Actual source code: baijfact13.c

petsc-3.7.3 2016-08-01
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  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: */
 13: PetscErrorCode MatLUFactorNumeric_SeqBAIJ_3_inplace(Mat C,Mat A,const MatFactorInfo *info)
 14: {
 15:   Mat_SeqBAIJ    *a    = (Mat_SeqBAIJ*)A->data,*b = (Mat_SeqBAIJ*)C->data;
 16:   IS             isrow = b->row,isicol = b->icol;
 18:   const PetscInt *r,*ic;
 19:   PetscInt       i,j,n = a->mbs,*bi = b->i,*bj = b->j;
 20:   PetscInt       *ajtmpold,*ajtmp,nz,row,*ai=a->i,*aj=a->j;
 21:   PetscInt       *diag_offset = b->diag,idx,*pj;
 22:   MatScalar      *pv,*v,*rtmp,*pc,*w,*x;
 23:   MatScalar      p1,p2,p3,p4,m1,m2,m3,m4,m5,m6,m7,m8,m9,x1,x2,x3,x4;
 24:   MatScalar      p5,p6,p7,p8,p9,x5,x6,x7,x8,x9;
 25:   MatScalar      *ba   = b->a,*aa = a->a;
 26:   PetscReal      shift = info->shiftamount;
 27:   PetscBool      allowzeropivot,zeropivotdetected;

 30:   ISGetIndices(isrow,&r);
 31:   ISGetIndices(isicol,&ic);
 32:   PetscMalloc1(9*(n+1),&rtmp);
 33:   allowzeropivot = PetscNot(A->erroriffailure);

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

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

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

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

 89:           x[6] -= m1*x7 + m4*x8 + m7*x9;
 90:           x[7] -= m2*x7 + m5*x8 + m8*x9;
 91:           x[8] -= m3*x7 + m6*x8 + m9*x9;
 92:           pv   += 9;
 93:         }
 94:         PetscLogFlops(54.0*nz+36.0);
 95:       }
 96:       row = *ajtmp++;
 97:     }
 98:     /* finished row so stick it into b->a */
 99:     pv = ba + 9*bi[i];
100:     pj = bj + bi[i];
101:     nz = bi[i+1] - bi[i];
102:     for (j=0; j<nz; j++) {
103:       x     = rtmp + 9*pj[j];
104:       pv[0] = x[0]; pv[1] = x[1]; pv[2] = x[2]; pv[3] = x[3];
105:       pv[4] = x[4]; pv[5] = x[5]; pv[6] = x[6]; pv[7] = x[7]; pv[8] = x[8];
106:       pv   += 9;
107:     }
108:     /* invert diagonal block */
109:     w    = ba + 9*diag_offset[i];
110:     PetscKernel_A_gets_inverse_A_3(w,shift,allowzeropivot,&zeropivotdetected);
111:     if (zeropivotdetected) C->errortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
112:   }

114:   PetscFree(rtmp);
115:   ISRestoreIndices(isicol,&ic);
116:   ISRestoreIndices(isrow,&r);

118:   C->ops->solve          = MatSolve_SeqBAIJ_3_inplace;
119:   C->ops->solvetranspose = MatSolveTranspose_SeqBAIJ_3_inplace;
120:   C->assembled           = PETSC_TRUE;

122:   PetscLogFlops(1.333333333333*3*3*3*b->mbs); /* from inverting diagonal blocks */
123:   return(0);
124: }

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

150:   ISGetIndices(isrow,&r);
151:   ISGetIndices(isicol,&ic);
152:   allowzeropivot = PetscNot(A->erroriffailure);

154:   /* generate work space needed by the factorization */
155:   PetscMalloc2(bs2*n,&rtmp,bs2,&mwork);
156:   PetscMemzero(rtmp,bs2*n*sizeof(MatScalar));

158:   for (i=0; i<n; i++) {
159:     /* zero rtmp */
160:     /* L part */
161:     nz    = bi[i+1] - bi[i];
162:     bjtmp = bj + bi[i];
163:     for  (j=0; j<nz; j++) {
164:       PetscMemzero(rtmp+bs2*bjtmp[j],bs2*sizeof(MatScalar));
165:     }

167:     /* U part */
168:     nz    = bdiag[i] - bdiag[i+1];
169:     bjtmp = bj + bdiag[i+1]+1;
170:     for  (j=0; j<nz; j++) {
171:       PetscMemzero(rtmp+bs2*bjtmp[j],bs2*sizeof(MatScalar));
172:     }

174:     /* load in initial (unfactored row) */
175:     nz    = ai[r[i]+1] - ai[r[i]];
176:     ajtmp = aj + ai[r[i]];
177:     v     = aa + bs2*ai[r[i]];
178:     for (j=0; j<nz; j++) {
179:       PetscMemcpy(rtmp+bs2*ic[ajtmp[j]],v+bs2*j,bs2*sizeof(MatScalar));
180:     }

182:     /* elimination */
183:     bjtmp = bj + bi[i];
184:     nzL   = bi[i+1] - bi[i];
185:     for (k = 0; k < nzL; k++) {
186:       row = bjtmp[k];
187:       pc  = rtmp + bs2*row;
188:       for (flg=0,j=0; j<bs2; j++) {
189:         if (pc[j]!=0.0) {
190:           flg = 1;
191:           break;
192:         }
193:       }
194:       if (flg) {
195:         pv = b->a + bs2*bdiag[row];
196:         /* PetscKernel_A_gets_A_times_B(bs,pc,pv,mwork); *pc = *pc * (*pv); */
197:         PetscKernel_A_gets_A_times_B_3(pc,pv,mwork);

199:         pj = b->j + bdiag[row+1] + 1; /* beginning of U(row,:) */
200:         pv = b->a + bs2*(bdiag[row+1]+1);
201:         nz = bdiag[row] - bdiag[row+1] - 1; /* num of entries in U(row,:) excluding diag */
202:         for (j=0; j<nz; j++) {
203:           /* PetscKernel_A_gets_A_minus_B_times_C(bs,rtmp+bs2*pj[j],pc,pv+bs2*j); */
204:           /* rtmp+bs2*pj[j] = rtmp+bs2*pj[j] - (*pc)*(pv+bs2*j) */
205:           v    = rtmp + bs2*pj[j];
206:           PetscKernel_A_gets_A_minus_B_times_C_3(v,pc,pv);
207:           pv  += bs2;
208:         }
209:         PetscLogFlops(54*nz+45); /* flops = 2*bs^3*nz + 2*bs^3 - bs2) */
210:       }
211:     }

213:     /* finished row so stick it into b->a */
214:     /* L part */
215:     pv = b->a + bs2*bi[i];
216:     pj = b->j + bi[i];
217:     nz = bi[i+1] - bi[i];
218:     for (j=0; j<nz; j++) {
219:       PetscMemcpy(pv+bs2*j,rtmp+bs2*pj[j],bs2*sizeof(MatScalar));
220:     }

222:     /* Mark diagonal and invert diagonal for simplier triangular solves */
223:     pv   = b->a + bs2*bdiag[i];
224:     pj   = b->j + bdiag[i];
225:     PetscMemcpy(pv,rtmp+bs2*pj[0],bs2*sizeof(MatScalar));
226:     PetscKernel_A_gets_inverse_A_3(pv,shift,allowzeropivot,&zeropivotdetected);
227:     if (zeropivotdetected) B->errortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;

229:     /* U part */
230:     pj = b->j + bdiag[i+1] + 1;
231:     pv = b->a + bs2*(bdiag[i+1]+1);
232:     nz = bdiag[i] - bdiag[i+1] - 1;
233:     for (j=0; j<nz; j++) {
234:       PetscMemcpy(pv+bs2*j,rtmp+bs2*pj[j],bs2*sizeof(MatScalar));
235:     }
236:   }

238:   PetscFree2(rtmp,mwork);
239:   ISRestoreIndices(isicol,&ic);
240:   ISRestoreIndices(isrow,&r);

242:   C->ops->solve          = MatSolve_SeqBAIJ_3;
243:   C->ops->solvetranspose = MatSolveTranspose_SeqBAIJ_3;
244:   C->assembled           = PETSC_TRUE;

246:   PetscLogFlops(1.333333333333*3*3*3*n); /* from inverting diagonal blocks */
247:   return(0);
248: }

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

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

270:   for (i=0; i<n; i++) {
271:     nz    = bi[i+1] - bi[i];
272:     ajtmp = bj + bi[i];
273:     for  (j=0; j<nz; j++) {
274:       x    = rtmp+9*ajtmp[j];
275:       x[0] = x[1]  = x[2]  = x[3]  = x[4]  = x[5]  = x[6] = x[7] = x[8] = 0.0;
276:     }
277:     /* load in initial (unfactored row) */
278:     nz       = ai[i+1] - ai[i];
279:     ajtmpold = aj + ai[i];
280:     v        = aa + 9*ai[i];
281:     for (j=0; j<nz; j++) {
282:       x    = rtmp+9*ajtmpold[j];
283:       x[0] = v[0];  x[1]  = v[1];  x[2]  = v[2];  x[3]  = v[3];
284:       x[4] = v[4];  x[5]  = v[5];  x[6]  = v[6];  x[7]  = v[7];  x[8]  = v[8];
285:       v   += 9;
286:     }
287:     row = *ajtmp++;
288:     while (row < i) {
289:       pc = rtmp + 9*row;
290:       p1 = pc[0];  p2  = pc[1];  p3  = pc[2];  p4  = pc[3];
291:       p5 = pc[4];  p6  = pc[5];  p7  = pc[6];  p8  = pc[7];  p9  = pc[8];
292:       if (p1 != 0.0 || p2 != 0.0 || p3 != 0.0 || p4 != 0.0 || p5 != 0.0 ||
293:           p6 != 0.0 || p7 != 0.0 || p8 != 0.0 || p9 != 0.0) {
294:         pv    = ba + 9*diag_offset[row];
295:         pj    = bj + diag_offset[row] + 1;
296:         x1    = pv[0];  x2  = pv[1];  x3  = pv[2];  x4  = pv[3];
297:         x5    = pv[4];  x6  = pv[5];  x7  = pv[6];  x8  = pv[7];  x9  = pv[8];
298:         pc[0] = m1 = p1*x1 + p4*x2 + p7*x3;
299:         pc[1] = m2 = p2*x1 + p5*x2 + p8*x3;
300:         pc[2] = m3 = p3*x1 + p6*x2 + p9*x3;

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

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

310:         nz  = bi[row+1] - diag_offset[row] - 1;
311:         pv += 9;
312:         for (j=0; j<nz; j++) {
313:           x1    = pv[0];  x2  = pv[1];   x3 = pv[2];  x4  = pv[3];
314:           x5    = pv[4];  x6  = pv[5];   x7 = pv[6];  x8  = pv[7]; x9 = pv[8];
315:           x     = rtmp + 9*pj[j];
316:           x[0] -= m1*x1 + m4*x2 + m7*x3;
317:           x[1] -= m2*x1 + m5*x2 + m8*x3;
318:           x[2] -= m3*x1 + m6*x2 + m9*x3;

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

324:           x[6] -= m1*x7 + m4*x8 + m7*x9;
325:           x[7] -= m2*x7 + m5*x8 + m8*x9;
326:           x[8] -= m3*x7 + m6*x8 + m9*x9;
327:           pv   += 9;
328:         }
329:         PetscLogFlops(54.0*nz+36.0);
330:       }
331:       row = *ajtmp++;
332:     }
333:     /* finished row so stick it into b->a */
334:     pv = ba + 9*bi[i];
335:     pj = bj + bi[i];
336:     nz = bi[i+1] - bi[i];
337:     for (j=0; j<nz; j++) {
338:       x     = rtmp+9*pj[j];
339:       pv[0] = x[0];  pv[1]  = x[1];  pv[2]  = x[2];  pv[3]  = x[3];
340:       pv[4] = x[4];  pv[5]  = x[5];  pv[6]  = x[6];  pv[7]  = x[7]; pv[8] = x[8];
341:       pv   += 9;
342:     }
343:     /* invert diagonal block */
344:     w    = ba + 9*diag_offset[i];
345:     PetscKernel_A_gets_inverse_A_3(w,shift,allowzeropivot,&zeropivotdetected);
346:     if (zeropivotdetected) C->errortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
347:   }

349:   PetscFree(rtmp);

351:   C->ops->solve          = MatSolve_SeqBAIJ_3_NaturalOrdering_inplace;
352:   C->ops->solvetranspose = MatSolveTranspose_SeqBAIJ_3_NaturalOrdering_inplace;
353:   C->assembled           = PETSC_TRUE;

355:   PetscLogFlops(1.333333333333*3*3*3*b->mbs); /* from inverting diagonal blocks */
356:   return(0);
357: }

359: /*
360:   MatLUFactorNumeric_SeqBAIJ_3_NaturalOrdering -
361:     copied from MatLUFactorNumeric_SeqBAIJ_2_NaturalOrdering_inplace()
362: */
365: PetscErrorCode MatLUFactorNumeric_SeqBAIJ_3_NaturalOrdering(Mat B,Mat A,const MatFactorInfo *info)
366: {
367:   Mat            C =B;
368:   Mat_SeqBAIJ    *a=(Mat_SeqBAIJ*)A->data,*b=(Mat_SeqBAIJ*)C->data;
370:   PetscInt       i,j,k,nz,nzL,row;
371:   const PetscInt n=a->mbs,*ai=a->i,*aj=a->j,*bi=b->i,*bj=b->j;
372:   const PetscInt *ajtmp,*bjtmp,*bdiag=b->diag,*pj,bs2=a->bs2;
373:   MatScalar      *rtmp,*pc,*mwork,*v,*pv,*aa=a->a;
374:   PetscInt       flg;
375:   PetscReal      shift = info->shiftamount;
376:   PetscBool      allowzeropivot,zeropivotdetected;

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

381:   /* generate work space needed by the factorization */
382:   PetscMalloc2(bs2*n,&rtmp,bs2,&mwork);
383:   PetscMemzero(rtmp,bs2*n*sizeof(MatScalar));

385:   for (i=0; i<n; i++) {
386:     /* zero rtmp */
387:     /* L part */
388:     nz    = bi[i+1] - bi[i];
389:     bjtmp = bj + bi[i];
390:     for  (j=0; j<nz; j++) {
391:       PetscMemzero(rtmp+bs2*bjtmp[j],bs2*sizeof(MatScalar));
392:     }

394:     /* U part */
395:     nz    = bdiag[i] - bdiag[i+1];
396:     bjtmp = bj + bdiag[i+1] + 1;
397:     for  (j=0; j<nz; j++) {
398:       PetscMemzero(rtmp+bs2*bjtmp[j],bs2*sizeof(MatScalar));
399:     }

401:     /* load in initial (unfactored row) */
402:     nz    = ai[i+1] - ai[i];
403:     ajtmp = aj + ai[i];
404:     v     = aa + bs2*ai[i];
405:     for (j=0; j<nz; j++) {
406:       PetscMemcpy(rtmp+bs2*ajtmp[j],v+bs2*j,bs2*sizeof(MatScalar));
407:     }

409:     /* elimination */
410:     bjtmp = bj + bi[i];
411:     nzL   = bi[i+1] - bi[i];
412:     for (k=0; k<nzL; k++) {
413:       row = bjtmp[k];
414:       pc  = rtmp + bs2*row;
415:       for (flg=0,j=0; j<bs2; j++) {
416:         if (pc[j]!=0.0) {
417:           flg = 1;
418:           break;
419:         }
420:       }
421:       if (flg) {
422:         pv = b->a + bs2*bdiag[row];
423:         /* PetscKernel_A_gets_A_times_B(bs,pc,pv,mwork); *pc = *pc * (*pv); */
424:         PetscKernel_A_gets_A_times_B_3(pc,pv,mwork);

426:         pj = b->j + bdiag[row+1]+1; /* beginning of U(row,:) */
427:         pv = b->a + bs2*(bdiag[row+1]+1);
428:         nz = bdiag[row] - bdiag[row+1] - 1; /* num of entries in U(row,:) excluding diag */
429:         for (j=0; j<nz; j++) {
430:           /* PetscKernel_A_gets_A_minus_B_times_C(bs,rtmp+bs2*pj[j],pc,pv+bs2*j); */
431:           /* rtmp+bs2*pj[j] = rtmp+bs2*pj[j] - (*pc)*(pv+bs2*j) */
432:           v    = rtmp + bs2*pj[j];
433:           PetscKernel_A_gets_A_minus_B_times_C_3(v,pc,pv);
434:           pv  += bs2;
435:         }
436:         PetscLogFlops(54*nz+45); /* flops = 2*bs^3*nz + 2*bs^3 - bs2) */
437:       }
438:     }

440:     /* finished row so stick it into b->a */
441:     /* L part */
442:     pv = b->a + bs2*bi[i];
443:     pj = b->j + bi[i];
444:     nz = bi[i+1] - bi[i];
445:     for (j=0; j<nz; j++) {
446:       PetscMemcpy(pv+bs2*j,rtmp+bs2*pj[j],bs2*sizeof(MatScalar));
447:     }

449:     /* Mark diagonal and invert diagonal for simplier triangular solves */
450:     pv   = b->a + bs2*bdiag[i];
451:     pj   = b->j + bdiag[i];
452:     PetscMemcpy(pv,rtmp+bs2*pj[0],bs2*sizeof(MatScalar));
453:     PetscKernel_A_gets_inverse_A_3(pv,shift,allowzeropivot,&zeropivotdetected);
454:     if (zeropivotdetected) B->errortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;

456:     /* U part */
457:     pv = b->a + bs2*(bdiag[i+1]+1);
458:     pj = b->j + bdiag[i+1]+1;
459:     nz = bdiag[i] - bdiag[i+1] - 1;
460:     for (j=0; j<nz; j++) {
461:       PetscMemcpy(pv+bs2*j,rtmp+bs2*pj[j],bs2*sizeof(MatScalar));
462:     }
463:   }
464:   PetscFree2(rtmp,mwork);

466:   C->ops->solve          = MatSolve_SeqBAIJ_3_NaturalOrdering;
467:   C->ops->forwardsolve   = MatForwardSolve_SeqBAIJ_3_NaturalOrdering;
468:   C->ops->backwardsolve  = MatBackwardSolve_SeqBAIJ_3_NaturalOrdering;
469:   C->ops->solvetranspose = MatSolveTranspose_SeqBAIJ_3_NaturalOrdering;
470:   C->assembled           = PETSC_TRUE;

472:   PetscLogFlops(1.333333333333*3*3*3*n); /* from inverting diagonal blocks */
473:   return(0);
474: }