63   ierr = VecRestoreArray(bb,&b); CHKERRQ(ierr);
64   ierr = VecRestoreArray(xx,&x); CHKERRQ(ierr);
65   PLogFlops(2*(a->bs2)*(a->nz) - a->bs*a->n);
66   PetscFunctionReturn(0);
67 }
68 
69 #undef __FUNC__
70 #define __FUNC__ "MatSolve_SeqBAIJ_7"
71 int MatSolve_SeqBAIJ_7(Mat A,Vec bb,Vec xx)
72 {
73   Mat_SeqBAIJ     *a=(Mat_SeqBAIJ *)A->data;
74   IS              iscol=a->col,isrow=a->row;
75   int             *r,*c,ierr,i,n=a->mbs,*vi,*ai=a->i,*aj=a->j,nz,idx,idt,idc,*rout,*cout;
76   int             *diag = a->diag;
77   Scalar          *aa=a->a,sum1,sum2,sum3,sum4,sum5,sum6,sum7,x1,x2,x3,x4,x5,x6,x7;
78   Scalar *x,*b,*tmp,*v;
79 
80   PetscFunctionBegin;
81   ierr = VecGetArray(bb,&b); CHKERRQ(ierr);
82   ierr = VecGetArray(xx,&x); CHKERRQ(ierr);
83   tmp  = a->solve_work;
84 
85   ierr = ISGetIndices(isrow,&rout);CHKERRQ(ierr); r = rout;
86   ierr = ISGetIndices(iscol,&cout);CHKERRQ(ierr); c = cout + (n-1);
87 
88   /* forward solve the lower triangular */
89   idx    = 7*(*r++);
90   tmp[0] = b[idx];   tmp[1] = b[1+idx];
91   tmp[2] = b[2+idx]; tmp[3] = b[3+idx]; tmp[4] = b[4+idx];
92   tmp[5] = b[5+idx]; tmp[6] = b[6+idx];
93 
94   for ( i=1; i<n; i++ ) {
95     v     = aa + 49*ai[i];
96     vi    = aj + ai[i];
97     nz    = diag[i] - ai[i];
98     idx   = 7*(*r++);
99     sum1  = b[idx];sum2 = b[1+idx];sum3 = b[2+idx];sum4 = b[3+idx];
100     sum5  = b[4+idx];sum6 = b[5+idx];sum7 = b[6+idx];
101     while (nz--) {
102       idx   = 7*(*vi++);
103       x1    = tmp[idx];  x2 = tmp[1+idx];x3 = tmp[2+idx];
104       x4    = tmp[3+idx];x5 = tmp[4+idx];
105       x6    = tmp[5+idx];x7 = tmp[6+idx];
106       sum1 -= v[0]*x1 + v[7]*x2  + v[14]*x3 + v[21]*x4 + v[28]*x5 + v[35]*x6 + v[42]*x7;
107       sum2 -= v[1]*x1 + v[8]*x2  + v[15]*x3 + v[22]*x4 + v[29]*x5 + v[36]*x6 + v[43]*x7;
108       sum3 -= v[2]*x1 + v[9]*x2  + v[16]*x3 + v[23]*x4 + v[30]*x5 + v[37]*x6 + v[44]*x7;
109       sum4 -= v[3]*x1 + v[10]*x2 + v[17]*x3 + v[24]*x4 + v[31]*x5 + v[38]*x6 + v[45]*x7;
110       sum5 -= v[4]*x1 + v[11]*x2 + v[18]*x3 + v[25]*x4 + v[32]*x5 + v[39]*x6 + v[46]*x7;
111       sum6 -= v[5]*x1 + v[12]*x2 + v[19]*x3 + v[26]*x4 + v[33]*x5 + v[40]*x6 + v[47]*x7;
112       sum7 -= v[6]*x1 + v[13]*x2 + v[20]*x3 + v[27]*x4 + v[34]*x5 + v[41]*x6 + v[48]*x7;
113       v += 49;
114     }
115     idx = 7*i;
116     tmp[idx]   = sum1;tmp[1+idx] = sum2;
117     tmp[2+idx] = sum3;tmp[3+idx] = sum4; tmp[4+idx] = sum5;
118     tmp[5+idx] = sum6;tmp[6+idx] = sum7;
119   }
120   /* backward solve the upper triangular */
121   for ( i=n-1; i>=0; i-- ){
122     v    = aa + 49*diag[i] + 49;
123     vi   = aj + diag[i] + 1;
124     nz   = ai[i+1] - diag[i] - 1;
125     idt  = 7*i;
126     sum1 = tmp[idt];  sum2 = tmp[1+idt];
127     sum3 = tmp[2+idt];sum4 = tmp[3+idt]; sum5 = tmp[4+idt];
128     sum6 = tmp[5+idt];sum7 = tmp[6+idt];
129     while (nz--) {
130       idx   = 7*(*vi++);
131       x1    = tmp[idx];   x2 = tmp[1+idx];
132       x3    = tmp[2+idx]; x4 = tmp[3+idx]; x5 = tmp[4+idx];
133       x6    = tmp[5+idx]; x7 = tmp[6+idx];
134       sum1 -= v[0]*x1 + v[7]*x2  + v[14]*x3 + v[21]*x4 + v[28]*x5 + v[35]*x6 + v[42]*x7;
135       sum2 -= v[1]*x1 + v[8]*x2  + v[15]*x3 + v[22]*x4 + v[29]*x5 + v[36]*x6 + v[43]*x7;
136       sum3 -= v[2]*x1 + v[9]*x2  + v[16]*x3 + v[23]*x4 + v[30]*x5 + v[37]*x6 + v[44]*x7;
137       sum4 -= v[3]*x1 + v[10]*x2 + v[17]*x3 + v[24]*x4 + v[31]*x5 + v[38]*x6 + v[45]*x7;
138       sum5 -= v[4]*x1 + v[11]*x2 + v[18]*x3 + v[25]*x4 + v[32]*x5 + v[39]*x6 + v[46]*x7;
139       sum6 -= v[5]*x1 + v[12]*x2 + v[19]*x3 + v[26]*x4 + v[33]*x5 + v[40]*x6 + v[47]*x7;
140       sum7 -= v[6]*x1 + v[13]*x2 + v[20]*x3 + v[27]*x4 + v[34]*x5 + v[41]*x6 + v[48]*x7;
141       v += 49;
142     }
143     idc = 7*(*c--);
144     v   = aa + 49*diag[i];
145     x[idc]   = tmp[idt]   = v[0]*sum1+v[7]*sum2+v[14]*sum3+
146                                  v[21]*sum4+v[28]*sum5+v[35]*sum6+v[42]*sum7;
147     x[1+idc] = tmp[1+idt] = v[1]*sum1+v[8]*sum2+v[15]*sum3+
148                                  v[22]*sum4+v[29]*sum5+v[36]*sum6+v[43]*sum7;
149     x[2+idc] = tmp[2+idt] = v[2]*sum1+v[9]*sum2+v[16]*sum3+
150                                  v[23]*sum4+v[30]*sum5+v[37]*sum6+v[44]*sum7;
151     x[3+idc] = tmp[3+idt] = v[3]*sum1+v[10]*sum2+v[17]*sum3+
152                                  v[24]*sum4+v[31]*sum5+v[38]*sum6+v[45]*sum7;
153     x[4+idc] = tmp[4+idt] = v[4]*sum1+v[11]*sum2+v[18]*sum3+
154                                  v[25]*sum4+v[32]*sum5+v[39]*sum6+v[46]*sum7;
155     x[5+idc] = tmp[5+idt] = v[5]*sum1+v[12]*sum2+v[19]*sum3+
156                                  v[26]*sum4+v[33]*sum5+v[40]*sum6+v[47]*sum7;
157     x[6+idc] = tmp[6+idt] = v[6]*sum1+v[13]*sum2+v[20]*sum3+
158                                  v[27]*sum4+v[34]*sum5+v[41]*sum6+v[48]*sum7;
159   }
160 
161   ierr = ISRestoreIndices(isrow,&rout); CHKERRQ(ierr);
162   ierr = ISRestoreIndices(iscol,&cout); CHKERRQ(ierr);
163   ierr = VecRestoreArray(bb,&b); CHKERRQ(ierr);
164   ierr = VecRestoreArray(xx,&x); CHKERRQ(ierr);
165   PLogFlops(2*49*(a->nz) - 7*a->n);
166   PetscFunctionReturn(0);
167 }
168 
169 #undef __FUNC__
170 #define __FUNC__ "MatSolve_SeqBAIJ_5"
171 int MatSolve_SeqBAIJ_5(Mat A,Vec bb,Vec xx)
172 {
173   Mat_SeqBAIJ     *a=(Mat_SeqBAIJ *)A->data;
174   IS              iscol=a->col,isrow=a->row;
175   int             *r,*c,ierr,i,n=a->mbs,*vi,*ai=a->i,*aj=a->j,nz,idx,idt,idc,*rout,*cout;
176   int             *diag = a->diag;
177   Scalar          *aa=a->a,sum1,sum2,sum3,sum4,sum5,x1,x2,x3,x4,x5;
178   Scalar *x,*b,*tmp,*v;
179 
180   PetscFunctionBegin;
181   ierr = VecGetArray(bb,&b); CHKERRQ(ierr);
182   ierr = VecGetArray(xx,&x); CHKERRQ(ierr);
183   tmp  = a->solve_work;
184 
185   ierr = ISGetIndices(isrow,&rout);CHKERRQ(ierr); r = rout;
186   ierr = ISGetIndices(iscol,&cout);CHKERRQ(ierr); c = cout + (n-1);
187 
188   /* forward solve the lower triangular */
189   idx    = 5*(*r++);
190   tmp[0] = b[idx];   tmp[1] = b[1+idx];
191   tmp[2] = b[2+idx]; tmp[3] = b[3+idx]; tmp[4] = b[4+idx];
192   for ( i=1; i<n; i++ ) {
193     v     = aa + 25*ai[i];
194     vi    = aj + ai[i];
195     nz    = diag[i] - ai[i];
196     idx   = 5*(*r++);
197     sum1  = b[idx];sum2 = b[1+idx];sum3 = b[2+idx];sum4 = b[3+idx];
198     sum5  = b[4+idx];
199     while (nz--) {
200       idx   = 5*(*vi++);
201       x1    = tmp[idx];  x2 = tmp[1+idx];x3 = tmp[2+idx];
202       x4    = tmp[3+idx];x5 = tmp[4+idx];
203       sum1 -= v[0]*x1 + v[5]*x2 + v[10]*x3 + v[15]*x4 + v[20]*x5;
204       sum2 -= v[1]*x1 + v[6]*x2 + v[11]*x3 + v[16]*x4 + v[21]*x5;
205       sum3 -= v[2]*x1 + v[7]*x2 + v[12]*x3 + v[17]*x4 + v[22]*x5;
206       sum4 -= v[3]*x1 + v[8]*x2 + v[13]*x3 + v[18]*x4 + v[23]*x5;
207       sum5 -= v[4]*x1 + v[9]*x2 + v[14]*x3 + v[19]*x4 + v[24]*x5;
208       v += 25;
209     }
210     idx = 5*i;
211     tmp[idx]   = sum1;tmp[1+idx] = sum2;
212     tmp[2+idx] = sum3;tmp[3+idx] = sum4; tmp[4+idx] = sum5;
213   }
214   /* backward solve the upper triangular */
215   for ( i=n-1; i>=0; i-- ){
216     v    = aa + 25*diag[i] + 25;
217     vi   = aj + diag[i] + 1;
218     nz   = ai[i+1] - diag[i] - 1;
219     idt  = 5*i;
220     sum1 = tmp[idt];  sum2 = tmp[1+idt];
221     sum3 = tmp[2+idt];sum4 = tmp[3+idt]; sum5 = tmp[4+idt];
222     while (nz--) {
223       idx   = 5*(*vi++);
224       x1    = tmp[idx];   x2 = tmp[1+idx];
225       x3    = tmp[2+idx]; x4 = tmp[3+idx]; x5 = tmp[4+idx];
226       sum1 -= v[0]*x1 + v[5]*x2 + v[10]*x3 + v[15]*x4 + v[20]*x5;
227       sum2 -= v[1]*x1 + v[6]*x2 + v[11]*x3 + v[16]*x4 + v[21]*x5;
228       sum3 -= v[2]*x1 + v[7]*x2 + v[12]*x3 + v[17]*x4 + v[22]*x5;
229       sum4 -= v[3]*x1 + v[8]*x2 + v[13]*x3 + v[18]*x4 + v[23]*x5;
230       sum5 -= v[4]*x1 + v[9]*x2 + v[14]*x3 + v[19]*x4 + v[24]*x5;
231       v += 25;
232     }
233     idc = 5*(*c--);
234     v   = aa + 25*diag[i];
235     x[idc]   = tmp[idt]   = v[0]*sum1+v[5]*sum2+v[10]*sum3+
236                                  v[15]*sum4+v[20]*sum5;
237     x[1+idc] = tmp[1+idt] = v[1]*sum1+v[6]*sum2+v[11]*sum3+
238                                  v[16]*sum4+v[21]*sum5;
239     x[2+idc] = tmp[2+idt] = v[2]*sum1+v[7]*sum2+v[12]*sum3+
240                                  v[17]*sum4+v[22]*sum5;
241     x[3+idc] = tmp[3+idt] = v[3]*sum1+v[8]*sum2+v[13]*sum3+
242                                  v[18]*sum4+v[23]*sum5;
243     x[4+idc] = tmp[4+idt] = v[4]*sum1+v[9]*sum2+v[14]*sum3+
244                                  v[19]*sum4+v[24]*sum5;
245   }
246 
247   ierr = ISRestoreIndices(isrow,&rout); CHKERRQ(ierr);
248   ierr = ISRestoreIndices(iscol,&cout); CHKERRQ(ierr);
249   ierr = VecRestoreArray(bb,&b); CHKERRQ(ierr);
250   ierr = VecRestoreArray(xx,&x); CHKERRQ(ierr);
251   PLogFlops(2*25*(a->nz) - 5*a->n);
252   PetscFunctionReturn(0);
253 }
254 
255 #undef __FUNC__
256 #define __FUNC__ "MatSolve_SeqBAIJ_4"
257 int MatSolve_SeqBAIJ_4(Mat A,Vec bb,Vec xx)
258 {
259   Mat_SeqBAIJ     *a = (Mat_SeqBAIJ *)A->data;
260   IS              iscol=a->col,isrow=a->row;
261   int             *r,*c,ierr,i,n=a->mbs,*vi,*ai=a->i,*aj=a->j,nz,idx,idt,idc,*rout,*cout;
262   int             *diag = a->diag;
263   Scalar          *aa=a->a,sum1,sum2,sum3,sum4,x1,x2,x3,x4;
264   Scalar          *x,*b,*tmp,*v;
265 
266   PetscFunctionBegin;
267   ierr = VecGetArray(bb,&b); CHKERRQ(ierr);
268   ierr = VecGetArray(xx,&x); CHKERRQ(ierr);
269   tmp  = a->solve_work;
270 
271   ierr = ISGetIndices(isrow,&rout);CHKERRQ(ierr); r = rout;
272   ierr = ISGetIndices(iscol,&cout);CHKERRQ(ierr); c = cout + (n-1);
273 
274   /* forward solve the lower triangular */
275   idx    = 4*(*r++);
276   tmp[0] = b[idx];   tmp[1] = b[1+idx];
277   tmp[2] = b[2+idx]; tmp[3] = b[3+idx];
278   for ( i=1; i<n; i++ ) {
279     v     = aa + 16*ai[i];
280     vi    = aj + ai[i];
281     nz    = diag[i] - ai[i];
282     idx   = 4*(*r++);
283     sum1  = b[idx];sum2 = b[1+idx];sum3 = b[2+idx];sum4 = b[3+idx];
284     while (nz--) {
285       idx   = 4*(*vi++);
286       x1    = tmp[idx];x2 = tmp[1+idx];x3 = tmp[2+idx];x4 = tmp[3+idx];
287       sum1 -= v[0]*x1 + v[4]*x2 + v[8]*x3  + v[12]*x4;
288       sum2 -= v[1]*x1 + v[5]*x2 + v[9]*x3  + v[13]*x4;
289       sum3 -= v[2]*x1 + v[6]*x2 + v[10]*x3 + v[14]*x4;
290       sum4 -= v[3]*x1 + v[7]*x2 + v[11]*x3 + v[15]*x4;
291       v    += 16;
292     }
293     idx        = 4*i;
294     tmp[idx]   = sum1;tmp[1+idx] = sum2;
295     tmp[2+idx] = sum3;tmp[3+idx] = sum4;
296   }
297   /* backward solve the upper triangular */
298   for ( i=n-1; i>=0; i-- ){
299     v    = aa + 16*diag[i] + 16;
300     vi   = aj + diag[i] + 1;
301     nz   = ai[i+1] - diag[i] - 1;
302     idt  = 4*i;
303     sum1 = tmp[idt];  sum2 = tmp[1+idt];
304     sum3 = tmp[2+idt];sum4 = tmp[3+idt];
305     while (nz--) {
306       idx   = 4*(*vi++);
307       x1    = tmp[idx];   x2 = tmp[1+idx];
308       x3    = tmp[2+idx]; x4 = tmp[3+idx];
309       sum1 -= v[0]*x1 + v[4]*x2 + v[8]*x3   + v[12]*x4;
310       sum2 -= v[1]*x1 + v[5]*x2 + v[9]*x3   + v[13]*x4;
311       sum3 -= v[2]*x1 + v[6]*x2 + v[10]*x3  + v[14]*x4;
312       sum4 -= v[3]*x1 + v[7]*x2 + v[11]*x3  + v[15]*x4;
313       v += 16;
314     }
315     idc      = 4*(*c--);
316     v        = aa + 16*diag[i];
317     x[idc]   = tmp[idt]   = v[0]*sum1+v[4]*sum2+v[8]*sum3+v[12]*sum4;
318     x[1+idc] = tmp[1+idt] = v[1]*sum1+v[5]*sum2+v[9]*sum3+v[13]*sum4;
319     x[2+idc] = tmp[2+idt] = v[2]*sum1+v[6]*sum2+v[10]*sum3+v[14]*sum4;
320     x[3+idc] = tmp[3+idt] = v[3]*sum1+v[7]*sum2+v[11]*sum3+v[15]*sum4;
321   }
322 
323   ierr = ISRestoreIndices(isrow,&rout); CHKERRQ(ierr);
324   ierr = ISRestoreIndices(iscol,&cout); CHKERRQ(ierr);
325   ierr = VecRestoreArray(bb,&b); CHKERRQ(ierr);
326   ierr = VecRestoreArray(xx,&x); CHKERRQ(ierr);
327   PLogFlops(2*16*(a->nz) - 4*a->n);
328   PetscFunctionReturn(0);
329 }
330 
331 /*
332       Special case where the matrix was ILU(0) factored in the natural
333    ordering. This eliminates the need for the column and row permutation.
334 */
335 #undef __FUNC__
336 #define __FUNC__ "MatSolve_SeqBAIJ_4_NaturalOrdering"
337 int MatSolve_SeqBAIJ_4_NaturalOrdering(Mat A,Vec bb,Vec xx)
338 {
339   Mat_SeqBAIJ     *a = (Mat_SeqBAIJ *)A->data;
340   int             n=a->mbs,*ai=a->i,*aj=a->j;
341   int             ierr,*diag = a->diag;
342   Scalar          *aa=a->a;
343   Scalar          *x,*b;
344 
345   PetscFunctionBegin;
346   ierr = VecGetArray(bb,&b);CHKERRQ(ierr);
347   ierr = VecGetArray(xx,&x);CHKERRQ(ierr);
348 
349 #if defined(USE_FORTRAN_KERNEL_SOLVEBAIJBLAS)
350   {
351     static Scalar w[2000]; /* very BAD need to fix */
352     fortransolvebaij4blas_(&n,x,ai,aj,diag,aa,b,w);
353   }
354 #elif defined(USE_FORTRAN_KERNEL_SOLVEBAIJ)
355   {
356     static Scalar w[2000]; /* very BAD need to fix */
357     fortransolvebaij4_(&n,x,ai,aj,diag,aa,b,w);
358   }
359 #elif defined(USE_FORTRAN_KERNEL_SOLVEBAIJUNROLL)
360   fortransolvebaij4unroll_(&n,x,ai,aj,diag,aa,b);
361 #else
362   {
363     Scalar sum1,sum2,sum3,sum4,x1,x2,x3,x4,*v;
364     int    jdx,idt,idx,nz,*vi,i;
365 
366   /* forward solve the lower triangular */
367   idx    = 0;
368   x[0]   = b[0]; x[1] = b[1]; x[2] = b[2]; x[3] = b[3];
369   for ( i=1; i<n; i++ ) {
370     v     =  aa      + 16*ai[i];
371     vi    =  aj      + ai[i];
372     nz    =  diag[i] - ai[i];
373     idx   +=  4;
374     sum1  =  b[idx];sum2 = b[1+idx];sum3 = b[2+idx];sum4 = b[3+idx];
375     while (nz--) {
376       jdx   = 4*(*vi++);
377       x1    = x[jdx];x2 = x[1+jdx];x3 = x[2+jdx];x4 = x[3+jdx];
378       sum1 -= v[0]*x1 + v[4]*x2 + v[8]*x3  + v[12]*x4;
379       sum2 -= v[1]*x1 + v[5]*x2 + v[9]*x3  + v[13]*x4;
380       sum3 -= v[2]*x1 + v[6]*x2 + v[10]*x3 + v[14]*x4;
381       sum4 -= v[3]*x1 + v[7]*x2 + v[11]*x3 + v[15]*x4;
382       v    += 16;
383     }
384     x[idx]   = sum1;
385     x[1+idx] = sum2;
386     x[2+idx] = sum3;
387     x[3+idx] = sum4;
388   }
389   /* backward solve the upper triangular */
390   for ( i=n-1; i>=0; i-- ){
391     v    = aa + 16*diag[i] + 16;
392     vi   = aj + diag[i] + 1;
393     nz   = ai[i+1] - diag[i] - 1;
394     idt  = 4*i;
395     sum1 = x[idt];  sum2 = x[1+idt];
396     sum3 = x[2+idt];sum4 = x[3+idt];
397     while (nz--) {
398       idx   = 4*(*vi++);
399       x1    = x[idx];   x2 = x[1+idx];x3    = x[2+idx]; x4 = x[3+idx];
400       sum1 -= v[0]*x1 + v[4]*x2 + v[8]*x3   + v[12]*x4;
401       sum2 -= v[1]*x1 + v[5]*x2 + v[9]*x3   + v[13]*x4;
402       sum3 -= v[2]*x1 + v[6]*x2 + v[10]*x3  + v[14]*x4;
403       sum4 -= v[3]*x1 + v[7]*x2 + v[11]*x3  + v[15]*x4;
404       v    += 16;
405     }
406     v        = aa + 16*diag[i];
407     x[idt]   = v[0]*sum1 + v[4]*sum2 + v[8]*sum3  + v[12]*sum4;
408     x[1+idt] = v[1]*sum1 + v[5]*sum2 + v[9]*sum3  + v[13]*sum4;
409     x[2+idt] = v[2]*sum1 + v[6]*sum2 + v[10]*sum3 + v[14]*sum4;
410     x[3+idt] = v[3]*sum1 + v[7]*sum2 + v[11]*sum3 + v[15]*sum4;
411   }
412   }
413 #endif
414 
415   ierr = VecRestoreArray(bb,&b);CHKERRQ(ierr);
416   ierr = VecRestoreArray(xx,&x);CHKERRQ(ierr);
417   PLogFlops(2*16*(a->nz) - 4*a->n);
418   PetscFunctionReturn(0);
419 }
420 
421 #undef __FUNC__
422 #define __FUNC__ "MatSolve_SeqBAIJ_5_NaturalOrdering"
423 int MatSolve_SeqBAIJ_5_NaturalOrdering(Mat A,Vec bb,Vec xx)
424 {
425   Mat_SeqBAIJ     *a = (Mat_SeqBAIJ *)A->data;
426   int             i,n=a->mbs,*vi,*ai=a->i,*aj=a->j,nz,idx,idt;
427   int             ierr,*diag = a->diag,jdx;
428   Scalar          *aa=a->a,sum1,sum2,sum3,sum4,sum5,x1,x2,x3,x4,x5;
429   Scalar *x,*b,*v;
430 
431   PetscFunctionBegin;
432   ierr = VecGetArray(bb,&b);CHKERRQ(ierr);
433   ierr = VecGetArray(xx,&x);CHKERRQ(ierr);
434   /* forward solve the lower triangular */
435   idx    = 0;
436   x[0] = b[idx]; x[1] = b[1+idx]; x[2] = b[2+idx]; x[3] = b[3+idx];x[4] = b[4+idx];
437   for ( i=1; i<n; i++ ) {
438     v     =  aa + 25*ai[i];
439     vi    =  aj + ai[i];
440     nz    =  diag[i] - ai[i];
441     idx   =  5*i;
442     sum1  =  b[idx];sum2 = b[1+idx];sum3 = b[2+idx];sum4 = b[3+idx];sum5 = b[4+idx];
443     while (nz--) {
444       jdx   = 5*(*vi++);
445       x1    = x[jdx];x2 = x[1+jdx];x3 = x[2+jdx];x4 = x[3+jdx];x5 = x[4+jdx];
446       sum1 -= v[0]*x1 + v[5]*x2 + v[10]*x3  + v[15]*x4 + v[20]*x5;
447       sum2 -= v[1]*x1 + v[6]*x2 + v[11]*x3  + v[16]*x4 + v[21]*x5;
448       sum3 -= v[2]*x1 + v[7]*x2 + v[12]*x3  + v[17]*x4 + v[22]*x5;
449       sum4 -= v[3]*x1 + v[8]*x2 + v[13]*x3  + v[18]*x4 + v[23]*x5;
450       sum5 -= v[4]*x1 + v[9]*x2 + v[14]*x3  + v[19]*x4 + v[24]*x5;
451       v    += 25;
452     }
453     x[idx]   = sum1;
454     x[1+idx] = sum2;
455     x[2+idx] = sum3;
456     x[3+idx] = sum4;
457     x[4+idx] = sum5;
458   }
459   /* backward solve the upper triangular */
460   for ( i=n-1; i>=0; i-- ){
461     v    = aa + 25*diag[i] + 25;
462     vi   = aj + diag[i] + 1;
463     nz   = ai[i+1] - diag[i] - 1;
464     idt  = 5*i;
465     sum1 = x[idt];  sum2 = x[1+idt];
466     sum3 = x[2+idt];sum4 = x[3+idt]; sum5 = x[4+idt];
467     while (nz--) {
468       idx   = 5*(*vi++);
469       x1    = x[idx];   x2 = x[1+idx];x3    = x[2+idx]; x4 = x[3+idx]; x5 = x[4+idx];
470       sum1 -= v[0]*x1 + v[5]*x2 + v[10]*x3  + v[15]*x4 + v[20]*x5;
471       sum2 -= v[1]*x1 + v[6]*x2 + v[11]*x3  + v[16]*x4 + v[21]*x5;
472       sum3 -= v[2]*x1 + v[7]*x2 + v[12]*x3  + v[17]*x4 + v[22]*x5;
473       sum4 -= v[3]*x1 + v[8]*x2 + v[13]*x3  + v[18]*x4 + v[23]*x5;
474       sum5 -= v[4]*x1 + v[9]*x2 + v[14]*x3  + v[19]*x4 + v[24]*x5;
475       v    += 25;
476     }
477     v        = aa + 25*diag[i];
478     x[idt]   = v[0]*sum1 + v[5]*sum2 + v[10]*sum3  + v[15]*sum4 + v[20]*sum5;
479     x[1+idt] = v[1]*sum1 + v[6]*sum2 + v[11]*sum3  + v[16]*sum4 + v[21]*sum5;
480     x[2+idt] = v[2]*sum1 + v[7]*sum2 + v[12]*sum3  + v[17]*sum4 + v[22]*sum5;
481     x[3+idt] = v[3]*sum1 + v[8]*sum2 + v[13]*sum3  + v[18]*sum4 + v[23]*sum5;
482     x[4+idt] = v[4]*sum1 + v[9]*sum2 + v[14]*sum3  + v[19]*sum4 + v[24]*sum5;
483   }
484 
485   ierr = VecRestoreArray(bb,&b);CHKERRQ(ierr);
486   ierr = VecRestoreArray(xx,&x);CHKERRQ(ierr);
487   PLogFlops(2*25*(a->nz) - 5*a->n);
488   PetscFunctionReturn(0);
489 }
490 
491 
492 #undef __FUNC__
493 #define __FUNC__ "MatSolve_SeqBAIJ_3"
494 int MatSolve_SeqBAIJ_3(Mat A,Vec bb,Vec xx)
495 {
496   Mat_SeqBAIJ     *a=(Mat_SeqBAIJ *)A->data;
497   IS              iscol=a->col,isrow=a->row;
498   int             *r,*c,ierr,i,n=a->mbs,*vi,*ai=a->i,*aj=a->j,nz,idx,idt,idc,*rout,*cout;
499   int             *diag = a->diag;
500   Scalar          *aa=a->a,sum1,sum2,sum3,x1,x2,x3;
501   Scalar *x,*b,*tmp,*v;
502 
503   PetscFunctionBegin;
504   ierr = VecGetArray(bb,&b); CHKERRQ(ierr);
505   ierr = VecGetArray(xx,&x); CHKERRQ(ierr);
506   tmp  = a->solve_work;
507 
508   ierr = ISGetIndices(isrow,&rout);CHKERRQ(ierr); r = rout;
509   ierr = ISGetIndices(iscol,&cout);CHKERRQ(ierr); c = cout + (n-1);
510 
511   /* forward solve the lower triangular */
512   idx    = 3*(*r++);
513   tmp[0] = b[idx]; tmp[1] = b[1+idx]; tmp[2] = b[2+idx];
514   for ( i=1; i<n; i++ ) {
515     v     = aa + 9*ai[i];
516     vi    = aj + ai[i];
517     nz    = diag[i] - ai[i];
518     idx   = 3*(*r++);
519     sum1  = b[idx]; sum2 = b[1+idx]; sum3 = b[2+idx];
520     while (nz--) {
521       idx   = 3*(*vi++);
522       x1    = tmp[idx]; x2 = tmp[1+idx]; x3 = tmp[2+idx];
523       sum1 -= v[0]*x1 + v[3]*x2 + v[6]*x3;
524       sum2 -= v[1]*x1 + v[4]*x2 + v[7]*x3;
525       sum3 -= v[2]*x1 + v[5]*x2 + v[8]*x3;
526       v += 9;
527     }
528     idx = 3*i;
529     tmp[idx] = sum1; tmp[1+idx] = sum2; tmp[2+idx] = sum3;
530   }
531   /* backward solve the upper triangular */
532   for ( i=n-1; i>=0; i-- ){
533     v    = aa + 9*diag[i] + 9;
534     vi   = aj + diag[i] + 1;
535     nz   = ai[i+1] - diag[i] - 1;
536     idt  = 3*i;
537     sum1 = tmp[idt]; sum2 = tmp[1+idt]; sum3 = tmp[2+idt];
538     while (nz--) {
539       idx   = 3*(*vi++);
540       x1    = tmp[idx]; x2 = tmp[1+idx]; x3 = tmp[2+idx];
541       sum1 -= v[0]*x1 + v[3]*x2 + v[6]*x3;
542       sum2 -= v[1]*x1 + v[4]*x2 + v[7]*x3;
543       sum3 -= v[2]*x1 + v[5]*x2 + v[8]*x3;
544       v += 9;
545     }
546     idc = 3*(*c--);
547     v   = aa + 9*diag[i];
548     x[idc]   = tmp[idt]   = v[0]*sum1 + v[3]*sum2 + v[6]*sum3;
549     x[1+idc] = tmp[1+idt] = v[1]*sum1 + v[4]*sum2 + v[7]*sum3;
550     x[2+idc] = tmp[2+idt] = v[2]*sum1 + v[5]*sum2 + v[8]*sum3;
551   }
552   ierr = ISRestoreIndices(isrow,&rout); CHKERRQ(ierr);
553   ierr = ISRestoreIndices(iscol,&cout); CHKERRQ(ierr);
554   ierr = VecRestoreArray(bb,&b);CHKERRQ(ierr);
555   ierr = VecRestoreArray(xx,&x);CHKERRQ(ierr);
556   PLogFlops(2*9*(a->nz) - 3*a->n);
557   PetscFunctionReturn(0);
558 }
559 
560 #undef __FUNC__
561 #define __FUNC__ "MatSolve_SeqBAIJ_2"
562 int MatSolve_SeqBAIJ_2(Mat A,Vec bb,Vec xx)
563 {
564   Mat_SeqBAIJ     *a=(Mat_SeqBAIJ *)A->data;
565   IS              iscol=a->col,isrow=a->row;
566   int             *r,*c,ierr,i,n=a->mbs,*vi,*ai=a->i,*aj=a->j,nz,idx,idt,idc,*rout,*cout;
567   int             *diag = a->diag;
568   Scalar          *aa=a->a,sum1,sum2,x1,x2;
569   Scalar *x,*b,*tmp,*v;
570 
571   PetscFunctionBegin;
572   ierr = VecGetArray(bb,&b); CHKERRQ(ierr);
573   ierr = VecGetArray(xx,&x); CHKERRQ(ierr);
574   tmp  = a->solve_work;
575 
576   ierr = ISGetIndices(isrow,&rout);CHKERRQ(ierr); r = rout;
577   ierr = ISGetIndices(iscol,&cout);CHKERRQ(ierr); c = cout + (n-1);
578 
579   /* forward solve the lower triangular */
580   idx    = 2*(*r++);
581   tmp[0] = b[idx]; tmp[1] = b[1+idx];
582   for ( i=1; i<n; i++ ) {
583     v     = aa + 4*ai[i];
584     vi    = aj + ai[i];
585     nz    = diag[i] - ai[i];
586     idx   = 2*(*r++);
587     sum1  = b[idx]; sum2 = b[1+idx];
588     while (nz--) {
589       idx   = 2*(*vi++);
590       x1    = tmp[idx]; x2 = tmp[1+idx];
591       sum1 -= v[0]*x1 + v[2]*x2;
592       sum2 -= v[1]*x1 + v[3]*x2;
593       v += 4;
594     }
595     idx = 2*i;
596     tmp[idx] = sum1; tmp[1+idx] = sum2;
597   }
598   /* backward solve the upper triangular */
599   for ( i=n-1; i>=0; i-- ){
600     v    = aa + 4*diag[i] + 4;
601     vi   = aj + diag[i] + 1;
602     nz   = ai[i+1] - diag[i] - 1;
603     idt  = 2*i;
604     sum1 = tmp[idt]; sum2 = tmp[1+idt];
605     while (nz--) {
606       idx   = 2*(*vi++);
607       x1    = tmp[idx]; x2 = tmp[1+idx];
608       sum1 -= v[0]*x1 + v[2]*x2;
609       sum2 -= v[1]*x1 + v[3]*x2;
610       v += 4;
611     }
612     idc = 2*(*c--);
613     v   = aa + 4*diag[i];
614     x[idc]   = tmp[idt]   = v[0]*sum1 + v[2]*sum2;
615     x[1+idc] = tmp[1+idt] = v[1]*sum1 + v[3]*sum2;
616   }
617   ierr = ISRestoreIndices(isrow,&rout); CHKERRQ(ierr);
618   ierr = ISRestoreIndices(iscol,&cout); CHKERRQ(ierr);
619   ierr = VecRestoreArray(bb,&b); CHKERRQ(ierr);
620   ierr = VecRestoreArray(xx,&x);CHKERRQ(ierr);
621   PLogFlops(2*4*(a->nz) - 2*a->n);
622   PetscFunctionReturn(0);
623 }
624 
625 
626 #undef __FUNC__
627 #define __FUNC__ "MatSolve_SeqBAIJ_1"
628 int MatSolve_SeqBAIJ_1(Mat A,Vec bb,Vec xx)
629 {
630   Mat_SeqBAIJ     *a=(Mat_SeqBAIJ *)A->data;
631   IS              iscol=a->col,isrow=a->row;
632   int             *r,*c,ierr,i,n=a->mbs,*vi,*ai=a->i,*aj=a->j,nz,*rout,*cout;
633   int             *diag = a->diag;
634   Scalar          *aa=a->a,sum1;
635   Scalar *x,*b,*tmp,*v;
636 
637   PetscFunctionBegin;
638   if (!n) PetscFunctionReturn(0);
639 
640   ierr = VecGetArray(bb,&b); CHKERRQ(ierr);
641   ierr = VecGetArray(xx,&x); CHKERRQ(ierr);
642   tmp  = a->solve_work;
643 
644   ierr = ISGetIndices(isrow,&rout);CHKERRQ(ierr); r = rout;
645   ierr = ISGetIndices(iscol,&cout);CHKERRQ(ierr); c = cout + (n-1);
646 
647   /* forward solve the lower triangular */
648   tmp[0] = b[*r++];
649   for ( i=1; i<n; i++ ) {
650     v     = aa + ai[i];
651     vi    = aj + ai[i];
652     nz    = diag[i] - ai[i];
653     sum1  = b[*r++];
654     while (nz--) {
655       sum1 -= (*v++)*tmp[*vi++];
656     }
657     tmp[i] = sum1;
658   }
659   /* backward solve the upper triangular */
660   for ( i=n-1; i>=0; i-- ){
661     v    = aa + diag[i] + 1;
662     vi   = aj + diag[i] + 1;
663     nz   = ai[i+1] - diag[i] - 1;
664     sum1 = tmp[i];
665     while (nz--) {
666       sum1 -= (*v++)*tmp[*vi++];
667     }
668     x[*c--] = tmp[i] = aa[diag[i]]*sum1;
669   }
670 
671   ierr = ISRestoreIndices(isrow,&rout); CHKERRQ(ierr);
672   ierr = ISRestoreIndices(iscol,&cout); CHKERRQ(ierr);
673   ierr = VecRestoreArray(bb,&b); CHKERRQ(ierr);
674   ierr = VecRestoreArray(xx,&x); CHKERRQ(ierr);
675   PLogFlops(2*1*(a->nz) - a->n);
676   PetscFunctionReturn(0);
677 }
678 
679 /* ----------------------------------------------------------------*/
680 /*
681      This code is virtually identical to MatILUFactorSymbolic_SeqAIJ
682    except that the data structure of Mat_SeqAIJ is slightly different.
683    Not a good example of code reuse.
684 */
685 #undef __FUNC__
686 #define __FUNC__ "MatILUFactorSymbolic_SeqBAIJ"
687 int MatILUFactorSymbolic_SeqBAIJ(Mat A,IS isrow,IS iscol,double f,int levels,Mat *fact)
688 {
689   Mat_SeqBAIJ *a = (Mat_SeqBAIJ *) A->data, *b;
690   IS          isicol;
691   int         *r,*ic, ierr, prow, n = a->mbs, *ai = a->i, *aj = a->j;
692   int         *ainew,*ajnew, jmax,*fill, *xi, nz, *im,*ajfill,*flev;
693   int         *dloc, idx, row,m,fm, nzf, nzi,len,  realloc = 0;
694   int         incrlev,nnz,i,bs = a->bs,bs2 = a->bs2;
695   PetscTruth  col_identity, row_identity;
696 
697   PetscFunctionBegin;
698   ierr = ISInvertPermutation(iscol,&isicol); CHKERRQ(ierr);
699 
700   /* special case that simply copies fill pattern */
701   PetscValidHeaderSpecific(isrow,IS_COOKIE);
702   PetscValidHeaderSpecific(iscol,IS_COOKIE);
703   ierr = ISIdentity(isrow,&row_identity); CHKERRQ(ierr);
704   ierr = ISIdentity(iscol,&col_identity); CHKERRQ(ierr);
705   if (levels == 0 && row_identity && col_identity) {
706     ierr = MatDuplicate_SeqBAIJ(A,MAT_DO_NOT_COPY_VALUES,fact); CHKERRQ(ierr);
707     (*fact)->factor = FACTOR_LU;
708     b               = (Mat_SeqBAIJ *) (*fact)->data;
709     if (!b->diag) {
710       ierr = MatMarkDiag_SeqBAIJ(*fact); CHKERRQ(ierr);
711     }
712     b->row        = isrow;
713     b->col        = iscol;
714     b->icol       = isicol;
715     b->solve_work = (Scalar *) PetscMalloc((b->m+1+b->bs)*sizeof(Scalar));CHKPTRQ(b->solve_work);
716     /*
717         Blocksize 4 and 5 a special faster solver for ILU(0) factorization
718         with natural ordering
719     */
720     if (b->bs == 4) {
721       (*fact)->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_4_NaturalOrdering;
722       (*fact)->ops->solve           = MatSolve_SeqBAIJ_4_NaturalOrdering;
723       PLogInfo(A,"Using special natural ordering factor and solve BS=4\n");
724     } else if (b->bs == 5) {
725       (*fact)->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_5_NaturalOrdering;
726       (*fact)->ops->solve           = MatSolve_SeqBAIJ_5_NaturalOrdering;
727       PLogInfo( A,"Using special natural ordering factor and solve BS=5\n");
728     }
729     PetscFunctionReturn(0);
730   }
731 
732   ierr = ISGetIndices(isrow,&r); CHKERRQ(ierr);
733   ierr = ISGetIndices(isicol,&ic); CHKERRQ(ierr);
734 
735   /* get new row pointers */
736   ainew = (int *) PetscMalloc( (n+1)*sizeof(int) ); CHKPTRQ(ainew);
737   ainew[0] = 0;
738   /* don't know how many column pointers are needed so estimate */
739   jmax = (int) (f*ai[n] + 1);
740   ajnew = (int *) PetscMalloc( (jmax)*sizeof(int) ); CHKPTRQ(ajnew);
741   /* ajfill is level of fill for each fill entry */
742   ajfill = (int *) PetscMalloc( (jmax)*sizeof(int) ); CHKPTRQ(ajfill);
743   /* fill is a linked list of nonzeros in active row */
744   fill = (int *) PetscMalloc( (n+1)*sizeof(int)); CHKPTRQ(fill);
745   /* im is level for each filled value */
746   im = (int *) PetscMalloc( (n+1)*sizeof(int)); CHKPTRQ(im);
747   /* dloc is location of diagonal in factor */
748   dloc = (int *) PetscMalloc( (n+1)*sizeof(int)); CHKPTRQ(dloc);
749   dloc[0]  = 0;
750   for ( prow=0; prow<n; prow++ ) {
751     /* first copy previous fill into linked list */
752     nzf     = nz  = ai[r[prow]+1] - ai[r[prow]];
753     if (!nz) SETERRQ(PETSC_ERR_MAT_LU_ZRPVT,1,"Empty row in matrix");
754     xi      = aj + ai[r[prow]];
755     fill[n] = n;
756     while (nz--) {
757       fm  = n;
758       idx = ic[*xi++];
759       do {
760         m  = fm;
761         fm = fill[m];
762       } while (fm < idx);
763       fill[m]   = idx;
764       fill[idx] = fm;
765       im[idx]   = 0;
766     }
767     nzi = 0;
768     row = fill[n];
769     while ( row < prow ) {
770       incrlev = im[row] + 1;
771       nz      = dloc[row];
772       xi      = ajnew  + ainew[row] + nz;
773       flev    = ajfill + ainew[row] + nz + 1;
774       nnz     = ainew[row+1] - ainew[row] - nz - 1;
775       if (*xi++ != row) {
776         SETERRQ(PETSC_ERR_MAT_LU_ZRPVT,0,"Zero pivot: try running with -pc_ilu_nonzeros_along_diagonal");
777       }
778       fm      = row;
779       while (nnz-- > 0) {
780         idx = *xi++;
781         if (*flev + incrlev > levels) {
782           flev++;
783           continue;
784         }
785         do {
786           m  = fm;
787           fm = fill[m];
788         } while (fm < idx);
789         if (fm != idx) {
790           im[idx]   = *flev + incrlev;
791           fill[m]   = idx;
792           fill[idx] = fm;
793           fm        = idx;
794           nzf++;
795         } else {
796           if (im[idx] > *flev + incrlev) im[idx] = *flev+incrlev;
797         }
798         flev++;
799       }
800       row = fill[row];
801       nzi++;
802     }
803     /* copy new filled row into permanent storage */
804     ainew[prow+1] = ainew[prow] + nzf;
805     if (ainew[prow+1] > jmax) {
806 
807       /* estimate how much additional space we will need */
808       /* use the strategy suggested by David Hysom <hysom@perch-t.icase.edu> */
809       /* just double the memory each time */
810       int maxadd = jmax;
811       /* maxadd = (int) (((f*ai[n]+1)*(n-prow+5))/n); */
812       if (maxadd < nzf) maxadd = (n-prow)*(nzf+1);
813       jmax += maxadd;
814 
815       /* allocate a longer ajnew and ajfill */
816       xi = (int *) PetscMalloc( jmax*sizeof(int) );CHKPTRQ(xi);
817       PetscMemcpy(xi,ajnew,ainew[prow]*sizeof(int));
818       PetscFree(ajnew);
819       ajnew = xi;
820       xi = (int *) PetscMalloc( jmax*sizeof(int) );CHKPTRQ(xi);
821       PetscMemcpy(xi,ajfill,ainew[prow]*sizeof(int));
822       PetscFree(ajfill);
823       ajfill = xi;
824       realloc++; /* count how many reallocations are needed */
825     }
826     xi          = ajnew + ainew[prow];
827     flev        = ajfill + ainew[prow];
828     dloc[prow]  = nzi;
829     fm          = fill[n];
830     while (nzf--) {
831       *xi++   = fm;
832       *flev++ = im[fm];
833       fm      = fill[fm];
834     }
835   }
836   PetscFree(ajfill);
837   ierr = ISRestoreIndices(isrow,&r); CHKERRQ(ierr);
838   ierr = ISRestoreIndices(isicol,&ic); CHKERRQ(ierr);
839   PetscFree(fill); PetscFree(im);
840 
841   {
842     double af = ((double)ainew[n])/((double)ai[n]);
843     PLogInfo(A,"MatILUFactorSymbolic_SeqBAIJ:Reallocs %d Fill ratio:given %g needed %g\n",
844              realloc,f,af);
845     PLogInfo(A,"MatILUFactorSymbolic_SeqBAIJ:Run with -pc_ilu_fill %g or use \n",af);
846     PLogInfo(A,"MatILUFactorSymbolic_SeqBAIJ:PCILUSetFill(pc,%g);\n",af);
847     PLogInfo(A,"MatILUFactorSymbolic_SeqBAIJ:for best performance.\n");
848   }
849 
850   /* put together the new matrix */
851   ierr = MatCreateSeqBAIJ(A->comm,bs,bs*n,bs*n,0,PETSC_NULL,fact);CHKERRQ(ierr);
852   PLogObjectParent(*fact,isicol);
853   b = (Mat_SeqBAIJ *) (*fact)->data;
854   PetscFree(b->imax);
855   b->singlemalloc = 0;
856   len = bs2*ainew[n]*sizeof(Scalar);
857   /* the next line frees the default space generated by the Create() */
858   PetscFree(b->a); PetscFree(b->ilen);
859   b->a          = (Scalar *) PetscMalloc( len ); CHKPTRQ(b->a);
860   b->j          = ajnew;
861   b->i          = ainew;
862   for ( i=0; i<n; i++ ) dloc[i] += ainew[i];
863   b->diag       = dloc;
864   b->ilen       = 0;
865   b->imax       = 0;
866   b->row        = isrow;
867   b->col        = iscol;
868   b->icol       = isicol;
869   b->solve_work = (Scalar *) PetscMalloc( (bs*n+bs)*sizeof(Scalar));CHKPTRQ(b->solve_work);
870   /* In b structure:  Free imax, ilen, old a, old j.
871      Allocate dloc, solve_work, new a, new j */
872   PLogObjectMemory(*fact,(ainew[n]-n)*(sizeof(int))+bs2*ainew[n]*sizeof(Scalar));
873   b->maxnz          = b->nz = ainew[n];
874   (*fact)->factor   = FACTOR_LU;
875 
876   (*fact)->info.factor_mallocs    = realloc;
877   (*fact)->info.fill_ratio_given  = f;
878   (*fact)->info.fill_ratio_needed = ((double)ainew[n])/((double)ai[prow]);
879 
880   PetscFunctionReturn(0);
881 }
882 
883 
884 
885 
886