Date: 2021-03-03T22:26:14+00:00

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

      2: /*
      3:    Support for the parallel AIJ matrix vector multiply
      4: */
      5: #include <../src/mat/impls/aij/mpi/mpiaij.h>
      6: #include <petsc/private/vecimpl.h>
      7: #include <petsc/private/isimpl.h>

      9: PetscErrorCode MatSetUpMultiply_MPIAIJ(Mat mat)
     10: {
     11:   Mat_MPIAIJ     *aij = (Mat_MPIAIJ*)mat->data;
     12:   Mat_SeqAIJ     *B   = (Mat_SeqAIJ*)(aij->B->data);
     14:   PetscInt       i,j,*aj = B->j,ec = 0,*garray;
     15:   IS             from,to;
     16:   Vec            gvec;
     17: #if defined(PETSC_USE_CTABLE)
     18:   PetscTable         gid1_lid1;
     19:   PetscTablePosition tpos;
     20:   PetscInt           gid,lid;
     21: #else
     22:   PetscInt N = mat->cmap->N,*indices;
     23: #endif

     26:   if (!aij->garray) {
     27: #if defined(PETSC_USE_CTABLE)
     28:     /* use a table */
     29:     PetscTableCreate(aij->B->rmap->n,mat->cmap->N+1,&gid1_lid1);
     30:     for (i=0; i<aij->B->rmap->n; i++) {
     31:       for (j=0; j<B->ilen[i]; j++) {
     32:         PetscInt data,gid1 = aj[B->i[i] + j] + 1;
     33:         PetscTableFind(gid1_lid1,gid1,&data);
     34:         if (!data) {
     35:           /* one based table */
     36:           PetscTableAdd(gid1_lid1,gid1,++ec,INSERT_VALUES);
     37:         }
     38:       }
     39:     }
     40:     /* form array of columns we need */
     41:     PetscMalloc1(ec+1,&garray);
     42:     PetscTableGetHeadPosition(gid1_lid1,&tpos);
     43:     while (tpos) {
     44:       PetscTableGetNext(gid1_lid1,&tpos,&gid,&lid);
     45:       gid--;
     46:       lid--;
     47:       garray[lid] = gid;
     48:     }
     49:     PetscSortInt(ec,garray); /* sort, and rebuild */
     50:     PetscTableRemoveAll(gid1_lid1);
     51:     for (i=0; i<ec; i++) {
     52:       PetscTableAdd(gid1_lid1,garray[i]+1,i+1,INSERT_VALUES);
     53:     }
     54:     /* compact out the extra columns in B */
     55:     for (i=0; i<aij->B->rmap->n; i++) {
     56:       for (j=0; j<B->ilen[i]; j++) {
     57:         PetscInt gid1 = aj[B->i[i] + j] + 1;
     58:         PetscTableFind(gid1_lid1,gid1,&lid);
     59:         lid--;
     60:         aj[B->i[i] + j] = lid;
     61:       }
     62:     }
     63:     PetscLayoutDestroy(&aij->B->cmap);
     64:     PetscLayoutCreateFromSizes(PetscObjectComm((PetscObject)aij->B),ec,ec,1,&aij->B->cmap);
     65:     PetscTableDestroy(&gid1_lid1);
     66: #else
     67:     /* Make an array as long as the number of columns */
     68:     /* mark those columns that are in aij->B */
     69:     PetscCalloc1(N+1,&indices);
     70:     for (i=0; i<aij->B->rmap->n; i++) {
     71:       for (j=0; j<B->ilen[i]; j++) {
     72:         if (!indices[aj[B->i[i] + j]]) ec++;
     73:         indices[aj[B->i[i] + j]] = 1;
     74:       }
     75:     }

     77:     /* form array of columns we need */
     78:     PetscMalloc1(ec+1,&garray);
     79:     ec   = 0;
     80:     for (i=0; i<N; i++) {
     81:       if (indices[i]) garray[ec++] = i;
     82:     }

     84:     /* make indices now point into garray */
     85:     for (i=0; i<ec; i++) {
     86:       indices[garray[i]] = i;
     87:     }

     89:     /* compact out the extra columns in B */
     90:     for (i=0; i<aij->B->rmap->n; i++) {
     91:       for (j=0; j<B->ilen[i]; j++) {
     92:         aj[B->i[i] + j] = indices[aj[B->i[i] + j]];
     93:       }
     94:     }
     95:     PetscLayoutDestroy(&aij->B->cmap);
     96:     PetscLayoutCreateFromSizes(PetscObjectComm((PetscObject)aij->B),ec,ec,1,&aij->B->cmap);
     97:     PetscFree(indices);
     98: #endif
     99:   } else {
    100:     garray = aij->garray;
    101:   }

    103:   if (!aij->lvec) {
    104:     /* create local vector that is used to scatter into */
    105:     VecCreateSeq(PETSC_COMM_SELF,ec,&aij->lvec);
    106:   } else {
    107:     VecGetSize(aij->lvec,&ec);
    108:   }

    110:   /* create two temporary Index sets for build scatter gather */
    111:   ISCreateGeneral(PETSC_COMM_SELF,ec,garray,PETSC_COPY_VALUES,&from);
    112:   ISCreateStride(PETSC_COMM_SELF,ec,0,1,&to);

    114:   /* create temporary global vector to generate scatter context */
    115:   /* This does not allocate the array's memory so is efficient */
    116:   VecCreateMPIWithArray(PetscObjectComm((PetscObject)mat),1,mat->cmap->n,mat->cmap->N,NULL,&gvec);

    118:   /* generate the scatter context */
    119:   if (aij->Mvctx_mpi1_flg) {
    120:     VecScatterDestroy(&aij->Mvctx_mpi1);
    121:     VecScatterCreate(gvec,from,aij->lvec,to,&aij->Mvctx_mpi1);
    122:     VecScatterSetType(aij->Mvctx_mpi1,VECSCATTERMPI1);
    123:     PetscLogObjectParent((PetscObject)mat,(PetscObject)aij->Mvctx_mpi1);
    124:   } else {
    125:     VecScatterDestroy(&aij->Mvctx);
    126:     VecScatterCreate(gvec,from,aij->lvec,to,&aij->Mvctx);
    127:     PetscLogObjectParent((PetscObject)mat,(PetscObject)aij->Mvctx);
    128:     PetscLogObjectParent((PetscObject)mat,(PetscObject)aij->lvec);
    129:     PetscLogObjectMemory((PetscObject)mat,(ec+1)*sizeof(PetscInt));
    130:   }
    131:   aij->garray = garray;

    133:   PetscLogObjectParent((PetscObject)mat,(PetscObject)from);
    134:   PetscLogObjectParent((PetscObject)mat,(PetscObject)to);

    136:   ISDestroy(&from);
    137:   ISDestroy(&to);
    138:   VecDestroy(&gvec);
    139:   return(0);
    140: }

    142: /*
    143:      Takes the local part of an already assembled MPIAIJ matrix
    144:    and disassembles it. This is to allow new nonzeros into the matrix
    145:    that require more communication in the matrix vector multiply.
    146:    Thus certain data-structures must be rebuilt.

    148:    Kind of slow! But that's what application programmers get when
    149:    they are sloppy.
    150: */
    151: PetscErrorCode MatDisAssemble_MPIAIJ(Mat A)
    152: {
    153:   Mat_MPIAIJ     *aij  = (Mat_MPIAIJ*)A->data;
    154:   Mat            B     = aij->B,Bnew;
    155:   Mat_SeqAIJ     *Baij = (Mat_SeqAIJ*)B->data;
    157:   PetscInt       i,j,m = B->rmap->n,n = A->cmap->N,col,ct = 0,*garray = aij->garray,*nz,ec;
    158:   PetscScalar    v;

    161:   /* free stuff related to matrix-vec multiply */
    162:   VecGetSize(aij->lvec,&ec); /* needed for PetscLogObjectMemory below */
    163:   VecDestroy(&aij->lvec);
    164:   if (aij->colmap) {
    165: #if defined(PETSC_USE_CTABLE)
    166:     PetscTableDestroy(&aij->colmap);
    167: #else
    168:     PetscFree(aij->colmap);
    169:     PetscLogObjectMemory((PetscObject)A,-aij->B->cmap->n*sizeof(PetscInt));
    170: #endif
    171:   }

    173:   /* make sure that B is assembled so we can access its values */
    174:   MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);
    175:   MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);

    177:   /* invent new B and copy stuff over */
    178:   PetscMalloc1(m+1,&nz);
    179:   for (i=0; i<m; i++) {
    180:     nz[i] = Baij->i[i+1] - Baij->i[i];
    181:   }
    182:   MatCreate(PETSC_COMM_SELF,&Bnew);
    183:   MatSetSizes(Bnew,m,n,m,n);
    184:   MatSetBlockSizesFromMats(Bnew,A,A);
    185:   MatSetType(Bnew,((PetscObject)B)->type_name);
    186:   MatSeqAIJSetPreallocation(Bnew,0,nz);

    188:   if (Baij->nonew >= 0) { /* Inherit insertion error options (if positive). */
    189:     ((Mat_SeqAIJ*)Bnew->data)->nonew = Baij->nonew;
    190:   }

    192:   /*
    193:    Ensure that B's nonzerostate is monotonically increasing.
    194:    Or should this follow the MatSetValues() loop to preserve B's nonzerstate across a MatDisAssemble() call?
    195:    */
    196:   Bnew->nonzerostate = B->nonzerostate;

    198:   PetscFree(nz);
    199:   for (i=0; i<m; i++) {
    200:     for (j=Baij->i[i]; j<Baij->i[i+1]; j++) {
    201:       col  = garray[Baij->j[ct]];
    202:       v    = Baij->a[ct++];
    203:       MatSetValues(Bnew,1,&i,1,&col,&v,B->insertmode);
    204:     }
    205:   }
    206:   PetscFree(aij->garray);
    207:   PetscLogObjectMemory((PetscObject)A,-ec*sizeof(PetscInt));
    208:   MatDestroy(&B);
    209:   PetscLogObjectParent((PetscObject)A,(PetscObject)Bnew);

    211:   aij->B           = Bnew;
    212:   A->was_assembled = PETSC_FALSE;
    213:   return(0);
    214: }

    216: /*      ugly stuff added for Glenn someday we should fix this up */

    218: static PetscInt *auglyrmapd = NULL,*auglyrmapo = NULL; /* mapping from the local ordering to the "diagonal" and "off-diagonal" parts of the local matrix */
    219: static Vec auglydd          = NULL,auglyoo     = NULL; /* work vectors used to scale the two parts of the local matrix */

    222: PetscErrorCode MatMPIAIJDiagonalScaleLocalSetUp(Mat inA,Vec scale)
    223: {
    224:   Mat_MPIAIJ     *ina = (Mat_MPIAIJ*) inA->data; /*access private part of matrix */
    226:   PetscInt       i,n,nt,cstart,cend,no,*garray = ina->garray,*lindices;
    227:   PetscInt       *r_rmapd,*r_rmapo;

    230:   MatGetOwnershipRange(inA,&cstart,&cend);
    231:   MatGetSize(ina->A,NULL,&n);
    232:   PetscCalloc1(inA->rmap->mapping->n+1,&r_rmapd);
    233:   nt   = 0;
    234:   for (i=0; i<inA->rmap->mapping->n; i++) {
    235:     if (inA->rmap->mapping->indices[i] >= cstart && inA->rmap->mapping->indices[i] < cend) {
    236:       nt++;
    237:       r_rmapd[i] = inA->rmap->mapping->indices[i] + 1;
    238:     }
    239:   }
    240:   if (nt != n) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Hmm nt %D n %D",nt,n);
    241:   PetscMalloc1(n+1,&auglyrmapd);
    242:   for (i=0; i<inA->rmap->mapping->n; i++) {
    243:     if (r_rmapd[i]) {
    244:       auglyrmapd[(r_rmapd[i]-1)-cstart] = i;
    245:     }
    246:   }
    247:   PetscFree(r_rmapd);
    248:   VecCreateSeq(PETSC_COMM_SELF,n,&auglydd);

    250:   PetscCalloc1(inA->cmap->N+1,&lindices);
    251:   for (i=0; i<ina->B->cmap->n; i++) {
    252:     lindices[garray[i]] = i+1;
    253:   }
    254:   no   = inA->rmap->mapping->n - nt;
    255:   PetscCalloc1(inA->rmap->mapping->n+1,&r_rmapo);
    256:   nt   = 0;
    257:   for (i=0; i<inA->rmap->mapping->n; i++) {
    258:     if (lindices[inA->rmap->mapping->indices[i]]) {
    259:       nt++;
    260:       r_rmapo[i] = lindices[inA->rmap->mapping->indices[i]];
    261:     }
    262:   }
    263:   if (nt > no) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Hmm nt %D no %D",nt,n);
    264:   PetscFree(lindices);
    265:   PetscMalloc1(nt+1,&auglyrmapo);
    266:   for (i=0; i<inA->rmap->mapping->n; i++) {
    267:     if (r_rmapo[i]) {
    268:       auglyrmapo[(r_rmapo[i]-1)] = i;
    269:     }
    270:   }
    271:   PetscFree(r_rmapo);
    272:   VecCreateSeq(PETSC_COMM_SELF,nt,&auglyoo);
    273:   return(0);
    274: }

    276: PetscErrorCode MatMPIAIJDiagonalScaleLocal(Mat A,Vec scale)
    277: {
    278:   /* This routine should really be abandoned as it duplicates MatDiagonalScaleLocal */

    282:   PetscTryMethod(A,"MatDiagonalScaleLocal_C",(Mat,Vec),(A,scale));
    283:   return(0);
    284: }

    286: PetscErrorCode  MatDiagonalScaleLocal_MPIAIJ(Mat A,Vec scale)
    287: {
    288:   Mat_MPIAIJ        *a = (Mat_MPIAIJ*) A->data; /*access private part of matrix */
    289:   PetscErrorCode    ierr;
    290:   PetscInt          n,i;
    291:   PetscScalar       *d,*o;
    292:   const PetscScalar *s;

    295:   if (!auglyrmapd) {
    296:     MatMPIAIJDiagonalScaleLocalSetUp(A,scale);
    297:   }

    299:   VecGetArrayRead(scale,&s);

    301:   VecGetLocalSize(auglydd,&n);
    302:   VecGetArray(auglydd,&d);
    303:   for (i=0; i<n; i++) {
    304:     d[i] = s[auglyrmapd[i]]; /* copy "diagonal" (true local) portion of scale into dd vector */
    305:   }
    306:   VecRestoreArray(auglydd,&d);
    307:   /* column scale "diagonal" portion of local matrix */
    308:   MatDiagonalScale(a->A,NULL,auglydd);

    310:   VecGetLocalSize(auglyoo,&n);
    311:   VecGetArray(auglyoo,&o);
    312:   for (i=0; i<n; i++) {
    313:     o[i] = s[auglyrmapo[i]]; /* copy "off-diagonal" portion of scale into oo vector */
    314:   }
    315:   VecRestoreArrayRead(scale,&s);
    316:   VecRestoreArray(auglyoo,&o);
    317:   /* column scale "off-diagonal" portion of local matrix */
    318:   MatDiagonalScale(a->B,NULL,auglyoo);
    319:   return(0);
    320: }