Actual source code: baijfact13.c


  2: /*
  3:     Factorization code for BAIJ format.
  4: */
  5: #include <../src/mat/impls/baij/seq/baij.h>
  6: #include <petsc/private/kernels/blockinvert.h>

  8: /*
  9:       Version for when blocks are 3 by 3
 10: */
 11: PetscErrorCode MatLUFactorNumeric_SeqBAIJ_3_inplace(Mat C,Mat A,const MatFactorInfo *info)
 12: {
 13:   Mat_SeqBAIJ    *a    = (Mat_SeqBAIJ*)A->data,*b = (Mat_SeqBAIJ*)C->data;
 14:   IS             isrow = b->row,isicol = b->icol;
 15:   const PetscInt *r,*ic;
 16:   PetscInt       i,j,n = a->mbs,*bi = b->i,*bj = b->j;
 17:   PetscInt       *ajtmpold,*ajtmp,nz,row,*ai=a->i,*aj=a->j;
 18:   PetscInt       *diag_offset = b->diag,idx,*pj;
 19:   MatScalar      *pv,*v,*rtmp,*pc,*w,*x;
 20:   MatScalar      p1,p2,p3,p4,m1,m2,m3,m4,m5,m6,m7,m8,m9,x1,x2,x3,x4;
 21:   MatScalar      p5,p6,p7,p8,p9,x5,x6,x7,x8,x9;
 22:   MatScalar      *ba   = b->a,*aa = a->a;
 23:   PetscReal      shift = info->shiftamount;
 24:   PetscBool      allowzeropivot,zeropivotdetected;

 26:   ISGetIndices(isrow,&r);
 27:   ISGetIndices(isicol,&ic);
 28:   PetscMalloc1(9*(n+1),&rtmp);
 29:   allowzeropivot = PetscNot(A->erroriffailure);

 31:   for (i=0; i<n; i++) {
 32:     nz    = bi[i+1] - bi[i];
 33:     ajtmp = bj + bi[i];
 34:     for  (j=0; j<nz; j++) {
 35:       x    = rtmp + 9*ajtmp[j];
 36:       x[0] = x[1] = x[2] = x[3] = x[4] = x[5] = x[6] = x[7] = x[8] = 0.0;
 37:     }
 38:     /* load in initial (unfactored row) */
 39:     idx      = r[i];
 40:     nz       = ai[idx+1] - ai[idx];
 41:     ajtmpold = aj + ai[idx];
 42:     v        = aa + 9*ai[idx];
 43:     for (j=0; j<nz; j++) {
 44:       x    = rtmp + 9*ic[ajtmpold[j]];
 45:       x[0] = v[0]; x[1] = v[1]; x[2] = v[2]; x[3] = v[3];
 46:       x[4] = v[4]; x[5] = v[5]; x[6] = v[6]; x[7] = v[7]; x[8] = v[8];
 47:       v   += 9;
 48:     }
 49:     row = *ajtmp++;
 50:     while (row < i) {
 51:       pc = rtmp + 9*row;
 52:       p1 = pc[0]; p2 = pc[1]; p3 = pc[2]; p4 = pc[3];
 53:       p5 = pc[4]; p6 = pc[5]; p7 = pc[6]; p8 = pc[7]; p9 = pc[8];
 54:       if (p1 != 0.0 || p2 != 0.0 || p3 != 0.0 || p4 != 0.0 || p5 != 0.0 ||
 55:           p6 != 0.0 || p7 != 0.0 || p8 != 0.0 || p9 != 0.0) {
 56:         pv    = ba + 9*diag_offset[row];
 57:         pj    = bj + diag_offset[row] + 1;
 58:         x1    = pv[0]; x2 = pv[1]; x3 = pv[2]; x4 = pv[3];
 59:         x5    = pv[4]; x6 = pv[5]; x7 = pv[6]; x8 = pv[7]; x9 = pv[8];
 60:         pc[0] = m1 = p1*x1 + p4*x2 + p7*x3;
 61:         pc[1] = m2 = p2*x1 + p5*x2 + p8*x3;
 62:         pc[2] = m3 = p3*x1 + p6*x2 + p9*x3;

 64:         pc[3] = m4 = p1*x4 + p4*x5 + p7*x6;
 65:         pc[4] = m5 = p2*x4 + p5*x5 + p8*x6;
 66:         pc[5] = m6 = p3*x4 + p6*x5 + p9*x6;

 68:         pc[6] = m7 = p1*x7 + p4*x8 + p7*x9;
 69:         pc[7] = m8 = p2*x7 + p5*x8 + p8*x9;
 70:         pc[8] = m9 = p3*x7 + p6*x8 + p9*x9;
 71:         nz    = bi[row+1] - diag_offset[row] - 1;
 72:         pv   += 9;
 73:         for (j=0; j<nz; j++) {
 74:           x1    = pv[0]; x2 = pv[1]; x3 = pv[2]; x4 = pv[3];
 75:           x5    = pv[4]; x6 = pv[5]; x7 = pv[6]; x8 = pv[7]; x9 = pv[8];
 76:           x     = rtmp + 9*pj[j];
 77:           x[0] -= m1*x1 + m4*x2 + m7*x3;
 78:           x[1] -= m2*x1 + m5*x2 + m8*x3;
 79:           x[2] -= m3*x1 + m6*x2 + m9*x3;

 81:           x[3] -= m1*x4 + m4*x5 + m7*x6;
 82:           x[4] -= m2*x4 + m5*x5 + m8*x6;
 83:           x[5] -= m3*x4 + m6*x5 + m9*x6;

 85:           x[6] -= m1*x7 + m4*x8 + m7*x9;
 86:           x[7] -= m2*x7 + m5*x8 + m8*x9;
 87:           x[8] -= m3*x7 + m6*x8 + m9*x9;
 88:           pv   += 9;
 89:         }
 90:         PetscLogFlops(54.0*nz+36.0);
 91:       }
 92:       row = *ajtmp++;
 93:     }
 94:     /* finished row so stick it into b->a */
 95:     pv = ba + 9*bi[i];
 96:     pj = bj + bi[i];
 97:     nz = bi[i+1] - bi[i];
 98:     for (j=0; j<nz; j++) {
 99:       x     = rtmp + 9*pj[j];
100:       pv[0] = x[0]; pv[1] = x[1]; pv[2] = x[2]; pv[3] = x[3];
101:       pv[4] = x[4]; pv[5] = x[5]; pv[6] = x[6]; pv[7] = x[7]; pv[8] = x[8];
102:       pv   += 9;
103:     }
104:     /* invert diagonal block */
105:     w    = ba + 9*diag_offset[i];
106:     PetscKernel_A_gets_inverse_A_3(w,shift,allowzeropivot,&zeropivotdetected);
107:     if (zeropivotdetected) C->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
108:   }

110:   PetscFree(rtmp);
111:   ISRestoreIndices(isicol,&ic);
112:   ISRestoreIndices(isrow,&r);

114:   C->ops->solve          = MatSolve_SeqBAIJ_3_inplace;
115:   C->ops->solvetranspose = MatSolveTranspose_SeqBAIJ_3_inplace;
116:   C->assembled           = PETSC_TRUE;

118:   PetscLogFlops(1.333333333333*3*3*3*b->mbs); /* from inverting diagonal blocks */
119:   return 0;
120: }

122: /* MatLUFactorNumeric_SeqBAIJ_3 -
123:      copied from MatLUFactorNumeric_SeqBAIJ_N_inplace() and manually re-implemented
124:        PetscKernel_A_gets_A_times_B()
125:        PetscKernel_A_gets_A_minus_B_times_C()
126:        PetscKernel_A_gets_inverse_A()
127: */
128: PetscErrorCode MatLUFactorNumeric_SeqBAIJ_3(Mat B,Mat A,const MatFactorInfo *info)
129: {
130:   Mat            C     =B;
131:   Mat_SeqBAIJ    *a    =(Mat_SeqBAIJ*)A->data,*b=(Mat_SeqBAIJ*)C->data;
132:   IS             isrow = b->row,isicol = b->icol;
133:   const PetscInt *r,*ic;
134:   PetscInt       i,j,k,nz,nzL,row;
135:   const PetscInt n=a->mbs,*ai=a->i,*aj=a->j,*bi=b->i,*bj=b->j;
136:   const PetscInt *ajtmp,*bjtmp,*bdiag=b->diag,*pj,bs2=a->bs2;
137:   MatScalar      *rtmp,*pc,*mwork,*v,*pv,*aa=a->a;
138:   PetscInt       flg;
139:   PetscReal      shift = info->shiftamount;
140:   PetscBool      allowzeropivot,zeropivotdetected;

142:   ISGetIndices(isrow,&r);
143:   ISGetIndices(isicol,&ic);
144:   allowzeropivot = PetscNot(A->erroriffailure);

146:   /* generate work space needed by the factorization */
147:   PetscMalloc2(bs2*n,&rtmp,bs2,&mwork);
148:   PetscArrayzero(rtmp,bs2*n);

150:   for (i=0; i<n; i++) {
151:     /* zero rtmp */
152:     /* L part */
153:     nz    = bi[i+1] - bi[i];
154:     bjtmp = bj + bi[i];
155:     for  (j=0; j<nz; j++) {
156:       PetscArrayzero(rtmp+bs2*bjtmp[j],bs2);
157:     }

159:     /* U part */
160:     nz    = bdiag[i] - bdiag[i+1];
161:     bjtmp = bj + bdiag[i+1]+1;
162:     for  (j=0; j<nz; j++) {
163:       PetscArrayzero(rtmp+bs2*bjtmp[j],bs2);
164:     }

166:     /* load in initial (unfactored row) */
167:     nz    = ai[r[i]+1] - ai[r[i]];
168:     ajtmp = aj + ai[r[i]];
169:     v     = aa + bs2*ai[r[i]];
170:     for (j=0; j<nz; j++) {
171:       PetscArraycpy(rtmp+bs2*ic[ajtmp[j]],v+bs2*j,bs2);
172:     }

174:     /* elimination */
175:     bjtmp = bj + bi[i];
176:     nzL   = bi[i+1] - bi[i];
177:     for (k = 0; k < nzL; k++) {
178:       row = bjtmp[k];
179:       pc  = rtmp + bs2*row;
180:       for (flg=0,j=0; j<bs2; j++) {
181:         if (pc[j]!=0.0) {
182:           flg = 1;
183:           break;
184:         }
185:       }
186:       if (flg) {
187:         pv = b->a + bs2*bdiag[row];
188:         /* PetscKernel_A_gets_A_times_B(bs,pc,pv,mwork); *pc = *pc * (*pv); */
189:         PetscKernel_A_gets_A_times_B_3(pc,pv,mwork);

191:         pj = b->j + bdiag[row+1] + 1; /* beginning of U(row,:) */
192:         pv = b->a + bs2*(bdiag[row+1]+1);
193:         nz = bdiag[row] - bdiag[row+1] - 1; /* num of entries in U(row,:) excluding diag */
194:         for (j=0; j<nz; j++) {
195:           /* PetscKernel_A_gets_A_minus_B_times_C(bs,rtmp+bs2*pj[j],pc,pv+bs2*j); */
196:           /* rtmp+bs2*pj[j] = rtmp+bs2*pj[j] - (*pc)*(pv+bs2*j) */
197:           v    = rtmp + bs2*pj[j];
198:           PetscKernel_A_gets_A_minus_B_times_C_3(v,pc,pv);
199:           pv  += bs2;
200:         }
201:         PetscLogFlops(54.0*nz+45); /* flops = 2*bs^3*nz + 2*bs^3 - bs2) */
202:       }
203:     }

205:     /* finished row so stick it into b->a */
206:     /* L part */
207:     pv = b->a + bs2*bi[i];
208:     pj = b->j + bi[i];
209:     nz = bi[i+1] - bi[i];
210:     for (j=0; j<nz; j++) {
211:       PetscArraycpy(pv+bs2*j,rtmp+bs2*pj[j],bs2);
212:     }

214:     /* Mark diagonal and invert diagonal for simpler triangular solves */
215:     pv   = b->a + bs2*bdiag[i];
216:     pj   = b->j + bdiag[i];
217:     PetscArraycpy(pv,rtmp+bs2*pj[0],bs2);
218:     PetscKernel_A_gets_inverse_A_3(pv,shift,allowzeropivot,&zeropivotdetected);
219:     if (zeropivotdetected) B->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;

221:     /* U part */
222:     pj = b->j + bdiag[i+1] + 1;
223:     pv = b->a + bs2*(bdiag[i+1]+1);
224:     nz = bdiag[i] - bdiag[i+1] - 1;
225:     for (j=0; j<nz; j++) {
226:       PetscArraycpy(pv+bs2*j,rtmp+bs2*pj[j],bs2);
227:     }
228:   }

230:   PetscFree2(rtmp,mwork);
231:   ISRestoreIndices(isicol,&ic);
232:   ISRestoreIndices(isrow,&r);

234:   C->ops->solve          = MatSolve_SeqBAIJ_3;
235:   C->ops->solvetranspose = MatSolveTranspose_SeqBAIJ_3;
236:   C->assembled           = PETSC_TRUE;

238:   PetscLogFlops(1.333333333333*3*3*3*n); /* from inverting diagonal blocks */
239:   return 0;
240: }

242: PetscErrorCode MatLUFactorNumeric_SeqBAIJ_3_NaturalOrdering_inplace(Mat C,Mat A,const MatFactorInfo *info)
243: {
244:   Mat_SeqBAIJ    *a = (Mat_SeqBAIJ*)A->data,*b = (Mat_SeqBAIJ*)C->data;
245:   PetscInt       i,j,n = a->mbs,*bi = b->i,*bj = b->j;
246:   PetscInt       *ajtmpold,*ajtmp,nz,row;
247:   PetscInt       *diag_offset = b->diag,*ai=a->i,*aj=a->j,*pj;
248:   MatScalar      *pv,*v,*rtmp,*pc,*w,*x;
249:   MatScalar      p1,p2,p3,p4,m1,m2,m3,m4,m5,m6,m7,m8,m9,x1,x2,x3,x4;
250:   MatScalar      p5,p6,p7,p8,p9,x5,x6,x7,x8,x9;
251:   MatScalar      *ba   = b->a,*aa = a->a;
252:   PetscReal      shift = info->shiftamount;
253:   PetscBool      allowzeropivot,zeropivotdetected;

255:   PetscMalloc1(9*(n+1),&rtmp);
256:   allowzeropivot = PetscNot(A->erroriffailure);

258:   for (i=0; i<n; i++) {
259:     nz    = bi[i+1] - bi[i];
260:     ajtmp = bj + bi[i];
261:     for  (j=0; j<nz; j++) {
262:       x    = rtmp+9*ajtmp[j];
263:       x[0] = x[1]  = x[2]  = x[3]  = x[4]  = x[5]  = x[6] = x[7] = x[8] = 0.0;
264:     }
265:     /* load in initial (unfactored row) */
266:     nz       = ai[i+1] - ai[i];
267:     ajtmpold = aj + ai[i];
268:     v        = aa + 9*ai[i];
269:     for (j=0; j<nz; j++) {
270:       x    = rtmp+9*ajtmpold[j];
271:       x[0] = v[0];  x[1]  = v[1];  x[2]  = v[2];  x[3]  = v[3];
272:       x[4] = v[4];  x[5]  = v[5];  x[6]  = v[6];  x[7]  = v[7];  x[8]  = v[8];
273:       v   += 9;
274:     }
275:     row = *ajtmp++;
276:     while (row < i) {
277:       pc = rtmp + 9*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:       if (p1 != 0.0 || p2 != 0.0 || p3 != 0.0 || p4 != 0.0 || p5 != 0.0 ||
281:           p6 != 0.0 || p7 != 0.0 || p8 != 0.0 || p9 != 0.0) {
282:         pv    = ba + 9*diag_offset[row];
283:         pj    = bj + diag_offset[row] + 1;
284:         x1    = pv[0];  x2  = pv[1];  x3  = pv[2];  x4  = pv[3];
285:         x5    = pv[4];  x6  = pv[5];  x7  = pv[6];  x8  = pv[7];  x9  = pv[8];
286:         pc[0] = m1 = p1*x1 + p4*x2 + p7*x3;
287:         pc[1] = m2 = p2*x1 + p5*x2 + p8*x3;
288:         pc[2] = m3 = p3*x1 + p6*x2 + p9*x3;

290:         pc[3] = m4 = p1*x4 + p4*x5 + p7*x6;
291:         pc[4] = m5 = p2*x4 + p5*x5 + p8*x6;
292:         pc[5] = m6 = p3*x4 + p6*x5 + p9*x6;

294:         pc[6] = m7 = p1*x7 + p4*x8 + p7*x9;
295:         pc[7] = m8 = p2*x7 + p5*x8 + p8*x9;
296:         pc[8] = m9 = p3*x7 + p6*x8 + p9*x9;

298:         nz  = bi[row+1] - diag_offset[row] - 1;
299:         pv += 9;
300:         for (j=0; j<nz; j++) {
301:           x1    = pv[0];  x2  = pv[1];   x3 = pv[2];  x4  = pv[3];
302:           x5    = pv[4];  x6  = pv[5];   x7 = pv[6];  x8  = pv[7]; x9 = pv[8];
303:           x     = rtmp + 9*pj[j];
304:           x[0] -= m1*x1 + m4*x2 + m7*x3;
305:           x[1] -= m2*x1 + m5*x2 + m8*x3;
306:           x[2] -= m3*x1 + m6*x2 + m9*x3;

308:           x[3] -= m1*x4 + m4*x5 + m7*x6;
309:           x[4] -= m2*x4 + m5*x5 + m8*x6;
310:           x[5] -= m3*x4 + m6*x5 + m9*x6;

312:           x[6] -= m1*x7 + m4*x8 + m7*x9;
313:           x[7] -= m2*x7 + m5*x8 + m8*x9;
314:           x[8] -= m3*x7 + m6*x8 + m9*x9;
315:           pv   += 9;
316:         }
317:         PetscLogFlops(54.0*nz+36.0);
318:       }
319:       row = *ajtmp++;
320:     }
321:     /* finished row so stick it into b->a */
322:     pv = ba + 9*bi[i];
323:     pj = bj + bi[i];
324:     nz = bi[i+1] - bi[i];
325:     for (j=0; j<nz; j++) {
326:       x     = rtmp+9*pj[j];
327:       pv[0] = x[0];  pv[1]  = x[1];  pv[2]  = x[2];  pv[3]  = x[3];
328:       pv[4] = x[4];  pv[5]  = x[5];  pv[6]  = x[6];  pv[7]  = x[7]; pv[8] = x[8];
329:       pv   += 9;
330:     }
331:     /* invert diagonal block */
332:     w    = ba + 9*diag_offset[i];
333:     PetscKernel_A_gets_inverse_A_3(w,shift,allowzeropivot,&zeropivotdetected);
334:     if (zeropivotdetected) C->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
335:   }

337:   PetscFree(rtmp);

339:   C->ops->solve          = MatSolve_SeqBAIJ_3_NaturalOrdering_inplace;
340:   C->ops->solvetranspose = MatSolveTranspose_SeqBAIJ_3_NaturalOrdering_inplace;
341:   C->assembled           = PETSC_TRUE;

343:   PetscLogFlops(1.333333333333*3*3*3*b->mbs); /* from inverting diagonal blocks */
344:   return 0;
345: }

347: /*
348:   MatLUFactorNumeric_SeqBAIJ_3_NaturalOrdering -
349:     copied from MatLUFactorNumeric_SeqBAIJ_2_NaturalOrdering_inplace()
350: */
351: PetscErrorCode MatLUFactorNumeric_SeqBAIJ_3_NaturalOrdering(Mat B,Mat A,const MatFactorInfo *info)
352: {
353:   Mat            C =B;
354:   Mat_SeqBAIJ    *a=(Mat_SeqBAIJ*)A->data,*b=(Mat_SeqBAIJ*)C->data;
355:   PetscInt       i,j,k,nz,nzL,row;
356:   const PetscInt n=a->mbs,*ai=a->i,*aj=a->j,*bi=b->i,*bj=b->j;
357:   const PetscInt *ajtmp,*bjtmp,*bdiag=b->diag,*pj,bs2=a->bs2;
358:   MatScalar      *rtmp,*pc,*mwork,*v,*pv,*aa=a->a;
359:   PetscInt       flg;
360:   PetscReal      shift = info->shiftamount;
361:   PetscBool      allowzeropivot,zeropivotdetected;

363:   allowzeropivot = PetscNot(A->erroriffailure);

365:   /* generate work space needed by the factorization */
366:   PetscMalloc2(bs2*n,&rtmp,bs2,&mwork);
367:   PetscArrayzero(rtmp,bs2*n);

369:   for (i=0; i<n; i++) {
370:     /* zero rtmp */
371:     /* L part */
372:     nz    = bi[i+1] - bi[i];
373:     bjtmp = bj + bi[i];
374:     for  (j=0; j<nz; j++) {
375:       PetscArrayzero(rtmp+bs2*bjtmp[j],bs2);
376:     }

378:     /* U part */
379:     nz    = bdiag[i] - bdiag[i+1];
380:     bjtmp = bj + bdiag[i+1] + 1;
381:     for  (j=0; j<nz; j++) {
382:       PetscArrayzero(rtmp+bs2*bjtmp[j],bs2);
383:     }

385:     /* load in initial (unfactored row) */
386:     nz    = ai[i+1] - ai[i];
387:     ajtmp = aj + ai[i];
388:     v     = aa + bs2*ai[i];
389:     for (j=0; j<nz; j++) {
390:       PetscArraycpy(rtmp+bs2*ajtmp[j],v+bs2*j,bs2);
391:     }

393:     /* elimination */
394:     bjtmp = bj + bi[i];
395:     nzL   = bi[i+1] - bi[i];
396:     for (k=0; k<nzL; k++) {
397:       row = bjtmp[k];
398:       pc  = rtmp + bs2*row;
399:       for (flg=0,j=0; j<bs2; j++) {
400:         if (pc[j]!=0.0) {
401:           flg = 1;
402:           break;
403:         }
404:       }
405:       if (flg) {
406:         pv = b->a + bs2*bdiag[row];
407:         /* PetscKernel_A_gets_A_times_B(bs,pc,pv,mwork); *pc = *pc * (*pv); */
408:         PetscKernel_A_gets_A_times_B_3(pc,pv,mwork);

410:         pj = b->j + bdiag[row+1]+1; /* beginning of U(row,:) */
411:         pv = b->a + bs2*(bdiag[row+1]+1);
412:         nz = bdiag[row] - bdiag[row+1] - 1; /* num of entries in U(row,:) excluding diag */
413:         for (j=0; j<nz; j++) {
414:           /* PetscKernel_A_gets_A_minus_B_times_C(bs,rtmp+bs2*pj[j],pc,pv+bs2*j); */
415:           /* rtmp+bs2*pj[j] = rtmp+bs2*pj[j] - (*pc)*(pv+bs2*j) */
416:           v    = rtmp + bs2*pj[j];
417:           PetscKernel_A_gets_A_minus_B_times_C_3(v,pc,pv);
418:           pv  += bs2;
419:         }
420:         PetscLogFlops(54.0*nz+45); /* flops = 2*bs^3*nz + 2*bs^3 - bs2) */
421:       }
422:     }

424:     /* finished row so stick it into b->a */
425:     /* L part */
426:     pv = b->a + bs2*bi[i];
427:     pj = b->j + bi[i];
428:     nz = bi[i+1] - bi[i];
429:     for (j=0; j<nz; j++) {
430:       PetscArraycpy(pv+bs2*j,rtmp+bs2*pj[j],bs2);
431:     }

433:     /* Mark diagonal and invert diagonal for simpler triangular solves */
434:     pv   = b->a + bs2*bdiag[i];
435:     pj   = b->j + bdiag[i];
436:     PetscArraycpy(pv,rtmp+bs2*pj[0],bs2);
437:     PetscKernel_A_gets_inverse_A_3(pv,shift,allowzeropivot,&zeropivotdetected);
438:     if (zeropivotdetected) B->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;

440:     /* U part */
441:     pv = b->a + bs2*(bdiag[i+1]+1);
442:     pj = b->j + bdiag[i+1]+1;
443:     nz = bdiag[i] - bdiag[i+1] - 1;
444:     for (j=0; j<nz; j++) {
445:       PetscArraycpy(pv+bs2*j,rtmp+bs2*pj[j],bs2);
446:     }
447:   }
448:   PetscFree2(rtmp,mwork);

450:   C->ops->solve          = MatSolve_SeqBAIJ_3_NaturalOrdering;
451:   C->ops->forwardsolve   = MatForwardSolve_SeqBAIJ_3_NaturalOrdering;
452:   C->ops->backwardsolve  = MatBackwardSolve_SeqBAIJ_3_NaturalOrdering;
453:   C->ops->solvetranspose = MatSolveTranspose_SeqBAIJ_3_NaturalOrdering;
454:   C->assembled           = PETSC_TRUE;

456:   PetscLogFlops(1.333333333333*3*3*3*n); /* from inverting diagonal blocks */
457:   return 0;
458: }