xref: /petsc/src/mat/impls/baij/seq/baijfact2.c (revision 2e8a6d31cfff42dc61c2443ddfa186a411c27ca7)
1 #ifdef PETSC_RCS_HEADER
2 static char vcid[] = "$Id: baijfact2.c,v 1.12 1998/10/08 17:55:25 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 
12 /* ----------------------------------------------------------- */
13 #undef __FUNC__
14 #define __FUNC__ "MatSolve_SeqBAIJ_N"
15 int MatSolve_SeqBAIJ_N(Mat A,Vec bb,Vec xx)
16 {
17   Mat_SeqBAIJ     *a=(Mat_SeqBAIJ *)A->data;
18   IS              iscol=a->col,isrow=a->row;
19   int             *r,*c,ierr,i,n=a->mbs,*vi,*ai=a->i,*aj=a->j;
20   int             nz,bs=a->bs,bs2=a->bs2,*rout,*cout;
21   Scalar          *aa=a->a,*sum;
22   Scalar *x,*b,*lsum,*tmp,*v;
23 
24   PetscFunctionBegin;
25   ierr = VecGetArray(bb,&b);CHKERRQ(ierr);
26   ierr = VecGetArray(xx,&x); CHKERRQ(ierr);
27   tmp  = a->solve_work;
28 
29   ierr = ISGetIndices(isrow,&rout);CHKERRQ(ierr); r = rout;
30   ierr = ISGetIndices(iscol,&cout);CHKERRQ(ierr); c = cout + (n-1);
31 
32   /* forward solve the lower triangular */
33   PetscMemcpy(tmp,b + bs*(*r++), bs*sizeof(Scalar));
34   for ( i=1; i<n; i++ ) {
35     v   = aa + bs2*ai[i];
36     vi  = aj + ai[i];
37     nz  = a->diag[i] - ai[i];
38     sum = tmp + bs*i;
39     PetscMemcpy(sum,b+bs*(*r++),bs*sizeof(Scalar));
40     while (nz--) {
41       Kernel_v_gets_v_minus_A_times_w(bs,sum,v,tmp+bs*(*vi++));
42       v += bs2;
43     }
44   }
45   /* backward solve the upper triangular */
46   lsum = a->solve_work + a->n;
47   for ( i=n-1; i>=0; i-- ){
48     v   = aa + bs2*(a->diag[i] + 1);
49     vi  = aj + a->diag[i] + 1;
50     nz  = ai[i+1] - a->diag[i] - 1;
51     PetscMemcpy(lsum,tmp+i*bs,bs*sizeof(Scalar));
52     while (nz--) {
53       Kernel_v_gets_v_minus_A_times_w(bs,lsum,v,tmp+bs*(*vi++));
54       v += bs2;
55     }
56     Kernel_w_gets_A_times_v(bs,lsum,aa+bs2*a->diag[i],tmp+i*bs);
57     PetscMemcpy(x + bs*(*c--),tmp+i*bs,bs*sizeof(Scalar));
58   }
59 
60   ierr = ISRestoreIndices(isrow,&rout); CHKERRQ(ierr);
61   ierr = ISRestoreIndices(iscol,&cout); CHKERRQ(ierr);
62   ierr = VecRestoreArray(bb,&b); CHKERRQ(ierr);
63   ierr = VecRestoreArray(xx,&x); CHKERRQ(ierr);
64   PLogFlops(2*(a->bs2)*(a->nz) - a->n);
65   PetscFunctionReturn(0);
66 }
67 
68 #undef __FUNC__
69 #define __FUNC__ "MatSolve_SeqBAIJ_7"
70 int MatSolve_SeqBAIJ_7(Mat A,Vec bb,Vec xx)
71 {
72   Mat_SeqBAIJ     *a=(Mat_SeqBAIJ *)A->data;
73   IS              iscol=a->col,isrow=a->row;
74   int             *r,*c,ierr,i,n=a->mbs,*vi,*ai=a->i,*aj=a->j,nz,idx,idt,idc,*rout,*cout;
75   int             *diag = a->diag;
76   Scalar          *aa=a->a,sum1,sum2,sum3,sum4,sum5,sum6,sum7,x1,x2,x3,x4,x5,x6,x7;
77   Scalar *x,*b,*tmp,*v;
78 
79   PetscFunctionBegin;
80   ierr = VecGetArray(bb,&b); CHKERRQ(ierr);
81   ierr = VecGetArray(xx,&x); CHKERRQ(ierr);
82   tmp  = a->solve_work;
83 
84   ierr = ISGetIndices(isrow,&rout);CHKERRQ(ierr); r = rout;
85   ierr = ISGetIndices(iscol,&cout);CHKERRQ(ierr); c = cout + (n-1);
86 
87   /* forward solve the lower triangular */
88   idx    = 7*(*r++);
89   tmp[0] = b[idx];   tmp[1] = b[1+idx];
90   tmp[2] = b[2+idx]; tmp[3] = b[3+idx]; tmp[4] = b[4+idx];
91   tmp[5] = b[5+idx]; tmp[6] = b[6+idx];
92 
93   for ( i=1; i<n; i++ ) {
94     v     = aa + 49*ai[i];
95     vi    = aj + ai[i];
96     nz    = diag[i] - ai[i];
97     idx   = 7*(*r++);
98     sum1  = b[idx];sum2 = b[1+idx];sum3 = b[2+idx];sum4 = b[3+idx];
99     sum5  = b[4+idx];sum6 = b[5+idx];sum7 = b[6+idx];
100     while (nz--) {
101       idx   = 7*(*vi++);
102       x1    = tmp[idx];  x2 = tmp[1+idx];x3 = tmp[2+idx];
103       x4    = tmp[3+idx];x5 = tmp[4+idx];
104       x6    = tmp[5+idx];x7 = tmp[6+idx];
105       sum1 -= v[0]*x1 + v[7]*x2  + v[14]*x3 + v[21]*x4 + v[28]*x5 + v[35]*x6 + v[42]*x7;
106       sum2 -= v[1]*x1 + v[8]*x2  + v[15]*x3 + v[22]*x4 + v[29]*x5 + v[36]*x6 + v[43]*x7;
107       sum3 -= v[2]*x1 + v[9]*x2  + v[16]*x3 + v[23]*x4 + v[30]*x5 + v[37]*x6 + v[44]*x7;
108       sum4 -= v[3]*x1 + v[10]*x2 + v[17]*x3 + v[24]*x4 + v[31]*x5 + v[38]*x6 + v[45]*x7;
109       sum5 -= v[4]*x1 + v[11]*x2 + v[18]*x3 + v[25]*x4 + v[32]*x5 + v[39]*x6 + v[46]*x7;
110       sum6 -= v[5]*x1 + v[12]*x2 + v[19]*x3 + v[26]*x4 + v[33]*x5 + v[40]*x6 + v[47]*x7;
111       sum7 -= v[6]*x1 + v[13]*x2 + v[20]*x3 + v[27]*x4 + v[34]*x5 + v[41]*x6 + v[48]*x7;
112       v += 49;
113     }
114     idx = 7*i;
115     tmp[idx]   = sum1;tmp[1+idx] = sum2;
116     tmp[2+idx] = sum3;tmp[3+idx] = sum4; tmp[4+idx] = sum5;
117     tmp[5+idx] = sum6;tmp[6+idx] = sum7;
118   }
119   /* backward solve the upper triangular */
120   for ( i=n-1; i>=0; i-- ){
121     v    = aa + 49*diag[i] + 49;
122     vi   = aj + diag[i] + 1;
123     nz   = ai[i+1] - diag[i] - 1;
124     idt  = 7*i;
125     sum1 = tmp[idt];  sum2 = tmp[1+idt];
126     sum3 = tmp[2+idt];sum4 = tmp[3+idt]; sum5 = tmp[4+idt];
127     sum6 = tmp[5+idt];sum7 = tmp[6+idt];
128     while (nz--) {
129       idx   = 7*(*vi++);
130       x1    = tmp[idx];   x2 = tmp[1+idx];
131       x3    = tmp[2+idx]; x4 = tmp[3+idx]; x5 = tmp[4+idx];
132       x6    = tmp[5+idx]; x7 = tmp[6+idx];
133       sum1 -= v[0]*x1 + v[7]*x2  + v[14]*x3 + v[21]*x4 + v[28]*x5 + v[35]*x6 + v[42]*x7;
134       sum2 -= v[1]*x1 + v[8]*x2  + v[15]*x3 + v[22]*x4 + v[29]*x5 + v[36]*x6 + v[43]*x7;
135       sum3 -= v[2]*x1 + v[9]*x2  + v[16]*x3 + v[23]*x4 + v[30]*x5 + v[37]*x6 + v[44]*x7;
136       sum4 -= v[3]*x1 + v[10]*x2 + v[17]*x3 + v[24]*x4 + v[31]*x5 + v[38]*x6 + v[45]*x7;
137       sum5 -= v[4]*x1 + v[11]*x2 + v[18]*x3 + v[25]*x4 + v[32]*x5 + v[39]*x6 + v[46]*x7;
138       sum6 -= v[5]*x1 + v[12]*x2 + v[19]*x3 + v[26]*x4 + v[33]*x5 + v[40]*x6 + v[47]*x7;
139       sum7 -= v[6]*x1 + v[13]*x2 + v[20]*x3 + v[27]*x4 + v[34]*x5 + v[41]*x6 + v[48]*x7;
140       v += 49;
141     }
142     idc = 7*(*c--);
143     v   = aa + 49*diag[i];
144     x[idc]   = tmp[idt]   = v[0]*sum1+v[7]*sum2+v[14]*sum3+
145                                  v[21]*sum4+v[28]*sum5+v[35]*sum6+v[42]*sum7;
146     x[1+idc] = tmp[1+idt] = v[1]*sum1+v[8]*sum2+v[15]*sum3+
147                                  v[22]*sum4+v[29]*sum5+v[36]*sum6+v[43]*sum7;
148     x[2+idc] = tmp[2+idt] = v[2]*sum1+v[9]*sum2+v[16]*sum3+
149                                  v[23]*sum4+v[30]*sum5+v[37]*sum6+v[44]*sum7;
150     x[3+idc] = tmp[3+idt] = v[3]*sum1+v[10]*sum2+v[17]*sum3+
151                                  v[24]*sum4+v[31]*sum5+v[38]*sum6+v[45]*sum7;
152     x[4+idc] = tmp[4+idt] = v[4]*sum1+v[11]*sum2+v[18]*sum3+
153                                  v[25]*sum4+v[32]*sum5+v[39]*sum6+v[46]*sum7;
154     x[5+idc] = tmp[5+idt] = v[5]*sum1+v[12]*sum2+v[19]*sum3+
155                                  v[26]*sum4+v[33]*sum5+v[40]*sum6+v[47]*sum7;
156     x[6+idc] = tmp[6+idt] = v[6]*sum1+v[13]*sum2+v[20]*sum3+
157                                  v[27]*sum4+v[34]*sum5+v[41]*sum6+v[48]*sum7;
158   }
159 
160   ierr = ISRestoreIndices(isrow,&rout); CHKERRQ(ierr);
161   ierr = ISRestoreIndices(iscol,&cout); CHKERRQ(ierr);
162   ierr = VecRestoreArray(bb,&b); CHKERRQ(ierr);
163   ierr = VecRestoreArray(xx,&x); CHKERRQ(ierr);
164   PLogFlops(2*49*(a->nz) - a->n);
165   PetscFunctionReturn(0);
166 }
167 
168 #undef __FUNC__
169 #define __FUNC__ "MatSolve_SeqBAIJ_5"
170 int MatSolve_SeqBAIJ_5(Mat A,Vec bb,Vec xx)
171 {
172   Mat_SeqBAIJ     *a=(Mat_SeqBAIJ *)A->data;
173   IS              iscol=a->col,isrow=a->row;
174   int             *r,*c,ierr,i,n=a->mbs,*vi,*ai=a->i,*aj=a->j,nz,idx,idt,idc,*rout,*cout;
175   int             *diag = a->diag;
176   Scalar          *aa=a->a,sum1,sum2,sum3,sum4,sum5,x1,x2,x3,x4,x5;
177   Scalar *x,*b,*tmp,*v;
178 
179   PetscFunctionBegin;
180   ierr = VecGetArray(bb,&b); CHKERRQ(ierr);
181   ierr = VecGetArray(xx,&x); CHKERRQ(ierr);
182   tmp  = a->solve_work;
183 
184   ierr = ISGetIndices(isrow,&rout);CHKERRQ(ierr); r = rout;
185   ierr = ISGetIndices(iscol,&cout);CHKERRQ(ierr); c = cout + (n-1);
186 
187   /* forward solve the lower triangular */
188   idx    = 5*(*r++);
189   tmp[0] = b[idx];   tmp[1] = b[1+idx];
190   tmp[2] = b[2+idx]; tmp[3] = b[3+idx]; tmp[4] = b[4+idx];
191   for ( i=1; i<n; i++ ) {
192     v     = aa + 25*ai[i];
193     vi    = aj + ai[i];
194     nz    = diag[i] - ai[i];
195     idx   = 5*(*r++);
196     sum1  = b[idx];sum2 = b[1+idx];sum3 = b[2+idx];sum4 = b[3+idx];
197     sum5  = b[4+idx];
198     while (nz--) {
199       idx   = 5*(*vi++);
200       x1    = tmp[idx];  x2 = tmp[1+idx];x3 = tmp[2+idx];
201       x4    = tmp[3+idx];x5 = tmp[4+idx];
202       sum1 -= v[0]*x1 + v[5]*x2 + v[10]*x3 + v[15]*x4 + v[20]*x5;
203       sum2 -= v[1]*x1 + v[6]*x2 + v[11]*x3 + v[16]*x4 + v[21]*x5;
204       sum3 -= v[2]*x1 + v[7]*x2 + v[12]*x3 + v[17]*x4 + v[22]*x5;
205       sum4 -= v[3]*x1 + v[8]*x2 + v[13]*x3 + v[18]*x4 + v[23]*x5;
206       sum5 -= v[4]*x1 + v[9]*x2 + v[14]*x3 + v[19]*x4 + v[24]*x5;
207       v += 25;
208     }
209     idx = 5*i;
210     tmp[idx]   = sum1;tmp[1+idx] = sum2;
211     tmp[2+idx] = sum3;tmp[3+idx] = sum4; tmp[4+idx] = sum5;
212   }
213   /* backward solve the upper triangular */
214   for ( i=n-1; i>=0; i-- ){
215     v    = aa + 25*diag[i] + 25;
216     vi   = aj + diag[i] + 1;
217     nz   = ai[i+1] - diag[i] - 1;
218     idt  = 5*i;
219     sum1 = tmp[idt];  sum2 = tmp[1+idt];
220     sum3 = tmp[2+idt];sum4 = tmp[3+idt]; sum5 = tmp[4+idt];
221     while (nz--) {
222       idx   = 5*(*vi++);
223       x1    = tmp[idx];   x2 = tmp[1+idx];
224       x3    = tmp[2+idx]; x4 = tmp[3+idx]; x5 = tmp[4+idx];
225       sum1 -= v[0]*x1 + v[5]*x2 + v[10]*x3 + v[15]*x4 + v[20]*x5;
226       sum2 -= v[1]*x1 + v[6]*x2 + v[11]*x3 + v[16]*x4 + v[21]*x5;
227       sum3 -= v[2]*x1 + v[7]*x2 + v[12]*x3 + v[17]*x4 + v[22]*x5;
228       sum4 -= v[3]*x1 + v[8]*x2 + v[13]*x3 + v[18]*x4 + v[23]*x5;
229       sum5 -= v[4]*x1 + v[9]*x2 + v[14]*x3 + v[19]*x4 + v[24]*x5;
230       v += 25;
231     }
232     idc = 5*(*c--);
233     v   = aa + 25*diag[i];
234     x[idc]   = tmp[idt]   = v[0]*sum1+v[5]*sum2+v[10]*sum3+
235                                  v[15]*sum4+v[20]*sum5;
236     x[1+idc] = tmp[1+idt] = v[1]*sum1+v[6]*sum2+v[11]*sum3+
237                                  v[16]*sum4+v[21]*sum5;
238     x[2+idc] = tmp[2+idt] = v[2]*sum1+v[7]*sum2+v[12]*sum3+
239                                  v[17]*sum4+v[22]*sum5;
240     x[3+idc] = tmp[3+idt] = v[3]*sum1+v[8]*sum2+v[13]*sum3+
241                                  v[18]*sum4+v[23]*sum5;
242     x[4+idc] = tmp[4+idt] = v[4]*sum1+v[9]*sum2+v[14]*sum3+
243                                  v[19]*sum4+v[24]*sum5;
244   }
245 
246   ierr = ISRestoreIndices(isrow,&rout); CHKERRQ(ierr);
247   ierr = ISRestoreIndices(iscol,&cout); CHKERRQ(ierr);
248   ierr = VecRestoreArray(bb,&b); CHKERRQ(ierr);
249   ierr = VecRestoreArray(xx,&x); CHKERRQ(ierr);
250   PLogFlops(2*25*(a->nz) - a->n);
251   PetscFunctionReturn(0);
252 }
253 
254 #undef __FUNC__
255 #define __FUNC__ "MatSolve_SeqBAIJ_4"
256 int MatSolve_SeqBAIJ_4(Mat A,Vec bb,Vec xx)
257 {
258   Mat_SeqBAIJ     *a = (Mat_SeqBAIJ *)A->data;
259   IS              iscol=a->col,isrow=a->row;
260   int             *r,*c,ierr,i,n=a->mbs,*vi,*ai=a->i,*aj=a->j,nz,idx,idt,idc,*rout,*cout;
261   int             *diag = a->diag;
262   Scalar          *aa=a->a,sum1,sum2,sum3,sum4,x1,x2,x3,x4;
263   Scalar          *x,*b,*tmp,*v;
264 
265   PetscFunctionBegin;
266   ierr = VecGetArray(bb,&b); CHKERRQ(ierr);
267   ierr = VecGetArray(xx,&x); CHKERRQ(ierr);
268   tmp  = a->solve_work;
269 
270   ierr = ISGetIndices(isrow,&rout);CHKERRQ(ierr); r = rout;
271   ierr = ISGetIndices(iscol,&cout);CHKERRQ(ierr); c = cout + (n-1);
272 
273   /* forward solve the lower triangular */
274   idx    = 4*(*r++);
275   tmp[0] = b[idx];   tmp[1] = b[1+idx];
276   tmp[2] = b[2+idx]; tmp[3] = b[3+idx];
277   for ( i=1; i<n; i++ ) {
278     v     = aa + 16*ai[i];
279     vi    = aj + ai[i];
280     nz    = diag[i] - ai[i];
281     idx   = 4*(*r++);
282     sum1  = b[idx];sum2 = b[1+idx];sum3 = b[2+idx];sum4 = b[3+idx];
283     while (nz--) {
284       idx   = 4*(*vi++);
285       x1    = tmp[idx];x2 = tmp[1+idx];x3 = tmp[2+idx];x4 = tmp[3+idx];
286       sum1 -= v[0]*x1 + v[4]*x2 + v[8]*x3  + v[12]*x4;
287       sum2 -= v[1]*x1 + v[5]*x2 + v[9]*x3  + v[13]*x4;
288       sum3 -= v[2]*x1 + v[6]*x2 + v[10]*x3 + v[14]*x4;
289       sum4 -= v[3]*x1 + v[7]*x2 + v[11]*x3 + v[15]*x4;
290       v    += 16;
291     }
292     idx        = 4*i;
293     tmp[idx]   = sum1;tmp[1+idx] = sum2;
294     tmp[2+idx] = sum3;tmp[3+idx] = sum4;
295   }
296   /* backward solve the upper triangular */
297   for ( i=n-1; i>=0; i-- ){
298     v    = aa + 16*diag[i] + 16;
299     vi   = aj + diag[i] + 1;
300     nz   = ai[i+1] - diag[i] - 1;
301     idt  = 4*i;
302     sum1 = tmp[idt];  sum2 = tmp[1+idt];
303     sum3 = tmp[2+idt];sum4 = tmp[3+idt];
304     while (nz--) {
305       idx   = 4*(*vi++);
306       x1    = tmp[idx];   x2 = tmp[1+idx];
307       x3    = tmp[2+idx]; x4 = tmp[3+idx];
308       sum1 -= v[0]*x1 + v[4]*x2 + v[8]*x3   + v[12]*x4;
309       sum2 -= v[1]*x1 + v[5]*x2 + v[9]*x3   + v[13]*x4;
310       sum3 -= v[2]*x1 + v[6]*x2 + v[10]*x3  + v[14]*x4;
311       sum4 -= v[3]*x1 + v[7]*x2 + v[11]*x3  + v[15]*x4;
312       v += 16;
313     }
314     idc      = 4*(*c--);
315     v        = aa + 16*diag[i];
316     x[idc]   = tmp[idt]   = v[0]*sum1+v[4]*sum2+v[8]*sum3+v[12]*sum4;
317     x[1+idc] = tmp[1+idt] = v[1]*sum1+v[5]*sum2+v[9]*sum3+v[13]*sum4;
318     x[2+idc] = tmp[2+idt] = v[2]*sum1+v[6]*sum2+v[10]*sum3+v[14]*sum4;
319     x[3+idc] = tmp[3+idt] = v[3]*sum1+v[7]*sum2+v[11]*sum3+v[15]*sum4;
320   }
321 
322   ierr = ISRestoreIndices(isrow,&rout); CHKERRQ(ierr);
323   ierr = ISRestoreIndices(iscol,&cout); CHKERRQ(ierr);
324   ierr = VecRestoreArray(bb,&b); CHKERRQ(ierr);
325   ierr = VecRestoreArray(xx,&x); CHKERRQ(ierr);
326   PLogFlops(2*16*(a->nz) - a->n);
327   PetscFunctionReturn(0);
328 }
329 
330 /*
331       Special case where the matrix was ILU(0) factored in the natural
332    ordering. This eliminates the need for the column and row permutation.
333 */
334 #undef __FUNC__
335 #define __FUNC__ "MatSolve_SeqBAIJ_4_NaturalOrdering"
336 int MatSolve_SeqBAIJ_4_NaturalOrdering(Mat A,Vec bb,Vec xx)
337 {
338   Mat_SeqBAIJ     *a = (Mat_SeqBAIJ *)A->data;
339   int             n=a->mbs,*ai=a->i,*aj=a->j;
340   int             ierr,*diag = a->diag;
341   Scalar          *aa=a->a;
342   Scalar          *x,*b;
343 
344   PetscFunctionBegin;
345   ierr = VecGetArray(bb,&b);CHKERRQ(ierr);
346   ierr = VecGetArray(xx,&x);CHKERRQ(ierr);
347 
348   /*#undef USE_FORTRAN_KERNEL_SOLVEBAIJ
349     #define USE_FORTRAN_KERNEL_SOLVEBAIJ */
350 
351 #if defined(USE_FORTRAN_KERNEL_SOLVEBAIJBLAS)
352   {
353     static Scalar w[2000]; /* very BAD need to fix */
354     fortransolvebaij4blas_(&n,x,ai,aj,diag,aa,b,w);
355   }
356 #elif defined(USE_FORTRAN_KERNEL_SOLVEBAIJ)
357   {
358     static Scalar w[2000]; /* very BAD need to fix */
359     fortransolvebaij4_(&n,x,ai,aj,diag,aa,b,w);
360   }
361 #elif defined(USE_FORTRAN_KERNEL_SOLVEBAIJUNROLL)
362   fortransolvebaij4unroll_(&n,x,ai,aj,diag,aa,b);
363 #else
364   {
365     Scalar sum1,sum2,sum3,sum4,x1,x2,x3,x4,*v;
366     int    jdx,idt,idx,nz,*vi,i;
367 
368   /* forward solve the lower triangular */
369   idx    = 0;
370   x[0]   = b[0]; x[1] = b[1]; x[2] = b[2]; x[3] = b[3];
371   for ( i=1; i<n; i++ ) {
372     v     =  aa      + 16*ai[i];
373     vi    =  aj      + ai[i];
374     nz    =  diag[i] - ai[i];
375     idx   +=  4;
376     sum1  =  b[idx];sum2 = b[1+idx];sum3 = b[2+idx];sum4 = b[3+idx];
377     while (nz--) {
378       jdx   = 4*(*vi++);
379       x1    = x[jdx];x2 = x[1+jdx];x3 = x[2+jdx];x4 = x[3+jdx];
380       sum1 -= v[0]*x1 + v[4]*x2 + v[8]*x3  + v[12]*x4;
381       sum2 -= v[1]*x1 + v[5]*x2 + v[9]*x3  + v[13]*x4;
382       sum3 -= v[2]*x1 + v[6]*x2 + v[10]*x3 + v[14]*x4;
383       sum4 -= v[3]*x1 + v[7]*x2 + v[11]*x3 + v[15]*x4;
384       v    += 16;
385     }
386     x[idx]   = sum1;
387     x[1+idx] = sum2;
388     x[2+idx] = sum3;
389     x[3+idx] = sum4;
390   }
391   /* backward solve the upper triangular */
392   for ( i=n-1; i>=0; i-- ){
393     v    = aa + 16*diag[i] + 16;
394     vi   = aj + diag[i] + 1;
395     nz   = ai[i+1] - diag[i] - 1;
396     idt  = 4*i;
397     sum1 = x[idt];  sum2 = x[1+idt];
398     sum3 = x[2+idt];sum4 = x[3+idt];
399     while (nz--) {
400       idx   = 4*(*vi++);
401       x1    = x[idx];   x2 = x[1+idx];x3    = x[2+idx]; x4 = x[3+idx];
402       sum1 -= v[0]*x1 + v[4]*x2 + v[8]*x3   + v[12]*x4;
403       sum2 -= v[1]*x1 + v[5]*x2 + v[9]*x3   + v[13]*x4;
404       sum3 -= v[2]*x1 + v[6]*x2 + v[10]*x3  + v[14]*x4;
405       sum4 -= v[3]*x1 + v[7]*x2 + v[11]*x3  + v[15]*x4;
406       v    += 16;
407     }
408     v        = aa + 16*diag[i];
409     x[idt]   = v[0]*sum1 + v[4]*sum2 + v[8]*sum3  + v[12]*sum4;
410     x[1+idt] = v[1]*sum1 + v[5]*sum2 + v[9]*sum3  + v[13]*sum4;
411     x[2+idt] = v[2]*sum1 + v[6]*sum2 + v[10]*sum3 + v[14]*sum4;
412     x[3+idt] = v[3]*sum1 + v[7]*sum2 + v[11]*sum3 + v[15]*sum4;
413   }
414   }
415 #endif
416 
417   ierr = VecRestoreArray(bb,&b);CHKERRQ(ierr);
418   ierr = VecRestoreArray(xx,&x);CHKERRQ(ierr);
419   PLogFlops(2*16*(a->nz) - a->n);
420   PetscFunctionReturn(0);
421 }
422 
423 
424 #undef __FUNC__
425 #define __FUNC__ "MatSolve_SeqBAIJ_3"
426 int MatSolve_SeqBAIJ_3(Mat A,Vec bb,Vec xx)
427 {
428   Mat_SeqBAIJ     *a=(Mat_SeqBAIJ *)A->data;
429   IS              iscol=a->col,isrow=a->row;
430   int             *r,*c,ierr,i,n=a->mbs,*vi,*ai=a->i,*aj=a->j,nz,idx,idt,idc,*rout,*cout;
431   int             *diag = a->diag;
432   Scalar          *aa=a->a,sum1,sum2,sum3,x1,x2,x3;
433   Scalar *x,*b,*tmp,*v;
434 
435   PetscFunctionBegin;
436   ierr = VecGetArray(bb,&b); CHKERRQ(ierr);
437   ierr = VecGetArray(xx,&x); CHKERRQ(ierr);
438   tmp  = a->solve_work;
439 
440   ierr = ISGetIndices(isrow,&rout);CHKERRQ(ierr); r = rout;
441   ierr = ISGetIndices(iscol,&cout);CHKERRQ(ierr); c = cout + (n-1);
442 
443   /* forward solve the lower triangular */
444   idx    = 3*(*r++);
445   tmp[0] = b[idx]; tmp[1] = b[1+idx]; tmp[2] = b[2+idx];
446   for ( i=1; i<n; i++ ) {
447     v     = aa + 9*ai[i];
448     vi    = aj + ai[i];
449     nz    = diag[i] - ai[i];
450     idx   = 3*(*r++);
451     sum1  = b[idx]; sum2 = b[1+idx]; sum3 = b[2+idx];
452     while (nz--) {
453       idx   = 3*(*vi++);
454       x1    = tmp[idx]; x2 = tmp[1+idx]; x3 = tmp[2+idx];
455       sum1 -= v[0]*x1 + v[3]*x2 + v[6]*x3;
456       sum2 -= v[1]*x1 + v[4]*x2 + v[7]*x3;
457       sum3 -= v[2]*x1 + v[5]*x2 + v[8]*x3;
458       v += 9;
459     }
460     idx = 3*i;
461     tmp[idx] = sum1; tmp[1+idx] = sum2; tmp[2+idx] = sum3;
462   }
463   /* backward solve the upper triangular */
464   for ( i=n-1; i>=0; i-- ){
465     v    = aa + 9*diag[i] + 9;
466     vi   = aj + diag[i] + 1;
467     nz   = ai[i+1] - diag[i] - 1;
468     idt  = 3*i;
469     sum1 = tmp[idt]; sum2 = tmp[1+idt]; sum3 = tmp[2+idt];
470     while (nz--) {
471       idx   = 3*(*vi++);
472       x1    = tmp[idx]; x2 = tmp[1+idx]; x3 = tmp[2+idx];
473       sum1 -= v[0]*x1 + v[3]*x2 + v[6]*x3;
474       sum2 -= v[1]*x1 + v[4]*x2 + v[7]*x3;
475       sum3 -= v[2]*x1 + v[5]*x2 + v[8]*x3;
476       v += 9;
477     }
478     idc = 3*(*c--);
479     v   = aa + 9*diag[i];
480     x[idc]   = tmp[idt]   = v[0]*sum1 + v[3]*sum2 + v[6]*sum3;
481     x[1+idc] = tmp[1+idt] = v[1]*sum1 + v[4]*sum2 + v[7]*sum3;
482     x[2+idc] = tmp[2+idt] = v[2]*sum1 + v[5]*sum2 + v[8]*sum3;
483   }
484   ierr = ISRestoreIndices(isrow,&rout); CHKERRQ(ierr);
485   ierr = ISRestoreIndices(iscol,&cout); CHKERRQ(ierr);
486   ierr = VecRestoreArray(bb,&b);CHKERRQ(ierr);
487   ierr = VecRestoreArray(xx,&x);CHKERRQ(ierr);
488   PLogFlops(2*9*(a->nz) - a->n);
489   PetscFunctionReturn(0);
490 }
491 
492 #undef __FUNC__
493 #define __FUNC__ "MatSolve_SeqBAIJ_2"
494 int MatSolve_SeqBAIJ_2(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,x1,x2;
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    = 2*(*r++);
513   tmp[0] = b[idx]; tmp[1] = b[1+idx];
514   for ( i=1; i<n; i++ ) {
515     v     = aa + 4*ai[i];
516     vi    = aj + ai[i];
517     nz    = diag[i] - ai[i];
518     idx   = 2*(*r++);
519     sum1  = b[idx]; sum2 = b[1+idx];
520     while (nz--) {
521       idx   = 2*(*vi++);
522       x1    = tmp[idx]; x2 = tmp[1+idx];
523       sum1 -= v[0]*x1 + v[2]*x2;
524       sum2 -= v[1]*x1 + v[3]*x2;
525       v += 4;
526     }
527     idx = 2*i;
528     tmp[idx] = sum1; tmp[1+idx] = sum2;
529   }
530   /* backward solve the upper triangular */
531   for ( i=n-1; i>=0; i-- ){
532     v    = aa + 4*diag[i] + 4;
533     vi   = aj + diag[i] + 1;
534     nz   = ai[i+1] - diag[i] - 1;
535     idt  = 2*i;
536     sum1 = tmp[idt]; sum2 = tmp[1+idt];
537     while (nz--) {
538       idx   = 2*(*vi++);
539       x1    = tmp[idx]; x2 = tmp[1+idx];
540       sum1 -= v[0]*x1 + v[2]*x2;
541       sum2 -= v[1]*x1 + v[3]*x2;
542       v += 4;
543     }
544     idc = 2*(*c--);
545     v   = aa + 4*diag[i];
546     x[idc]   = tmp[idt]   = v[0]*sum1 + v[2]*sum2;
547     x[1+idc] = tmp[1+idt] = v[1]*sum1 + v[3]*sum2;
548   }
549   ierr = ISRestoreIndices(isrow,&rout); CHKERRQ(ierr);
550   ierr = ISRestoreIndices(iscol,&cout); CHKERRQ(ierr);
551   ierr = VecRestoreArray(bb,&b); CHKERRQ(ierr);
552   ierr = VecRestoreArray(xx,&x);CHKERRQ(ierr);
553   PLogFlops(2*4*(a->nz) - a->n);
554   PetscFunctionReturn(0);
555 }
556 
557 
558 #undef __FUNC__
559 #define __FUNC__ "MatSolve_SeqBAIJ_1"
560 int MatSolve_SeqBAIJ_1(Mat A,Vec bb,Vec xx)
561 {
562   Mat_SeqBAIJ     *a=(Mat_SeqBAIJ *)A->data;
563   IS              iscol=a->col,isrow=a->row;
564   int             *r,*c,ierr,i,n=a->mbs,*vi,*ai=a->i,*aj=a->j,nz,*rout,*cout;
565   int             *diag = a->diag;
566   Scalar          *aa=a->a,sum1;
567   Scalar *x,*b,*tmp,*v;
568 
569   PetscFunctionBegin;
570   if (!n) PetscFunctionReturn(0);
571 
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   tmp[0] = b[*r++];
581   for ( i=1; i<n; i++ ) {
582     v     = aa + ai[i];
583     vi    = aj + ai[i];
584     nz    = diag[i] - ai[i];
585     sum1  = b[*r++];
586     while (nz--) {
587       sum1 -= (*v++)*tmp[*vi++];
588     }
589     tmp[i] = sum1;
590   }
591   /* backward solve the upper triangular */
592   for ( i=n-1; i>=0; i-- ){
593     v    = aa + diag[i] + 1;
594     vi   = aj + diag[i] + 1;
595     nz   = ai[i+1] - diag[i] - 1;
596     sum1 = tmp[i];
597     while (nz--) {
598       sum1 -= (*v++)*tmp[*vi++];
599     }
600     x[*c--] = tmp[i] = aa[diag[i]]*sum1;
601   }
602 
603   ierr = ISRestoreIndices(isrow,&rout); CHKERRQ(ierr);
604   ierr = ISRestoreIndices(iscol,&cout); CHKERRQ(ierr);
605   ierr = VecRestoreArray(bb,&b); CHKERRQ(ierr);
606   ierr = VecRestoreArray(xx,&x); CHKERRQ(ierr);
607   PLogFlops(2*1*(a->nz) - a->n);
608   PetscFunctionReturn(0);
609 }
610 
611 extern int MatLUFactorNumeric_SeqBAIJ_4_NaturalOrdering(Mat,Mat*);
612 extern int MatSolve_SeqBAIJ_4_NaturalOrdering(Mat,Vec,Vec);
613 /* ----------------------------------------------------------------*/
614 /*
615      This code is virtually identical to MatILUFactorSymbolic_SeqAIJ
616    except that the data structure of Mat_SeqAIJ is slightly different.
617    Not a good example of code reuse.
618 */
619 #undef __FUNC__
620 #define __FUNC__ "MatILUFactorSymbolic_SeqBAIJ"
621 int MatILUFactorSymbolic_SeqBAIJ(Mat A,IS isrow,IS iscol,double f,int levels,
622                                  Mat *fact)
623 {
624   Mat_SeqBAIJ *a = (Mat_SeqBAIJ *) A->data, *b;
625   IS          isicol;
626   int         *r,*ic, ierr, prow, n = a->mbs, *ai = a->i, *aj = a->j;
627   int         *ainew,*ajnew, jmax,*fill, *xi, nz, *im,*ajfill,*flev;
628   int         *dloc, idx, row,m,fm, nzf, nzi,len,  realloc = 0;
629   int         incrlev,nnz,i,bs = a->bs,bs2 = a->bs2;
630   PetscTruth  col_identity, row_identity;
631 
632   PetscFunctionBegin;
633   ierr = ISInvertPermutation(iscol,&isicol); CHKERRQ(ierr);
634 
635   /* special case that simply copies fill pattern */
636   PetscValidHeaderSpecific(isrow,IS_COOKIE);
637   PetscValidHeaderSpecific(iscol,IS_COOKIE);
638   ISIdentity(isrow,&row_identity); ISIdentity(iscol,&col_identity);
639   if (levels == 0 && row_identity && col_identity) {
640     ierr = MatDuplicate_SeqBAIJ(A,MAT_DO_NOT_COPY_VALUES,fact); CHKERRQ(ierr);
641     (*fact)->factor = FACTOR_LU;
642     b               = (Mat_SeqBAIJ *) (*fact)->data;
643     if (!b->diag) {
644       ierr = MatMarkDiag_SeqBAIJ(*fact); CHKERRQ(ierr);
645     }
646     b->row        = isrow;
647     b->col        = iscol;
648     b->icol       = isicol;
649     b->solve_work = (Scalar *) PetscMalloc((b->m+1+b->bs)*sizeof(Scalar));CHKPTRQ(b->solve_work);
650     /*
651         Blocksize 4 has a special faster solver for ILU(0) factorization
652         with natural ordering
653     */
654     if (b->bs == 4) {
655       (*fact)->ops->lufactornumeric = MatLUFactorNumeric_SeqBAIJ_4_NaturalOrdering;
656       (*fact)->ops->solve           = MatSolve_SeqBAIJ_4_NaturalOrdering;
657     }
658     PetscFunctionReturn(0);
659   }
660 
661   ierr = ISGetIndices(isrow,&r); CHKERRQ(ierr);
662   ierr = ISGetIndices(isicol,&ic); CHKERRQ(ierr);
663 
664   /* get new row pointers */
665   ainew = (int *) PetscMalloc( (n+1)*sizeof(int) ); CHKPTRQ(ainew);
666   ainew[0] = 0;
667   /* don't know how many column pointers are needed so estimate */
668   jmax = (int) (f*ai[n] + 1);
669   ajnew = (int *) PetscMalloc( (jmax)*sizeof(int) ); CHKPTRQ(ajnew);
670   /* ajfill is level of fill for each fill entry */
671   ajfill = (int *) PetscMalloc( (jmax)*sizeof(int) ); CHKPTRQ(ajfill);
672   /* fill is a linked list of nonzeros in active row */
673   fill = (int *) PetscMalloc( (n+1)*sizeof(int)); CHKPTRQ(fill);
674   /* im is level for each filled value */
675   im = (int *) PetscMalloc( (n+1)*sizeof(int)); CHKPTRQ(im);
676   /* dloc is location of diagonal in factor */
677   dloc = (int *) PetscMalloc( (n+1)*sizeof(int)); CHKPTRQ(dloc);
678   dloc[0]  = 0;
679   for ( prow=0; prow<n; prow++ ) {
680     /* first copy previous fill into linked list */
681     nzf     = nz  = ai[r[prow]+1] - ai[r[prow]];
682     if (!nz) SETERRQ(PETSC_ERR_MAT_LU_ZRPVT,1,"Empty row in matrix");
683     xi      = aj + ai[r[prow]];
684     fill[n] = n;
685     while (nz--) {
686       fm  = n;
687       idx = ic[*xi++];
688       do {
689         m  = fm;
690         fm = fill[m];
691       } while (fm < idx);
692       fill[m]   = idx;
693       fill[idx] = fm;
694       im[idx]   = 0;
695     }
696     nzi = 0;
697     row = fill[n];
698     while ( row < prow ) {
699       incrlev = im[row] + 1;
700       nz      = dloc[row];
701       xi      = ajnew  + ainew[row] + nz;
702       flev    = ajfill + ainew[row] + nz + 1;
703       nnz     = ainew[row+1] - ainew[row] - nz - 1;
704       if (*xi++ != row) {
705         SETERRQ(PETSC_ERR_MAT_LU_ZRPVT,0,"Zero pivot: try running with -pc_ilu_nonzeros_along_diagonal");
706       }
707       fm      = row;
708       while (nnz-- > 0) {
709         idx = *xi++;
710         if (*flev + incrlev > levels) {
711           flev++;
712           continue;
713         }
714         do {
715           m  = fm;
716           fm = fill[m];
717         } while (fm < idx);
718         if (fm != idx) {
719           im[idx]   = *flev + incrlev;
720           fill[m]   = idx;
721           fill[idx] = fm;
722           fm        = idx;
723           nzf++;
724         } else {
725           if (im[idx] > *flev + incrlev) im[idx] = *flev+incrlev;
726         }
727         flev++;
728       }
729       row = fill[row];
730       nzi++;
731     }
732     /* copy new filled row into permanent storage */
733     ainew[prow+1] = ainew[prow] + nzf;
734     if (ainew[prow+1] > jmax) {
735 
736       /* estimate how much additional space we will need */
737       /* use the strategy suggested by David Hysom <hysom@perch-t.icase.edu> */
738       /* just double the memory each time */
739       int maxadd = jmax;
740       /* maxadd = (int) (((f*ai[n]+1)*(n-prow+5))/n); */
741       if (maxadd < nzf) maxadd = (n-prow)*(nzf+1);
742       jmax += maxadd;
743 
744       /* allocate a longer ajnew and ajfill */
745       xi = (int *) PetscMalloc( jmax*sizeof(int) );CHKPTRQ(xi);
746       PetscMemcpy(xi,ajnew,ainew[prow]*sizeof(int));
747       PetscFree(ajnew);
748       ajnew = xi;
749       xi = (int *) PetscMalloc( jmax*sizeof(int) );CHKPTRQ(xi);
750       PetscMemcpy(xi,ajfill,ainew[prow]*sizeof(int));
751       PetscFree(ajfill);
752       ajfill = xi;
753       realloc++; /* count how many reallocations are needed */
754     }
755     xi          = ajnew + ainew[prow];
756     flev        = ajfill + ainew[prow];
757     dloc[prow]  = nzi;
758     fm          = fill[n];
759     while (nzf--) {
760       *xi++   = fm;
761       *flev++ = im[fm];
762       fm      = fill[fm];
763     }
764   }
765   PetscFree(ajfill);
766   ierr = ISRestoreIndices(isrow,&r); CHKERRQ(ierr);
767   ierr = ISRestoreIndices(isicol,&ic); CHKERRQ(ierr);
768   PetscFree(fill); PetscFree(im);
769 
770   {
771     double af = ((double)ainew[n])/((double)ai[n]);
772     PLogInfo(A,"MatILUFactorSymbolic_SeqBAIJ:Reallocs %d Fill ratio:given %g needed %g\n",
773              realloc,f,af);
774     PLogInfo(A,"MatILUFactorSymbolic_SeqBAIJ:Run with -pc_ilu_fill %g or use \n",af);
775     PLogInfo(A,"MatILUFactorSymbolic_SeqBAIJ:PCILUSetFill(pc,%g);\n",af);
776     PLogInfo(A,"MatILUFactorSymbolic_SeqBAIJ:for best performance.\n");
777   }
778 
779   /* put together the new matrix */
780   ierr = MatCreateSeqBAIJ(A->comm,bs,bs*n,bs*n,0,PETSC_NULL,fact);CHKERRQ(ierr);
781   PLogObjectParent(*fact,isicol);
782   b = (Mat_SeqBAIJ *) (*fact)->data;
783   PetscFree(b->imax);
784   b->singlemalloc = 0;
785   len = bs2*ainew[n]*sizeof(Scalar);
786   /* the next line frees the default space generated by the Create() */
787   PetscFree(b->a); PetscFree(b->ilen);
788   b->a          = (Scalar *) PetscMalloc( len ); CHKPTRQ(b->a);
789   b->j          = ajnew;
790   b->i          = ainew;
791   for ( i=0; i<n; i++ ) dloc[i] += ainew[i];
792   b->diag       = dloc;
793   b->ilen       = 0;
794   b->imax       = 0;
795   b->row        = isrow;
796   b->col        = iscol;
797   b->icol       = isicol;
798   b->solve_work = (Scalar *) PetscMalloc( (bs*n+bs)*sizeof(Scalar));CHKPTRQ(b->solve_work);
799   /* In b structure:  Free imax, ilen, old a, old j.
800      Allocate dloc, solve_work, new a, new j */
801   PLogObjectMemory(*fact,(ainew[n]-n)*(sizeof(int))+bs2*ainew[n]*sizeof(Scalar));
802   b->maxnz          = b->nz = ainew[n];
803   (*fact)->factor   = FACTOR_LU;
804 
805   (*fact)->info.factor_mallocs    = realloc;
806   (*fact)->info.fill_ratio_given  = f;
807   (*fact)->info.fill_ratio_needed = ((double)ainew[n])/((double)ai[prow]);
808 
809   PetscFunctionReturn(0);
810 }
811 
812 
813 
814 
815