Date: 2021-03-03T22:26:11+00:00

Actual source code: inode.c
petsc-3.14.5 2021-03-03
Report Typos and Errors

      2: /*
      3:   This file provides high performance routines for the Inode format (compressed sparse row)
      4:   by taking advantage of rows with identical nonzero structure (I-nodes).
      5: */
      6: #include <../src/mat/impls/aij/seq/aij.h>

      8: static PetscErrorCode MatCreateColInode_Private(Mat A,PetscInt *size,PetscInt **ns)
      9: {
     10:   Mat_SeqAIJ     *a = (Mat_SeqAIJ*)A->data;
     12:   PetscInt       i,count,m,n,min_mn,*ns_row,*ns_col;

     15:   n = A->cmap->n;
     16:   m = A->rmap->n;
     17:   if (!a->inode.size) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_COR,"Missing Inode Structure");
     18:   ns_row = a->inode.size;

     20:   min_mn = (m < n) ? m : n;
     21:   if (!ns) {
     22:     for (count=0,i=0; count<min_mn; count+=ns_row[i],i++) ;
     23:     for (; count+1 < n; count++,i++) ;
     24:     if (count < n)  {
     25:       i++;
     26:     }
     27:     *size = i;
     28:     return(0);
     29:   }
     30:   PetscMalloc1(n+1,&ns_col);

     32:   /* Use the same row structure wherever feasible. */
     33:   for (count=0,i=0; count<min_mn; count+=ns_row[i],i++) {
     34:     ns_col[i] = ns_row[i];
     35:   }

     37:   /* if m < n; pad up the remainder with inode_limit */
     38:   for (; count+1 < n; count++,i++) {
     39:     ns_col[i] = 1;
     40:   }
     41:   /* The last node is the odd ball. padd it up with the remaining rows; */
     42:   if (count < n) {
     43:     ns_col[i] = n - count;
     44:     i++;
     45:   } else if (count > n) {
     46:     /* Adjust for the over estimation */
     47:     ns_col[i-1] += n - count;
     48:   }
     49:   *size = i;
     50:   *ns   = ns_col;
     51:   return(0);
     52: }

     55: /*
     56:       This builds symmetric version of nonzero structure,
     57: */
     58: static PetscErrorCode MatGetRowIJ_SeqAIJ_Inode_Symmetric(Mat A,const PetscInt *iia[],const PetscInt *jja[],PetscInt ishift,PetscInt oshift)
     59: {
     60:   Mat_SeqAIJ     *a = (Mat_SeqAIJ*)A->data;
     62:   PetscInt       *work,*ia,*ja,nz,nslim_row,nslim_col,m,row,col,n;
     63:   PetscInt       *tns,*tvc,*ns_row = a->inode.size,*ns_col,nsz,i1,i2;
     64:   const PetscInt *j,*jmax,*ai= a->i,*aj = a->j;

     67:   nslim_row = a->inode.node_count;
     68:   m         = A->rmap->n;
     69:   n         = A->cmap->n;
     70:   if (m != n) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"MatGetRowIJ_SeqAIJ_Inode_Symmetric: Matrix should be square");
     71:   if (!a->inode.size) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_COR,"Missing Inode Structure");

     73:   /* Use the row_inode as column_inode */
     74:   nslim_col = nslim_row;
     75:   ns_col    = ns_row;

     77:   /* allocate space for reformated inode structure */
     78:   PetscMalloc2(nslim_col+1,&tns,n+1,&tvc);
     79:   for (i1=0,tns[0]=0; i1<nslim_col; ++i1) tns[i1+1] = tns[i1]+ ns_row[i1];

     81:   for (i1=0,col=0; i1<nslim_col; ++i1) {
     82:     nsz = ns_col[i1];
     83:     for (i2=0; i2<nsz; ++i2,++col) tvc[col] = i1;
     84:   }
     85:   /* allocate space for row pointers */
     86:   PetscCalloc1(nslim_row+1,&ia);
     87:   *iia = ia;
     88:   PetscMalloc1(nslim_row+1,&work);

     90:   /* determine the number of columns in each row */
     91:   ia[0] = oshift;
     92:   for (i1=0,row=0; i1<nslim_row; row+=ns_row[i1],i1++) {

     94:     j    = aj + ai[row] + ishift;
     95:     jmax = aj + ai[row+1] + ishift;
     96:     if (j==jmax) continue; /* empty row */
     97:     col  = *j++ + ishift;
     98:     i2   = tvc[col];
     99:     while (i2<i1 && j<jmax) { /* 1.[-xx-d-xx--] 2.[-xx-------],off-diagonal elemets */
    100:       ia[i1+1]++;
    101:       ia[i2+1]++;
    102:       i2++;                     /* Start col of next node */
    103:       while ((j<jmax) && ((col=*j+ishift)<tns[i2])) ++j;
    104:       i2 = tvc[col];
    105:     }
    106:     if (i2 == i1) ia[i2+1]++;    /* now the diagonal element */
    107:   }

    109:   /* shift ia[i] to point to next row */
    110:   for (i1=1; i1<nslim_row+1; i1++) {
    111:     row        = ia[i1-1];
    112:     ia[i1]    += row;
    113:     work[i1-1] = row - oshift;
    114:   }

    116:   /* allocate space for column pointers */
    117:   nz   = ia[nslim_row] + (!ishift);
    118:   PetscMalloc1(nz,&ja);
    119:   *jja = ja;

    121:   /* loop over lower triangular part putting into ja */
    122:   for (i1=0,row=0; i1<nslim_row; row += ns_row[i1],i1++) {
    123:     j    = aj + ai[row] + ishift;
    124:     jmax = aj + ai[row+1] + ishift;
    125:     if (j==jmax) continue; /* empty row */
    126:     col  = *j++ + ishift;
    127:     i2   = tvc[col];
    128:     while (i2<i1 && j<jmax) {
    129:       ja[work[i2]++] = i1 + oshift;
    130:       ja[work[i1]++] = i2 + oshift;
    131:       ++i2;
    132:       while ((j<jmax) && ((col=*j+ishift)< tns[i2])) ++j; /* Skip rest col indices in this node */
    133:       i2 = tvc[col];
    134:     }
    135:     if (i2 == i1) ja[work[i1]++] = i2 + oshift;

    137:   }
    138:   PetscFree(work);
    139:   PetscFree2(tns,tvc);
    140:   return(0);
    141: }

    143: /*
    144:       This builds nonsymmetric version of nonzero structure,
    145: */
    146: static PetscErrorCode MatGetRowIJ_SeqAIJ_Inode_Nonsymmetric(Mat A,const PetscInt *iia[],const PetscInt *jja[],PetscInt ishift,PetscInt oshift)
    147: {
    148:   Mat_SeqAIJ     *a = (Mat_SeqAIJ*)A->data;
    150:   PetscInt       *work,*ia,*ja,nz,nslim_row,n,row,col,*ns_col,nslim_col;
    151:   PetscInt       *tns,*tvc,nsz,i1,i2;
    152:   const PetscInt *j,*ai= a->i,*aj = a->j,*ns_row = a->inode.size;

    155:   if (!a->inode.size) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_COR,"Missing Inode Structure");
    156:   nslim_row = a->inode.node_count;
    157:   n         = A->cmap->n;

    159:   /* Create The column_inode for this matrix */
    160:   MatCreateColInode_Private(A,&nslim_col,&ns_col);

    162:   /* allocate space for reformated column_inode structure */
    163:   PetscMalloc2(nslim_col +1,&tns,n + 1,&tvc);
    164:   for (i1=0,tns[0]=0; i1<nslim_col; ++i1) tns[i1+1] = tns[i1] + ns_col[i1];

    166:   for (i1=0,col=0; i1<nslim_col; ++i1) {
    167:     nsz = ns_col[i1];
    168:     for (i2=0; i2<nsz; ++i2,++col) tvc[col] = i1;
    169:   }
    170:   /* allocate space for row pointers */
    171:   PetscCalloc1(nslim_row+1,&ia);
    172:   *iia = ia;
    173:   PetscMalloc1(nslim_row+1,&work);

    175:   /* determine the number of columns in each row */
    176:   ia[0] = oshift;
    177:   for (i1=0,row=0; i1<nslim_row; row+=ns_row[i1],i1++) {
    178:     j   = aj + ai[row] + ishift;
    179:     nz  = ai[row+1] - ai[row];
    180:     if (!nz) continue; /* empty row */
    181:     col = *j++ + ishift;
    182:     i2  = tvc[col];
    183:     while (nz-- > 0) {           /* off-diagonal elemets */
    184:       ia[i1+1]++;
    185:       i2++;                     /* Start col of next node */
    186:       while (nz > 0 && ((col = *j++ + ishift) < tns[i2])) nz--;
    187:       if (nz > 0) i2 = tvc[col];
    188:     }
    189:   }

    191:   /* shift ia[i] to point to next row */
    192:   for (i1=1; i1<nslim_row+1; i1++) {
    193:     row        = ia[i1-1];
    194:     ia[i1]    += row;
    195:     work[i1-1] = row - oshift;
    196:   }

    198:   /* allocate space for column pointers */
    199:   nz   = ia[nslim_row] + (!ishift);
    200:   PetscMalloc1(nz,&ja);
    201:   *jja = ja;

    203:   /* loop over matrix putting into ja */
    204:   for (i1=0,row=0; i1<nslim_row; row+=ns_row[i1],i1++) {
    205:     j   = aj + ai[row] + ishift;
    206:     nz  = ai[row+1] - ai[row];
    207:     if (!nz) continue; /* empty row */
    208:     col = *j++ + ishift;
    209:     i2  = tvc[col];
    210:     while (nz-- > 0) {
    211:       ja[work[i1]++] = i2 + oshift;
    212:       ++i2;
    213:       while (nz > 0 && ((col = *j++ + ishift) < tns[i2])) nz--;
    214:       if (nz > 0) i2 = tvc[col];
    215:     }
    216:   }
    217:   PetscFree(ns_col);
    218:   PetscFree(work);
    219:   PetscFree2(tns,tvc);
    220:   return(0);
    221: }

    223: static PetscErrorCode MatGetRowIJ_SeqAIJ_Inode(Mat A,PetscInt oshift,PetscBool symmetric,PetscBool blockcompressed,PetscInt *n,const PetscInt *ia[],const PetscInt *ja[],PetscBool  *done)
    224: {
    225:   Mat_SeqAIJ     *a = (Mat_SeqAIJ*)A->data;

    229:   *n = a->inode.node_count;
    230:   if (!ia) return(0);
    231:   if (!blockcompressed) {
    232:     MatGetRowIJ_SeqAIJ(A,oshift,symmetric,blockcompressed,n,ia,ja,done);
    233:   } else if (symmetric) {
    234:     MatGetRowIJ_SeqAIJ_Inode_Symmetric(A,ia,ja,0,oshift);
    235:   } else {
    236:     MatGetRowIJ_SeqAIJ_Inode_Nonsymmetric(A,ia,ja,0,oshift);
    237:   }
    238:   return(0);
    239: }

    241: static PetscErrorCode MatRestoreRowIJ_SeqAIJ_Inode(Mat A,PetscInt oshift,PetscBool symmetric,PetscBool blockcompressed,PetscInt *n,const PetscInt *ia[],const PetscInt *ja[],PetscBool  *done)
    242: {

    246:   if (!ia) return(0);

    248:   if (!blockcompressed) {
    249:     MatRestoreRowIJ_SeqAIJ(A,oshift,symmetric,blockcompressed,n,ia,ja,done);
    250:   } else {
    251:     PetscFree(*ia);
    252:     PetscFree(*ja);
    253:   }
    254:   return(0);
    255: }

    257: /* ----------------------------------------------------------- */

    259: static PetscErrorCode MatGetColumnIJ_SeqAIJ_Inode_Nonsymmetric(Mat A,const PetscInt *iia[],const PetscInt *jja[],PetscInt ishift,PetscInt oshift)
    260: {
    261:   Mat_SeqAIJ     *a = (Mat_SeqAIJ*)A->data;
    263:   PetscInt       *work,*ia,*ja,*j,nz,nslim_row, n,row,col,*ns_col,nslim_col;
    264:   PetscInt       *tns,*tvc,*ns_row = a->inode.size,nsz,i1,i2,*ai= a->i,*aj = a->j;

    267:   if (!a->inode.size) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_COR,"Missing Inode Structure");
    268:   nslim_row = a->inode.node_count;
    269:   n         = A->cmap->n;

    271:   /* Create The column_inode for this matrix */
    272:   MatCreateColInode_Private(A,&nslim_col,&ns_col);

    274:   /* allocate space for reformated column_inode structure */
    275:   PetscMalloc2(nslim_col + 1,&tns,n + 1,&tvc);
    276:   for (i1=0,tns[0]=0; i1<nslim_col; ++i1) tns[i1+1] = tns[i1] + ns_col[i1];

    278:   for (i1=0,col=0; i1<nslim_col; ++i1) {
    279:     nsz = ns_col[i1];
    280:     for (i2=0; i2<nsz; ++i2,++col) tvc[col] = i1;
    281:   }
    282:   /* allocate space for column pointers */
    283:   PetscCalloc1(nslim_col+1,&ia);
    284:   *iia = ia;
    285:   PetscMalloc1(nslim_col+1,&work);

    287:   /* determine the number of columns in each row */
    288:   ia[0] = oshift;
    289:   for (i1=0,row=0; i1<nslim_row; row+=ns_row[i1],i1++) {
    290:     j   = aj + ai[row] + ishift;
    291:     col = *j++ + ishift;
    292:     i2  = tvc[col];
    293:     nz  = ai[row+1] - ai[row];
    294:     while (nz-- > 0) {           /* off-diagonal elemets */
    295:       /* ia[i1+1]++; */
    296:       ia[i2+1]++;
    297:       i2++;
    298:       while (nz > 0 && ((col = *j++ + ishift) < tns[i2])) nz--;
    299:       if (nz > 0) i2 = tvc[col];
    300:     }
    301:   }

    303:   /* shift ia[i] to point to next col */
    304:   for (i1=1; i1<nslim_col+1; i1++) {
    305:     col        = ia[i1-1];
    306:     ia[i1]    += col;
    307:     work[i1-1] = col - oshift;
    308:   }

    310:   /* allocate space for column pointers */
    311:   nz   = ia[nslim_col] + (!ishift);
    312:   PetscMalloc1(nz,&ja);
    313:   *jja = ja;

    315:   /* loop over matrix putting into ja */
    316:   for (i1=0,row=0; i1<nslim_row; row+=ns_row[i1],i1++) {
    317:     j   = aj + ai[row] + ishift;
    318:     col = *j++ + ishift;
    319:     i2  = tvc[col];
    320:     nz  = ai[row+1] - ai[row];
    321:     while (nz-- > 0) {
    322:       /* ja[work[i1]++] = i2 + oshift; */
    323:       ja[work[i2]++] = i1 + oshift;
    324:       i2++;
    325:       while (nz > 0 && ((col = *j++ + ishift) < tns[i2])) nz--;
    326:       if (nz > 0) i2 = tvc[col];
    327:     }
    328:   }
    329:   PetscFree(ns_col);
    330:   PetscFree(work);
    331:   PetscFree2(tns,tvc);
    332:   return(0);
    333: }

    335: static PetscErrorCode MatGetColumnIJ_SeqAIJ_Inode(Mat A,PetscInt oshift,PetscBool symmetric,PetscBool blockcompressed,PetscInt *n,const PetscInt *ia[],const PetscInt *ja[],PetscBool  *done)
    336: {

    340:   MatCreateColInode_Private(A,n,NULL);
    341:   if (!ia) return(0);

    343:   if (!blockcompressed) {
    344:     MatGetColumnIJ_SeqAIJ(A,oshift,symmetric,blockcompressed,n,ia,ja,done);
    345:   } else if (symmetric) {
    346:     /* Since the indices are symmetric it does'nt matter */
    347:     MatGetRowIJ_SeqAIJ_Inode_Symmetric(A,ia,ja,0,oshift);
    348:   } else {
    349:     MatGetColumnIJ_SeqAIJ_Inode_Nonsymmetric(A,ia,ja,0,oshift);
    350:   }
    351:   return(0);
    352: }

    354: static PetscErrorCode MatRestoreColumnIJ_SeqAIJ_Inode(Mat A,PetscInt oshift,PetscBool symmetric,PetscBool blockcompressed,PetscInt *n,const PetscInt *ia[],const PetscInt *ja[],PetscBool  *done)
    355: {

    359:   if (!ia) return(0);
    360:   if (!blockcompressed) {
    361:     MatRestoreColumnIJ_SeqAIJ(A,oshift,symmetric,blockcompressed,n,ia,ja,done);
    362:   } else {
    363:     PetscFree(*ia);
    364:     PetscFree(*ja);
    365:   }
    366:   return(0);
    367: }

    369: /* ----------------------------------------------------------- */

    371: PetscErrorCode MatMult_SeqAIJ_Inode(Mat A,Vec xx,Vec yy)
    372: {
    373:   Mat_SeqAIJ        *a = (Mat_SeqAIJ*)A->data;
    374:   PetscScalar       sum1,sum2,sum3,sum4,sum5,tmp0,tmp1;
    375:   PetscScalar       *y;
    376:   const PetscScalar *x;
    377:   const MatScalar   *v1,*v2,*v3,*v4,*v5;
    378:   PetscErrorCode    ierr;
    379:   PetscInt          i1,i2,n,i,row,node_max,nsz,sz,nonzerorow=0;
    380:   const PetscInt    *idx,*ns,*ii;

    382: #if defined(PETSC_HAVE_PRAGMA_DISJOINT)
    383: #pragma disjoint(*x,*y,*v1,*v2,*v3,*v4,*v5)
    384: #endif

    387:   if (!a->inode.size) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_COR,"Missing Inode Structure");
    388:   node_max = a->inode.node_count;
    389:   ns       = a->inode.size;     /* Node Size array */
    390:   VecGetArrayRead(xx,&x);
    391:   VecGetArray(yy,&y);
    392:   idx      = a->j;
    393:   v1       = a->a;
    394:   ii       = a->i;

    396:   for (i = 0,row = 0; i< node_max; ++i) {
    397:     nsz         = ns[i];
    398:     n           = ii[1] - ii[0];
    399:     nonzerorow += (n>0)*nsz;
    400:     ii         += nsz;
    401:     PetscPrefetchBlock(idx+nsz*n,n,0,PETSC_PREFETCH_HINT_NTA);    /* Prefetch the indices for the block row after the current one */
    402:     PetscPrefetchBlock(v1+nsz*n,nsz*n,0,PETSC_PREFETCH_HINT_NTA); /* Prefetch the values for the block row after the current one  */
    403:     sz = n;                     /* No of non zeros in this row */
    404:                                 /* Switch on the size of Node */
    405:     switch (nsz) {               /* Each loop in 'case' is unrolled */
    406:     case 1:
    407:       sum1 = 0.;

    409:       for (n = 0; n< sz-1; n+=2) {
    410:         i1    = idx[0];         /* The instructions are ordered to */
    411:         i2    = idx[1];         /* make the compiler's job easy */
    412:         idx  += 2;
    413:         tmp0  = x[i1];
    414:         tmp1  = x[i2];
    415:         sum1 += v1[0] * tmp0 + v1[1] * tmp1; v1 += 2;
    416:       }

    418:       if (n == sz-1) {          /* Take care of the last nonzero  */
    419:         tmp0  = x[*idx++];
    420:         sum1 += *v1++ *tmp0;
    421:       }
    422:       y[row++]=sum1;
    423:       break;
    424:     case 2:
    425:       sum1 = 0.;
    426:       sum2 = 0.;
    427:       v2   = v1 + n;

    429:       for (n = 0; n< sz-1; n+=2) {
    430:         i1    = idx[0];
    431:         i2    = idx[1];
    432:         idx  += 2;
    433:         tmp0  = x[i1];
    434:         tmp1  = x[i2];
    435:         sum1 += v1[0] * tmp0 + v1[1] * tmp1; v1 += 2;
    436:         sum2 += v2[0] * tmp0 + v2[1] * tmp1; v2 += 2;
    437:       }
    438:       if (n == sz-1) {
    439:         tmp0  = x[*idx++];
    440:         sum1 += *v1++ * tmp0;
    441:         sum2 += *v2++ * tmp0;
    442:       }
    443:       y[row++]=sum1;
    444:       y[row++]=sum2;
    445:       v1      =v2;              /* Since the next block to be processed starts there*/
    446:       idx    +=sz;
    447:       break;
    448:     case 3:
    449:       sum1 = 0.;
    450:       sum2 = 0.;
    451:       sum3 = 0.;
    452:       v2   = v1 + n;
    453:       v3   = v2 + n;

    455:       for (n = 0; n< sz-1; n+=2) {
    456:         i1    = idx[0];
    457:         i2    = idx[1];
    458:         idx  += 2;
    459:         tmp0  = x[i1];
    460:         tmp1  = x[i2];
    461:         sum1 += v1[0] * tmp0 + v1[1] * tmp1; v1 += 2;
    462:         sum2 += v2[0] * tmp0 + v2[1] * tmp1; v2 += 2;
    463:         sum3 += v3[0] * tmp0 + v3[1] * tmp1; v3 += 2;
    464:       }
    465:       if (n == sz-1) {
    466:         tmp0  = x[*idx++];
    467:         sum1 += *v1++ * tmp0;
    468:         sum2 += *v2++ * tmp0;
    469:         sum3 += *v3++ * tmp0;
    470:       }
    471:       y[row++]=sum1;
    472:       y[row++]=sum2;
    473:       y[row++]=sum3;
    474:       v1      =v3;              /* Since the next block to be processed starts there*/
    475:       idx    +=2*sz;
    476:       break;
    477:     case 4:
    478:       sum1 = 0.;
    479:       sum2 = 0.;
    480:       sum3 = 0.;
    481:       sum4 = 0.;
    482:       v2   = v1 + n;
    483:       v3   = v2 + n;
    484:       v4   = v3 + n;

    486:       for (n = 0; n< sz-1; n+=2) {
    487:         i1    = idx[0];
    488:         i2    = idx[1];
    489:         idx  += 2;
    490:         tmp0  = x[i1];
    491:         tmp1  = x[i2];
    492:         sum1 += v1[0] * tmp0 + v1[1] *tmp1; v1 += 2;
    493:         sum2 += v2[0] * tmp0 + v2[1] *tmp1; v2 += 2;
    494:         sum3 += v3[0] * tmp0 + v3[1] *tmp1; v3 += 2;
    495:         sum4 += v4[0] * tmp0 + v4[1] *tmp1; v4 += 2;
    496:       }
    497:       if (n == sz-1) {
    498:         tmp0  = x[*idx++];
    499:         sum1 += *v1++ * tmp0;
    500:         sum2 += *v2++ * tmp0;
    501:         sum3 += *v3++ * tmp0;
    502:         sum4 += *v4++ * tmp0;
    503:       }
    504:       y[row++]=sum1;
    505:       y[row++]=sum2;
    506:       y[row++]=sum3;
    507:       y[row++]=sum4;
    508:       v1      =v4;              /* Since the next block to be processed starts there*/
    509:       idx    +=3*sz;
    510:       break;
    511:     case 5:
    512:       sum1 = 0.;
    513:       sum2 = 0.;
    514:       sum3 = 0.;
    515:       sum4 = 0.;
    516:       sum5 = 0.;
    517:       v2   = v1 + n;
    518:       v3   = v2 + n;
    519:       v4   = v3 + n;
    520:       v5   = v4 + n;

    522:       for (n = 0; n<sz-1; n+=2) {
    523:         i1    = idx[0];
    524:         i2    = idx[1];
    525:         idx  += 2;
    526:         tmp0  = x[i1];
    527:         tmp1  = x[i2];
    528:         sum1 += v1[0] * tmp0 + v1[1] *tmp1; v1 += 2;
    529:         sum2 += v2[0] * tmp0 + v2[1] *tmp1; v2 += 2;
    530:         sum3 += v3[0] * tmp0 + v3[1] *tmp1; v3 += 2;
    531:         sum4 += v4[0] * tmp0 + v4[1] *tmp1; v4 += 2;
    532:         sum5 += v5[0] * tmp0 + v5[1] *tmp1; v5 += 2;
    533:       }
    534:       if (n == sz-1) {
    535:         tmp0  = x[*idx++];
    536:         sum1 += *v1++ * tmp0;
    537:         sum2 += *v2++ * tmp0;
    538:         sum3 += *v3++ * tmp0;
    539:         sum4 += *v4++ * tmp0;
    540:         sum5 += *v5++ * tmp0;
    541:       }
    542:       y[row++]=sum1;
    543:       y[row++]=sum2;
    544:       y[row++]=sum3;
    545:       y[row++]=sum4;
    546:       y[row++]=sum5;
    547:       v1      =v5;       /* Since the next block to be processed starts there */
    548:       idx    +=4*sz;
    549:       break;
    550:     default:
    551:       SETERRQ(PETSC_COMM_SELF,PETSC_ERR_COR,"Node size not yet supported");
    552:     }
    553:   }
    554:   VecRestoreArrayRead(xx,&x);
    555:   VecRestoreArray(yy,&y);
    556:   PetscLogFlops(2.0*a->nz - nonzerorow);
    557:   return(0);
    558: }
    559: /* ----------------------------------------------------------- */
    560: /* Almost same code as the MatMult_SeqAIJ_Inode() */
    561: PetscErrorCode MatMultAdd_SeqAIJ_Inode(Mat A,Vec xx,Vec zz,Vec yy)
    562: {
    563:   Mat_SeqAIJ        *a = (Mat_SeqAIJ*)A->data;
    564:   PetscScalar       sum1,sum2,sum3,sum4,sum5,tmp0,tmp1;
    565:   const MatScalar   *v1,*v2,*v3,*v4,*v5;
    566:   const PetscScalar *x;
    567:   PetscScalar       *y,*z,*zt;
    568:   PetscErrorCode    ierr;
    569:   PetscInt          i1,i2,n,i,row,node_max,nsz,sz;
    570:   const PetscInt    *idx,*ns,*ii;

    573:   if (!a->inode.size) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_COR,"Missing Inode Structure");
    574:   node_max = a->inode.node_count;
    575:   ns       = a->inode.size;     /* Node Size array */

    577:   VecGetArrayRead(xx,&x);
    578:   VecGetArrayPair(zz,yy,&z,&y);
    579:   zt = z;

    581:   idx = a->j;
    582:   v1  = a->a;
    583:   ii  = a->i;

    585:   for (i = 0,row = 0; i< node_max; ++i) {
    586:     nsz = ns[i];
    587:     n   = ii[1] - ii[0];
    588:     ii += nsz;
    589:     sz  = n;                    /* No of non zeros in this row */
    590:                                 /* Switch on the size of Node */
    591:     switch (nsz) {               /* Each loop in 'case' is unrolled */
    592:     case 1:
    593:       sum1 = *zt++;

    595:       for (n = 0; n< sz-1; n+=2) {
    596:         i1    = idx[0];         /* The instructions are ordered to */
    597:         i2    = idx[1];         /* make the compiler's job easy */
    598:         idx  += 2;
    599:         tmp0  = x[i1];
    600:         tmp1  = x[i2];
    601:         sum1 += v1[0] * tmp0 + v1[1] * tmp1; v1 += 2;
    602:       }

    604:       if (n   == sz-1) {          /* Take care of the last nonzero  */
    605:         tmp0  = x[*idx++];
    606:         sum1 += *v1++ * tmp0;
    607:       }
    608:       y[row++]=sum1;
    609:       break;
    610:     case 2:
    611:       sum1 = *zt++;
    612:       sum2 = *zt++;
    613:       v2   = v1 + n;

    615:       for (n = 0; n< sz-1; n+=2) {
    616:         i1    = idx[0];
    617:         i2    = idx[1];
    618:         idx  += 2;
    619:         tmp0  = x[i1];
    620:         tmp1  = x[i2];
    621:         sum1 += v1[0] * tmp0 + v1[1] * tmp1; v1 += 2;
    622:         sum2 += v2[0] * tmp0 + v2[1] * tmp1; v2 += 2;
    623:       }
    624:       if (n   == sz-1) {
    625:         tmp0  = x[*idx++];
    626:         sum1 += *v1++ * tmp0;
    627:         sum2 += *v2++ * tmp0;
    628:       }
    629:       y[row++]=sum1;
    630:       y[row++]=sum2;
    631:       v1      =v2;              /* Since the next block to be processed starts there*/
    632:       idx    +=sz;
    633:       break;
    634:     case 3:
    635:       sum1 = *zt++;
    636:       sum2 = *zt++;
    637:       sum3 = *zt++;
    638:       v2   = v1 + n;
    639:       v3   = v2 + n;

    641:       for (n = 0; n< sz-1; n+=2) {
    642:         i1    = idx[0];
    643:         i2    = idx[1];
    644:         idx  += 2;
    645:         tmp0  = x[i1];
    646:         tmp1  = x[i2];
    647:         sum1 += v1[0] * tmp0 + v1[1] * tmp1; v1 += 2;
    648:         sum2 += v2[0] * tmp0 + v2[1] * tmp1; v2 += 2;
    649:         sum3 += v3[0] * tmp0 + v3[1] * tmp1; v3 += 2;
    650:       }
    651:       if (n == sz-1) {
    652:         tmp0  = x[*idx++];
    653:         sum1 += *v1++ * tmp0;
    654:         sum2 += *v2++ * tmp0;
    655:         sum3 += *v3++ * tmp0;
    656:       }
    657:       y[row++]=sum1;
    658:       y[row++]=sum2;
    659:       y[row++]=sum3;
    660:       v1      =v3;              /* Since the next block to be processed starts there*/
    661:       idx    +=2*sz;
    662:       break;
    663:     case 4:
    664:       sum1 = *zt++;
    665:       sum2 = *zt++;
    666:       sum3 = *zt++;
    667:       sum4 = *zt++;
    668:       v2   = v1 + n;
    669:       v3   = v2 + n;
    670:       v4   = v3 + n;

    672:       for (n = 0; n< sz-1; n+=2) {
    673:         i1    = idx[0];
    674:         i2    = idx[1];
    675:         idx  += 2;
    676:         tmp0  = x[i1];
    677:         tmp1  = x[i2];
    678:         sum1 += v1[0] * tmp0 + v1[1] *tmp1; v1 += 2;
    679:         sum2 += v2[0] * tmp0 + v2[1] *tmp1; v2 += 2;
    680:         sum3 += v3[0] * tmp0 + v3[1] *tmp1; v3 += 2;
    681:         sum4 += v4[0] * tmp0 + v4[1] *tmp1; v4 += 2;
    682:       }
    683:       if (n == sz-1) {
    684:         tmp0  = x[*idx++];
    685:         sum1 += *v1++ * tmp0;
    686:         sum2 += *v2++ * tmp0;
    687:         sum3 += *v3++ * tmp0;
    688:         sum4 += *v4++ * tmp0;
    689:       }
    690:       y[row++]=sum1;
    691:       y[row++]=sum2;
    692:       y[row++]=sum3;
    693:       y[row++]=sum4;
    694:       v1      =v4;              /* Since the next block to be processed starts there*/
    695:       idx    +=3*sz;
    696:       break;
    697:     case 5:
    698:       sum1 = *zt++;
    699:       sum2 = *zt++;
    700:       sum3 = *zt++;
    701:       sum4 = *zt++;
    702:       sum5 = *zt++;
    703:       v2   = v1 + n;
    704:       v3   = v2 + n;
    705:       v4   = v3 + n;
    706:       v5   = v4 + n;

    708:       for (n = 0; n<sz-1; n+=2) {
    709:         i1    = idx[0];
    710:         i2    = idx[1];
    711:         idx  += 2;
    712:         tmp0  = x[i1];
    713:         tmp1  = x[i2];
    714:         sum1 += v1[0] * tmp0 + v1[1] *tmp1; v1 += 2;
    715:         sum2 += v2[0] * tmp0 + v2[1] *tmp1; v2 += 2;
    716:         sum3 += v3[0] * tmp0 + v3[1] *tmp1; v3 += 2;
    717:         sum4 += v4[0] * tmp0 + v4[1] *tmp1; v4 += 2;
    718:         sum5 += v5[0] * tmp0 + v5[1] *tmp1; v5 += 2;
    719:       }
    720:       if (n   == sz-1) {
    721:         tmp0  = x[*idx++];
    722:         sum1 += *v1++ * tmp0;
    723:         sum2 += *v2++ * tmp0;
    724:         sum3 += *v3++ * tmp0;
    725:         sum4 += *v4++ * tmp0;
    726:         sum5 += *v5++ * tmp0;
    727:       }
    728:       y[row++]=sum1;
    729:       y[row++]=sum2;
    730:       y[row++]=sum3;
    731:       y[row++]=sum4;
    732:       y[row++]=sum5;
    733:       v1      =v5;       /* Since the next block to be processed starts there */
    734:       idx    +=4*sz;
    735:       break;
    736:     default:
    737:       SETERRQ(PETSC_COMM_SELF,PETSC_ERR_COR,"Node size not yet supported");
    738:     }
    739:   }
    740:   VecRestoreArrayRead(xx,&x);
    741:   VecRestoreArrayPair(zz,yy,&z,&y);
    742:   PetscLogFlops(2.0*a->nz);
    743:   return(0);
    744: }

    746: /* ----------------------------------------------------------- */
    747: PetscErrorCode MatSolve_SeqAIJ_Inode_inplace(Mat A,Vec bb,Vec xx)
    748: {
    749:   Mat_SeqAIJ        *a    = (Mat_SeqAIJ*)A->data;
    750:   IS                iscol = a->col,isrow = a->row;
    751:   PetscErrorCode    ierr;
    752:   const PetscInt    *r,*c,*rout,*cout;
    753:   PetscInt          i,j,n = A->rmap->n,nz;
    754:   PetscInt          node_max,*ns,row,nsz,aii,i0,i1;
    755:   const PetscInt    *ai = a->i,*a_j = a->j,*vi,*ad,*aj;
    756:   PetscScalar       *x,*tmp,*tmps,tmp0,tmp1;
    757:   PetscScalar       sum1,sum2,sum3,sum4,sum5;
    758:   const MatScalar   *v1,*v2,*v3,*v4,*v5,*a_a = a->a,*aa;
    759:   const PetscScalar *b;

    762:   if (!a->inode.size) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_COR,"Missing Inode Structure");
    763:   node_max = a->inode.node_count;
    764:   ns       = a->inode.size;     /* Node Size array */

    766:   VecGetArrayRead(bb,&b);
    767:   VecGetArrayWrite(xx,&x);
    768:   tmp  = a->solve_work;

    770:   ISGetIndices(isrow,&rout); r = rout;
    771:   ISGetIndices(iscol,&cout); c = cout + (n-1);

    773:   /* forward solve the lower triangular */
    774:   tmps = tmp;
    775:   aa   = a_a;
    776:   aj   = a_j;
    777:   ad   = a->diag;

    779:   for (i = 0,row = 0; i< node_max; ++i) {
    780:     nsz = ns[i];
    781:     aii = ai[row];
    782:     v1  = aa + aii;
    783:     vi  = aj + aii;
    784:     nz  = ad[row]- aii;
    785:     if (i < node_max-1) {
    786:       /* Prefetch the block after the current one, the prefetch itself can't cause a memory error,
    787:       * but our indexing to determine it's size could. */
    788:       PetscPrefetchBlock(aj+ai[row+nsz],ad[row+nsz]-ai[row+nsz],0,PETSC_PREFETCH_HINT_NTA); /* indices */
    789:       /* In my tests, it seems to be better to fetch entire rows instead of just the lower-triangular part */
    790:       PetscPrefetchBlock(aa+ai[row+nsz],ad[row+nsz+ns[i+1]-1]-ai[row+nsz],0,PETSC_PREFETCH_HINT_NTA);
    791:       /* for (j=0; j<ns[i+1]; j++) PetscPrefetchBlock(aa+ai[row+nsz+j],ad[row+nsz+j]-ai[row+nsz+j],0,0); */
    792:     }

    794:     switch (nsz) {               /* Each loop in 'case' is unrolled */
    795:     case 1:
    796:       sum1 = b[*r++];
    797:       for (j=0; j<nz-1; j+=2) {
    798:         i0    = vi[0];
    799:         i1    = vi[1];
    800:         vi   +=2;
    801:         tmp0  = tmps[i0];
    802:         tmp1  = tmps[i1];
    803:         sum1 -= v1[0] * tmp0 + v1[1] * tmp1; v1 += 2;
    804:       }
    805:       if (j == nz-1) {
    806:         tmp0  = tmps[*vi++];
    807:         sum1 -= *v1++ *tmp0;
    808:       }
    809:       tmp[row++]=sum1;
    810:       break;
    811:     case 2:
    812:       sum1 = b[*r++];
    813:       sum2 = b[*r++];
    814:       v2   = aa + ai[row+1];

    816:       for (j=0; j<nz-1; j+=2) {
    817:         i0    = vi[0];
    818:         i1    = vi[1];
    819:         vi   +=2;
    820:         tmp0  = tmps[i0];
    821:         tmp1  = tmps[i1];
    822:         sum1 -= v1[0] * tmp0 + v1[1] * tmp1; v1 += 2;
    823:         sum2 -= v2[0] * tmp0 + v2[1] * tmp1; v2 += 2;
    824:       }
    825:       if (j == nz-1) {
    826:         tmp0  = tmps[*vi++];
    827:         sum1 -= *v1++ *tmp0;
    828:         sum2 -= *v2++ *tmp0;
    829:       }
    830:       sum2     -= *v2++ *sum1;
    831:       tmp[row++]=sum1;
    832:       tmp[row++]=sum2;
    833:       break;
    834:     case 3:
    835:       sum1 = b[*r++];
    836:       sum2 = b[*r++];
    837:       sum3 = b[*r++];
    838:       v2   = aa + ai[row+1];
    839:       v3   = aa + ai[row+2];

    841:       for (j=0; j<nz-1; j+=2) {
    842:         i0    = vi[0];
    843:         i1    = vi[1];
    844:         vi   +=2;
    845:         tmp0  = tmps[i0];
    846:         tmp1  = tmps[i1];
    847:         sum1 -= v1[0] * tmp0 + v1[1] * tmp1; v1 += 2;
    848:         sum2 -= v2[0] * tmp0 + v2[1] * tmp1; v2 += 2;
    849:         sum3 -= v3[0] * tmp0 + v3[1] * tmp1; v3 += 2;
    850:       }
    851:       if (j == nz-1) {
    852:         tmp0  = tmps[*vi++];
    853:         sum1 -= *v1++ *tmp0;
    854:         sum2 -= *v2++ *tmp0;
    855:         sum3 -= *v3++ *tmp0;
    856:       }
    857:       sum2 -= *v2++ * sum1;
    858:       sum3 -= *v3++ * sum1;
    859:       sum3 -= *v3++ * sum2;

    861:       tmp[row++]=sum1;
    862:       tmp[row++]=sum2;
    863:       tmp[row++]=sum3;
    864:       break;

    866:     case 4:
    867:       sum1 = b[*r++];
    868:       sum2 = b[*r++];
    869:       sum3 = b[*r++];
    870:       sum4 = b[*r++];
    871:       v2   = aa + ai[row+1];
    872:       v3   = aa + ai[row+2];
    873:       v4   = aa + ai[row+3];

    875:       for (j=0; j<nz-1; j+=2) {
    876:         i0    = vi[0];
    877:         i1    = vi[1];
    878:         vi   +=2;
    879:         tmp0  = tmps[i0];
    880:         tmp1  = tmps[i1];
    881:         sum1 -= v1[0] * tmp0 + v1[1] * tmp1; v1 += 2;
    882:         sum2 -= v2[0] * tmp0 + v2[1] * tmp1; v2 += 2;
    883:         sum3 -= v3[0] * tmp0 + v3[1] * tmp1; v3 += 2;
    884:         sum4 -= v4[0] * tmp0 + v4[1] * tmp1; v4 += 2;
    885:       }
    886:       if (j == nz-1) {
    887:         tmp0  = tmps[*vi++];
    888:         sum1 -= *v1++ *tmp0;
    889:         sum2 -= *v2++ *tmp0;
    890:         sum3 -= *v3++ *tmp0;
    891:         sum4 -= *v4++ *tmp0;
    892:       }
    893:       sum2 -= *v2++ * sum1;
    894:       sum3 -= *v3++ * sum1;
    895:       sum4 -= *v4++ * sum1;
    896:       sum3 -= *v3++ * sum2;
    897:       sum4 -= *v4++ * sum2;
    898:       sum4 -= *v4++ * sum3;

    900:       tmp[row++]=sum1;
    901:       tmp[row++]=sum2;
    902:       tmp[row++]=sum3;
    903:       tmp[row++]=sum4;
    904:       break;
    905:     case 5:
    906:       sum1 = b[*r++];
    907:       sum2 = b[*r++];
    908:       sum3 = b[*r++];
    909:       sum4 = b[*r++];
    910:       sum5 = b[*r++];
    911:       v2   = aa + ai[row+1];
    912:       v3   = aa + ai[row+2];
    913:       v4   = aa + ai[row+3];
    914:       v5   = aa + ai[row+4];

    916:       for (j=0; j<nz-1; j+=2) {
    917:         i0    = vi[0];
    918:         i1    = vi[1];
    919:         vi   +=2;
    920:         tmp0  = tmps[i0];
    921:         tmp1  = tmps[i1];
    922:         sum1 -= v1[0] * tmp0 + v1[1] * tmp1; v1 += 2;
    923:         sum2 -= v2[0] * tmp0 + v2[1] * tmp1; v2 += 2;
    924:         sum3 -= v3[0] * tmp0 + v3[1] * tmp1; v3 += 2;
    925:         sum4 -= v4[0] * tmp0 + v4[1] * tmp1; v4 += 2;
    926:         sum5 -= v5[0] * tmp0 + v5[1] * tmp1; v5 += 2;
    927:       }
    928:       if (j == nz-1) {
    929:         tmp0  = tmps[*vi++];
    930:         sum1 -= *v1++ *tmp0;
    931:         sum2 -= *v2++ *tmp0;
    932:         sum3 -= *v3++ *tmp0;
    933:         sum4 -= *v4++ *tmp0;
    934:         sum5 -= *v5++ *tmp0;
    935:       }

    937:       sum2 -= *v2++ * sum1;
    938:       sum3 -= *v3++ * sum1;
    939:       sum4 -= *v4++ * sum1;
    940:       sum5 -= *v5++ * sum1;
    941:       sum3 -= *v3++ * sum2;
    942:       sum4 -= *v4++ * sum2;
    943:       sum5 -= *v5++ * sum2;
    944:       sum4 -= *v4++ * sum3;
    945:       sum5 -= *v5++ * sum3;
    946:       sum5 -= *v5++ * sum4;

    948:       tmp[row++]=sum1;
    949:       tmp[row++]=sum2;
    950:       tmp[row++]=sum3;
    951:       tmp[row++]=sum4;
    952:       tmp[row++]=sum5;
    953:       break;
    954:     default:
    955:       SETERRQ(PETSC_COMM_SELF,PETSC_ERR_COR,"Node size not yet supported \n");
    956:     }
    957:   }
    958:   /* backward solve the upper triangular */
    959:   for (i=node_max -1,row = n-1; i>=0; i--) {
    960:     nsz = ns[i];
    961:     aii = ai[row+1] -1;
    962:     v1  = aa + aii;
    963:     vi  = aj + aii;
    964:     nz  = aii- ad[row];
    965:     switch (nsz) {               /* Each loop in 'case' is unrolled */
    966:     case 1:
    967:       sum1 = tmp[row];

    969:       for (j=nz; j>1; j-=2) {
    970:         vi   -=2;
    971:         i0    = vi[2];
    972:         i1    = vi[1];
    973:         tmp0  = tmps[i0];
    974:         tmp1  = tmps[i1];
    975:         v1   -= 2;
    976:         sum1 -= v1[2] * tmp0 + v1[1] * tmp1;
    977:       }
    978:       if (j==1) {
    979:         tmp0  = tmps[*vi--];
    980:         sum1 -= *v1-- * tmp0;
    981:       }
    982:       x[*c--] = tmp[row] = sum1*a_a[ad[row]]; row--;
    983:       break;
    984:     case 2:
    985:       sum1 = tmp[row];
    986:       sum2 = tmp[row -1];
    987:       v2   = aa + ai[row]-1;
    988:       for (j=nz; j>1; j-=2) {
    989:         vi   -=2;
    990:         i0    = vi[2];
    991:         i1    = vi[1];
    992:         tmp0  = tmps[i0];
    993:         tmp1  = tmps[i1];
    994:         v1   -= 2;
    995:         v2   -= 2;
    996:         sum1 -= v1[2] * tmp0 + v1[1] * tmp1;
    997:         sum2 -= v2[2] * tmp0 + v2[1] * tmp1;
    998:       }
    999:       if (j==1) {
    1000:         tmp0  = tmps[*vi--];
    1001:         sum1 -= *v1-- * tmp0;
    1002:         sum2 -= *v2-- * tmp0;
    1003:       }

    1005:       tmp0    = x[*c--] = tmp[row] = sum1*a_a[ad[row]]; row--;
    1006:       sum2   -= *v2-- * tmp0;
    1007:       x[*c--] = tmp[row] = sum2*a_a[ad[row]]; row--;
    1008:       break;
    1009:     case 3:
    1010:       sum1 = tmp[row];
    1011:       sum2 = tmp[row -1];
    1012:       sum3 = tmp[row -2];
    1013:       v2   = aa + ai[row]-1;
    1014:       v3   = aa + ai[row -1]-1;
    1015:       for (j=nz; j>1; j-=2) {
    1016:         vi   -=2;
    1017:         i0    = vi[2];
    1018:         i1    = vi[1];
    1019:         tmp0  = tmps[i0];
    1020:         tmp1  = tmps[i1];
    1021:         v1   -= 2;
    1022:         v2   -= 2;
    1023:         v3   -= 2;
    1024:         sum1 -= v1[2] * tmp0 + v1[1] * tmp1;
    1025:         sum2 -= v2[2] * tmp0 + v2[1] * tmp1;
    1026:         sum3 -= v3[2] * tmp0 + v3[1] * tmp1;
    1027:       }
    1028:       if (j==1) {
    1029:         tmp0  = tmps[*vi--];
    1030:         sum1 -= *v1-- * tmp0;
    1031:         sum2 -= *v2-- * tmp0;
    1032:         sum3 -= *v3-- * tmp0;
    1033:       }
    1034:       tmp0    = x[*c--] = tmp[row] = sum1*a_a[ad[row]]; row--;
    1035:       sum2   -= *v2-- * tmp0;
    1036:       sum3   -= *v3-- * tmp0;
    1037:       tmp0    = x[*c--] = tmp[row] = sum2*a_a[ad[row]]; row--;
    1038:       sum3   -= *v3-- * tmp0;
    1039:       x[*c--] = tmp[row] = sum3*a_a[ad[row]]; row--;

    1041:       break;
    1042:     case 4:
    1043:       sum1 = tmp[row];
    1044:       sum2 = tmp[row -1];
    1045:       sum3 = tmp[row -2];
    1046:       sum4 = tmp[row -3];
    1047:       v2   = aa + ai[row]-1;
    1048:       v3   = aa + ai[row -1]-1;
    1049:       v4   = aa + ai[row -2]-1;

    1051:       for (j=nz; j>1; j-=2) {
    1052:         vi   -=2;
    1053:         i0    = vi[2];
    1054:         i1    = vi[1];
    1055:         tmp0  = tmps[i0];
    1056:         tmp1  = tmps[i1];
    1057:         v1   -= 2;
    1058:         v2   -= 2;
    1059:         v3   -= 2;
    1060:         v4   -= 2;
    1061:         sum1 -= v1[2] * tmp0 + v1[1] * tmp1;
    1062:         sum2 -= v2[2] * tmp0 + v2[1] * tmp1;
    1063:         sum3 -= v3[2] * tmp0 + v3[1] * tmp1;
    1064:         sum4 -= v4[2] * tmp0 + v4[1] * tmp1;
    1065:       }
    1066:       if (j==1) {
    1067:         tmp0  = tmps[*vi--];
    1068:         sum1 -= *v1-- * tmp0;
    1069:         sum2 -= *v2-- * tmp0;
    1070:         sum3 -= *v3-- * tmp0;
    1071:         sum4 -= *v4-- * tmp0;
    1072:       }

    1074:       tmp0    = x[*c--] = tmp[row] = sum1*a_a[ad[row]]; row--;
    1075:       sum2   -= *v2-- * tmp0;
    1076:       sum3   -= *v3-- * tmp0;
    1077:       sum4   -= *v4-- * tmp0;
    1078:       tmp0    = x[*c--] = tmp[row] = sum2*a_a[ad[row]]; row--;
    1079:       sum3   -= *v3-- * tmp0;
    1080:       sum4   -= *v4-- * tmp0;
    1081:       tmp0    = x[*c--] = tmp[row] = sum3*a_a[ad[row]]; row--;
    1082:       sum4   -= *v4-- * tmp0;
    1083:       x[*c--] = tmp[row] = sum4*a_a[ad[row]]; row--;
    1084:       break;
    1085:     case 5:
    1086:       sum1 = tmp[row];
    1087:       sum2 = tmp[row -1];
    1088:       sum3 = tmp[row -2];
    1089:       sum4 = tmp[row -3];
    1090:       sum5 = tmp[row -4];
    1091:       v2   = aa + ai[row]-1;
    1092:       v3   = aa + ai[row -1]-1;
    1093:       v4   = aa + ai[row -2]-1;
    1094:       v5   = aa + ai[row -3]-1;
    1095:       for (j=nz; j>1; j-=2) {
    1096:         vi   -= 2;
    1097:         i0    = vi[2];
    1098:         i1    = vi[1];
    1099:         tmp0  = tmps[i0];
    1100:         tmp1  = tmps[i1];
    1101:         v1   -= 2;
    1102:         v2   -= 2;
    1103:         v3   -= 2;
    1104:         v4   -= 2;
    1105:         v5   -= 2;
    1106:         sum1 -= v1[2] * tmp0 + v1[1] * tmp1;
    1107:         sum2 -= v2[2] * tmp0 + v2[1] * tmp1;
    1108:         sum3 -= v3[2] * tmp0 + v3[1] * tmp1;
    1109:         sum4 -= v4[2] * tmp0 + v4[1] * tmp1;
    1110:         sum5 -= v5[2] * tmp0 + v5[1] * tmp1;
    1111:       }
    1112:       if (j==1) {
    1113:         tmp0  = tmps[*vi--];
    1114:         sum1 -= *v1-- * tmp0;
    1115:         sum2 -= *v2-- * tmp0;
    1116:         sum3 -= *v3-- * tmp0;
    1117:         sum4 -= *v4-- * tmp0;
    1118:         sum5 -= *v5-- * tmp0;
    1119:       }

    1121:       tmp0    = x[*c--] = tmp[row] = sum1*a_a[ad[row]]; row--;
    1122:       sum2   -= *v2-- * tmp0;
    1123:       sum3   -= *v3-- * tmp0;
    1124:       sum4   -= *v4-- * tmp0;
    1125:       sum5   -= *v5-- * tmp0;
    1126:       tmp0    = x[*c--] = tmp[row] = sum2*a_a[ad[row]]; row--;
    1127:       sum3   -= *v3-- * tmp0;
    1128:       sum4   -= *v4-- * tmp0;
    1129:       sum5   -= *v5-- * tmp0;
    1130:       tmp0    = x[*c--] = tmp[row] = sum3*a_a[ad[row]]; row--;
    1131:       sum4   -= *v4-- * tmp0;
    1132:       sum5   -= *v5-- * tmp0;
    1133:       tmp0    = x[*c--] = tmp[row] = sum4*a_a[ad[row]]; row--;
    1134:       sum5   -= *v5-- * tmp0;
    1135:       x[*c--] = tmp[row] = sum5*a_a[ad[row]]; row--;
    1136:       break;
    1137:     default:
    1138:       SETERRQ(PETSC_COMM_SELF,PETSC_ERR_COR,"Node size not yet supported \n");
    1139:     }
    1140:   }
    1141:   ISRestoreIndices(isrow,&rout);
    1142:   ISRestoreIndices(iscol,&cout);
    1143:   VecRestoreArrayRead(bb,&b);
    1144:   VecRestoreArrayWrite(xx,&x);
    1145:   PetscLogFlops(2.0*a->nz - A->cmap->n);
    1146:   return(0);
    1147: }

    1149: PetscErrorCode MatLUFactorNumeric_SeqAIJ_Inode(Mat B,Mat A,const MatFactorInfo *info)
    1150: {
    1151:   Mat             C     =B;
    1152:   Mat_SeqAIJ      *a    =(Mat_SeqAIJ*)A->data,*b=(Mat_SeqAIJ*)C->data;
    1153:   IS              isrow = b->row,isicol = b->icol;
    1154:   PetscErrorCode  ierr;
    1155:   const PetscInt  *r,*ic,*ics;
    1156:   const PetscInt  n=A->rmap->n,*ai=a->i,*aj=a->j,*bi=b->i,*bj=b->j,*bdiag=b->diag;
    1157:   PetscInt        i,j,k,nz,nzL,row,*pj;
    1158:   const PetscInt  *ajtmp,*bjtmp;
    1159:   MatScalar       *pc,*pc1,*pc2,*pc3,*pc4,mul1,mul2,mul3,mul4,*pv,*rtmp1,*rtmp2,*rtmp3,*rtmp4;
    1160:   const MatScalar *aa=a->a,*v,*v1,*v2,*v3,*v4;
    1161:   FactorShiftCtx  sctx;
    1162:   const PetscInt  *ddiag;
    1163:   PetscReal       rs;
    1164:   MatScalar       d;
    1165:   PetscInt        inod,nodesz,node_max,col;
    1166:   const PetscInt  *ns;
    1167:   PetscInt        *tmp_vec1,*tmp_vec2,*nsmap;

    1170:   /* MatPivotSetUp(): initialize shift context sctx */
    1171:   PetscMemzero(&sctx,sizeof(FactorShiftCtx));

    1173:   if (info->shifttype == (PetscReal)MAT_SHIFT_POSITIVE_DEFINITE) { /* set sctx.shift_top=max{rs} */
    1174:     ddiag          = a->diag;
    1175:     sctx.shift_top = info->zeropivot;
    1176:     for (i=0; i<n; i++) {
    1177:       /* calculate sum(|aij|)-RealPart(aii), amt of shift needed for this row */
    1178:       d  = (aa)[ddiag[i]];
    1179:       rs = -PetscAbsScalar(d) - PetscRealPart(d);
    1180:       v  = aa+ai[i];
    1181:       nz = ai[i+1] - ai[i];
    1182:       for (j=0; j<nz; j++) rs += PetscAbsScalar(v[j]);
    1183:       if (rs>sctx.shift_top) sctx.shift_top = rs;
    1184:     }
    1185:     sctx.shift_top *= 1.1;
    1186:     sctx.nshift_max = 5;
    1187:     sctx.shift_lo   = 0.;
    1188:     sctx.shift_hi   = 1.;
    1189:   }

    1191:   ISGetIndices(isrow,&r);
    1192:   ISGetIndices(isicol,&ic);

    1194:   PetscCalloc4(n,&rtmp1,n,&rtmp2,n,&rtmp3,n,&rtmp4);
    1195:   ics   = ic;

    1197:   node_max = a->inode.node_count;
    1198:   ns       = a->inode.size;
    1199:   if (!ns) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Matrix without inode information");

    1201:   /* If max inode size > 4, split it into two inodes.*/
    1202:   /* also map the inode sizes according to the ordering */
    1203:   PetscMalloc1(n+1,&tmp_vec1);
    1204:   for (i=0,j=0; i<node_max; ++i,++j) {
    1205:     if (ns[i] > 4) {
    1206:       tmp_vec1[j] = 4;
    1207:       ++j;
    1208:       tmp_vec1[j] = ns[i] - tmp_vec1[j-1];
    1209:     } else {
    1210:       tmp_vec1[j] = ns[i];
    1211:     }
    1212:   }
    1213:   /* Use the correct node_max */
    1214:   node_max = j;

    1216:   /* Now reorder the inode info based on mat re-ordering info */
    1217:   /* First create a row -> inode_size_array_index map */
    1218:   PetscMalloc1(n+1,&nsmap);
    1219:   PetscMalloc1(node_max+1,&tmp_vec2);
    1220:   for (i=0,row=0; i<node_max; i++) {
    1221:     nodesz = tmp_vec1[i];
    1222:     for (j=0; j<nodesz; j++,row++) {
    1223:       nsmap[row] = i;
    1224:     }
    1225:   }
    1226:   /* Using nsmap, create a reordered ns structure */
    1227:   for (i=0,j=0; i< node_max; i++) {
    1228:     nodesz      = tmp_vec1[nsmap[r[j]]];     /* here the reordered row_no is in r[] */
    1229:     tmp_vec2[i] = nodesz;
    1230:     j          += nodesz;
    1231:   }
    1232:   PetscFree(nsmap);
    1233:   PetscFree(tmp_vec1);

    1235:   /* Now use the correct ns */
    1236:   ns = tmp_vec2;

    1238:   do {
    1239:     sctx.newshift = PETSC_FALSE;
    1240:     /* Now loop over each block-row, and do the factorization */
    1241:     for (inod=0,i=0; inod<node_max; inod++) { /* i: row index; inod: inode index */
    1242:       nodesz = ns[inod];

    1244:       switch (nodesz) {
    1245:       case 1:
    1246:         /*----------*/
    1247:         /* zero rtmp1 */
    1248:         /* L part */
    1249:         nz    = bi[i+1] - bi[i];
    1250:         bjtmp = bj + bi[i];
    1251:         for (j=0; j<nz; j++) rtmp1[bjtmp[j]] = 0.0;

    1253:         /* U part */
    1254:         nz    = bdiag[i]-bdiag[i+1];
    1255:         bjtmp = bj + bdiag[i+1]+1;
    1256:         for (j=0; j<nz; j++) rtmp1[bjtmp[j]] = 0.0;

    1258:         /* load in initial (unfactored row) */
    1259:         nz    = ai[r[i]+1] - ai[r[i]];
    1260:         ajtmp = aj + ai[r[i]];
    1261:         v     = aa + ai[r[i]];
    1262:         for (j=0; j<nz; j++) rtmp1[ics[ajtmp[j]]] = v[j];

    1264:         /* ZeropivotApply() */
    1265:         rtmp1[i] += sctx.shift_amount;  /* shift the diagonal of the matrix */

    1267:         /* elimination */
    1268:         bjtmp = bj + bi[i];
    1269:         row   = *bjtmp++;
    1270:         nzL   = bi[i+1] - bi[i];
    1271:         for (k=0; k < nzL; k++) {
    1272:           pc = rtmp1 + row;
    1273:           if (*pc != 0.0) {
    1274:             pv   = b->a + bdiag[row];
    1275:             mul1 = *pc * (*pv);
    1276:             *pc  = mul1;
    1277:             pj   = b->j + bdiag[row+1]+1; /* beginning of U(row,:) */
    1278:             pv   = b->a + bdiag[row+1]+1;
    1279:             nz   = bdiag[row]-bdiag[row+1]-1; /* num of entries in U(row,:) excluding diag */
    1280:             for (j=0; j<nz; j++) rtmp1[pj[j]] -= mul1 * pv[j];
    1281:             PetscLogFlops(1+2.0*nz);
    1282:           }
    1283:           row = *bjtmp++;
    1284:         }

    1286:         /* finished row so stick it into b->a */
    1287:         rs = 0.0;
    1288:         /* L part */
    1289:         pv = b->a + bi[i];
    1290:         pj = b->j + bi[i];
    1291:         nz = bi[i+1] - bi[i];
    1292:         for (j=0; j<nz; j++) {
    1293:           pv[j] = rtmp1[pj[j]]; rs += PetscAbsScalar(pv[j]);
    1294:         }

    1296:         /* U part */
    1297:         pv = b->a + bdiag[i+1]+1;
    1298:         pj = b->j + bdiag[i+1]+1;
    1299:         nz = bdiag[i] - bdiag[i+1]-1;
    1300:         for (j=0; j<nz; j++) {
    1301:           pv[j] = rtmp1[pj[j]]; rs += PetscAbsScalar(pv[j]);
    1302:         }

    1304:         /* Check zero pivot */
    1305:         sctx.rs = rs;
    1306:         sctx.pv = rtmp1[i];
    1307:         MatPivotCheck(B,A,info,&sctx,i);
    1308:         if (sctx.newshift) break;

    1310:         /* Mark diagonal and invert diagonal for simplier triangular solves */
    1311:         pv  = b->a + bdiag[i];
    1312:         *pv = 1.0/sctx.pv; /* sctx.pv = rtmp1[i]+shiftamount if shifttype==MAT_SHIFT_INBLOCKS */
    1313:         break;

    1315:       case 2:
    1316:         /*----------*/
    1317:         /* zero rtmp1 and rtmp2 */
    1318:         /* L part */
    1319:         nz    = bi[i+1] - bi[i];
    1320:         bjtmp = bj + bi[i];
    1321:         for  (j=0; j<nz; j++) {
    1322:           col        = bjtmp[j];
    1323:           rtmp1[col] = 0.0; rtmp2[col] = 0.0;
    1324:         }

    1326:         /* U part */
    1327:         nz    = bdiag[i]-bdiag[i+1];
    1328:         bjtmp = bj + bdiag[i+1]+1;
    1329:         for  (j=0; j<nz; j++) {
    1330:           col        = bjtmp[j];
    1331:           rtmp1[col] = 0.0; rtmp2[col] = 0.0;
    1332:         }

    1334:         /* load in initial (unfactored row) */
    1335:         nz    = ai[r[i]+1] - ai[r[i]];
    1336:         ajtmp = aj + ai[r[i]];
    1337:         v1    = aa + ai[r[i]]; v2 = aa + ai[r[i]+1];
    1338:         for (j=0; j<nz; j++) {
    1339:           col        = ics[ajtmp[j]];
    1340:           rtmp1[col] = v1[j]; rtmp2[col] = v2[j];
    1341:         }
    1342:         /* ZeropivotApply(): shift the diagonal of the matrix  */
    1343:         rtmp1[i] += sctx.shift_amount; rtmp2[i+1] += sctx.shift_amount;

    1345:         /* elimination */
    1346:         bjtmp = bj + bi[i];
    1347:         row   = *bjtmp++; /* pivot row */
    1348:         nzL   = bi[i+1] - bi[i];
    1349:         for (k=0; k < nzL; k++) {
    1350:           pc1 = rtmp1 + row;
    1351:           pc2 = rtmp2 + row;
    1352:           if (*pc1 != 0.0 || *pc2 != 0.0) {
    1353:             pv   = b->a + bdiag[row];
    1354:             mul1 = *pc1*(*pv); mul2 = *pc2*(*pv);
    1355:             *pc1 = mul1;       *pc2 = mul2;

    1357:             pj = b->j + bdiag[row+1]+1;     /* beginning of U(row,:) */
    1358:             pv = b->a + bdiag[row+1]+1;
    1359:             nz = bdiag[row]-bdiag[row+1]-1; /* num of entries in U(row,:) excluding diag */
    1360:             for (j=0; j<nz; j++) {
    1361:               col         = pj[j];
    1362:               rtmp1[col] -= mul1 * pv[j];
    1363:               rtmp2[col] -= mul2 * pv[j];
    1364:             }
    1365:             PetscLogFlops(2+4.0*nz);
    1366:           }
    1367:           row = *bjtmp++;
    1368:         }

    1370:         /* finished row i; check zero pivot, then stick row i into b->a */
    1371:         rs = 0.0;
    1372:         /* L part */
    1373:         pc1 = b->a + bi[i];
    1374:         pj  = b->j + bi[i];
    1375:         nz  = bi[i+1] - bi[i];
    1376:         for (j=0; j<nz; j++) {
    1377:           col    = pj[j];
    1378:           pc1[j] = rtmp1[col]; rs += PetscAbsScalar(pc1[j]);
    1379:         }
    1380:         /* U part */
    1381:         pc1 = b->a + bdiag[i+1]+1;
    1382:         pj  = b->j + bdiag[i+1]+1;
    1383:         nz  = bdiag[i] - bdiag[i+1] - 1; /* exclude diagonal */
    1384:         for (j=0; j<nz; j++) {
    1385:           col    = pj[j];
    1386:           pc1[j] = rtmp1[col]; rs += PetscAbsScalar(pc1[j]);
    1387:         }

    1389:         sctx.rs = rs;
    1390:         sctx.pv = rtmp1[i];
    1391:         MatPivotCheck(B,A,info,&sctx,i);
    1392:         if (sctx.newshift) break;
    1393:         pc1  = b->a + bdiag[i]; /* Mark diagonal */
    1394:         *pc1 = 1.0/sctx.pv;

    1396:         /* Now take care of diagonal 2x2 block. */
    1397:         pc2 = rtmp2 + i;
    1398:         if (*pc2 != 0.0) {
    1399:           mul1 = (*pc2)*(*pc1); /* *pc1=diag[i] is inverted! */
    1400:           *pc2 = mul1;          /* insert L entry */
    1401:           pj   = b->j + bdiag[i+1]+1;   /* beginning of U(i,:) */
    1402:           nz   = bdiag[i]-bdiag[i+1]-1; /* num of entries in U(i,:) excluding diag */
    1403:           for (j=0; j<nz; j++) {
    1404:             col = pj[j]; rtmp2[col] -= mul1 * rtmp1[col];
    1405:           }
    1406:           PetscLogFlops(1+2.0*nz);
    1407:         }

    1409:         /* finished row i+1; check zero pivot, then stick row i+1 into b->a */
    1410:         rs = 0.0;
    1411:         /* L part */
    1412:         pc2 = b->a + bi[i+1];
    1413:         pj  = b->j + bi[i+1];
    1414:         nz  = bi[i+2] - bi[i+1];
    1415:         for (j=0; j<nz; j++) {
    1416:           col    = pj[j];
    1417:           pc2[j] = rtmp2[col]; rs += PetscAbsScalar(pc2[j]);
    1418:         }
    1419:         /* U part */
    1420:         pc2 = b->a + bdiag[i+2]+1;
    1421:         pj  = b->j + bdiag[i+2]+1;
    1422:         nz  = bdiag[i+1] - bdiag[i+2] - 1; /* exclude diagonal */
    1423:         for (j=0; j<nz; j++) {
    1424:           col    = pj[j];
    1425:           pc2[j] = rtmp2[col]; rs += PetscAbsScalar(pc2[j]);
    1426:         }

    1428:         sctx.rs = rs;
    1429:         sctx.pv = rtmp2[i+1];
    1430:         MatPivotCheck(B,A,info,&sctx,i+1);
    1431:         if (sctx.newshift) break;
    1432:         pc2  = b->a + bdiag[i+1];
    1433:         *pc2 = 1.0/sctx.pv;
    1434:         break;

    1436:       case 3:
    1437:         /*----------*/
    1438:         /* zero rtmp */
    1439:         /* L part */
    1440:         nz    = bi[i+1] - bi[i];
    1441:         bjtmp = bj + bi[i];
    1442:         for  (j=0; j<nz; j++) {
    1443:           col        = bjtmp[j];
    1444:           rtmp1[col] = 0.0; rtmp2[col] = 0.0; rtmp3[col] = 0.0;
    1445:         }

    1447:         /* U part */
    1448:         nz    = bdiag[i]-bdiag[i+1];
    1449:         bjtmp = bj + bdiag[i+1]+1;
    1450:         for  (j=0; j<nz; j++) {
    1451:           col        = bjtmp[j];
    1452:           rtmp1[col] = 0.0; rtmp2[col] = 0.0; rtmp3[col] = 0.0;
    1453:         }

    1455:         /* load in initial (unfactored row) */
    1456:         nz    = ai[r[i]+1] - ai[r[i]];
    1457:         ajtmp = aj + ai[r[i]];
    1458:         v1    = aa + ai[r[i]]; v2 = aa + ai[r[i]+1]; v3 = aa + ai[r[i]+2];
    1459:         for (j=0; j<nz; j++) {
    1460:           col        = ics[ajtmp[j]];
    1461:           rtmp1[col] = v1[j]; rtmp2[col] = v2[j]; rtmp3[col] = v3[j];
    1462:         }
    1463:         /* ZeropivotApply(): shift the diagonal of the matrix  */
    1464:         rtmp1[i] += sctx.shift_amount; rtmp2[i+1] += sctx.shift_amount; rtmp3[i+2] += sctx.shift_amount;

    1466:         /* elimination */
    1467:         bjtmp = bj + bi[i];
    1468:         row   = *bjtmp++; /* pivot row */
    1469:         nzL   = bi[i+1] - bi[i];
    1470:         for (k=0; k < nzL; k++) {
    1471:           pc1 = rtmp1 + row;
    1472:           pc2 = rtmp2 + row;
    1473:           pc3 = rtmp3 + row;
    1474:           if (*pc1 != 0.0 || *pc2 != 0.0 || *pc3 != 0.0) {
    1475:             pv   = b->a + bdiag[row];
    1476:             mul1 = *pc1*(*pv); mul2 = *pc2*(*pv); mul3 = *pc3*(*pv);
    1477:             *pc1 = mul1; *pc2 = mul2; *pc3 = mul3;

    1479:             pj = b->j + bdiag[row+1]+1;     /* beginning of U(row,:) */
    1480:             pv = b->a + bdiag[row+1]+1;
    1481:             nz = bdiag[row]-bdiag[row+1]-1; /* num of entries in U(row,:) excluding diag */
    1482:             for (j=0; j<nz; j++) {
    1483:               col         = pj[j];
    1484:               rtmp1[col] -= mul1 * pv[j];
    1485:               rtmp2[col] -= mul2 * pv[j];
    1486:               rtmp3[col] -= mul3 * pv[j];
    1487:             }
    1488:             PetscLogFlops(3+6.0*nz);
    1489:           }
    1490:           row = *bjtmp++;
    1491:         }

    1493:         /* finished row i; check zero pivot, then stick row i into b->a */
    1494:         rs = 0.0;
    1495:         /* L part */
    1496:         pc1 = b->a + bi[i];
    1497:         pj  = b->j + bi[i];
    1498:         nz  = bi[i+1] - bi[i];
    1499:         for (j=0; j<nz; j++) {
    1500:           col    = pj[j];
    1501:           pc1[j] = rtmp1[col]; rs += PetscAbsScalar(pc1[j]);
    1502:         }
    1503:         /* U part */
    1504:         pc1 = b->a + bdiag[i+1]+1;
    1505:         pj  = b->j + bdiag[i+1]+1;
    1506:         nz  = bdiag[i] - bdiag[i+1] - 1; /* exclude diagonal */
    1507:         for (j=0; j<nz; j++) {
    1508:           col    = pj[j];
    1509:           pc1[j] = rtmp1[col]; rs += PetscAbsScalar(pc1[j]);
    1510:         }

    1512:         sctx.rs = rs;
    1513:         sctx.pv = rtmp1[i];
    1514:         MatPivotCheck(B,A,info,&sctx,i);
    1515:         if (sctx.newshift) break;
    1516:         pc1  = b->a + bdiag[i]; /* Mark diag[i] */
    1517:         *pc1 = 1.0/sctx.pv;

    1519:         /* Now take care of 1st column of diagonal 3x3 block. */
    1520:         pc2 = rtmp2 + i;
    1521:         pc3 = rtmp3 + i;
    1522:         if (*pc2 != 0.0 || *pc3 != 0.0) {
    1523:           mul2 = (*pc2)*(*pc1); *pc2 = mul2;
    1524:           mul3 = (*pc3)*(*pc1); *pc3 = mul3;
    1525:           pj   = b->j + bdiag[i+1]+1;   /* beginning of U(i,:) */
    1526:           nz   = bdiag[i]-bdiag[i+1]-1; /* num of entries in U(i,:) excluding diag */
    1527:           for (j=0; j<nz; j++) {
    1528:             col         = pj[j];
    1529:             rtmp2[col] -= mul2 * rtmp1[col];
    1530:             rtmp3[col] -= mul3 * rtmp1[col];
    1531:           }
    1532:           PetscLogFlops(2+4.0*nz);
    1533:         }

    1535:         /* finished row i+1; check zero pivot, then stick row i+1 into b->a */
    1536:         rs = 0.0;
    1537:         /* L part */
    1538:         pc2 = b->a + bi[i+1];
    1539:         pj  = b->j + bi[i+1];
    1540:         nz  = bi[i+2] - bi[i+1];
    1541:         for (j=0; j<nz; j++) {
    1542:           col    = pj[j];
    1543:           pc2[j] = rtmp2[col]; rs += PetscAbsScalar(pc2[j]);
    1544:         }
    1545:         /* U part */
    1546:         pc2 = b->a + bdiag[i+2]+1;
    1547:         pj  = b->j + bdiag[i+2]+1;
    1548:         nz  = bdiag[i+1] - bdiag[i+2] - 1; /* exclude diagonal */
    1549:         for (j=0; j<nz; j++) {
    1550:           col    = pj[j];
    1551:           pc2[j] = rtmp2[col]; rs += PetscAbsScalar(pc2[j]);
    1552:         }

    1554:         sctx.rs = rs;
    1555:         sctx.pv = rtmp2[i+1];
    1556:         MatPivotCheck(B,A,info,&sctx,i+1);
    1557:         if (sctx.newshift) break;
    1558:         pc2  = b->a + bdiag[i+1];
    1559:         *pc2 = 1.0/sctx.pv; /* Mark diag[i+1] */

    1561:         /* Now take care of 2nd column of diagonal 3x3 block. */
    1562:         pc3 = rtmp3 + i+1;
    1563:         if (*pc3 != 0.0) {
    1564:           mul3 = (*pc3)*(*pc2); *pc3 = mul3;
    1565:           pj   = b->j + bdiag[i+2]+1;     /* beginning of U(i+1,:) */
    1566:           nz   = bdiag[i+1]-bdiag[i+2]-1; /* num of entries in U(i+1,:) excluding diag */
    1567:           for (j=0; j<nz; j++) {
    1568:             col         = pj[j];
    1569:             rtmp3[col] -= mul3 * rtmp2[col];
    1570:           }
    1571:           PetscLogFlops(1+2.0*nz);
    1572:         }

    1574:         /* finished i+2; check zero pivot, then stick row i+2 into b->a */
    1575:         rs = 0.0;
    1576:         /* L part */
    1577:         pc3 = b->a + bi[i+2];
    1578:         pj  = b->j + bi[i+2];
    1579:         nz  = bi[i+3] - bi[i+2];
    1580:         for (j=0; j<nz; j++) {
    1581:           col    = pj[j];
    1582:           pc3[j] = rtmp3[col]; rs += PetscAbsScalar(pc3[j]);
    1583:         }
    1584:         /* U part */
    1585:         pc3 = b->a + bdiag[i+3]+1;
    1586:         pj  = b->j + bdiag[i+3]+1;
    1587:         nz  = bdiag[i+2] - bdiag[i+3] - 1; /* exclude diagonal */
    1588:         for (j=0; j<nz; j++) {
    1589:           col    = pj[j];
    1590:           pc3[j] = rtmp3[col]; rs += PetscAbsScalar(pc3[j]);
    1591:         }

    1593:         sctx.rs = rs;
    1594:         sctx.pv = rtmp3[i+2];
    1595:         MatPivotCheck(B,A,info,&sctx,i+2);
    1596:         if (sctx.newshift) break;
    1597:         pc3  = b->a + bdiag[i+2];
    1598:         *pc3 = 1.0/sctx.pv; /* Mark diag[i+2] */
    1599:         break;
    1600:       case 4:
    1601:         /*----------*/
    1602:         /* zero rtmp */
    1603:         /* L part */
    1604:         nz    = bi[i+1] - bi[i];
    1605:         bjtmp = bj + bi[i];
    1606:         for  (j=0; j<nz; j++) {
    1607:           col        = bjtmp[j];
    1608:           rtmp1[col] = 0.0; rtmp2[col] = 0.0; rtmp3[col] = 0.0;rtmp4[col] = 0.0;
    1609:         }

    1611:         /* U part */
    1612:         nz    = bdiag[i]-bdiag[i+1];
    1613:         bjtmp = bj + bdiag[i+1]+1;
    1614:         for  (j=0; j<nz; j++) {
    1615:           col        = bjtmp[j];
    1616:           rtmp1[col] = 0.0; rtmp2[col] = 0.0; rtmp3[col] = 0.0; rtmp4[col] = 0.0;
    1617:         }

    1619:         /* load in initial (unfactored row) */
    1620:         nz    = ai[r[i]+1] - ai[r[i]];
    1621:         ajtmp = aj + ai[r[i]];
    1622:         v1    = aa + ai[r[i]]; v2 = aa + ai[r[i]+1]; v3 = aa + ai[r[i]+2]; v4 = aa + ai[r[i]+3];
    1623:         for (j=0; j<nz; j++) {
    1624:           col        = ics[ajtmp[j]];
    1625:           rtmp1[col] = v1[j]; rtmp2[col] = v2[j]; rtmp3[col] = v3[j]; rtmp4[col] = v4[j];
    1626:         }
    1627:         /* ZeropivotApply(): shift the diagonal of the matrix  */
    1628:         rtmp1[i] += sctx.shift_amount; rtmp2[i+1] += sctx.shift_amount; rtmp3[i+2] += sctx.shift_amount; rtmp4[i+3] += sctx.shift_amount;

    1630:         /* elimination */
    1631:         bjtmp = bj + bi[i];
    1632:         row   = *bjtmp++; /* pivot row */
    1633:         nzL   = bi[i+1] - bi[i];
    1634:         for (k=0; k < nzL; k++) {
    1635:           pc1 = rtmp1 + row;
    1636:           pc2 = rtmp2 + row;
    1637:           pc3 = rtmp3 + row;
    1638:           pc4 = rtmp4 + row;
    1639:           if (*pc1 != 0.0 || *pc2 != 0.0 || *pc3 != 0.0 || *pc4 != 0.0) {
    1640:             pv   = b->a + bdiag[row];
    1641:             mul1 = *pc1*(*pv); mul2 = *pc2*(*pv); mul3 = *pc3*(*pv); mul4 = *pc4*(*pv);
    1642:             *pc1 = mul1; *pc2 = mul2; *pc3 = mul3; *pc4 = mul4;

    1644:             pj = b->j + bdiag[row+1]+1; /* beginning of U(row,:) */
    1645:             pv = b->a + bdiag[row+1]+1;
    1646:             nz = bdiag[row]-bdiag[row+1]-1; /* num of entries in U(row,:) excluding diag */
    1647:             for (j=0; j<nz; j++) {
    1648:               col         = pj[j];
    1649:               rtmp1[col] -= mul1 * pv[j];
    1650:               rtmp2[col] -= mul2 * pv[j];
    1651:               rtmp3[col] -= mul3 * pv[j];
    1652:               rtmp4[col] -= mul4 * pv[j];
    1653:             }
    1654:             PetscLogFlops(4+8.0*nz);
    1655:           }
    1656:           row = *bjtmp++;
    1657:         }

    1659:         /* finished row i; check zero pivot, then stick row i into b->a */
    1660:         rs = 0.0;
    1661:         /* L part */
    1662:         pc1 = b->a + bi[i];
    1663:         pj  = b->j + bi[i];
    1664:         nz  = bi[i+1] - bi[i];
    1665:         for (j=0; j<nz; j++) {
    1666:           col    = pj[j];
    1667:           pc1[j] = rtmp1[col]; rs += PetscAbsScalar(pc1[j]);
    1668:         }
    1669:         /* U part */
    1670:         pc1 = b->a + bdiag[i+1]+1;
    1671:         pj  = b->j + bdiag[i+1]+1;
    1672:         nz  = bdiag[i] - bdiag[i+1] - 1; /* exclude diagonal */
    1673:         for (j=0; j<nz; j++) {
    1674:           col    = pj[j];
    1675:           pc1[j] = rtmp1[col]; rs += PetscAbsScalar(pc1[j]);
    1676:         }

    1678:         sctx.rs = rs;
    1679:         sctx.pv = rtmp1[i];
    1680:         MatPivotCheck(B,A,info,&sctx,i);
    1681:         if (sctx.newshift) break;
    1682:         pc1  = b->a + bdiag[i]; /* Mark diag[i] */
    1683:         *pc1 = 1.0/sctx.pv;

    1685:         /* Now take care of 1st column of diagonal 4x4 block. */
    1686:         pc2 = rtmp2 + i;
    1687:         pc3 = rtmp3 + i;
    1688:         pc4 = rtmp4 + i;
    1689:         if (*pc2 != 0.0 || *pc3 != 0.0 || *pc4 != 0.0) {
    1690:           mul2 = (*pc2)*(*pc1); *pc2 = mul2;
    1691:           mul3 = (*pc3)*(*pc1); *pc3 = mul3;
    1692:           mul4 = (*pc4)*(*pc1); *pc4 = mul4;
    1693:           pj   = b->j + bdiag[i+1]+1;   /* beginning of U(i,:) */
    1694:           nz   = bdiag[i]-bdiag[i+1]-1; /* num of entries in U(i,:) excluding diag */
    1695:           for (j=0; j<nz; j++) {
    1696:             col         = pj[j];
    1697:             rtmp2[col] -= mul2 * rtmp1[col];
    1698:             rtmp3[col] -= mul3 * rtmp1[col];
    1699:             rtmp4[col] -= mul4 * rtmp1[col];
    1700:           }
    1701:           PetscLogFlops(3+6.0*nz);
    1702:         }

    1704:         /* finished row i+1; check zero pivot, then stick row i+1 into b->a */
    1705:         rs = 0.0;
    1706:         /* L part */
    1707:         pc2 = b->a + bi[i+1];
    1708:         pj  = b->j + bi[i+1];
    1709:         nz  = bi[i+2] - bi[i+1];
    1710:         for (j=0; j<nz; j++) {
    1711:           col    = pj[j];
    1712:           pc2[j] = rtmp2[col]; rs += PetscAbsScalar(pc2[j]);
    1713:         }
    1714:         /* U part */
    1715:         pc2 = b->a + bdiag[i+2]+1;
    1716:         pj  = b->j + bdiag[i+2]+1;
    1717:         nz  = bdiag[i+1] - bdiag[i+2] - 1; /* exclude diagonal */
    1718:         for (j=0; j<nz; j++) {
    1719:           col    = pj[j];
    1720:           pc2[j] = rtmp2[col]; rs += PetscAbsScalar(pc2[j]);
    1721:         }

    1723:         sctx.rs = rs;
    1724:         sctx.pv = rtmp2[i+1];
    1725:         MatPivotCheck(B,A,info,&sctx,i+1);
    1726:         if (sctx.newshift) break;
    1727:         pc2  = b->a + bdiag[i+1];
    1728:         *pc2 = 1.0/sctx.pv; /* Mark diag[i+1] */

    1730:         /* Now take care of 2nd column of diagonal 4x4 block. */
    1731:         pc3 = rtmp3 + i+1;
    1732:         pc4 = rtmp4 + i+1;
    1733:         if (*pc3 != 0.0 || *pc4 != 0.0) {
    1734:           mul3 = (*pc3)*(*pc2); *pc3 = mul3;
    1735:           mul4 = (*pc4)*(*pc2); *pc4 = mul4;
    1736:           pj   = b->j + bdiag[i+2]+1;     /* beginning of U(i+1,:) */
    1737:           nz   = bdiag[i+1]-bdiag[i+2]-1; /* num of entries in U(i+1,:) excluding diag */
    1738:           for (j=0; j<nz; j++) {
    1739:             col         = pj[j];
    1740:             rtmp3[col] -= mul3 * rtmp2[col];
    1741:             rtmp4[col] -= mul4 * rtmp2[col];
    1742:           }
    1743:           PetscLogFlops(4.0*nz);
    1744:         }

    1746:         /* finished i+2; check zero pivot, then stick row i+2 into b->a */
    1747:         rs = 0.0;
    1748:         /* L part */
    1749:         pc3 = b->a + bi[i+2];
    1750:         pj  = b->j + bi[i+2];
    1751:         nz  = bi[i+3] - bi[i+2];
    1752:         for (j=0; j<nz; j++) {
    1753:           col    = pj[j];
    1754:           pc3[j] = rtmp3[col]; rs += PetscAbsScalar(pc3[j]);
    1755:         }
    1756:         /* U part */
    1757:         pc3 = b->a + bdiag[i+3]+1;
    1758:         pj  = b->j + bdiag[i+3]+1;
    1759:         nz  = bdiag[i+2] - bdiag[i+3] - 1; /* exclude diagonal */
    1760:         for (j=0; j<nz; j++) {
    1761:           col    = pj[j];
    1762:           pc3[j] = rtmp3[col]; rs += PetscAbsScalar(pc3[j]);
    1763:         }

    1765:         sctx.rs = rs;
    1766:         sctx.pv = rtmp3[i+2];
    1767:         MatPivotCheck(B,A,info,&sctx,i+2);
    1768:         if (sctx.newshift) break;
    1769:         pc3  = b->a + bdiag[i+2];
    1770:         *pc3 = 1.0/sctx.pv; /* Mark diag[i+2] */

    1772:         /* Now take care of 3rd column of diagonal 4x4 block. */
    1773:         pc4 = rtmp4 + i+2;
    1774:         if (*pc4 != 0.0) {
    1775:           mul4 = (*pc4)*(*pc3); *pc4 = mul4;
    1776:           pj   = b->j + bdiag[i+3]+1;     /* beginning of U(i+2,:) */
    1777:           nz   = bdiag[i+2]-bdiag[i+3]-1; /* num of entries in U(i+2,:) excluding diag */
    1778:           for (j=0; j<nz; j++) {
    1779:             col         = pj[j];
    1780:             rtmp4[col] -= mul4 * rtmp3[col];
    1781:           }
    1782:           PetscLogFlops(1+2.0*nz);
    1783:         }

    1785:         /* finished i+3; check zero pivot, then stick row i+3 into b->a */
    1786:         rs = 0.0;
    1787:         /* L part */
    1788:         pc4 = b->a + bi[i+3];
    1789:         pj  = b->j + bi[i+3];
    1790:         nz  = bi[i+4] - bi[i+3];
    1791:         for (j=0; j<nz; j++) {
    1792:           col    = pj[j];
    1793:           pc4[j] = rtmp4[col]; rs += PetscAbsScalar(pc4[j]);
    1794:         }
    1795:         /* U part */
    1796:         pc4 = b->a + bdiag[i+4]+1;
    1797:         pj  = b->j + bdiag[i+4]+1;
    1798:         nz  = bdiag[i+3] - bdiag[i+4] - 1; /* exclude diagonal */
    1799:         for (j=0; j<nz; j++) {
    1800:           col    = pj[j];
    1801:           pc4[j] = rtmp4[col]; rs += PetscAbsScalar(pc4[j]);
    1802:         }

    1804:         sctx.rs = rs;
    1805:         sctx.pv = rtmp4[i+3];
    1806:         MatPivotCheck(B,A,info,&sctx,i+3);
    1807:         if (sctx.newshift) break;
    1808:         pc4  = b->a + bdiag[i+3];
    1809:         *pc4 = 1.0/sctx.pv; /* Mark diag[i+3] */
    1810:         break;

    1812:       default:
    1813:         SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"Node size not yet supported \n");
    1814:       }
    1815:       if (sctx.newshift) break; /* break for (inod=0,i=0; inod<node_max; inod++) */
    1816:       i += nodesz;                 /* Update the row */
    1817:     }

    1819:     /* MatPivotRefine() */
    1820:     if (info->shifttype == (PetscReal) MAT_SHIFT_POSITIVE_DEFINITE && !sctx.newshift && sctx.shift_fraction>0 && sctx.nshift<sctx.nshift_max) {
    1821:       /*
    1822:        * if no shift in this attempt & shifting & started shifting & can refine,
    1823:        * then try lower shift
    1824:        */
    1825:       sctx.shift_hi       = sctx.shift_fraction;
    1826:       sctx.shift_fraction = (sctx.shift_hi+sctx.shift_lo)/2.;
    1827:       sctx.shift_amount   = sctx.shift_fraction * sctx.shift_top;
    1828:       sctx.newshift       = PETSC_TRUE;
    1829:       sctx.nshift++;
    1830:     }
    1831:   } while (sctx.newshift);

    1833:   PetscFree4(rtmp1,rtmp2,rtmp3,rtmp4);
    1834:   PetscFree(tmp_vec2);
    1835:   ISRestoreIndices(isicol,&ic);
    1836:   ISRestoreIndices(isrow,&r);

    1838:   if (b->inode.size) {
    1839:     C->ops->solve           = MatSolve_SeqAIJ_Inode;
    1840:   } else {
    1841:     C->ops->solve           = MatSolve_SeqAIJ;
    1842:   }
    1843:   C->ops->solveadd          = MatSolveAdd_SeqAIJ;
    1844:   C->ops->solvetranspose    = MatSolveTranspose_SeqAIJ;
    1845:   C->ops->solvetransposeadd = MatSolveTransposeAdd_SeqAIJ;
    1846:   C->ops->matsolve          = MatMatSolve_SeqAIJ;
    1847:   C->assembled              = PETSC_TRUE;
    1848:   C->preallocated           = PETSC_TRUE;

    1850:   PetscLogFlops(C->cmap->n);

    1852:   /* MatShiftView(A,info,&sctx) */
    1853:   if (sctx.nshift) {
    1854:     if (info->shifttype == (PetscReal) MAT_SHIFT_POSITIVE_DEFINITE) {
    1855:       PetscInfo4(A,"number of shift_pd tries %D, shift_amount %g, diagonal shifted up by %e fraction top_value %e\n",sctx.nshift,(double)sctx.shift_amount,(double)sctx.shift_fraction,(double)sctx.shift_top);
    1856:     } else if (info->shifttype == (PetscReal)MAT_SHIFT_NONZERO) {
    1857:       PetscInfo2(A,"number of shift_nz tries %D, shift_amount %g\n",sctx.nshift,(double)sctx.shift_amount);
    1858:     } else if (info->shifttype == (PetscReal)MAT_SHIFT_INBLOCKS) {
    1859:       PetscInfo2(A,"number of shift_inblocks applied %D, each shift_amount %g\n",sctx.nshift,(double)info->shiftamount);
    1860:     }
    1861:   }
    1862:   return(0);
    1863: }

    1865: PetscErrorCode MatLUFactorNumeric_SeqAIJ_Inode_inplace(Mat B,Mat A,const MatFactorInfo *info)
    1866: {
    1867:   Mat             C     = B;
    1868:   Mat_SeqAIJ      *a    = (Mat_SeqAIJ*)A->data,*b = (Mat_SeqAIJ*)C->data;
    1869:   IS              iscol = b->col,isrow = b->row,isicol = b->icol;
    1870:   PetscErrorCode  ierr;
    1871:   const PetscInt  *r,*ic,*c,*ics;
    1872:   PetscInt        n   = A->rmap->n,*bi = b->i;
    1873:   PetscInt        *bj = b->j,*nbj=b->j +1,*ajtmp,*bjtmp,nz,nz_tmp,row,prow;
    1874:   PetscInt        i,j,idx,*bd = b->diag,node_max,nodesz;
    1875:   PetscInt        *ai = a->i,*aj = a->j;
    1876:   PetscInt        *ns,*tmp_vec1,*tmp_vec2,*nsmap,*pj;
    1877:   PetscScalar     mul1,mul2,mul3,tmp;
    1878:   MatScalar       *pc1,*pc2,*pc3,*ba = b->a,*pv,*rtmp11,*rtmp22,*rtmp33;
    1879:   const MatScalar *v1,*v2,*v3,*aa = a->a,*rtmp1;
    1880:   PetscReal       rs=0.0;
    1881:   FactorShiftCtx  sctx;

    1884:   sctx.shift_top      = 0;
    1885:   sctx.nshift_max     = 0;
    1886:   sctx.shift_lo       = 0;
    1887:   sctx.shift_hi       = 0;
    1888:   sctx.shift_fraction = 0;

    1890:   /* if both shift schemes are chosen by user, only use info->shiftpd */
    1891:   if (info->shifttype==(PetscReal)MAT_SHIFT_POSITIVE_DEFINITE) { /* set sctx.shift_top=max{rs} */
    1892:     sctx.shift_top = 0;
    1893:     for (i=0; i<n; i++) {
    1894:       /* calculate rs = sum(|aij|)-RealPart(aii), amt of shift needed for this row */
    1895:       rs    = 0.0;
    1896:       ajtmp = aj + ai[i];
    1897:       rtmp1 = aa + ai[i];
    1898:       nz    = ai[i+1] - ai[i];
    1899:       for (j=0; j<nz; j++) {
    1900:         if (*ajtmp != i) {
    1901:           rs += PetscAbsScalar(*rtmp1++);
    1902:         } else {
    1903:           rs -= PetscRealPart(*rtmp1++);
    1904:         }
    1905:         ajtmp++;
    1906:       }
    1907:       if (rs>sctx.shift_top) sctx.shift_top = rs;
    1908:     }
    1909:     if (sctx.shift_top == 0.0) sctx.shift_top += 1.e-12;
    1910:     sctx.shift_top *= 1.1;
    1911:     sctx.nshift_max = 5;
    1912:     sctx.shift_lo   = 0.;
    1913:     sctx.shift_hi   = 1.;
    1914:   }
    1915:   sctx.shift_amount = 0;
    1916:   sctx.nshift       = 0;

    1918:   ISGetIndices(isrow,&r);
    1919:   ISGetIndices(iscol,&c);
    1920:   ISGetIndices(isicol,&ic);
    1921:   PetscCalloc3(n,&rtmp11,n,&rtmp22,n,&rtmp33);
    1922:   ics    = ic;

    1924:   node_max = a->inode.node_count;
    1925:   ns       = a->inode.size;
    1926:   if (!ns) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Matrix without inode information");

    1928:   /* If max inode size > 3, split it into two inodes.*/
    1929:   /* also map the inode sizes according to the ordering */
    1930:   PetscMalloc1(n+1,&tmp_vec1);
    1931:   for (i=0,j=0; i<node_max; ++i,++j) {
    1932:     if (ns[i]>3) {
    1933:       tmp_vec1[j] = ns[i]/2; /* Assuming ns[i] < =5  */
    1934:       ++j;
    1935:       tmp_vec1[j] = ns[i] - tmp_vec1[j-1];
    1936:     } else {
    1937:       tmp_vec1[j] = ns[i];
    1938:     }
    1939:   }
    1940:   /* Use the correct node_max */
    1941:   node_max = j;

    1943:   /* Now reorder the inode info based on mat re-ordering info */
    1944:   /* First create a row -> inode_size_array_index map */
    1945:   PetscMalloc2(n+1,&nsmap,node_max+1,&tmp_vec2);
    1946:   for (i=0,row=0; i<node_max; i++) {
    1947:     nodesz = tmp_vec1[i];
    1948:     for (j=0; j<nodesz; j++,row++) {
    1949:       nsmap[row] = i;
    1950:     }
    1951:   }
    1952:   /* Using nsmap, create a reordered ns structure */
    1953:   for (i=0,j=0; i< node_max; i++) {
    1954:     nodesz      = tmp_vec1[nsmap[r[j]]];     /* here the reordered row_no is in r[] */
    1955:     tmp_vec2[i] = nodesz;
    1956:     j          += nodesz;
    1957:   }
    1958:   PetscFree2(nsmap,tmp_vec1);
    1959:   /* Now use the correct ns */
    1960:   ns = tmp_vec2;

    1962:   do {
    1963:     sctx.newshift = PETSC_FALSE;
    1964:     /* Now loop over each block-row, and do the factorization */
    1965:     for (i=0,row=0; i<node_max; i++) {
    1966:       nodesz = ns[i];
    1967:       nz     = bi[row+1] - bi[row];
    1968:       bjtmp  = bj + bi[row];

    1970:       switch (nodesz) {
    1971:       case 1:
    1972:         for  (j=0; j<nz; j++) {
    1973:           idx         = bjtmp[j];
    1974:           rtmp11[idx] = 0.0;
    1975:         }

    1977:         /* load in initial (unfactored row) */
    1978:         idx    = r[row];
    1979:         nz_tmp = ai[idx+1] - ai[idx];
    1980:         ajtmp  = aj + ai[idx];
    1981:         v1     = aa + ai[idx];

    1983:         for (j=0; j<nz_tmp; j++) {
    1984:           idx         = ics[ajtmp[j]];
    1985:           rtmp11[idx] = v1[j];
    1986:         }
    1987:         rtmp11[ics[r[row]]] += sctx.shift_amount;

    1989:         prow = *bjtmp++;
    1990:         while (prow < row) {
    1991:           pc1 = rtmp11 + prow;
    1992:           if (*pc1 != 0.0) {
    1993:             pv     = ba + bd[prow];
    1994:             pj     = nbj + bd[prow];
    1995:             mul1   = *pc1 * *pv++;
    1996:             *pc1   = mul1;
    1997:             nz_tmp = bi[prow+1] - bd[prow] - 1;
    1998:             PetscLogFlops(1+2.0*nz_tmp);
    1999:             for (j=0; j<nz_tmp; j++) {
    2000:               tmp          = pv[j];
    2001:               idx          = pj[j];
    2002:               rtmp11[idx] -= mul1 * tmp;
    2003:             }
    2004:           }
    2005:           prow = *bjtmp++;
    2006:         }
    2007:         pj  = bj + bi[row];
    2008:         pc1 = ba + bi[row];

    2010:         sctx.pv     = rtmp11[row];
    2011:         rtmp11[row] = 1.0/rtmp11[row]; /* invert diag */
    2012:         rs          = 0.0;
    2013:         for (j=0; j<nz; j++) {
    2014:           idx    = pj[j];
    2015:           pc1[j] = rtmp11[idx]; /* rtmp11 -> ba */
    2016:           if (idx != row) rs += PetscAbsScalar(pc1[j]);
    2017:         }
    2018:         sctx.rs = rs;
    2019:         MatPivotCheck(B,A,info,&sctx,row);
    2020:         if (sctx.newshift) goto endofwhile;
    2021:         break;

    2023:       case 2:
    2024:         for (j=0; j<nz; j++) {
    2025:           idx         = bjtmp[j];
    2026:           rtmp11[idx] = 0.0;
    2027:           rtmp22[idx] = 0.0;
    2028:         }

    2030:         /* load in initial (unfactored row) */
    2031:         idx    = r[row];
    2032:         nz_tmp = ai[idx+1] - ai[idx];
    2033:         ajtmp  = aj + ai[idx];
    2034:         v1     = aa + ai[idx];
    2035:         v2     = aa + ai[idx+1];
    2036:         for (j=0; j<nz_tmp; j++) {
    2037:           idx         = ics[ajtmp[j]];
    2038:           rtmp11[idx] = v1[j];
    2039:           rtmp22[idx] = v2[j];
    2040:         }
    2041:         rtmp11[ics[r[row]]]   += sctx.shift_amount;
    2042:         rtmp22[ics[r[row+1]]] += sctx.shift_amount;

    2044:         prow = *bjtmp++;
    2045:         while (prow < row) {
    2046:           pc1 = rtmp11 + prow;
    2047:           pc2 = rtmp22 + prow;
    2048:           if (*pc1 != 0.0 || *pc2 != 0.0) {
    2049:             pv   = ba + bd[prow];
    2050:             pj   = nbj + bd[prow];
    2051:             mul1 = *pc1 * *pv;
    2052:             mul2 = *pc2 * *pv;
    2053:             ++pv;
    2054:             *pc1 = mul1;
    2055:             *pc2 = mul2;

    2057:             nz_tmp = bi[prow+1] - bd[prow] - 1;
    2058:             for (j=0; j<nz_tmp; j++) {
    2059:               tmp          = pv[j];
    2060:               idx          = pj[j];
    2061:               rtmp11[idx] -= mul1 * tmp;
    2062:               rtmp22[idx] -= mul2 * tmp;
    2063:             }
    2064:             PetscLogFlops(2+4.0*nz_tmp);
    2065:           }
    2066:           prow = *bjtmp++;
    2067:         }

    2069:         /* Now take care of diagonal 2x2 block. Note: prow = row here */
    2070:         pc1 = rtmp11 + prow;
    2071:         pc2 = rtmp22 + prow;

    2073:         sctx.pv = *pc1;
    2074:         pj      = bj + bi[prow];
    2075:         rs      = 0.0;
    2076:         for (j=0; j<nz; j++) {
    2077:           idx = pj[j];
    2078:           if (idx != prow) rs += PetscAbsScalar(rtmp11[idx]);
    2079:         }
    2080:         sctx.rs = rs;
    2081:         MatPivotCheck(B,A,info,&sctx,row);
    2082:         if (sctx.newshift) goto endofwhile;

    2084:         if (*pc2 != 0.0) {
    2085:           pj     = nbj + bd[prow];
    2086:           mul2   = (*pc2)/(*pc1); /* since diag is not yet inverted.*/
    2087:           *pc2   = mul2;
    2088:           nz_tmp = bi[prow+1] - bd[prow] - 1;
    2089:           for (j=0; j<nz_tmp; j++) {
    2090:             idx          = pj[j];
    2091:             tmp          = rtmp11[idx];
    2092:             rtmp22[idx] -= mul2 * tmp;
    2093:           }
    2094:           PetscLogFlops(1+2.0*nz_tmp);
    2095:         }

    2097:         pj  = bj + bi[row];
    2098:         pc1 = ba + bi[row];
    2099:         pc2 = ba + bi[row+1];

    2101:         sctx.pv       = rtmp22[row+1];
    2102:         rs            = 0.0;
    2103:         rtmp11[row]   = 1.0/rtmp11[row];
    2104:         rtmp22[row+1] = 1.0/rtmp22[row+1];
    2105:         /* copy row entries from dense representation to sparse */
    2106:         for (j=0; j<nz; j++) {
    2107:           idx    = pj[j];
    2108:           pc1[j] = rtmp11[idx];
    2109:           pc2[j] = rtmp22[idx];
    2110:           if (idx != row+1) rs += PetscAbsScalar(pc2[j]);
    2111:         }
    2112:         sctx.rs = rs;
    2113:         MatPivotCheck(B,A,info,&sctx,row+1);
    2114:         if (sctx.newshift) goto endofwhile;
    2115:         break;

    2117:       case 3:
    2118:         for  (j=0; j<nz; j++) {
    2119:           idx         = bjtmp[j];
    2120:           rtmp11[idx] = 0.0;
    2121:           rtmp22[idx] = 0.0;
    2122:           rtmp33[idx] = 0.0;
    2123:         }
    2124:         /* copy the nonzeros for the 3 rows from sparse representation to dense in rtmp*[] */
    2125:         idx    = r[row];
    2126:         nz_tmp = ai[idx+1] - ai[idx];
    2127:         ajtmp  = aj + ai[idx];
    2128:         v1     = aa + ai[idx];
    2129:         v2     = aa + ai[idx+1];
    2130:         v3     = aa + ai[idx+2];
    2131:         for (j=0; j<nz_tmp; j++) {
    2132:           idx         = ics[ajtmp[j]];
    2133:           rtmp11[idx] = v1[j];
    2134:           rtmp22[idx] = v2[j];
    2135:           rtmp33[idx] = v3[j];
    2136:         }
    2137:         rtmp11[ics[r[row]]]   += sctx.shift_amount;
    2138:         rtmp22[ics[r[row+1]]] += sctx.shift_amount;
    2139:         rtmp33[ics[r[row+2]]] += sctx.shift_amount;

    2141:         /* loop over all pivot row blocks above this row block */
    2142:         prow = *bjtmp++;
    2143:         while (prow < row) {
    2144:           pc1 = rtmp11 + prow;
    2145:           pc2 = rtmp22 + prow;
    2146:           pc3 = rtmp33 + prow;
    2147:           if (*pc1 != 0.0 || *pc2 != 0.0 || *pc3 !=0.0) {
    2148:             pv   = ba  + bd[prow];
    2149:             pj   = nbj + bd[prow];
    2150:             mul1 = *pc1 * *pv;
    2151:             mul2 = *pc2 * *pv;
    2152:             mul3 = *pc3 * *pv;
    2153:             ++pv;
    2154:             *pc1 = mul1;
    2155:             *pc2 = mul2;
    2156:             *pc3 = mul3;

    2158:             nz_tmp = bi[prow+1] - bd[prow] - 1;
    2159:             /* update this row based on pivot row */
    2160:             for (j=0; j<nz_tmp; j++) {
    2161:               tmp          = pv[j];
    2162:               idx          = pj[j];
    2163:               rtmp11[idx] -= mul1 * tmp;
    2164:               rtmp22[idx] -= mul2 * tmp;
    2165:               rtmp33[idx] -= mul3 * tmp;
    2166:             }
    2167:             PetscLogFlops(3+6.0*nz_tmp);
    2168:           }
    2169:           prow = *bjtmp++;
    2170:         }

    2172:         /* Now take care of diagonal 3x3 block in this set of rows */
    2173:         /* note: prow = row here */
    2174:         pc1 = rtmp11 + prow;
    2175:         pc2 = rtmp22 + prow;
    2176:         pc3 = rtmp33 + prow;

    2178:         sctx.pv = *pc1;
    2179:         pj      = bj + bi[prow];
    2180:         rs      = 0.0;
    2181:         for (j=0; j<nz; j++) {
    2182:           idx = pj[j];
    2183:           if (idx != row) rs += PetscAbsScalar(rtmp11[idx]);
    2184:         }
    2185:         sctx.rs = rs;
    2186:         MatPivotCheck(B,A,info,&sctx,row);
    2187:         if (sctx.newshift) goto endofwhile;

    2189:         if (*pc2 != 0.0 || *pc3 != 0.0) {
    2190:           mul2   = (*pc2)/(*pc1);
    2191:           mul3   = (*pc3)/(*pc1);
    2192:           *pc2   = mul2;
    2193:           *pc3   = mul3;
    2194:           nz_tmp = bi[prow+1] - bd[prow] - 1;
    2195:           pj     = nbj + bd[prow];
    2196:           for (j=0; j<nz_tmp; j++) {
    2197:             idx          = pj[j];
    2198:             tmp          = rtmp11[idx];
    2199:             rtmp22[idx] -= mul2 * tmp;
    2200:             rtmp33[idx] -= mul3 * tmp;
    2201:           }
    2202:           PetscLogFlops(2+4.0*nz_tmp);
    2203:         }
    2204:         ++prow;

    2206:         pc2     = rtmp22 + prow;
    2207:         pc3     = rtmp33 + prow;
    2208:         sctx.pv = *pc2;
    2209:         pj      = bj + bi[prow];
    2210:         rs      = 0.0;
    2211:         for (j=0; j<nz; j++) {
    2212:           idx = pj[j];
    2213:           if (idx != prow) rs += PetscAbsScalar(rtmp22[idx]);
    2214:         }
    2215:         sctx.rs = rs;
    2216:         MatPivotCheck(B,A,info,&sctx,row+1);
    2217:         if (sctx.newshift) goto endofwhile;

    2219:         if (*pc3 != 0.0) {
    2220:           mul3   = (*pc3)/(*pc2);
    2221:           *pc3   = mul3;
    2222:           pj     = nbj + bd[prow];
    2223:           nz_tmp = bi[prow+1] - bd[prow] - 1;
    2224:           for (j=0; j<nz_tmp; j++) {
    2225:             idx          = pj[j];
    2226:             tmp          = rtmp22[idx];
    2227:             rtmp33[idx] -= mul3 * tmp;
    2228:           }
    2229:           PetscLogFlops(1+2.0*nz_tmp);
    2230:         }

    2232:         pj  = bj + bi[row];
    2233:         pc1 = ba + bi[row];
    2234:         pc2 = ba + bi[row+1];
    2235:         pc3 = ba + bi[row+2];

    2237:         sctx.pv       = rtmp33[row+2];
    2238:         rs            = 0.0;
    2239:         rtmp11[row]   = 1.0/rtmp11[row];
    2240:         rtmp22[row+1] = 1.0/rtmp22[row+1];
    2241:         rtmp33[row+2] = 1.0/rtmp33[row+2];
    2242:         /* copy row entries from dense representation to sparse */
    2243:         for (j=0; j<nz; j++) {
    2244:           idx    = pj[j];
    2245:           pc1[j] = rtmp11[idx];
    2246:           pc2[j] = rtmp22[idx];
    2247:           pc3[j] = rtmp33[idx];
    2248:           if (idx != row+2) rs += PetscAbsScalar(pc3[j]);
    2249:         }

    2251:         sctx.rs = rs;
    2252:         MatPivotCheck(B,A,info,&sctx,row+2);
    2253:         if (sctx.newshift) goto endofwhile;
    2254:         break;

    2256:       default:
    2257:         SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"Node size not yet supported \n");
    2258:       }
    2259:       row += nodesz;                 /* Update the row */
    2260:     }
    2261: endofwhile:;
    2262:   } while (sctx.newshift);
    2263:   PetscFree3(rtmp11,rtmp22,rtmp33);
    2264:   PetscFree(tmp_vec2);
    2265:   ISRestoreIndices(isicol,&ic);
    2266:   ISRestoreIndices(isrow,&r);
    2267:   ISRestoreIndices(iscol,&c);

    2269:   (B)->ops->solve = MatSolve_SeqAIJ_inplace;
    2270:   /* do not set solve add, since MatSolve_Inode + Add is faster */
    2271:   C->ops->solvetranspose    = MatSolveTranspose_SeqAIJ_inplace;
    2272:   C->ops->solvetransposeadd = MatSolveTransposeAdd_SeqAIJ_inplace;
    2273:   C->assembled              = PETSC_TRUE;
    2274:   C->preallocated           = PETSC_TRUE;
    2275:   if (sctx.nshift) {
    2276:     if (info->shifttype == (PetscReal)MAT_SHIFT_POSITIVE_DEFINITE) {
    2277:       PetscInfo4(A,"number of shift_pd tries %D, shift_amount %g, diagonal shifted up by %e fraction top_value %e\n",sctx.nshift,(double)sctx.shift_amount,(double)sctx.shift_fraction,(double)sctx.shift_top);
    2278:     } else if (info->shifttype == (PetscReal)MAT_SHIFT_NONZERO) {
    2279:       PetscInfo2(A,"number of shift_nz tries %D, shift_amount %g\n",sctx.nshift,(double)sctx.shift_amount);
    2280:     }
    2281:   }
    2282:   PetscLogFlops(C->cmap->n);
    2283:   MatSeqAIJCheckInode(C);
    2284:   return(0);
    2285: }

    2288: /* ----------------------------------------------------------- */
    2289: PetscErrorCode MatSolve_SeqAIJ_Inode(Mat A,Vec bb,Vec xx)
    2290: {
    2291:   Mat_SeqAIJ        *a    = (Mat_SeqAIJ*)A->data;
    2292:   IS                iscol = a->col,isrow = a->row;
    2293:   PetscErrorCode    ierr;
    2294:   const PetscInt    *r,*c,*rout,*cout;
    2295:   PetscInt          i,j,n = A->rmap->n;
    2296:   PetscInt          node_max,row,nsz,aii,i0,i1,nz;
    2297:   const PetscInt    *ai = a->i,*a_j = a->j,*ns,*vi,*ad,*aj;
    2298:   PetscScalar       *x,*tmp,*tmps,tmp0,tmp1;
    2299:   PetscScalar       sum1,sum2,sum3,sum4,sum5;
    2300:   const MatScalar   *v1,*v2,*v3,*v4,*v5,*a_a = a->a,*aa;
    2301:   const PetscScalar *b;

    2304:   if (!a->inode.size) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_COR,"Missing Inode Structure");
    2305:   node_max = a->inode.node_count;
    2306:   ns       = a->inode.size;     /* Node Size array */

    2308:   VecGetArrayRead(bb,&b);
    2309:   VecGetArrayWrite(xx,&x);
    2310:   tmp  = a->solve_work;

    2312:   ISGetIndices(isrow,&rout); r = rout;
    2313:   ISGetIndices(iscol,&cout); c = cout;

    2315:   /* forward solve the lower triangular */
    2316:   tmps = tmp;
    2317:   aa   = a_a;
    2318:   aj   = a_j;
    2319:   ad   = a->diag;

    2321:   for (i = 0,row = 0; i< node_max; ++i) {
    2322:     nsz = ns[i];
    2323:     aii = ai[row];
    2324:     v1  = aa + aii;
    2325:     vi  = aj + aii;
    2326:     nz  = ai[row+1]- ai[row];

    2328:     if (i < node_max-1) {
    2329:       /* Prefetch the indices for the next block */
    2330:       PetscPrefetchBlock(aj+ai[row+nsz],ai[row+nsz+1]-ai[row+nsz],0,PETSC_PREFETCH_HINT_NTA); /* indices */
    2331:       /* Prefetch the data for the next block */
    2332:       PetscPrefetchBlock(aa+ai[row+nsz],ai[row+nsz+ns[i+1]]-ai[row+nsz],0,PETSC_PREFETCH_HINT_NTA);
    2333:     }

    2335:     switch (nsz) {               /* Each loop in 'case' is unrolled */
    2336:     case 1:
    2337:       sum1 = b[r[row]];
    2338:       for (j=0; j<nz-1; j+=2) {
    2339:         i0    = vi[j];
    2340:         i1    = vi[j+1];
    2341:         tmp0  = tmps[i0];
    2342:         tmp1  = tmps[i1];
    2343:         sum1 -= v1[j]*tmp0 + v1[j+1]*tmp1;
    2344:       }
    2345:       if (j == nz-1) {
    2346:         tmp0  = tmps[vi[j]];
    2347:         sum1 -= v1[j]*tmp0;
    2348:       }
    2349:       tmp[row++]=sum1;
    2350:       break;
    2351:     case 2:
    2352:       sum1 = b[r[row]];
    2353:       sum2 = b[r[row+1]];
    2354:       v2   = aa + ai[row+1];

    2356:       for (j=0; j<nz-1; j+=2) {
    2357:         i0    = vi[j];
    2358:         i1    = vi[j+1];
    2359:         tmp0  = tmps[i0];
    2360:         tmp1  = tmps[i1];
    2361:         sum1 -= v1[j] * tmp0 + v1[j+1] * tmp1;
    2362:         sum2 -= v2[j] * tmp0 + v2[j+1] * tmp1;
    2363:       }
    2364:       if (j == nz-1) {
    2365:         tmp0  = tmps[vi[j]];
    2366:         sum1 -= v1[j] *tmp0;
    2367:         sum2 -= v2[j] *tmp0;
    2368:       }
    2369:       sum2     -= v2[nz] * sum1;
    2370:       tmp[row++]=sum1;
    2371:       tmp[row++]=sum2;
    2372:       break;
    2373:     case 3:
    2374:       sum1 = b[r[row]];
    2375:       sum2 = b[r[row+1]];
    2376:       sum3 = b[r[row+2]];
    2377:       v2   = aa + ai[row+1];
    2378:       v3   = aa + ai[row+2];

    2380:       for (j=0; j<nz-1; j+=2) {
    2381:         i0    = vi[j];
    2382:         i1    = vi[j+1];
    2383:         tmp0  = tmps[i0];
    2384:         tmp1  = tmps[i1];
    2385:         sum1 -= v1[j] * tmp0 + v1[j+1] * tmp1;
    2386:         sum2 -= v2[j] * tmp0 + v2[j+1] * tmp1;
    2387:         sum3 -= v3[j] * tmp0 + v3[j+1] * tmp1;
    2388:       }
    2389:       if (j == nz-1) {
    2390:         tmp0  = tmps[vi[j]];
    2391:         sum1 -= v1[j] *tmp0;
    2392:         sum2 -= v2[j] *tmp0;
    2393:         sum3 -= v3[j] *tmp0;
    2394:       }
    2395:       sum2     -= v2[nz] * sum1;
    2396:       sum3     -= v3[nz] * sum1;
    2397:       sum3     -= v3[nz+1] * sum2;
    2398:       tmp[row++]=sum1;
    2399:       tmp[row++]=sum2;
    2400:       tmp[row++]=sum3;
    2401:       break;

    2403:     case 4:
    2404:       sum1 = b[r[row]];
    2405:       sum2 = b[r[row+1]];
    2406:       sum3 = b[r[row+2]];
    2407:       sum4 = b[r[row+3]];
    2408:       v2   = aa + ai[row+1];
    2409:       v3   = aa + ai[row+2];
    2410:       v4   = aa + ai[row+3];

    2412:       for (j=0; j<nz-1; j+=2) {
    2413:         i0    = vi[j];
    2414:         i1    = vi[j+1];
    2415:         tmp0  = tmps[i0];
    2416:         tmp1  = tmps[i1];
    2417:         sum1 -= v1[j] * tmp0 + v1[j+1] * tmp1;
    2418:         sum2 -= v2[j] * tmp0 + v2[j+1] * tmp1;
    2419:         sum3 -= v3[j] * tmp0 + v3[j+1] * tmp1;
    2420:         sum4 -= v4[j] * tmp0 + v4[j+1] * tmp1;
    2421:       }
    2422:       if (j == nz-1) {
    2423:         tmp0  = tmps[vi[j]];
    2424:         sum1 -= v1[j] *tmp0;
    2425:         sum2 -= v2[j] *tmp0;
    2426:         sum3 -= v3[j] *tmp0;
    2427:         sum4 -= v4[j] *tmp0;
    2428:       }
    2429:       sum2 -= v2[nz] * sum1;
    2430:       sum3 -= v3[nz] * sum1;
    2431:       sum4 -= v4[nz] * sum1;
    2432:       sum3 -= v3[nz+1] * sum2;
    2433:       sum4 -= v4[nz+1] * sum2;
    2434:       sum4 -= v4[nz+2] * sum3;

    2436:       tmp[row++]=sum1;
    2437:       tmp[row++]=sum2;
    2438:       tmp[row++]=sum3;
    2439:       tmp[row++]=sum4;
    2440:       break;
    2441:     case 5:
    2442:       sum1 = b[r[row]];
    2443:       sum2 = b[r[row+1]];
    2444:       sum3 = b[r[row+2]];
    2445:       sum4 = b[r[row+3]];
    2446:       sum5 = b[r[row+4]];
    2447:       v2   = aa + ai[row+1];
    2448:       v3   = aa + ai[row+2];
    2449:       v4   = aa + ai[row+3];
    2450:       v5   = aa + ai[row+4];

    2452:       for (j=0; j<nz-1; j+=2) {
    2453:         i0    = vi[j];
    2454:         i1    = vi[j+1];
    2455:         tmp0  = tmps[i0];
    2456:         tmp1  = tmps[i1];
    2457:         sum1 -= v1[j] * tmp0 + v1[j+1] * tmp1;
    2458:         sum2 -= v2[j] * tmp0 + v2[j+1] * tmp1;
    2459:         sum3 -= v3[j] * tmp0 + v3[j+1] * tmp1;
    2460:         sum4 -= v4[j] * tmp0 + v4[j+1] * tmp1;
    2461:         sum5 -= v5[j] * tmp0 + v5[j+1] * tmp1;
    2462:       }
    2463:       if (j == nz-1) {
    2464:         tmp0  = tmps[vi[j]];
    2465:         sum1 -= v1[j] *tmp0;
    2466:         sum2 -= v2[j] *tmp0;
    2467:         sum3 -= v3[j] *tmp0;
    2468:         sum4 -= v4[j] *tmp0;
    2469:         sum5 -= v5[j] *tmp0;
    2470:       }

    2472:       sum2 -= v2[nz] * sum1;
    2473:       sum3 -= v3[nz] * sum1;
    2474:       sum4 -= v4[nz] * sum1;
    2475:       sum5 -= v5[nz] * sum1;
    2476:       sum3 -= v3[nz+1] * sum2;
    2477:       sum4 -= v4[nz+1] * sum2;
    2478:       sum5 -= v5[nz+1] * sum2;
    2479:       sum4 -= v4[nz+2] * sum3;
    2480:       sum5 -= v5[nz+2] * sum3;
    2481:       sum5 -= v5[nz+3] * sum4;

    2483:       tmp[row++]=sum1;
    2484:       tmp[row++]=sum2;
    2485:       tmp[row++]=sum3;
    2486:       tmp[row++]=sum4;
    2487:       tmp[row++]=sum5;
    2488:       break;
    2489:     default:
    2490:       SETERRQ(PETSC_COMM_SELF,PETSC_ERR_COR,"Node size not yet supported \n");
    2491:     }
    2492:   }
    2493:   /* backward solve the upper triangular */
    2494:   for (i=node_max -1,row = n-1; i>=0; i--) {
    2495:     nsz = ns[i];
    2496:     aii = ad[row+1] + 1;
    2497:     v1  = aa + aii;
    2498:     vi  = aj + aii;
    2499:     nz  = ad[row]- ad[row+1] - 1;

    2501:     if (i > 0) {
    2502:       /* Prefetch the indices for the next block */
    2503:       PetscPrefetchBlock(aj+ad[row-nsz+1]+1,ad[row-nsz]-ad[row-nsz+1],0,PETSC_PREFETCH_HINT_NTA);
    2504:       /* Prefetch the data for the next block */
    2505:       PetscPrefetchBlock(aa+ad[row-nsz+1]+1,ad[row-nsz-ns[i-1]+1]-ad[row-nsz+1],0,PETSC_PREFETCH_HINT_NTA);
    2506:     }

    2508:     switch (nsz) {               /* Each loop in 'case' is unrolled */
    2509:     case 1:
    2510:       sum1 = tmp[row];

    2512:       for (j=0; j<nz-1; j+=2) {
    2513:         i0    = vi[j];
    2514:         i1    = vi[j+1];
    2515:         tmp0  = tmps[i0];
    2516:         tmp1  = tmps[i1];
    2517:         sum1 -= v1[j] * tmp0 + v1[j+1] * tmp1;
    2518:       }
    2519:       if (j == nz-1) {
    2520:         tmp0  = tmps[vi[j]];
    2521:         sum1 -= v1[j]*tmp0;
    2522:       }
    2523:       x[c[row]] = tmp[row] = sum1*v1[nz]; row--;
    2524:       break;
    2525:     case 2:
    2526:       sum1 = tmp[row];
    2527:       sum2 = tmp[row-1];
    2528:       v2   = aa + ad[row] + 1;
    2529:       for (j=0; j<nz-1; j+=2) {
    2530:         i0    = vi[j];
    2531:         i1    = vi[j+1];
    2532:         tmp0  = tmps[i0];
    2533:         tmp1  = tmps[i1];
    2534:         sum1 -= v1[j] * tmp0 + v1[j+1] * tmp1;
    2535:         sum2 -= v2[j+1] * tmp0 + v2[j+2] * tmp1;
    2536:       }
    2537:       if (j == nz-1) {
    2538:         tmp0  = tmps[vi[j]];
    2539:         sum1 -= v1[j]* tmp0;
    2540:         sum2 -= v2[j+1]* tmp0;
    2541:       }

    2543:       tmp0      = x[c[row]] = tmp[row] = sum1*v1[nz]; row--;
    2544:       sum2     -= v2[0] * tmp0;
    2545:       x[c[row]] = tmp[row] = sum2*v2[nz+1]; row--;
    2546:       break;
    2547:     case 3:
    2548:       sum1 = tmp[row];
    2549:       sum2 = tmp[row -1];
    2550:       sum3 = tmp[row -2];
    2551:       v2   = aa + ad[row] + 1;
    2552:       v3   = aa + ad[row -1] + 1;
    2553:       for (j=0; j<nz-1; j+=2) {
    2554:         i0    = vi[j];
    2555:         i1    = vi[j+1];
    2556:         tmp0  = tmps[i0];
    2557:         tmp1  = tmps[i1];
    2558:         sum1 -= v1[j] * tmp0 + v1[j+1] * tmp1;
    2559:         sum2 -= v2[j+1] * tmp0 + v2[j+2] * tmp1;
    2560:         sum3 -= v3[j+2] * tmp0 + v3[j+3] * tmp1;
    2561:       }
    2562:       if (j== nz-1) {
    2563:         tmp0  = tmps[vi[j]];
    2564:         sum1 -= v1[j] * tmp0;
    2565:         sum2 -= v2[j+1] * tmp0;
    2566:         sum3 -= v3[j+2] * tmp0;
    2567:       }
    2568:       tmp0      = x[c[row]] = tmp[row] = sum1*v1[nz]; row--;
    2569:       sum2     -= v2[0]* tmp0;
    2570:       sum3     -= v3[1] * tmp0;
    2571:       tmp0      = x[c[row]] = tmp[row] = sum2*v2[nz+1]; row--;
    2572:       sum3     -= v3[0]* tmp0;
    2573:       x[c[row]] = tmp[row] = sum3*v3[nz+2]; row--;

    2575:       break;
    2576:     case 4:
    2577:       sum1 = tmp[row];
    2578:       sum2 = tmp[row -1];
    2579:       sum3 = tmp[row -2];
    2580:       sum4 = tmp[row -3];
    2581:       v2   = aa + ad[row]+1;
    2582:       v3   = aa + ad[row -1]+1;
    2583:       v4   = aa + ad[row -2]+1;

    2585:       for (j=0; j<nz-1; j+=2) {
    2586:         i0    = vi[j];
    2587:         i1    = vi[j+1];
    2588:         tmp0  = tmps[i0];
    2589:         tmp1  = tmps[i1];
    2590:         sum1 -= v1[j] * tmp0   + v1[j+1] * tmp1;
    2591:         sum2 -= v2[j+1] * tmp0 + v2[j+2] * tmp1;
    2592:         sum3 -= v3[j+2] * tmp0 + v3[j+3] * tmp1;
    2593:         sum4 -= v4[j+3] * tmp0 + v4[j+4] * tmp1;
    2594:       }
    2595:       if (j== nz-1) {
    2596:         tmp0  = tmps[vi[j]];
    2597:         sum1 -= v1[j] * tmp0;
    2598:         sum2 -= v2[j+1] * tmp0;
    2599:         sum3 -= v3[j+2] * tmp0;
    2600:         sum4 -= v4[j+3] * tmp0;
    2601:       }

    2603:       tmp0      = x[c[row]] = tmp[row] = sum1*v1[nz]; row--;
    2604:       sum2     -= v2[0] * tmp0;
    2605:       sum3     -= v3[1] * tmp0;
    2606:       sum4     -= v4[2] * tmp0;
    2607:       tmp0      = x[c[row]] = tmp[row] = sum2*v2[nz+1]; row--;
    2608:       sum3     -= v3[0] * tmp0;
    2609:       sum4     -= v4[1] * tmp0;
    2610:       tmp0      = x[c[row]] = tmp[row] = sum3*v3[nz+2]; row--;
    2611:       sum4     -= v4[0] * tmp0;
    2612:       x[c[row]] = tmp[row] = sum4*v4[nz+3]; row--;
    2613:       break;
    2614:     case 5:
    2615:       sum1 = tmp[row];
    2616:       sum2 = tmp[row -1];
    2617:       sum3 = tmp[row -2];
    2618:       sum4 = tmp[row -3];
    2619:       sum5 = tmp[row -4];
    2620:       v2   = aa + ad[row]+1;
    2621:       v3   = aa + ad[row -1]+1;
    2622:       v4   = aa + ad[row -2]+1;
    2623:       v5   = aa + ad[row -3]+1;
    2624:       for (j=0; j<nz-1; j+=2) {
    2625:         i0    = vi[j];
    2626:         i1    = vi[j+1];
    2627:         tmp0  = tmps[i0];
    2628:         tmp1  = tmps[i1];
    2629:         sum1 -= v1[j] * tmp0 + v1[j+1] * tmp1;
    2630:         sum2 -= v2[j+1] * tmp0 + v2[j+2] * tmp1;
    2631:         sum3 -= v3[j+2] * tmp0 + v3[j+3] * tmp1;
    2632:         sum4 -= v4[j+3] * tmp0 + v4[j+4] * tmp1;
    2633:         sum5 -= v5[j+4] * tmp0 + v5[j+5] * tmp1;
    2634:       }
    2635:       if (j==nz-1) {
    2636:         tmp0  = tmps[vi[j]];
    2637:         sum1 -= v1[j] * tmp0;
    2638:         sum2 -= v2[j+1] * tmp0;
    2639:         sum3 -= v3[j+2] * tmp0;
    2640:         sum4 -= v4[j+3] * tmp0;
    2641:         sum5 -= v5[j+4] * tmp0;
    2642:       }

    2644:       tmp0      = x[c[row]] = tmp[row] = sum1*v1[nz]; row--;
    2645:       sum2     -= v2[0] * tmp0;
    2646:       sum3     -= v3[1] * tmp0;
    2647:       sum4     -= v4[2] * tmp0;
    2648:       sum5     -= v5[3] * tmp0;
    2649:       tmp0      = x[c[row]] = tmp[row] = sum2*v2[nz+1]; row--;
    2650:       sum3     -= v3[0] * tmp0;
    2651:       sum4     -= v4[1] * tmp0;
    2652:       sum5     -= v5[2] * tmp0;
    2653:       tmp0      = x[c[row]] = tmp[row] = sum3*v3[nz+2]; row--;
    2654:       sum4     -= v4[0] * tmp0;
    2655:       sum5     -= v5[1] * tmp0;
    2656:       tmp0      = x[c[row]] = tmp[row] = sum4*v4[nz+3]; row--;
    2657:       sum5     -= v5[0] * tmp0;
    2658:       x[c[row]] = tmp[row] = sum5*v5[nz+4]; row--;
    2659:       break;
    2660:     default:
    2661:       SETERRQ(PETSC_COMM_SELF,PETSC_ERR_COR,"Node size not yet supported \n");
    2662:     }
    2663:   }
    2664:   ISRestoreIndices(isrow,&rout);
    2665:   ISRestoreIndices(iscol,&cout);
    2666:   VecRestoreArrayRead(bb,&b);
    2667:   VecRestoreArrayWrite(xx,&x);
    2668:   PetscLogFlops(2.0*a->nz - A->cmap->n);
    2669:   return(0);
    2670: }

    2673: /*
    2674:      Makes a longer coloring[] array and calls the usual code with that
    2675: */
    2676: PetscErrorCode MatColoringPatch_SeqAIJ_Inode(Mat mat,PetscInt ncolors,PetscInt nin,ISColoringValue coloring[],ISColoring *iscoloring)
    2677: {
    2678:   Mat_SeqAIJ      *a = (Mat_SeqAIJ*)mat->data;
    2679:   PetscErrorCode  ierr;
    2680:   PetscInt        n = mat->cmap->n,m = a->inode.node_count,j,*ns = a->inode.size,row;
    2681:   PetscInt        *colorused,i;
    2682:   ISColoringValue *newcolor;

    2685:   if (!a->inode.size) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_COR,"Missing Inode Structure");
    2686:   PetscMalloc1(n+1,&newcolor);
    2687:   /* loop over inodes, marking a color for each column*/
    2688:   row = 0;
    2689:   for (i=0; i<m; i++) {
    2690:     for (j=0; j<ns[i]; j++) {
    2691:       newcolor[row++] = coloring[i] + j*ncolors;
    2692:     }
    2693:   }

    2695:   /* eliminate unneeded colors */
    2696:   PetscCalloc1(5*ncolors,&colorused);
    2697:   for (i=0; i<n; i++) {
    2698:     colorused[newcolor[i]] = 1;
    2699:   }

    2701:   for (i=1; i<5*ncolors; i++) {
    2702:     colorused[i] += colorused[i-1];
    2703:   }
    2704:   ncolors = colorused[5*ncolors-1];
    2705:   for (i=0; i<n; i++) {
    2706:     newcolor[i] = colorused[newcolor[i]]-1;
    2707:   }
    2708:   PetscFree(colorused);
    2709:   ISColoringCreate(PetscObjectComm((PetscObject)mat),ncolors,n,newcolor,PETSC_OWN_POINTER,iscoloring);
    2710:   PetscFree(coloring);
    2711:   return(0);
    2712: }

    2714: #include <petsc/private/kernels/blockinvert.h>

    2716: PetscErrorCode MatSOR_SeqAIJ_Inode(Mat A,Vec bb,PetscReal omega,MatSORType flag,PetscReal fshift,PetscInt its,PetscInt lits,Vec xx)
    2717: {
    2718:   Mat_SeqAIJ        *a = (Mat_SeqAIJ*)A->data;
    2719:   PetscScalar       sum1 = 0.0,sum2 = 0.0,sum3 = 0.0,sum4 = 0.0,sum5 = 0.0,tmp0,tmp1,tmp2,tmp3;
    2720:   MatScalar         *ibdiag,*bdiag,work[25],*t;
    2721:   PetscScalar       *x,tmp4,tmp5,x1,x2,x3,x4,x5;
    2722:   const MatScalar   *v = a->a,*v1 = NULL,*v2 = NULL,*v3 = NULL,*v4 = NULL,*v5 = NULL;
    2723:   const PetscScalar *xb, *b;
    2724:   PetscReal         zeropivot = 100.*PETSC_MACHINE_EPSILON, shift = 0.0;
    2725:   PetscErrorCode    ierr;
    2726:   PetscInt          n,m = a->inode.node_count,cnt = 0,i,j,row,i1,i2;
    2727:   PetscInt          sz,k,ipvt[5];
    2728:   PetscBool         allowzeropivot,zeropivotdetected;
    2729:   const PetscInt    *sizes = a->inode.size,*idx,*diag = a->diag,*ii = a->i;

    2732:   allowzeropivot = PetscNot(A->erroriffailure);
    2733:   if (!a->inode.size) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_COR,"Missing Inode Structure");
    2734:   if (omega != 1.0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"No support for omega != 1.0; use -mat_no_inode");
    2735:   if (fshift != 0.0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"No support for fshift != 0.0; use -mat_no_inode");

    2737:   if (!a->inode.ibdiagvalid) {
    2738:     if (!a->inode.ibdiag) {
    2739:       /* calculate space needed for diagonal blocks */
    2740:       for (i=0; i<m; i++) {
    2741:         cnt += sizes[i]*sizes[i];
    2742:       }
    2743:       a->inode.bdiagsize = cnt;

    2745:       PetscMalloc3(cnt,&a->inode.ibdiag,cnt,&a->inode.bdiag,A->rmap->n,&a->inode.ssor_work);
    2746:     }

    2748:     /* copy over the diagonal blocks and invert them */
    2749:     ibdiag = a->inode.ibdiag;
    2750:     bdiag  = a->inode.bdiag;
    2751:     cnt    = 0;
    2752:     for (i=0, row = 0; i<m; i++) {
    2753:       for (j=0; j<sizes[i]; j++) {
    2754:         for (k=0; k<sizes[i]; k++) {
    2755:           bdiag[cnt+k*sizes[i]+j] = v[diag[row+j] - j + k];
    2756:         }
    2757:       }
    2758:       PetscArraycpy(ibdiag+cnt,bdiag+cnt,sizes[i]*sizes[i]);

    2760:       switch (sizes[i]) {
    2761:       case 1:
    2762:         /* Create matrix data structure */
    2763:         if (PetscAbsScalar(ibdiag[cnt]) < zeropivot) {
    2764:           if (allowzeropivot) {
    2765:             A->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
    2766:             A->factorerror_zeropivot_value = PetscAbsScalar(ibdiag[cnt]);
    2767:             A->factorerror_zeropivot_row   = row;
    2768:             PetscInfo1(A,"Zero pivot, row %D\n",row);
    2769:           } else SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_MAT_LU_ZRPVT,"Zero pivot on row %D",row);
    2770:         }
    2771:         ibdiag[cnt] = 1.0/ibdiag[cnt];
    2772:         break;
    2773:       case 2:
    2774:         PetscKernel_A_gets_inverse_A_2(ibdiag+cnt,shift,allowzeropivot,&zeropivotdetected);
    2775:         if (zeropivotdetected) A->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
    2776:         break;
    2777:       case 3:
    2778:         PetscKernel_A_gets_inverse_A_3(ibdiag+cnt,shift,allowzeropivot,&zeropivotdetected);
    2779:         if (zeropivotdetected) A->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
    2780:         break;
    2781:       case 4:
    2782:         PetscKernel_A_gets_inverse_A_4(ibdiag+cnt,shift,allowzeropivot,&zeropivotdetected);
    2783:         if (zeropivotdetected) A->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
    2784:         break;
    2785:       case 5:
    2786:         PetscKernel_A_gets_inverse_A_5(ibdiag+cnt,ipvt,work,shift,allowzeropivot,&zeropivotdetected);
    2787:         if (zeropivotdetected) A->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
    2788:         break;
    2789:       default:
    2790:         SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_SUP,"Inode size %D not supported",sizes[i]);
    2791:       }
    2792:       cnt += sizes[i]*sizes[i];
    2793:       row += sizes[i];
    2794:     }
    2795:     a->inode.ibdiagvalid = PETSC_TRUE;
    2796:   }
    2797:   ibdiag = a->inode.ibdiag;
    2798:   bdiag  = a->inode.bdiag;
    2799:   t      = a->inode.ssor_work;

    2801:   VecGetArray(xx,&x);
    2802:   VecGetArrayRead(bb,&b);
    2803:   /* We count flops by assuming the upper triangular and lower triangular parts have the same number of nonzeros */
    2804:   if (flag & SOR_ZERO_INITIAL_GUESS) {
    2805:     if (flag & SOR_FORWARD_SWEEP || flag & SOR_LOCAL_FORWARD_SWEEP) {

    2807:       for (i=0, row=0; i<m; i++) {
    2808:         sz  = diag[row] - ii[row];
    2809:         v1  = a->a + ii[row];
    2810:         idx = a->j + ii[row];

    2812:         /* see comments for MatMult_SeqAIJ_Inode() for how this is coded */
    2813:         switch (sizes[i]) {
    2814:         case 1:

    2816:           sum1 = b[row];
    2817:           for (n = 0; n<sz-1; n+=2) {
    2818:             i1    = idx[0];
    2819:             i2    = idx[1];
    2820:             idx  += 2;
    2821:             tmp0  = x[i1];
    2822:             tmp1  = x[i2];
    2823:             sum1 -= v1[0] * tmp0 + v1[1] * tmp1; v1 += 2;
    2824:           }

    2826:           if (n == sz-1) {
    2827:             tmp0  = x[*idx];
    2828:             sum1 -= *v1 * tmp0;
    2829:           }
    2830:           t[row]   = sum1;
    2831:           x[row++] = sum1*(*ibdiag++);
    2832:           break;
    2833:         case 2:
    2834:           v2   = a->a + ii[row+1];
    2835:           sum1 = b[row];
    2836:           sum2 = b[row+1];
    2837:           for (n = 0; n<sz-1; n+=2) {
    2838:             i1    = idx[0];
    2839:             i2    = idx[1];
    2840:             idx  += 2;
    2841:             tmp0  = x[i1];
    2842:             tmp1  = x[i2];
    2843:             sum1 -= v1[0] * tmp0 + v1[1] * tmp1; v1 += 2;
    2844:             sum2 -= v2[0] * tmp0 + v2[1] * tmp1; v2 += 2;
    2845:           }

    2847:           if (n == sz-1) {
    2848:             tmp0  = x[*idx];
    2849:             sum1 -= v1[0] * tmp0;
    2850:             sum2 -= v2[0] * tmp0;
    2851:           }
    2852:           t[row]   = sum1;
    2853:           t[row+1] = sum2;
    2854:           x[row++] = sum1*ibdiag[0] + sum2*ibdiag[2];
    2855:           x[row++] = sum1*ibdiag[1] + sum2*ibdiag[3];
    2856:           ibdiag  += 4;
    2857:           break;
    2858:         case 3:
    2859:           v2   = a->a + ii[row+1];
    2860:           v3   = a->a + ii[row+2];
    2861:           sum1 = b[row];
    2862:           sum2 = b[row+1];
    2863:           sum3 = b[row+2];
    2864:           for (n = 0; n<sz-1; n+=2) {
    2865:             i1    = idx[0];
    2866:             i2    = idx[1];
    2867:             idx  += 2;
    2868:             tmp0  = x[i1];
    2869:             tmp1  = x[i2];
    2870:             sum1 -= v1[0] * tmp0 + v1[1] * tmp1; v1 += 2;
    2871:             sum2 -= v2[0] * tmp0 + v2[1] * tmp1; v2 += 2;
    2872:             sum3 -= v3[0] * tmp0 + v3[1] * tmp1; v3 += 2;
    2873:           }

    2875:           if (n == sz-1) {
    2876:             tmp0  = x[*idx];
    2877:             sum1 -= v1[0] * tmp0;
    2878:             sum2 -= v2[0] * tmp0;
    2879:             sum3 -= v3[0] * tmp0;
    2880:           }
    2881:           t[row]   = sum1;
    2882:           t[row+1] = sum2;
    2883:           t[row+2] = sum3;
    2884:           x[row++] = sum1*ibdiag[0] + sum2*ibdiag[3] + sum3*ibdiag[6];
    2885:           x[row++] = sum1*ibdiag[1] + sum2*ibdiag[4] + sum3*ibdiag[7];
    2886:           x[row++] = sum1*ibdiag[2] + sum2*ibdiag[5] + sum3*ibdiag[8];
    2887:           ibdiag  += 9;
    2888:           break;
    2889:         case 4:
    2890:           v2   = a->a + ii[row+1];
    2891:           v3   = a->a + ii[row+2];
    2892:           v4   = a->a + ii[row+3];
    2893:           sum1 = b[row];
    2894:           sum2 = b[row+1];
    2895:           sum3 = b[row+2];
    2896:           sum4 = b[row+3];
    2897:           for (n = 0; n<sz-1; n+=2) {
    2898:             i1    = idx[0];
    2899:             i2    = idx[1];
    2900:             idx  += 2;
    2901:             tmp0  = x[i1];
    2902:             tmp1  = x[i2];
    2903:             sum1 -= v1[0] * tmp0 + v1[1] * tmp1; v1 += 2;
    2904:             sum2 -= v2[0] * tmp0 + v2[1] * tmp1; v2 += 2;
    2905:             sum3 -= v3[0] * tmp0 + v3[1] * tmp1; v3 += 2;
    2906:             sum4 -= v4[0] * tmp0 + v4[1] * tmp1; v4 += 2;
    2907:           }

    2909:           if (n == sz-1) {
    2910:             tmp0  = x[*idx];
    2911:             sum1 -= v1[0] * tmp0;
    2912:             sum2 -= v2[0] * tmp0;
    2913:             sum3 -= v3[0] * tmp0;
    2914:             sum4 -= v4[0] * tmp0;
    2915:           }
    2916:           t[row]   = sum1;
    2917:           t[row+1] = sum2;
    2918:           t[row+2] = sum3;
    2919:           t[row+3] = sum4;
    2920:           x[row++] = sum1*ibdiag[0] + sum2*ibdiag[4] + sum3*ibdiag[8] + sum4*ibdiag[12];
    2921:           x[row++] = sum1*ibdiag[1] + sum2*ibdiag[5] + sum3*ibdiag[9] + sum4*ibdiag[13];
    2922:           x[row++] = sum1*ibdiag[2] + sum2*ibdiag[6] + sum3*ibdiag[10] + sum4*ibdiag[14];
    2923:           x[row++] = sum1*ibdiag[3] + sum2*ibdiag[7] + sum3*ibdiag[11] + sum4*ibdiag[15];
    2924:           ibdiag  += 16;
    2925:           break;
    2926:         case 5:
    2927:           v2   = a->a + ii[row+1];
    2928:           v3   = a->a + ii[row+2];
    2929:           v4   = a->a + ii[row+3];
    2930:           v5   = a->a + ii[row+4];
    2931:           sum1 = b[row];
    2932:           sum2 = b[row+1];
    2933:           sum3 = b[row+2];
    2934:           sum4 = b[row+3];
    2935:           sum5 = b[row+4];
    2936:           for (n = 0; n<sz-1; n+=2) {
    2937:             i1    = idx[0];
    2938:             i2    = idx[1];
    2939:             idx  += 2;
    2940:             tmp0  = x[i1];
    2941:             tmp1  = x[i2];
    2942:             sum1 -= v1[0] * tmp0 + v1[1] * tmp1; v1 += 2;
    2943:             sum2 -= v2[0] * tmp0 + v2[1] * tmp1; v2 += 2;
    2944:             sum3 -= v3[0] * tmp0 + v3[1] * tmp1; v3 += 2;
    2945:             sum4 -= v4[0] * tmp0 + v4[1] * tmp1; v4 += 2;
    2946:             sum5 -= v5[0] * tmp0 + v5[1] * tmp1; v5 += 2;
    2947:           }

    2949:           if (n == sz-1) {
    2950:             tmp0  = x[*idx];
    2951:             sum1 -= v1[0] * tmp0;
    2952:             sum2 -= v2[0] * tmp0;
    2953:             sum3 -= v3[0] * tmp0;
    2954:             sum4 -= v4[0] * tmp0;
    2955:             sum5 -= v5[0] * tmp0;
    2956:           }
    2957:           t[row]   = sum1;
    2958:           t[row+1] = sum2;
    2959:           t[row+2] = sum3;
    2960:           t[row+3] = sum4;
    2961:           t[row+4] = sum5;
    2962:           x[row++] = sum1*ibdiag[0] + sum2*ibdiag[5] + sum3*ibdiag[10] + sum4*ibdiag[15] + sum5*ibdiag[20];
    2963:           x[row++] = sum1*ibdiag[1] + sum2*ibdiag[6] + sum3*ibdiag[11] + sum4*ibdiag[16] + sum5*ibdiag[21];
    2964:           x[row++] = sum1*ibdiag[2] + sum2*ibdiag[7] + sum3*ibdiag[12] + sum4*ibdiag[17] + sum5*ibdiag[22];
    2965:           x[row++] = sum1*ibdiag[3] + sum2*ibdiag[8] + sum3*ibdiag[13] + sum4*ibdiag[18] + sum5*ibdiag[23];
    2966:           x[row++] = sum1*ibdiag[4] + sum2*ibdiag[9] + sum3*ibdiag[14] + sum4*ibdiag[19] + sum5*ibdiag[24];
    2967:           ibdiag  += 25;
    2968:           break;
    2969:         default:
    2970:           SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_SUP,"Inode size %D not supported",sizes[i]);
    2971:         }
    2972:       }

    2974:       xb   = t;
    2975:       PetscLogFlops(a->nz);
    2976:     } else xb = b;
    2977:     if (flag & SOR_BACKWARD_SWEEP || flag & SOR_LOCAL_BACKWARD_SWEEP) {

    2979:       ibdiag = a->inode.ibdiag+a->inode.bdiagsize;
    2980:       for (i=m-1, row=A->rmap->n-1; i>=0; i--) {
    2981:         ibdiag -= sizes[i]*sizes[i];
    2982:         sz      = ii[row+1] - diag[row] - 1;
    2983:         v1      = a->a + diag[row] + 1;
    2984:         idx     = a->j + diag[row] + 1;

    2986:         /* see comments for MatMult_SeqAIJ_Inode() for how this is coded */
    2987:         switch (sizes[i]) {
    2988:         case 1:

    2990:           sum1 = xb[row];
    2991:           for (n = 0; n<sz-1; n+=2) {
    2992:             i1    = idx[0];
    2993:             i2    = idx[1];
    2994:             idx  += 2;
    2995:             tmp0  = x[i1];
    2996:             tmp1  = x[i2];
    2997:             sum1 -= v1[0] * tmp0 + v1[1] * tmp1; v1 += 2;
    2998:           }

    3000:           if (n == sz-1) {
    3001:             tmp0  = x[*idx];
    3002:             sum1 -= *v1*tmp0;
    3003:           }
    3004:           x[row--] = sum1*(*ibdiag);
    3005:           break;

    3007:         case 2:

    3009:           sum1 = xb[row];
    3010:           sum2 = xb[row-1];
    3011:           /* note that sum1 is associated with the second of the two rows */
    3012:           v2 = a->a + diag[row-1] + 2;
    3013:           for (n = 0; n<sz-1; n+=2) {
    3014:             i1    = idx[0];
    3015:             i2    = idx[1];
    3016:             idx  += 2;
    3017:             tmp0  = x[i1];
    3018:             tmp1  = x[i2];
    3019:             sum1 -= v1[0] * tmp0 + v1[1] * tmp1; v1 += 2;
    3020:             sum2 -= v2[0] * tmp0 + v2[1] * tmp1; v2 += 2;
    3021:           }

    3023:           if (n == sz-1) {
    3024:             tmp0  = x[*idx];
    3025:             sum1 -= *v1*tmp0;
    3026:             sum2 -= *v2*tmp0;
    3027:           }
    3028:           x[row--] = sum2*ibdiag[1] + sum1*ibdiag[3];
    3029:           x[row--] = sum2*ibdiag[0] + sum1*ibdiag[2];
    3030:           break;
    3031:         case 3:

    3033:           sum1 = xb[row];
    3034:           sum2 = xb[row-1];
    3035:           sum3 = xb[row-2];
    3036:           v2   = a->a + diag[row-1] + 2;
    3037:           v3   = a->a + diag[row-2] + 3;
    3038:           for (n = 0; n<sz-1; n+=2) {
    3039:             i1    = idx[0];
    3040:             i2    = idx[1];
    3041:             idx  += 2;
    3042:             tmp0  = x[i1];
    3043:             tmp1  = x[i2];
    3044:             sum1 -= v1[0] * tmp0 + v1[1] * tmp1; v1 += 2;
    3045:             sum2 -= v2[0] * tmp0 + v2[1] * tmp1; v2 += 2;
    3046:             sum3 -= v3[0] * tmp0 + v3[1] * tmp1; v3 += 2;
    3047:           }

    3049:           if (n == sz-1) {
    3050:             tmp0  = x[*idx];
    3051:             sum1 -= *v1*tmp0;
    3052:             sum2 -= *v2*tmp0;
    3053:             sum3 -= *v3*tmp0;
    3054:           }
    3055:           x[row--] = sum3*ibdiag[2] + sum2*ibdiag[5] + sum1*ibdiag[8];
    3056:           x[row--] = sum3*ibdiag[1] + sum2*ibdiag[4] + sum1*ibdiag[7];
    3057:           x[row--] = sum3*ibdiag[0] + sum2*ibdiag[3] + sum1*ibdiag[6];
    3058:           break;
    3059:         case 4:

    3061:           sum1 = xb[row];
    3062:           sum2 = xb[row-1];
    3063:           sum3 = xb[row-2];
    3064:           sum4 = xb[row-3];
    3065:           v2   = a->a + diag[row-1] + 2;
    3066:           v3   = a->a + diag[row-2] + 3;
    3067:           v4   = a->a + diag[row-3] + 4;
    3068:           for (n = 0; n<sz-1; n+=2) {
    3069:             i1    = idx[0];
    3070:             i2    = idx[1];
    3071:             idx  += 2;
    3072:             tmp0  = x[i1];
    3073:             tmp1  = x[i2];
    3074:             sum1 -= v1[0] * tmp0 + v1[1] * tmp1; v1 += 2;
    3075:             sum2 -= v2[0] * tmp0 + v2[1] * tmp1; v2 += 2;
    3076:             sum3 -= v3[0] * tmp0 + v3[1] * tmp1; v3 += 2;
    3077:             sum4 -= v4[0] * tmp0 + v4[1] * tmp1; v4 += 2;
    3078:           }

    3080:           if (n == sz-1) {
    3081:             tmp0  = x[*idx];
    3082:             sum1 -= *v1*tmp0;
    3083:             sum2 -= *v2*tmp0;
    3084:             sum3 -= *v3*tmp0;
    3085:             sum4 -= *v4*tmp0;
    3086:           }
    3087:           x[row--] = sum4*ibdiag[3] + sum3*ibdiag[7] + sum2*ibdiag[11] + sum1*ibdiag[15];
    3088:           x[row--] = sum4*ibdiag[2] + sum3*ibdiag[6] + sum2*ibdiag[10] + sum1*ibdiag[14];
    3089:           x[row--] = sum4*ibdiag[1] + sum3*ibdiag[5] + sum2*ibdiag[9] + sum1*ibdiag[13];
    3090:           x[row--] = sum4*ibdiag[0] + sum3*ibdiag[4] + sum2*ibdiag[8] + sum1*ibdiag[12];
    3091:           break;
    3092:         case 5:

    3094:           sum1 = xb[row];
    3095:           sum2 = xb[row-1];
    3096:           sum3 = xb[row-2];
    3097:           sum4 = xb[row-3];
    3098:           sum5 = xb[row-4];
    3099:           v2   = a->a + diag[row-1] + 2;
    3100:           v3   = a->a + diag[row-2] + 3;
    3101:           v4   = a->a + diag[row-3] + 4;
    3102:           v5   = a->a + diag[row-4] + 5;
    3103:           for (n = 0; n<sz-1; n+=2) {
    3104:             i1    = idx[0];
    3105:             i2    = idx[1];
    3106:             idx  += 2;
    3107:             tmp0  = x[i1];
    3108:             tmp1  = x[i2];
    3109:             sum1 -= v1[0] * tmp0 + v1[1] * tmp1; v1 += 2;
    3110:             sum2 -= v2[0] * tmp0 + v2[1] * tmp1; v2 += 2;
    3111:             sum3 -= v3[0] * tmp0 + v3[1] * tmp1; v3 += 2;
    3112:             sum4 -= v4[0] * tmp0 + v4[1] * tmp1; v4 += 2;
    3113:             sum5 -= v5[0] * tmp0 + v5[1] * tmp1; v5 += 2;
    3114:           }

    3116:           if (n == sz-1) {
    3117:             tmp0  = x[*idx];
    3118:             sum1 -= *v1*tmp0;
    3119:             sum2 -= *v2*tmp0;
    3120:             sum3 -= *v3*tmp0;
    3121:             sum4 -= *v4*tmp0;
    3122:             sum5 -= *v5*tmp0;
    3123:           }
    3124:           x[row--] = sum5*ibdiag[4] + sum4*ibdiag[9] + sum3*ibdiag[14] + sum2*ibdiag[19] + sum1*ibdiag[24];
    3125:           x[row--] = sum5*ibdiag[3] + sum4*ibdiag[8] + sum3*ibdiag[13] + sum2*ibdiag[18] + sum1*ibdiag[23];
    3126:           x[row--] = sum5*ibdiag[2] + sum4*ibdiag[7] + sum3*ibdiag[12] + sum2*ibdiag[17] + sum1*ibdiag[22];
    3127:           x[row--] = sum5*ibdiag[1] + sum4*ibdiag[6] + sum3*ibdiag[11] + sum2*ibdiag[16] + sum1*ibdiag[21];
    3128:           x[row--] = sum5*ibdiag[0] + sum4*ibdiag[5] + sum3*ibdiag[10] + sum2*ibdiag[15] + sum1*ibdiag[20];
    3129:           break;
    3130:         default:
    3131:           SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_SUP,"Inode size %D not supported",sizes[i]);
    3132:         }
    3133:       }

    3135:       PetscLogFlops(a->nz);
    3136:     }
    3137:     its--;
    3138:   }
    3139:   while (its--) {

    3141:     if (flag & SOR_FORWARD_SWEEP || flag & SOR_LOCAL_FORWARD_SWEEP) {
    3142:       for (i=0, row=0, ibdiag = a->inode.ibdiag;
    3143:            i<m;
    3144:            row += sizes[i], ibdiag += sizes[i]*sizes[i], i++) {

    3146:         sz  = diag[row] - ii[row];
    3147:         v1  = a->a + ii[row];
    3148:         idx = a->j + ii[row];
    3149:         /* see comments for MatMult_SeqAIJ_Inode() for how this is coded */
    3150:         switch (sizes[i]) {
    3151:         case 1:
    3152:           sum1 = b[row];
    3153:           for (n = 0; n<sz-1; n+=2) {
    3154:             i1    = idx[0];
    3155:             i2    = idx[1];
    3156:             idx  += 2;
    3157:             tmp0  = x[i1];
    3158:             tmp1  = x[i2];
    3159:             sum1 -= v1[0] * tmp0 + v1[1] * tmp1; v1 += 2;
    3160:           }
    3161:           if (n == sz-1) {
    3162:             tmp0  = x[*idx++];
    3163:             sum1 -= *v1 * tmp0;
    3164:             v1++;
    3165:           }
    3166:           t[row]   = sum1;
    3167:           sz      = ii[row+1] - diag[row] - 1;
    3168:           idx     = a->j + diag[row] + 1;
    3169:           v1 += 1;
    3170:           for (n = 0; n<sz-1; n+=2) {
    3171:             i1    = idx[0];
    3172:             i2    = idx[1];
    3173:             idx  += 2;
    3174:             tmp0  = x[i1];
    3175:             tmp1  = x[i2];
    3176:             sum1 -= v1[0] * tmp0 + v1[1] * tmp1; v1 += 2;
    3177:           }
    3178:           if (n == sz-1) {
    3179:             tmp0  = x[*idx++];
    3180:             sum1 -= *v1 * tmp0;
    3181:           }
    3182:           /* in MatSOR_SeqAIJ this line would be
    3183:            *
    3184:            * x[row] = (1-omega)*x[row]+(sum1+(*bdiag++)*x[row])*(*ibdiag++);
    3185:            *
    3186:            * but omega == 1, so this becomes
    3187:            *
    3188:            * x[row] = sum1*(*ibdiag++);
    3189:            *
    3190:            */
    3191:           x[row] = sum1*(*ibdiag);
    3192:           break;
    3193:         case 2:
    3194:           v2   = a->a + ii[row+1];
    3195:           sum1 = b[row];
    3196:           sum2 = b[row+1];
    3197:           for (n = 0; n<sz-1; n+=2) {
    3198:             i1    = idx[0];
    3199:             i2    = idx[1];
    3200:             idx  += 2;
    3201:             tmp0  = x[i1];
    3202:             tmp1  = x[i2];
    3203:             sum1 -= v1[0] * tmp0 + v1[1] * tmp1; v1 += 2;
    3204:             sum2 -= v2[0] * tmp0 + v2[1] * tmp1; v2 += 2;
    3205:           }
    3206:           if (n == sz-1) {
    3207:             tmp0  = x[*idx++];
    3208:             sum1 -= v1[0] * tmp0;
    3209:             sum2 -= v2[0] * tmp0;
    3210:             v1++; v2++;
    3211:           }
    3212:           t[row]   = sum1;
    3213:           t[row+1] = sum2;
    3214:           sz      = ii[row+1] - diag[row] - 2;
    3215:           idx     = a->j + diag[row] + 2;
    3216:           v1 += 2;
    3217:           v2 += 2;
    3218:           for (n = 0; n<sz-1; n+=2) {
    3219:             i1    = idx[0];
    3220:             i2    = idx[1];
    3221:             idx  += 2;
    3222:             tmp0  = x[i1];
    3223:             tmp1  = x[i2];
    3224:             sum1 -= v1[0] * tmp0 + v1[1] * tmp1; v1 += 2;
    3225:             sum2 -= v2[0] * tmp0 + v2[1] * tmp1; v2 += 2;
    3226:           }
    3227:           if (n == sz-1) {
    3228:             tmp0  = x[*idx];
    3229:             sum1 -= v1[0] * tmp0;
    3230:             sum2 -= v2[0] * tmp0;
    3231:           }
    3232:           x[row] = sum1*ibdiag[0] + sum2*ibdiag[2];
    3233:           x[row+1] = sum1*ibdiag[1] + sum2*ibdiag[3];
    3234:           break;
    3235:         case 3:
    3236:           v2   = a->a + ii[row+1];
    3237:           v3   = a->a + ii[row+2];
    3238:           sum1 = b[row];
    3239:           sum2 = b[row+1];
    3240:           sum3 = b[row+2];
    3241:           for (n = 0; n<sz-1; n+=2) {
    3242:             i1    = idx[0];
    3243:             i2    = idx[1];
    3244:             idx  += 2;
    3245:             tmp0  = x[i1];
    3246:             tmp1  = x[i2];
    3247:             sum1 -= v1[0] * tmp0 + v1[1] * tmp1; v1 += 2;
    3248:             sum2 -= v2[0] * tmp0 + v2[1] * tmp1; v2 += 2;
    3249:             sum3 -= v3[0] * tmp0 + v3[1] * tmp1; v3 += 2;
    3250:           }
    3251:           if (n == sz-1) {
    3252:             tmp0  = x[*idx++];
    3253:             sum1 -= v1[0] * tmp0;
    3254:             sum2 -= v2[0] * tmp0;
    3255:             sum3 -= v3[0] * tmp0;
    3256:             v1++; v2++; v3++;
    3257:           }
    3258:           t[row]   = sum1;
    3259:           t[row+1] = sum2;
    3260:           t[row+2] = sum3;
    3261:           sz      = ii[row+1] - diag[row] - 3;
    3262:           idx     = a->j + diag[row] + 3;
    3263:           v1 += 3;
    3264:           v2 += 3;
    3265:           v3 += 3;
    3266:           for (n = 0; n<sz-1; n+=2) {
    3267:             i1    = idx[0];
    3268:             i2    = idx[1];
    3269:             idx  += 2;
    3270:             tmp0  = x[i1];
    3271:             tmp1  = x[i2];
    3272:             sum1 -= v1[0] * tmp0 + v1[1] * tmp1; v1 += 2;
    3273:             sum2 -= v2[0] * tmp0 + v2[1] * tmp1; v2 += 2;
    3274:             sum3 -= v3[0] * tmp0 + v3[1] * tmp1; v3 += 2;
    3275:           }
    3276:           if (n == sz-1) {
    3277:             tmp0  = x[*idx];
    3278:             sum1 -= v1[0] * tmp0;
    3279:             sum2 -= v2[0] * tmp0;
    3280:             sum3 -= v3[0] * tmp0;
    3281:           }
    3282:           x[row] = sum1*ibdiag[0] + sum2*ibdiag[3] + sum3*ibdiag[6];
    3283:           x[row+1] = sum1*ibdiag[1] + sum2*ibdiag[4] + sum3*ibdiag[7];
    3284:           x[row+2] = sum1*ibdiag[2] + sum2*ibdiag[5] + sum3*ibdiag[8];
    3285:           break;
    3286:         case 4:
    3287:           v2   = a->a + ii[row+1];
    3288:           v3   = a->a + ii[row+2];
    3289:           v4   = a->a + ii[row+3];
    3290:           sum1 = b[row];
    3291:           sum2 = b[row+1];
    3292:           sum3 = b[row+2];
    3293:           sum4 = b[row+3];
    3294:           for (n = 0; n<sz-1; n+=2) {
    3295:             i1    = idx[0];
    3296:             i2    = idx[1];
    3297:             idx  += 2;
    3298:             tmp0  = x[i1];
    3299:             tmp1  = x[i2];
    3300:             sum1 -= v1[0] * tmp0 + v1[1] * tmp1; v1 += 2;
    3301:             sum2 -= v2[0] * tmp0 + v2[1] * tmp1; v2 += 2;
    3302:             sum3 -= v3[0] * tmp0 + v3[1] * tmp1; v3 += 2;
    3303:             sum4 -= v4[0] * tmp0 + v4[1] * tmp1; v4 += 2;
    3304:           }
    3305:           if (n == sz-1) {
    3306:             tmp0  = x[*idx++];
    3307:             sum1 -= v1[0] * tmp0;
    3308:             sum2 -= v2[0] * tmp0;
    3309:             sum3 -= v3[0] * tmp0;
    3310:             sum4 -= v4[0] * tmp0;
    3311:             v1++; v2++; v3++; v4++;
    3312:           }
    3313:           t[row]   = sum1;
    3314:           t[row+1] = sum2;
    3315:           t[row+2] = sum3;
    3316:           t[row+3] = sum4;
    3317:           sz      = ii[row+1] - diag[row] - 4;
    3318:           idx     = a->j + diag[row] + 4;
    3319:           v1 += 4;
    3320:           v2 += 4;
    3321:           v3 += 4;
    3322:           v4 += 4;
    3323:           for (n = 0; n<sz-1; n+=2) {
    3324:             i1    = idx[0];
    3325:             i2    = idx[1];
    3326:             idx  += 2;
    3327:             tmp0  = x[i1];
    3328:             tmp1  = x[i2];
    3329:             sum1 -= v1[0] * tmp0 + v1[1] * tmp1; v1 += 2;
    3330:             sum2 -= v2[0] * tmp0 + v2[1] * tmp1; v2 += 2;
    3331:             sum3 -= v3[0] * tmp0 + v3[1] * tmp1; v3 += 2;
    3332:             sum4 -= v4[0] * tmp0 + v4[1] * tmp1; v4 += 2;
    3333:           }
    3334:           if (n == sz-1) {
    3335:             tmp0  = x[*idx];
    3336:             sum1 -= v1[0] * tmp0;
    3337:             sum2 -= v2[0] * tmp0;
    3338:             sum3 -= v3[0] * tmp0;
    3339:             sum4 -= v4[0] * tmp0;
    3340:           }
    3341:           x[row] =   sum1*ibdiag[0] + sum2*ibdiag[4] + sum3*ibdiag[8] + sum4*ibdiag[12];
    3342:           x[row+1] = sum1*ibdiag[1] + sum2*ibdiag[5] + sum3*ibdiag[9] + sum4*ibdiag[13];
    3343:           x[row+2] = sum1*ibdiag[2] + sum2*ibdiag[6] + sum3*ibdiag[10] + sum4*ibdiag[14];
    3344:           x[row+3] = sum1*ibdiag[3] + sum2*ibdiag[7] + sum3*ibdiag[11] + sum4*ibdiag[15];
    3345:           break;
    3346:         case 5:
    3347:           v2   = a->a + ii[row+1];
    3348:           v3   = a->a + ii[row+2];
    3349:           v4   = a->a + ii[row+3];
    3350:           v5   = a->a + ii[row+4];
    3351:           sum1 = b[row];
    3352:           sum2 = b[row+1];
    3353:           sum3 = b[row+2];
    3354:           sum4 = b[row+3];
    3355:           sum5 = b[row+4];
    3356:           for (n = 0; n<sz-1; n+=2) {
    3357:             i1    = idx[0];
    3358:             i2    = idx[1];
    3359:             idx  += 2;
    3360:             tmp0  = x[i1];
    3361:             tmp1  = x[i2];
    3362:             sum1 -= v1[0] * tmp0 + v1[1] * tmp1; v1 += 2;
    3363:             sum2 -= v2[0] * tmp0 + v2[1] * tmp1; v2 += 2;
    3364:             sum3 -= v3[0] * tmp0 + v3[1] * tmp1; v3 += 2;
    3365:             sum4 -= v4[0] * tmp0 + v4[1] * tmp1; v4 += 2;
    3366:             sum5 -= v5[0] * tmp0 + v5[1] * tmp1; v5 += 2;
    3367:           }
    3368:           if (n == sz-1) {
    3369:             tmp0  = x[*idx++];
    3370:             sum1 -= v1[0] * tmp0;
    3371:             sum2 -= v2[0] * tmp0;
    3372:             sum3 -= v3[0] * tmp0;
    3373:             sum4 -= v4[0] * tmp0;
    3374:             sum5 -= v5[0] * tmp0;
    3375:             v1++; v2++; v3++; v4++; v5++;
    3376:           }
    3377:           t[row]   = sum1;
    3378:           t[row+1] = sum2;
    3379:           t[row+2] = sum3;
    3380:           t[row+3] = sum4;
    3381:           t[row+4] = sum5;
    3382:           sz      = ii[row+1] - diag[row] - 5;
    3383:           idx     = a->j + diag[row] + 5;
    3384:           v1 += 5;
    3385:           v2 += 5;
    3386:           v3 += 5;
    3387:           v4 += 5;
    3388:           v5 += 5;
    3389:           for (n = 0; n<sz-1; n+=2) {
    3390:             i1    = idx[0];
    3391:             i2    = idx[1];
    3392:             idx  += 2;
    3393:             tmp0  = x[i1];
    3394:             tmp1  = x[i2];
    3395:             sum1 -= v1[0] * tmp0 + v1[1] * tmp1; v1 += 2;
    3396:             sum2 -= v2[0] * tmp0 + v2[1] * tmp1; v2 += 2;
    3397:             sum3 -= v3[0] * tmp0 + v3[1] * tmp1; v3 += 2;
    3398:             sum4 -= v4[0] * tmp0 + v4[1] * tmp1; v4 += 2;
    3399:             sum5 -= v5[0] * tmp0 + v5[1] * tmp1; v5 += 2;
    3400:           }
    3401:           if (n == sz-1) {
    3402:             tmp0  = x[*idx];
    3403:             sum1 -= v1[0] * tmp0;
    3404:             sum2 -= v2[0] * tmp0;
    3405:             sum3 -= v3[0] * tmp0;
    3406:             sum4 -= v4[0] * tmp0;
    3407:             sum5 -= v5[0] * tmp0;
    3408:           }
    3409:           x[row]   = sum1*ibdiag[0] + sum2*ibdiag[5] + sum3*ibdiag[10] + sum4*ibdiag[15] + sum5*ibdiag[20];
    3410:           x[row+1] = sum1*ibdiag[1] + sum2*ibdiag[6] + sum3*ibdiag[11] + sum4*ibdiag[16] + sum5*ibdiag[21];
    3411:           x[row+2] = sum1*ibdiag[2] + sum2*ibdiag[7] + sum3*ibdiag[12] + sum4*ibdiag[17] + sum5*ibdiag[22];
    3412:           x[row+3] = sum1*ibdiag[3] + sum2*ibdiag[8] + sum3*ibdiag[13] + sum4*ibdiag[18] + sum5*ibdiag[23];
    3413:           x[row+4] = sum1*ibdiag[4] + sum2*ibdiag[9] + sum3*ibdiag[14] + sum4*ibdiag[19] + sum5*ibdiag[24];
    3414:           break;
    3415:         default:
    3416:           SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_SUP,"Inode size %D not supported",sizes[i]);
    3417:         }
    3418:       }
    3419:       xb   = t;
    3420:       PetscLogFlops(2.0*a->nz);  /* undercounts diag inverse */
    3421:     } else xb = b;

    3423:     if (flag & SOR_BACKWARD_SWEEP || flag & SOR_LOCAL_BACKWARD_SWEEP) {

    3425:       ibdiag = a->inode.ibdiag+a->inode.bdiagsize;
    3426:       for (i=m-1, row=A->rmap->n-1; i>=0; i--) {
    3427:         ibdiag -= sizes[i]*sizes[i];

    3429:         /* set RHS */
    3430:         if (xb == b) {
    3431:           /* whole (old way) */
    3432:           sz      = ii[row+1] - ii[row];
    3433:           idx     = a->j + ii[row];
    3434:           switch (sizes[i]) {
    3435:           case 5:
    3436:             v5      = a->a + ii[row-4];
    3437:           case 4: /* fall through */
    3438:             v4      = a->a + ii[row-3];
    3439:           case 3:
    3440:             v3      = a->a + ii[row-2];
    3441:           case 2:
    3442:             v2      = a->a + ii[row-1];
    3443:           case 1:
    3444:             v1      = a->a + ii[row];
    3445:             break;
    3446:           default:
    3447:             SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_SUP,"Inode size %D not supported",sizes[i]);
    3448:           }
    3449:         } else {
    3450:           /* upper, no diag */
    3451:           sz      = ii[row+1] - diag[row] - 1;
    3452:           idx     = a->j + diag[row] + 1;
    3453:           switch (sizes[i]) {
    3454:           case 5:
    3455:             v5      = a->a + diag[row-4] + 5;
    3456:           case 4: /* fall through */
    3457:             v4      = a->a + diag[row-3] + 4;
    3458:           case 3:
    3459:             v3      = a->a + diag[row-2] + 3;
    3460:           case 2:
    3461:             v2      = a->a + diag[row-1] + 2;
    3462:           case 1:
    3463:             v1      = a->a + diag[row] + 1;
    3464:           }
    3465:         }
    3466:         /* set sum */
    3467:         switch (sizes[i]) {
    3468:         case 5:
    3469:           sum5 = xb[row-4];
    3470:         case 4: /* fall through */
    3471:           sum4 = xb[row-3];
    3472:         case 3:
    3473:           sum3 = xb[row-2];
    3474:         case 2:
    3475:           sum2 = xb[row-1];
    3476:         case 1:
    3477:           /* note that sum1 is associated with the last row */
    3478:           sum1 = xb[row];
    3479:         }
    3480:         /* do sums */
    3481:         for (n = 0; n<sz-1; n+=2) {
    3482:             i1    = idx[0];
    3483:             i2    = idx[1];
    3484:             idx  += 2;
    3485:             tmp0  = x[i1];
    3486:             tmp1  = x[i2];
    3487:             switch (sizes[i]) {
    3488:             case 5:
    3489:               sum5 -= v5[0] * tmp0 + v5[1] * tmp1; v5 += 2;
    3490:             case 4: /* fall through */
    3491:               sum4 -= v4[0] * tmp0 + v4[1] * tmp1; v4 += 2;
    3492:             case 3:
    3493:               sum3 -= v3[0] * tmp0 + v3[1] * tmp1; v3 += 2;
    3494:             case 2:
    3495:               sum2 -= v2[0] * tmp0 + v2[1] * tmp1; v2 += 2;
    3496:             case 1:
    3497:               sum1 -= v1[0] * tmp0 + v1[1] * tmp1; v1 += 2;
    3498:             }
    3499:         }
    3500:         /* ragged edge */
    3501:         if (n == sz-1) {
    3502:           tmp0  = x[*idx];
    3503:           switch (sizes[i]) {
    3504:           case 5:
    3505:             sum5 -= *v5*tmp0;
    3506:           case 4: /* fall through */
    3507:             sum4 -= *v4*tmp0;
    3508:           case 3:
    3509:             sum3 -= *v3*tmp0;
    3510:           case 2:
    3511:             sum2 -= *v2*tmp0;
    3512:           case 1:
    3513:             sum1 -= *v1*tmp0;
    3514:           }
    3515:         }
    3516:         /* update */
    3517:         if (xb == b) {
    3518:           /* whole (old way) w/ diag */
    3519:           switch (sizes[i]) {
    3520:           case 5:
    3521:             x[row--] += sum5*ibdiag[4] + sum4*ibdiag[9] + sum3*ibdiag[14] + sum2*ibdiag[19] + sum1*ibdiag[24];
    3522:             x[row--] += sum5*ibdiag[3] + sum4*ibdiag[8] + sum3*ibdiag[13] + sum2*ibdiag[18] + sum1*ibdiag[23];
    3523:             x[row--] += sum5*ibdiag[2] + sum4*ibdiag[7] + sum3*ibdiag[12] + sum2*ibdiag[17] + sum1*ibdiag[22];
    3524:             x[row--] += sum5*ibdiag[1] + sum4*ibdiag[6] + sum3*ibdiag[11] + sum2*ibdiag[16] + sum1*ibdiag[21];
    3525:             x[row--] += sum5*ibdiag[0] + sum4*ibdiag[5] + sum3*ibdiag[10] + sum2*ibdiag[15] + sum1*ibdiag[20];
    3526:             break;
    3527:           case 4:
    3528:             x[row--] += sum4*ibdiag[3] + sum3*ibdiag[7] + sum2*ibdiag[11] + sum1*ibdiag[15];
    3529:             x[row--] += sum4*ibdiag[2] + sum3*ibdiag[6] + sum2*ibdiag[10] + sum1*ibdiag[14];
    3530:             x[row--] += sum4*ibdiag[1] + sum3*ibdiag[5] + sum2*ibdiag[9] + sum1*ibdiag[13];
    3531:             x[row--] += sum4*ibdiag[0] + sum3*ibdiag[4] + sum2*ibdiag[8] + sum1*ibdiag[12];
    3532:             break;
    3533:           case 3:
    3534:             x[row--] += sum3*ibdiag[2] + sum2*ibdiag[5] + sum1*ibdiag[8];
    3535:             x[row--] += sum3*ibdiag[1] + sum2*ibdiag[4] + sum1*ibdiag[7];
    3536:             x[row--] += sum3*ibdiag[0] + sum2*ibdiag[3] + sum1*ibdiag[6];
    3537:             break;
    3538:           case 2:
    3539:             x[row--] += sum2*ibdiag[1] + sum1*ibdiag[3];
    3540:             x[row--] += sum2*ibdiag[0] + sum1*ibdiag[2];
    3541:             break;
    3542:           case 1:
    3543:             x[row--] += sum1*(*ibdiag);
    3544:             break;
    3545:           }
    3546:         } else {
    3547:           /* no diag so set =  */
    3548:           switch (sizes[i]) {
    3549:           case 5:
    3550:             x[row--] = sum5*ibdiag[4] + sum4*ibdiag[9] + sum3*ibdiag[14] + sum2*ibdiag[19] + sum1*ibdiag[24];
    3551:             x[row--] = sum5*ibdiag[3] + sum4*ibdiag[8] + sum3*ibdiag[13] + sum2*ibdiag[18] + sum1*ibdiag[23];
    3552:             x[row--] = sum5*ibdiag[2] + sum4*ibdiag[7] + sum3*ibdiag[12] + sum2*ibdiag[17] + sum1*ibdiag[22];
    3553:             x[row--] = sum5*ibdiag[1] + sum4*ibdiag[6] + sum3*ibdiag[11] + sum2*ibdiag[16] + sum1*ibdiag[21];
    3554:             x[row--] = sum5*ibdiag[0] + sum4*ibdiag[5] + sum3*ibdiag[10] + sum2*ibdiag[15] + sum1*ibdiag[20];
    3555:             break;
    3556:           case 4:
    3557:             x[row--] = sum4*ibdiag[3] + sum3*ibdiag[7] + sum2*ibdiag[11] + sum1*ibdiag[15];
    3558:             x[row--] = sum4*ibdiag[2] + sum3*ibdiag[6] + sum2*ibdiag[10] + sum1*ibdiag[14];
    3559:             x[row--] = sum4*ibdiag[1] + sum3*ibdiag[5] + sum2*ibdiag[9] + sum1*ibdiag[13];
    3560:             x[row--] = sum4*ibdiag[0] + sum3*ibdiag[4] + sum2*ibdiag[8] + sum1*ibdiag[12];
    3561:             break;
    3562:           case 3:
    3563:             x[row--] = sum3*ibdiag[2] + sum2*ibdiag[5] + sum1*ibdiag[8];
    3564:             x[row--] = sum3*ibdiag[1] + sum2*ibdiag[4] + sum1*ibdiag[7];
    3565:             x[row--] = sum3*ibdiag[0] + sum2*ibdiag[3] + sum1*ibdiag[6];
    3566:             break;
    3567:           case 2:
    3568:             x[row--] = sum2*ibdiag[1] + sum1*ibdiag[3];
    3569:             x[row--] = sum2*ibdiag[0] + sum1*ibdiag[2];
    3570:             break;
    3571:           case 1:
    3572:             x[row--] = sum1*(*ibdiag);
    3573:             break;
    3574:           }
    3575:         }
    3576:       }
    3577:       if (xb == b) {
    3578:         PetscLogFlops(2.0*a->nz);
    3579:       } else {
    3580:         PetscLogFlops(a->nz); /* assumes 1/2 in upper, undercounts diag inverse */
    3581:       }
    3582:     }
    3583:   }
    3584:   if (flag & SOR_EISENSTAT) {
    3585:     /*
    3586:           Apply  (U + D)^-1  where D is now the block diagonal
    3587:     */
    3588:     ibdiag = a->inode.ibdiag+a->inode.bdiagsize;
    3589:     for (i=m-1, row=A->rmap->n-1; i>=0; i--) {
    3590:       ibdiag -= sizes[i]*sizes[i];
    3591:       sz      = ii[row+1] - diag[row] - 1;
    3592:       v1      = a->a + diag[row] + 1;
    3593:       idx     = a->j + diag[row] + 1;
    3594:       /* see comments for MatMult_SeqAIJ_Inode() for how this is coded */
    3595:       switch (sizes[i]) {
    3596:       case 1:

    3598:         sum1 = b[row];
    3599:         for (n = 0; n<sz-1; n+=2) {
    3600:           i1    = idx[0];
    3601:           i2    = idx[1];
    3602:           idx  += 2;
    3603:           tmp0  = x[i1];
    3604:           tmp1  = x[i2];
    3605:           sum1 -= v1[0] * tmp0 + v1[1] * tmp1; v1 += 2;
    3606:         }

    3608:         if (n == sz-1) {
    3609:           tmp0  = x[*idx];
    3610:           sum1 -= *v1*tmp0;
    3611:         }
    3612:         x[row] = sum1*(*ibdiag);row--;
    3613:         break;

    3615:       case 2:

    3617:         sum1 = b[row];
    3618:         sum2 = b[row-1];
    3619:         /* note that sum1 is associated with the second of the two rows */
    3620:         v2 = a->a + diag[row-1] + 2;
    3621:         for (n = 0; n<sz-1; n+=2) {
    3622:           i1    = idx[0];
    3623:           i2    = idx[1];
    3624:           idx  += 2;
    3625:           tmp0  = x[i1];
    3626:           tmp1  = x[i2];
    3627:           sum1 -= v1[0] * tmp0 + v1[1] * tmp1; v1 += 2;
    3628:           sum2 -= v2[0] * tmp0 + v2[1] * tmp1; v2 += 2;
    3629:         }

    3631:         if (n == sz-1) {
    3632:           tmp0  = x[*idx];
    3633:           sum1 -= *v1*tmp0;
    3634:           sum2 -= *v2*tmp0;
    3635:         }
    3636:         x[row]   = sum2*ibdiag[1] + sum1*ibdiag[3];
    3637:         x[row-1] = sum2*ibdiag[0] + sum1*ibdiag[2];
    3638:         row     -= 2;
    3639:         break;
    3640:       case 3:

    3642:         sum1 = b[row];
    3643:         sum2 = b[row-1];
    3644:         sum3 = b[row-2];
    3645:         v2   = a->a + diag[row-1] + 2;
    3646:         v3   = a->a + diag[row-2] + 3;
    3647:         for (n = 0; n<sz-1; n+=2) {
    3648:           i1    = idx[0];
    3649:           i2    = idx[1];
    3650:           idx  += 2;
    3651:           tmp0  = x[i1];
    3652:           tmp1  = x[i2];
    3653:           sum1 -= v1[0] * tmp0 + v1[1] * tmp1; v1 += 2;
    3654:           sum2 -= v2[0] * tmp0 + v2[1] * tmp1; v2 += 2;
    3655:           sum3 -= v3[0] * tmp0 + v3[1] * tmp1; v3 += 2;
    3656:         }

    3658:         if (n == sz-1) {
    3659:           tmp0  = x[*idx];
    3660:           sum1 -= *v1*tmp0;
    3661:           sum2 -= *v2*tmp0;
    3662:           sum3 -= *v3*tmp0;
    3663:         }
    3664:         x[row]   = sum3*ibdiag[2] + sum2*ibdiag[5] + sum1*ibdiag[8];
    3665:         x[row-1] = sum3*ibdiag[1] + sum2*ibdiag[4] + sum1*ibdiag[7];
    3666:         x[row-2] = sum3*ibdiag[0] + sum2*ibdiag[3] + sum1*ibdiag[6];
    3667:         row     -= 3;
    3668:         break;
    3669:       case 4:

    3671:         sum1 = b[row];
    3672:         sum2 = b[row-1];
    3673:         sum3 = b[row-2];
    3674:         sum4 = b[row-3];
    3675:         v2   = a->a + diag[row-1] + 2;
    3676:         v3   = a->a + diag[row-2] + 3;
    3677:         v4   = a->a + diag[row-3] + 4;
    3678:         for (n = 0; n<sz-1; n+=2) {
    3679:           i1    = idx[0];
    3680:           i2    = idx[1];
    3681:           idx  += 2;
    3682:           tmp0  = x[i1];
    3683:           tmp1  = x[i2];
    3684:           sum1 -= v1[0] * tmp0 + v1[1] * tmp1; v1 += 2;
    3685:           sum2 -= v2[0] * tmp0 + v2[1] * tmp1; v2 += 2;
    3686:           sum3 -= v3[0] * tmp0 + v3[1] * tmp1; v3 += 2;
    3687:           sum4 -= v4[0] * tmp0 + v4[1] * tmp1; v4 += 2;
    3688:         }

    3690:         if (n == sz-1) {
    3691:           tmp0  = x[*idx];
    3692:           sum1 -= *v1*tmp0;
    3693:           sum2 -= *v2*tmp0;
    3694:           sum3 -= *v3*tmp0;
    3695:           sum4 -= *v4*tmp0;
    3696:         }
    3697:         x[row]   = sum4*ibdiag[3] + sum3*ibdiag[7] + sum2*ibdiag[11] + sum1*ibdiag[15];
    3698:         x[row-1] = sum4*ibdiag[2] + sum3*ibdiag[6] + sum2*ibdiag[10] + sum1*ibdiag[14];
    3699:         x[row-2] = sum4*ibdiag[1] + sum3*ibdiag[5] + sum2*ibdiag[9] + sum1*ibdiag[13];
    3700:         x[row-3] = sum4*ibdiag[0] + sum3*ibdiag[4] + sum2*ibdiag[8] + sum1*ibdiag[12];
    3701:         row     -= 4;
    3702:         break;
    3703:       case 5:

    3705:         sum1 = b[row];
    3706:         sum2 = b[row-1];
    3707:         sum3 = b[row-2];
    3708:         sum4 = b[row-3];
    3709:         sum5 = b[row-4];
    3710:         v2   = a->a + diag[row-1] + 2;
    3711:         v3   = a->a + diag[row-2] + 3;
    3712:         v4   = a->a + diag[row-3] + 4;
    3713:         v5   = a->a + diag[row-4] + 5;
    3714:         for (n = 0; n<sz-1; n+=2) {
    3715:           i1    = idx[0];
    3716:           i2    = idx[1];
    3717:           idx  += 2;
    3718:           tmp0  = x[i1];
    3719:           tmp1  = x[i2];
    3720:           sum1 -= v1[0] * tmp0 + v1[1] * tmp1; v1 += 2;
    3721:           sum2 -= v2[0] * tmp0 + v2[1] * tmp1; v2 += 2;
    3722:           sum3 -= v3[0] * tmp0 + v3[1] * tmp1; v3 += 2;
    3723:           sum4 -= v4[0] * tmp0 + v4[1] * tmp1; v4 += 2;
    3724:           sum5 -= v5[0] * tmp0 + v5[1] * tmp1; v5 += 2;
    3725:         }

    3727:         if (n == sz-1) {
    3728:           tmp0  = x[*idx];
    3729:           sum1 -= *v1*tmp0;
    3730:           sum2 -= *v2*tmp0;
    3731:           sum3 -= *v3*tmp0;
    3732:           sum4 -= *v4*tmp0;
    3733:           sum5 -= *v5*tmp0;
    3734:         }
    3735:         x[row]   = sum5*ibdiag[4] + sum4*ibdiag[9] + sum3*ibdiag[14] + sum2*ibdiag[19] + sum1*ibdiag[24];
    3736:         x[row-1] = sum5*ibdiag[3] + sum4*ibdiag[8] + sum3*ibdiag[13] + sum2*ibdiag[18] + sum1*ibdiag[23];
    3737:         x[row-2] = sum5*ibdiag[2] + sum4*ibdiag[7] + sum3*ibdiag[12] + sum2*ibdiag[17] + sum1*ibdiag[22];
    3738:         x[row-3] = sum5*ibdiag[1] + sum4*ibdiag[6] + sum3*ibdiag[11] + sum2*ibdiag[16] + sum1*ibdiag[21];
    3739:         x[row-4] = sum5*ibdiag[0] + sum4*ibdiag[5] + sum3*ibdiag[10] + sum2*ibdiag[15] + sum1*ibdiag[20];
    3740:         row     -= 5;
    3741:         break;
    3742:       default:
    3743:         SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_SUP,"Inode size %D not supported",sizes[i]);
    3744:       }
    3745:     }
    3746:     PetscLogFlops(a->nz);

    3748:     /*
    3749:            t = b - D x    where D is the block diagonal
    3750:     */
    3751:     cnt = 0;
    3752:     for (i=0, row=0; i<m; i++) {
    3753:       switch (sizes[i]) {
    3754:       case 1:
    3755:         t[row] = b[row] - bdiag[cnt++]*x[row]; row++;
    3756:         break;
    3757:       case 2:
    3758:         x1       = x[row]; x2 = x[row+1];
    3759:         tmp1     = x1*bdiag[cnt] + x2*bdiag[cnt+2];
    3760:         tmp2     = x1*bdiag[cnt+1] + x2*bdiag[cnt+3];
    3761:         t[row]   = b[row] - tmp1;
    3762:         t[row+1] = b[row+1] - tmp2; row += 2;
    3763:         cnt     += 4;
    3764:         break;
    3765:       case 3:
    3766:         x1       = x[row]; x2 = x[row+1]; x3 = x[row+2];
    3767:         tmp1     = x1*bdiag[cnt] + x2*bdiag[cnt+3] + x3*bdiag[cnt+6];
    3768:         tmp2     = x1*bdiag[cnt+1] + x2*bdiag[cnt+4] + x3*bdiag[cnt+7];
    3769:         tmp3     = x1*bdiag[cnt+2] + x2*bdiag[cnt+5] + x3*bdiag[cnt+8];
    3770:         t[row]   = b[row] - tmp1;
    3771:         t[row+1] = b[row+1] - tmp2;
    3772:         t[row+2] = b[row+2] - tmp3; row += 3;
    3773:         cnt     += 9;
    3774:         break;
    3775:       case 4:
    3776:         x1       = x[row]; x2 = x[row+1]; x3 = x[row+2]; x4 = x[row+3];
    3777:         tmp1     = x1*bdiag[cnt] + x2*bdiag[cnt+4] + x3*bdiag[cnt+8] + x4*bdiag[cnt+12];
    3778:         tmp2     = x1*bdiag[cnt+1] + x2*bdiag[cnt+5] + x3*bdiag[cnt+9] + x4*bdiag[cnt+13];
    3779:         tmp3     = x1*bdiag[cnt+2] + x2*bdiag[cnt+6] + x3*bdiag[cnt+10] + x4*bdiag[cnt+14];
    3780:         tmp4     = x1*bdiag[cnt+3] + x2*bdiag[cnt+7] + x3*bdiag[cnt+11] + x4*bdiag[cnt+15];
    3781:         t[row]   = b[row] - tmp1;
    3782:         t[row+1] = b[row+1] - tmp2;
    3783:         t[row+2] = b[row+2] - tmp3;
    3784:         t[row+3] = b[row+3] - tmp4; row += 4;
    3785:         cnt     += 16;
    3786:         break;
    3787:       case 5:
    3788:         x1       = x[row]; x2 = x[row+1]; x3 = x[row+2]; x4 = x[row+3]; x5 = x[row+4];
    3789:         tmp1     = x1*bdiag[cnt] + x2*bdiag[cnt+5] + x3*bdiag[cnt+10] + x4*bdiag[cnt+15] + x5*bdiag[cnt+20];
    3790:         tmp2     = x1*bdiag[cnt+1] + x2*bdiag[cnt+6] + x3*bdiag[cnt+11] + x4*bdiag[cnt+16] + x5*bdiag[cnt+21];
    3791:         tmp3     = x1*bdiag[cnt+2] + x2*bdiag[cnt+7] + x3*bdiag[cnt+12] + x4*bdiag[cnt+17] + x5*bdiag[cnt+22];
    3792:         tmp4     = x1*bdiag[cnt+3] + x2*bdiag[cnt+8] + x3*bdiag[cnt+13] + x4*bdiag[cnt+18] + x5*bdiag[cnt+23];
    3793:         tmp5     = x1*bdiag[cnt+4] + x2*bdiag[cnt+9] + x3*bdiag[cnt+14] + x4*bdiag[cnt+19] + x5*bdiag[cnt+24];
    3794:         t[row]   = b[row] - tmp1;
    3795:         t[row+1] = b[row+1] - tmp2;
    3796:         t[row+2] = b[row+2] - tmp3;
    3797:         t[row+3] = b[row+3] - tmp4;
    3798:         t[row+4] = b[row+4] - tmp5;row += 5;
    3799:         cnt     += 25;
    3800:         break;
    3801:       default:
    3802:         SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_SUP,"Inode size %D not supported",sizes[i]);
    3803:       }
    3804:     }
    3805:     PetscLogFlops(m);

    3809:     /*
    3810:           Apply (L + D)^-1 where D is the block diagonal
    3811:     */
    3812:     for (i=0, row=0; i<m; i++) {
    3813:       sz  = diag[row] - ii[row];
    3814:       v1  = a->a + ii[row];
    3815:       idx = a->j + ii[row];
    3816:       /* see comments for MatMult_SeqAIJ_Inode() for how this is coded */
    3817:       switch (sizes[i]) {
    3818:       case 1:

    3820:         sum1 = t[row];
    3821:         for (n = 0; n<sz-1; n+=2) {
    3822:           i1    = idx[0];
    3823:           i2    = idx[1];
    3824:           idx  += 2;
    3825:           tmp0  = t[i1];
    3826:           tmp1  = t[i2];
    3827:           sum1 -= v1[0] * tmp0 + v1[1] * tmp1; v1 += 2;
    3828:         }

    3830:         if (n == sz-1) {
    3831:           tmp0  = t[*idx];
    3832:           sum1 -= *v1 * tmp0;
    3833:         }
    3834:         x[row] += t[row] = sum1*(*ibdiag++); row++;
    3835:         break;
    3836:       case 2:
    3837:         v2   = a->a + ii[row+1];
    3838:         sum1 = t[row];
    3839:         sum2 = t[row+1];
    3840:         for (n = 0; n<sz-1; n+=2) {
    3841:           i1    = idx[0];
    3842:           i2    = idx[1];
    3843:           idx  += 2;
    3844:           tmp0  = t[i1];
    3845:           tmp1  = t[i2];
    3846:           sum1 -= v1[0] * tmp0 + v1[1] * tmp1; v1 += 2;
    3847:           sum2 -= v2[0] * tmp0 + v2[1] * tmp1; v2 += 2;
    3848:         }

    3850:         if (n == sz-1) {
    3851:           tmp0  = t[*idx];
    3852:           sum1 -= v1[0] * tmp0;
    3853:           sum2 -= v2[0] * tmp0;
    3854:         }
    3855:         x[row]   += t[row] = sum1*ibdiag[0] + sum2*ibdiag[2];
    3856:         x[row+1] += t[row+1] = sum1*ibdiag[1] + sum2*ibdiag[3];
    3857:         ibdiag   += 4; row += 2;
    3858:         break;
    3859:       case 3:
    3860:         v2   = a->a + ii[row+1];
    3861:         v3   = a->a + ii[row+2];
    3862:         sum1 = t[row];
    3863:         sum2 = t[row+1];
    3864:         sum3 = t[row+2];
    3865:         for (n = 0; n<sz-1; n+=2) {
    3866:           i1    = idx[0];
    3867:           i2    = idx[1];
    3868:           idx  += 2;
    3869:           tmp0  = t[i1];
    3870:           tmp1  = t[i2];
    3871:           sum1 -= v1[0] * tmp0 + v1[1] * tmp1; v1 += 2;
    3872:           sum2 -= v2[0] * tmp0 + v2[1] * tmp1; v2 += 2;
    3873:           sum3 -= v3[0] * tmp0 + v3[1] * tmp1; v3 += 2;
    3874:         }

    3876:         if (n == sz-1) {
    3877:           tmp0  = t[*idx];
    3878:           sum1 -= v1[0] * tmp0;
    3879:           sum2 -= v2[0] * tmp0;
    3880:           sum3 -= v3[0] * tmp0;
    3881:         }
    3882:         x[row]   += t[row] = sum1*ibdiag[0] + sum2*ibdiag[3] + sum3*ibdiag[6];
    3883:         x[row+1] += t[row+1] = sum1*ibdiag[1] + sum2*ibdiag[4] + sum3*ibdiag[7];
    3884:         x[row+2] += t[row+2] = sum1*ibdiag[2] + sum2*ibdiag[5] + sum3*ibdiag[8];
    3885:         ibdiag   += 9; row += 3;
    3886:         break;
    3887:       case 4:
    3888:         v2   = a->a + ii[row+1];
    3889:         v3   = a->a + ii[row+2];
    3890:         v4   = a->a + ii[row+3];
    3891:         sum1 = t[row];
    3892:         sum2 = t[row+1];
    3893:         sum3 = t[row+2];
    3894:         sum4 = t[row+3];
    3895:         for (n = 0; n<sz-1; n+=2) {
    3896:           i1    = idx[0];
    3897:           i2    = idx[1];
    3898:           idx  += 2;
    3899:           tmp0  = t[i1];
    3900:           tmp1  = t[i2];
    3901:           sum1 -= v1[0] * tmp0 + v1[1] * tmp1; v1 += 2;
    3902:           sum2 -= v2[0] * tmp0 + v2[1] * tmp1; v2 += 2;
    3903:           sum3 -= v3[0] * tmp0 + v3[1] * tmp1; v3 += 2;
    3904:           sum4 -= v4[0] * tmp0 + v4[1] * tmp1; v4 += 2;
    3905:         }

    3907:         if (n == sz-1) {
    3908:           tmp0  = t[*idx];
    3909:           sum1 -= v1[0] * tmp0;
    3910:           sum2 -= v2[0] * tmp0;
    3911:           sum3 -= v3[0] * tmp0;
    3912:           sum4 -= v4[0] * tmp0;
    3913:         }
    3914:         x[row]   += t[row] = sum1*ibdiag[0] + sum2*ibdiag[4] + sum3*ibdiag[8] + sum4*ibdiag[12];
    3915:         x[row+1] += t[row+1] = sum1*ibdiag[1] + sum2*ibdiag[5] + sum3*ibdiag[9] + sum4*ibdiag[13];
    3916:         x[row+2] += t[row+2] = sum1*ibdiag[2] + sum2*ibdiag[6] + sum3*ibdiag[10] + sum4*ibdiag[14];
    3917:         x[row+3] += t[row+3] = sum1*ibdiag[3] + sum2*ibdiag[7] + sum3*ibdiag[11] + sum4*ibdiag[15];
    3918:         ibdiag   += 16; row += 4;
    3919:         break;
    3920:       case 5:
    3921:         v2   = a->a + ii[row+1];
    3922:         v3   = a->a + ii[row+2];
    3923:         v4   = a->a + ii[row+3];
    3924:         v5   = a->a + ii[row+4];
    3925:         sum1 = t[row];
    3926:         sum2 = t[row+1];
    3927:         sum3 = t[row+2];
    3928:         sum4 = t[row+3];
    3929:         sum5 = t[row+4];
    3930:         for (n = 0; n<sz-1; n+=2) {
    3931:           i1    = idx[0];
    3932:           i2    = idx[1];
    3933:           idx  += 2;
    3934:           tmp0  = t[i1];
    3935:           tmp1  = t[i2];
    3936:           sum1 -= v1[0] * tmp0 + v1[1] * tmp1; v1 += 2;
    3937:           sum2 -= v2[0] * tmp0 + v2[1] * tmp1; v2 += 2;
    3938:           sum3 -= v3[0] * tmp0 + v3[1] * tmp1; v3 += 2;
    3939:           sum4 -= v4[0] * tmp0 + v4[1] * tmp1; v4 += 2;
    3940:           sum5 -= v5[0] * tmp0 + v5[1] * tmp1; v5 += 2;
    3941:         }

    3943:         if (n == sz-1) {
    3944:           tmp0  = t[*idx];
    3945:           sum1 -= v1[0] * tmp0;
    3946:           sum2 -= v2[0] * tmp0;
    3947:           sum3 -= v3[0] * tmp0;
    3948:           sum4 -= v4[0] * tmp0;
    3949:           sum5 -= v5[0] * tmp0;
    3950:         }
    3951:         x[row]   += t[row] = sum1*ibdiag[0] + sum2*ibdiag[5] + sum3*ibdiag[10] + sum4*ibdiag[15] + sum5*ibdiag[20];
    3952:         x[row+1] += t[row+1] = sum1*ibdiag[1] + sum2*ibdiag[6] + sum3*ibdiag[11] + sum4*ibdiag[16] + sum5*ibdiag[21];
    3953:         x[row+2] += t[row+2] = sum1*ibdiag[2] + sum2*ibdiag[7] + sum3*ibdiag[12] + sum4*ibdiag[17] + sum5*ibdiag[22];
    3954:         x[row+3] += t[row+3] = sum1*ibdiag[3] + sum2*ibdiag[8] + sum3*ibdiag[13] + sum4*ibdiag[18] + sum5*ibdiag[23];
    3955:         x[row+4] += t[row+4] = sum1*ibdiag[4] + sum2*ibdiag[9] + sum3*ibdiag[14] + sum4*ibdiag[19] + sum5*ibdiag[24];
    3956:         ibdiag   += 25; row += 5;
    3957:         break;
    3958:       default:
    3959:         SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_SUP,"Inode size %D not supported",sizes[i]);
    3960:       }
    3961:     }
    3962:     PetscLogFlops(a->nz);
    3963:   }
    3964:   VecRestoreArray(xx,&x);
    3965:   VecRestoreArrayRead(bb,&b);
    3966:   return(0);
    3967: }

    3969: PetscErrorCode MatMultDiagonalBlock_SeqAIJ_Inode(Mat A,Vec bb,Vec xx)
    3970: {
    3971:   Mat_SeqAIJ        *a = (Mat_SeqAIJ*)A->data;
    3972:   PetscScalar       *x,tmp1,tmp2,tmp3,tmp4,tmp5,x1,x2,x3,x4,x5;
    3973:   const MatScalar   *bdiag = a->inode.bdiag;
    3974:   const PetscScalar *b;
    3975:   PetscErrorCode    ierr;
    3976:   PetscInt          m      = a->inode.node_count,cnt = 0,i,row;
    3977:   const PetscInt    *sizes = a->inode.size;

    3980:   if (!a->inode.size) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_COR,"Missing Inode Structure");
    3981:   VecGetArray(xx,&x);
    3982:   VecGetArrayRead(bb,&b);
    3983:   cnt  = 0;
    3984:   for (i=0, row=0; i<m; i++) {
    3985:     switch (sizes[i]) {
    3986:     case 1:
    3987:       x[row] = b[row]*bdiag[cnt++];row++;
    3988:       break;
    3989:     case 2:
    3990:       x1       = b[row]; x2 = b[row+1];
    3991:       tmp1     = x1*bdiag[cnt] + x2*bdiag[cnt+2];
    3992:       tmp2     = x1*bdiag[cnt+1] + x2*bdiag[cnt+3];
    3993:       x[row++] = tmp1;
    3994:       x[row++] = tmp2;
    3995:       cnt     += 4;
    3996:       break;
    3997:     case 3:
    3998:       x1       = b[row]; x2 = b[row+1]; x3 = b[row+2];
    3999:       tmp1     = x1*bdiag[cnt] + x2*bdiag[cnt+3] + x3*bdiag[cnt+6];
    4000:       tmp2     = x1*bdiag[cnt+1] + x2*bdiag[cnt+4] + x3*bdiag[cnt+7];
    4001:       tmp3     = x1*bdiag[cnt+2] + x2*bdiag[cnt+5] + x3*bdiag[cnt+8];
    4002:       x[row++] = tmp1;
    4003:       x[row++] = tmp2;
    4004:       x[row++] = tmp3;
    4005:       cnt     += 9;
    4006:       break;
    4007:     case 4:
    4008:       x1       = b[row]; x2 = b[row+1]; x3 = b[row+2]; x4 = b[row+3];
    4009:       tmp1     = x1*bdiag[cnt] + x2*bdiag[cnt+4] + x3*bdiag[cnt+8] + x4*bdiag[cnt+12];
    4010:       tmp2     = x1*bdiag[cnt+1] + x2*bdiag[cnt+5] + x3*bdiag[cnt+9] + x4*bdiag[cnt+13];
    4011:       tmp3     = x1*bdiag[cnt+2] + x2*bdiag[cnt+6] + x3*bdiag[cnt+10] + x4*bdiag[cnt+14];
    4012:       tmp4     = x1*bdiag[cnt+3] + x2*bdiag[cnt+7] + x3*bdiag[cnt+11] + x4*bdiag[cnt+15];
    4013:       x[row++] = tmp1;
    4014:       x[row++] = tmp2;
    4015:       x[row++] = tmp3;
    4016:       x[row++] = tmp4;
    4017:       cnt     += 16;
    4018:       break;
    4019:     case 5:
    4020:       x1       = b[row]; x2 = b[row+1]; x3 = b[row+2]; x4 = b[row+3]; x5 = b[row+4];
    4021:       tmp1     = x1*bdiag[cnt] + x2*bdiag[cnt+5] + x3*bdiag[cnt+10] + x4*bdiag[cnt+15] + x5*bdiag[cnt+20];
    4022:       tmp2     = x1*bdiag[cnt+1] + x2*bdiag[cnt+6] + x3*bdiag[cnt+11] + x4*bdiag[cnt+16] + x5*bdiag[cnt+21];
    4023:       tmp3     = x1*bdiag[cnt+2] + x2*bdiag[cnt+7] + x3*bdiag[cnt+12] + x4*bdiag[cnt+17] + x5*bdiag[cnt+22];
    4024:       tmp4     = x1*bdiag[cnt+3] + x2*bdiag[cnt+8] + x3*bdiag[cnt+13] + x4*bdiag[cnt+18] + x5*bdiag[cnt+23];
    4025:       tmp5     = x1*bdiag[cnt+4] + x2*bdiag[cnt+9] + x3*bdiag[cnt+14] + x4*bdiag[cnt+19] + x5*bdiag[cnt+24];
    4026:       x[row++] = tmp1;
    4027:       x[row++] = tmp2;
    4028:       x[row++] = tmp3;
    4029:       x[row++] = tmp4;
    4030:       x[row++] = tmp5;
    4031:       cnt     += 25;
    4032:       break;
    4033:     default:
    4034:       SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_SUP,"Inode size %D not supported",sizes[i]);
    4035:     }
    4036:   }
    4037:   PetscLogFlops(2.0*cnt);
    4038:   VecRestoreArray(xx,&x);
    4039:   VecRestoreArrayRead(bb,&b);
    4040:   return(0);
    4041: }

    4043: static PetscErrorCode MatSeqAIJ_Inode_ResetOps(Mat A)
    4044: {
    4045:   Mat_SeqAIJ *a = (Mat_SeqAIJ*)A->data;

    4048:   a->inode.node_count       = 0;
    4049:   a->inode.use              = PETSC_FALSE;
    4050:   a->inode.checked          = PETSC_FALSE;
    4051:   a->inode.mat_nonzerostate = -1;
    4052:   A->ops->getrowij          = MatGetRowIJ_SeqAIJ;
    4053:   A->ops->restorerowij      = MatRestoreRowIJ_SeqAIJ;
    4054:   A->ops->getcolumnij       = MatGetColumnIJ_SeqAIJ;
    4055:   A->ops->restorecolumnij   = MatRestoreColumnIJ_SeqAIJ;
    4056:   A->ops->coloringpatch     = NULL;
    4057:   A->ops->multdiagonalblock = NULL;
    4058:   if (A->factortype) {
    4059:     A->ops->solve = MatSolve_SeqAIJ_inplace;
    4060:   }
    4061:   return(0);
    4062: }

    4064: /*
    4065:     samestructure indicates that the matrix has not changed its nonzero structure so we
    4066:     do not need to recompute the inodes
    4067: */
    4068: PetscErrorCode MatSeqAIJCheckInode(Mat A)
    4069: {
    4070:   Mat_SeqAIJ     *a = (Mat_SeqAIJ*)A->data;
    4072:   PetscInt       i,j,m,nzx,nzy,*ns,node_count,blk_size;
    4073:   PetscBool      flag;
    4074:   const PetscInt *idx,*idy,*ii;

    4077:   if (!a->inode.use) {
    4078:     MatSeqAIJ_Inode_ResetOps(A);
    4079:     PetscFree(a->inode.size);
    4080:     return(0);
    4081:   }
    4082:   if (a->inode.checked && A->nonzerostate == a->inode.mat_nonzerostate) return(0);

    4084:   m = A->rmap->n;
    4085:   if (!a->inode.size) { PetscMalloc1(m+1,&a->inode.size); }
    4086:   ns = a->inode.size;

    4088:   i          = 0;
    4089:   node_count = 0;
    4090:   idx        = a->j;
    4091:   ii         = a->i;
    4092:   while (i < m) {                /* For each row */
    4093:     nzx = ii[i+1] - ii[i];       /* Number of nonzeros */
    4094:     /* Limits the number of elements in a node to 'a->inode.limit' */
    4095:     for (j=i+1,idy=idx,blk_size=1; j<m && blk_size <a->inode.limit; ++j,++blk_size) {
    4096:       nzy = ii[j+1] - ii[j];     /* Same number of nonzeros */
    4097:       if (nzy != nzx) break;
    4098:       idy += nzx;              /* Same nonzero pattern */
    4099:       PetscArraycmp(idx,idy,nzx,&flag);
    4100:       if (!flag) break;
    4101:     }
    4102:     ns[node_count++] = blk_size;
    4103:     idx             += blk_size*nzx;
    4104:     i                = j;
    4105:   }

    4107:   /* If not enough inodes found,, do not use inode version of the routines */
    4108:   if (!m || node_count > .8*m) {
    4109:     MatSeqAIJ_Inode_ResetOps(A);
    4110:     PetscFree(a->inode.size);
    4111:     PetscInfo2(A,"Found %D nodes out of %D rows. Not using Inode routines\n",node_count,m);
    4112:   } else {
    4113:     if (!A->factortype) {
    4114:       A->ops->multdiagonalblock = MatMultDiagonalBlock_SeqAIJ_Inode;
    4115:       if (A->rmap->n == A->cmap->n) {
    4116:         A->ops->getrowij        = MatGetRowIJ_SeqAIJ_Inode;
    4117:         A->ops->restorerowij    = MatRestoreRowIJ_SeqAIJ_Inode;
    4118:         A->ops->getcolumnij     = MatGetColumnIJ_SeqAIJ_Inode;
    4119:         A->ops->restorecolumnij = MatRestoreColumnIJ_SeqAIJ_Inode;
    4120:         A->ops->coloringpatch   = MatColoringPatch_SeqAIJ_Inode;
    4121:       }
    4122:     } else {
    4123:       A->ops->solve = MatSolve_SeqAIJ_Inode_inplace;
    4124:     }
    4125:     a->inode.node_count = node_count;
    4126:     PetscInfo3(A,"Found %D nodes of %D. Limit used: %D. Using Inode routines\n",node_count,m,a->inode.limit);
    4127:   }
    4128:   a->inode.checked          = PETSC_TRUE;
    4129:   a->inode.mat_nonzerostate = A->nonzerostate;
    4130:   return(0);
    4131: }

    4133: PetscErrorCode MatDuplicate_SeqAIJ_Inode(Mat A,MatDuplicateOption cpvalues,Mat *C)
    4134: {
    4135:   Mat            B =*C;
    4136:   Mat_SeqAIJ     *c=(Mat_SeqAIJ*)B->data,*a=(Mat_SeqAIJ*)A->data;
    4138:   PetscInt       m=A->rmap->n;

    4141:   c->inode.use              = a->inode.use;
    4142:   c->inode.limit            = a->inode.limit;
    4143:   c->inode.max_limit        = a->inode.max_limit;
    4144:   c->inode.checked          = PETSC_FALSE;
    4145:   c->inode.size             = NULL;
    4146:   c->inode.node_count       = 0;
    4147:   c->inode.ibdiagvalid      = PETSC_FALSE;
    4148:   c->inode.ibdiag           = NULL;
    4149:   c->inode.bdiag            = NULL;
    4150:   c->inode.mat_nonzerostate = -1;
    4151:   if (a->inode.use) {
    4152:     if (a->inode.checked && a->inode.size) {
    4153:       PetscMalloc1(m+1,&c->inode.size);
    4154:       PetscArraycpy(c->inode.size,a->inode.size,m+1);

    4156:       c->inode.checked          = PETSC_TRUE;
    4157:       c->inode.node_count       = a->inode.node_count;
    4158:       c->inode.mat_nonzerostate = (*C)->nonzerostate;
    4159:     }
    4160:     /* note the table of functions below should match that in MatSeqAIJCheckInode() */
    4161:     if (!B->factortype) {
    4162:       B->ops->getrowij          = MatGetRowIJ_SeqAIJ_Inode;
    4163:       B->ops->restorerowij      = MatRestoreRowIJ_SeqAIJ_Inode;
    4164:       B->ops->getcolumnij       = MatGetColumnIJ_SeqAIJ_Inode;
    4165:       B->ops->restorecolumnij   = MatRestoreColumnIJ_SeqAIJ_Inode;
    4166:       B->ops->coloringpatch     = MatColoringPatch_SeqAIJ_Inode;
    4167:       B->ops->multdiagonalblock = MatMultDiagonalBlock_SeqAIJ_Inode;
    4168:     } else {
    4169:       B->ops->solve = MatSolve_SeqAIJ_Inode_inplace;
    4170:     }
    4171:   }
    4172:   return(0);
    4173: }

    4175: PETSC_STATIC_INLINE PetscErrorCode MatGetRow_FactoredLU(PetscInt *cols,PetscInt nzl,PetscInt nzu,PetscInt nz,const PetscInt *ai,const PetscInt *aj,const PetscInt *adiag,PetscInt row)
    4176: {
    4177:   PetscInt       k;
    4178:   const PetscInt *vi;

    4181:   vi = aj + ai[row];
    4182:   for (k=0; k<nzl; k++) cols[k] = vi[k];
    4183:   vi        = aj + adiag[row];
    4184:   cols[nzl] = vi[0];
    4185:   vi        = aj + adiag[row+1]+1;
    4186:   for (k=0; k<nzu; k++) cols[nzl+1+k] = vi[k];
    4187:   return(0);
    4188: }
    4189: /*
    4190:    MatSeqAIJCheckInode_FactorLU - Check Inode for factored seqaij matrix.
    4191:    Modified from MatSeqAIJCheckInode().

    4193:    Input Parameters:
    4194: .  Mat A - ILU or LU matrix factor

    4196: */
    4197: PetscErrorCode MatSeqAIJCheckInode_FactorLU(Mat A)
    4198: {
    4199:   Mat_SeqAIJ     *a = (Mat_SeqAIJ*)A->data;
    4201:   PetscInt       i,j,m,nzl1,nzu1,nzl2,nzu2,nzx,nzy,node_count,blk_size;
    4202:   PetscInt       *cols1,*cols2,*ns;
    4203:   const PetscInt *ai = a->i,*aj = a->j, *adiag = a->diag;
    4204:   PetscBool      flag;

    4207:   if (!a->inode.use)    return(0);
    4208:   if (a->inode.checked) return(0);

    4210:   m = A->rmap->n;
    4211:   if (a->inode.size) ns = a->inode.size;
    4212:   else {
    4213:     PetscMalloc1(m+1,&ns);
    4214:   }

    4216:   i          = 0;
    4217:   node_count = 0;
    4218:   PetscMalloc2(m,&cols1,m,&cols2);
    4219:   while (i < m) {                /* For each row */
    4220:     nzl1 = ai[i+1] - ai[i];       /* Number of nonzeros in L */
    4221:     nzu1 = adiag[i] - adiag[i+1] - 1; /* Number of nonzeros in U excluding diagonal*/
    4222:     nzx  = nzl1 + nzu1 + 1;
    4223:     MatGetRow_FactoredLU(cols1,nzl1,nzu1,nzx,ai,aj,adiag,i);

    4225:     /* Limits the number of elements in a node to 'a->inode.limit' */
    4226:     for (j=i+1,blk_size=1; j<m && blk_size <a->inode.limit; ++j,++blk_size) {
    4227:       nzl2 = ai[j+1] - ai[j];
    4228:       nzu2 = adiag[j] - adiag[j+1] - 1;
    4229:       nzy  = nzl2 + nzu2 + 1;
    4230:       if (nzy != nzx) break;
    4231:       MatGetRow_FactoredLU(cols2,nzl2,nzu2,nzy,ai,aj,adiag,j);
    4232:       PetscArraycmp(cols1,cols2,nzx,&flag);
    4233:       if (!flag) break;
    4234:     }
    4235:     ns[node_count++] = blk_size;
    4236:     i                = j;
    4237:   }
    4238:   PetscFree2(cols1,cols2);
    4239:   /* If not enough inodes found,, do not use inode version of the routines */
    4240:   if (!m || node_count > .8*m) {
    4241:     PetscFree(ns);

    4243:     a->inode.node_count = 0;
    4244:     a->inode.size       = NULL;
    4245:     a->inode.use        = PETSC_FALSE;

    4247:     PetscInfo2(A,"Found %D nodes out of %D rows. Not using Inode routines\n",node_count,m);
    4248:   } else {
    4249:     A->ops->mult              = NULL;
    4250:     A->ops->sor               = NULL;
    4251:     A->ops->multadd           = NULL;
    4252:     A->ops->getrowij          = NULL;
    4253:     A->ops->restorerowij      = NULL;
    4254:     A->ops->getcolumnij       = NULL;
    4255:     A->ops->restorecolumnij   = NULL;
    4256:     A->ops->coloringpatch     = NULL;
    4257:     A->ops->multdiagonalblock = NULL;
    4258:     a->inode.node_count       = node_count;
    4259:     a->inode.size             = ns;

    4261:     PetscInfo3(A,"Found %D nodes of %D. Limit used: %D. Using Inode routines\n",node_count,m,a->inode.limit);
    4262:   }
    4263:   a->inode.checked = PETSC_TRUE;
    4264:   return(0);
    4265: }

    4267: PetscErrorCode MatSeqAIJInvalidateDiagonal_Inode(Mat A)
    4268: {
    4269:   Mat_SeqAIJ *a=(Mat_SeqAIJ*)A->data;

    4272:   a->inode.ibdiagvalid = PETSC_FALSE;
    4273:   return(0);
    4274: }

    4276: /*
    4277:      This is really ugly. if inodes are used this replaces the
    4278:   permutations with ones that correspond to rows/cols of the matrix
    4279:   rather then inode blocks
    4280: */
    4281: PetscErrorCode  MatInodeAdjustForInodes(Mat A,IS *rperm,IS *cperm)
    4282: {

    4286:   PetscTryMethod(A,"MatInodeAdjustForInodes_C",(Mat,IS*,IS*),(A,rperm,cperm));
    4287:   return(0);
    4288: }

    4290: PetscErrorCode  MatInodeAdjustForInodes_SeqAIJ_Inode(Mat A,IS *rperm,IS *cperm)
    4291: {
    4292:   Mat_SeqAIJ     *a=(Mat_SeqAIJ*)A->data;
    4294:   PetscInt       m = A->rmap->n,n = A->cmap->n,i,j,nslim_row = a->inode.node_count;
    4295:   const PetscInt *ridx,*cidx;
    4296:   PetscInt       row,col,*permr,*permc,*ns_row =  a->inode.size,*tns,start_val,end_val,indx;
    4297:   PetscInt       nslim_col,*ns_col;
    4298:   IS             ris = *rperm,cis = *cperm;

    4301:   if (!a->inode.size) return(0); /* no inodes so return */
    4302:   if (a->inode.node_count == m) return(0); /* all inodes are of size 1 */

    4304:   MatCreateColInode_Private(A,&nslim_col,&ns_col);
    4305:   PetscMalloc1(((nslim_row>nslim_col) ? nslim_row : nslim_col)+1,&tns);
    4306:   PetscMalloc2(m,&permr,n,&permc);

    4308:   ISGetIndices(ris,&ridx);
    4309:   ISGetIndices(cis,&cidx);

    4311:   /* Form the inode structure for the rows of permuted matric using inv perm*/
    4312:   for (i=0,tns[0]=0; i<nslim_row; ++i) tns[i+1] = tns[i] + ns_row[i];

    4314:   /* Construct the permutations for rows*/
    4315:   for (i=0,row = 0; i<nslim_row; ++i) {
    4316:     indx      = ridx[i];
    4317:     start_val = tns[indx];
    4318:     end_val   = tns[indx + 1];
    4319:     for (j=start_val; j<end_val; ++j,++row) permr[row]= j;
    4320:   }

    4322:   /* Form the inode structure for the columns of permuted matrix using inv perm*/
    4323:   for (i=0,tns[0]=0; i<nslim_col; ++i) tns[i+1] = tns[i] + ns_col[i];

    4325:   /* Construct permutations for columns */
    4326:   for (i=0,col=0; i<nslim_col; ++i) {
    4327:     indx      = cidx[i];
    4328:     start_val = tns[indx];
    4329:     end_val   = tns[indx + 1];
    4330:     for (j = start_val; j<end_val; ++j,++col) permc[col]= j;
    4331:   }

    4333:   ISCreateGeneral(PETSC_COMM_SELF,n,permr,PETSC_COPY_VALUES,rperm);
    4334:   ISSetPermutation(*rperm);
    4335:   ISCreateGeneral(PETSC_COMM_SELF,n,permc,PETSC_COPY_VALUES,cperm);
    4336:   ISSetPermutation(*cperm);

    4338:   ISRestoreIndices(ris,&ridx);
    4339:   ISRestoreIndices(cis,&cidx);

    4341:   PetscFree(ns_col);
    4342:   PetscFree2(permr,permc);
    4343:   ISDestroy(&cis);
    4344:   ISDestroy(&ris);
    4345:   PetscFree(tns);
    4346:   return(0);
    4347: }

    4349: /*@C
    4350:    MatInodeGetInodeSizes - Returns the inode information of the Inode matrix.

    4352:    Not Collective

    4354:    Input Parameter:
    4355: .  A - the Inode matrix or matrix derived from the Inode class -- e.g., SeqAIJ

    4357:    Output Parameter:
    4358: +  node_count - no of inodes present in the matrix.
    4359: .  sizes      - an array of size node_count,with sizes of each inode.
    4360: -  limit      - the max size used to generate the inodes.

    4362:    Level: advanced

    4364:    Notes:
    4365:     This routine returns some internal storage information
    4366:    of the matrix, it is intended to be used by advanced users.
    4367:    It should be called after the matrix is assembled.
    4368:    The contents of the sizes[] array should not be changed.
    4369:    NULL may be passed for information not requested.

    4371: .seealso: MatGetInfo()
    4372: @*/
    4373: PetscErrorCode  MatInodeGetInodeSizes(Mat A,PetscInt *node_count,PetscInt *sizes[],PetscInt *limit)
    4374: {
    4375:   PetscErrorCode ierr,(*f)(Mat,PetscInt*,PetscInt*[],PetscInt*);

    4378:   if (!A->assembled) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Not for unassembled matrix");
    4379:   PetscObjectQueryFunction((PetscObject)A,"MatInodeGetInodeSizes_C",&f);
    4380:   if (f) {
    4381:     (*f)(A,node_count,sizes,limit);
    4382:   }
    4383:   return(0);
    4384: }

    4386: PetscErrorCode  MatInodeGetInodeSizes_SeqAIJ_Inode(Mat A,PetscInt *node_count,PetscInt *sizes[],PetscInt *limit)
    4387: {
    4388:   Mat_SeqAIJ *a = (Mat_SeqAIJ*)A->data;

    4391:   if (node_count) *node_count = a->inode.node_count;
    4392:   if (sizes)      *sizes      = a->inode.size;
    4393:   if (limit)      *limit      = a->inode.limit;
    4394:   return(0);
    4395: }