Date: 2022-08-02T03:13:48+00:00

Actual source code: mmaij.c

      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);
     13:   PetscInt           i,j,*aj = B->j,*garray;
     14:   PetscInt           ec = 0; /* Number of nonzero external columns */
     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

     25:   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,&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,&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,&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) {
    105:     MatCreateVecs(aij->B,&aij->lvec,NULL);
    106:   }
    107:   VecGetSize(aij->lvec,&ec);

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

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

    117:   /* generate the scatter context */
    118:   VecScatterDestroy(&aij->Mvctx);
    119:   VecScatterCreate(gvec,from,aij->lvec,to,&aij->Mvctx);
    120:   VecScatterViewFromOptions(aij->Mvctx,(PetscObject)mat,"-matmult_vecscatter_view");
    121:   PetscLogObjectParent((PetscObject)mat,(PetscObject)aij->Mvctx);
    122:   PetscLogObjectParent((PetscObject)mat,(PetscObject)aij->lvec);
    123:   PetscLogObjectMemory((PetscObject)mat,ec*sizeof(PetscInt));
    124:   aij->garray = garray;

    126:   PetscLogObjectParent((PetscObject)mat,(PetscObject)from);
    127:   PetscLogObjectParent((PetscObject)mat,(PetscObject)to);

    129:   ISDestroy(&from);
    130:   ISDestroy(&to);
    131:   VecDestroy(&gvec);
    132:   return 0;
    133: }

    135: /* Disassemble the off-diag portion of the MPIAIJXxx matrix.
    136:    In other words, change the B from reduced format using local col ids
    137:    to expanded format using global col ids, which will make it easier to
    138:    insert new nonzeros (with global col ids) into the matrix.
    139:    The off-diag B determines communication in the matrix vector multiply.
    140: */
    141: PetscErrorCode MatDisAssemble_MPIAIJ(Mat A)
    142: {
    143:   Mat_MPIAIJ        *aij  = (Mat_MPIAIJ*)A->data;
    144:   Mat               B     = aij->B,Bnew;
    145:   Mat_SeqAIJ        *Baij = (Mat_SeqAIJ*)B->data;
    146:   PetscInt          i,j,m = B->rmap->n,n = A->cmap->N,col,ct = 0,*garray = aij->garray,*nz,ec;
    147:   PetscScalar       v;
    148:   const PetscScalar *ba;

    150:   /* free stuff related to matrix-vec multiply */
    151:   VecGetSize(aij->lvec,&ec); /* needed for PetscLogObjectMemory below */
    152:   VecDestroy(&aij->lvec);
    153:   if (aij->colmap) {
    154: #if defined(PETSC_USE_CTABLE)
    155:     PetscTableDestroy(&aij->colmap);
    156: #else
    157:     PetscFree(aij->colmap);
    158:     PetscLogObjectMemory((PetscObject)A,-aij->B->cmap->n*sizeof(PetscInt));
    159: #endif
    160:   }

    162:   /* make sure that B is assembled so we can access its values */
    163:   MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);
    164:   MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);

    166:   /* invent new B and copy stuff over */
    167:   PetscMalloc1(m+1,&nz);
    168:   for (i=0; i<m; i++) {
    169:     nz[i] = Baij->i[i+1] - Baij->i[i];
    170:   }
    171:   MatCreate(PETSC_COMM_SELF,&Bnew);
    172:   MatSetSizes(Bnew,m,n,m,n); /* Bnew now uses A->cmap->N as its col size */
    173:   MatSetBlockSizesFromMats(Bnew,A,A);
    174:   MatSetType(Bnew,((PetscObject)B)->type_name);
    175:   MatSeqAIJSetPreallocation(Bnew,0,nz);

    177:   if (Baij->nonew >= 0) { /* Inherit insertion error options (if positive). */
    178:     ((Mat_SeqAIJ*)Bnew->data)->nonew = Baij->nonew;
    179:   }

    181:   /*
    182:    Ensure that B's nonzerostate is monotonically increasing.
    183:    Or should this follow the MatSetValues() loop to preserve B's nonzerstate across a MatDisAssemble() call?
    184:    */
    185:   Bnew->nonzerostate = B->nonzerostate;

    187:   PetscFree(nz);
    188:   MatSeqAIJGetArrayRead(B,&ba);
    189:   for (i=0; i<m; i++) {
    190:     for (j=Baij->i[i]; j<Baij->i[i+1]; j++) {
    191:       col  = garray[Baij->j[ct]];
    192:       v    = ba[ct++];
    193:       MatSetValues(Bnew,1,&i,1,&col,&v,B->insertmode);
    194:     }
    195:   }
    196:   MatSeqAIJRestoreArrayRead(B,&ba);

    198:   PetscFree(aij->garray);
    199:   PetscLogObjectMemory((PetscObject)A,-ec*sizeof(PetscInt));
    200:   MatDestroy(&B);
    201:   PetscLogObjectParent((PetscObject)A,(PetscObject)Bnew);

    203:   aij->B           = Bnew;
    204:   A->was_assembled = PETSC_FALSE;
    205:   return 0;
    206: }

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

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

    213: PetscErrorCode MatMPIAIJDiagonalScaleLocalSetUp(Mat inA,Vec scale)
    214: {
    215:   Mat_MPIAIJ     *ina = (Mat_MPIAIJ*) inA->data; /*access private part of matrix */
    216:   PetscInt       i,n,nt,cstart,cend,no,*garray = ina->garray,*lindices;
    217:   PetscInt       *r_rmapd,*r_rmapo;

    219:   MatGetOwnershipRange(inA,&cstart,&cend);
    220:   MatGetSize(ina->A,NULL,&n);
    221:   PetscCalloc1(inA->rmap->mapping->n+1,&r_rmapd);
    222:   nt   = 0;
    223:   for (i=0; i<inA->rmap->mapping->n; i++) {
    224:     if (inA->rmap->mapping->indices[i] >= cstart && inA->rmap->mapping->indices[i] < cend) {
    225:       nt++;
    226:       r_rmapd[i] = inA->rmap->mapping->indices[i] + 1;
    227:     }
    228:   }
    230:   PetscMalloc1(n+1,&auglyrmapd);
    231:   for (i=0; i<inA->rmap->mapping->n; i++) {
    232:     if (r_rmapd[i]) {
    233:       auglyrmapd[(r_rmapd[i]-1)-cstart] = i;
    234:     }
    235:   }
    236:   PetscFree(r_rmapd);
    237:   VecCreateSeq(PETSC_COMM_SELF,n,&auglydd);

    239:   PetscCalloc1(inA->cmap->N+1,&lindices);
    240:   for (i=0; i<ina->B->cmap->n; i++) {
    241:     lindices[garray[i]] = i+1;
    242:   }
    243:   no   = inA->rmap->mapping->n - nt;
    244:   PetscCalloc1(inA->rmap->mapping->n+1,&r_rmapo);
    245:   nt   = 0;
    246:   for (i=0; i<inA->rmap->mapping->n; i++) {
    247:     if (lindices[inA->rmap->mapping->indices[i]]) {
    248:       nt++;
    249:       r_rmapo[i] = lindices[inA->rmap->mapping->indices[i]];
    250:     }
    251:   }
    253:   PetscFree(lindices);
    254:   PetscMalloc1(nt+1,&auglyrmapo);
    255:   for (i=0; i<inA->rmap->mapping->n; i++) {
    256:     if (r_rmapo[i]) {
    257:       auglyrmapo[(r_rmapo[i]-1)] = i;
    258:     }
    259:   }
    260:   PetscFree(r_rmapo);
    261:   VecCreateSeq(PETSC_COMM_SELF,nt,&auglyoo);
    262:   return 0;
    263: }

    265: PetscErrorCode MatMPIAIJDiagonalScaleLocal(Mat A,Vec scale)
    266: {
    267:   /* This routine should really be abandoned as it duplicates MatDiagonalScaleLocal */

    269:   PetscTryMethod(A,"MatDiagonalScaleLocal_C",(Mat,Vec),(A,scale));
    270:   return 0;
    271: }

    273: PetscErrorCode  MatDiagonalScaleLocal_MPIAIJ(Mat A,Vec scale)
    274: {
    275:   Mat_MPIAIJ        *a = (Mat_MPIAIJ*) A->data; /*access private part of matrix */
    276:   PetscInt          n,i;
    277:   PetscScalar       *d,*o;
    278:   const PetscScalar *s;

    280:   if (!auglyrmapd) {
    281:     MatMPIAIJDiagonalScaleLocalSetUp(A,scale);
    282:   }

    284:   VecGetArrayRead(scale,&s);

    286:   VecGetLocalSize(auglydd,&n);
    287:   VecGetArray(auglydd,&d);
    288:   for (i=0; i<n; i++) {
    289:     d[i] = s[auglyrmapd[i]]; /* copy "diagonal" (true local) portion of scale into dd vector */
    290:   }
    291:   VecRestoreArray(auglydd,&d);
    292:   /* column scale "diagonal" portion of local matrix */
    293:   MatDiagonalScale(a->A,NULL,auglydd);

    295:   VecGetLocalSize(auglyoo,&n);
    296:   VecGetArray(auglyoo,&o);
    297:   for (i=0; i<n; i++) {
    298:     o[i] = s[auglyrmapo[i]]; /* copy "off-diagonal" portion of scale into oo vector */
    299:   }
    300:   VecRestoreArrayRead(scale,&s);
    301:   VecRestoreArray(auglyoo,&o);
    302:   /* column scale "off-diagonal" portion of local matrix */
    303:   MatDiagonalScale(a->B,NULL,auglyoo);
    304:   return 0;
    305: }