Actual source code: mmaij.c
petsc-3.10.5 2019-03-28
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      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:     aij->B->cmap->n = aij->B->cmap->N = ec;
     64:     aij->B->cmap->bs = 1;

     66:     PetscLayoutSetUp((aij->B->cmap));
     67:     PetscTableDestroy(&gid1_lid1);
     68: #else
     69:     /* Make an array as long as the number of columns */
     70:     /* mark those columns that are in aij->B */
     71:     PetscCalloc1(N+1,&indices);
     72:     for (i=0; i<aij->B->rmap->n; i++) {
     73:       for (j=0; j<B->ilen[i]; j++) {
     74:         if (!indices[aj[B->i[i] + j]]) ec++;
     75:         indices[aj[B->i[i] + j]] = 1;
     76:       }
     77:     }

     79:     /* form array of columns we need */
     80:     PetscMalloc1(ec+1,&garray);
     81:     ec   = 0;
     82:     for (i=0; i<N; i++) {
     83:       if (indices[i]) garray[ec++] = i;
     84:     }

     86:     /* make indices now point into garray */
     87:     for (i=0; i<ec; i++) {
     88:       indices[garray[i]] = i;
     89:     }

     91:     /* compact out the extra columns in B */
     92:     for (i=0; i<aij->B->rmap->n; i++) {
     93:       for (j=0; j<B->ilen[i]; j++) {
     94:         aj[B->i[i] + j] = indices[aj[B->i[i] + j]];
     95:       }
     96:     }
     97:     aij->B->cmap->n = aij->B->cmap->N = ec;
     98:     aij->B->cmap->bs = 1;

    100:     PetscLayoutSetUp((aij->B->cmap));
    101:     PetscFree(indices);
    102: #endif
    103:   } else {
    104:     garray = aij->garray;
    105:   }

    107:   if (!aij->lvec) {
    108:     /* create local vector that is used to scatter into */
    109:     VecCreateSeq(PETSC_COMM_SELF,ec,&aij->lvec);
    110:   } else {
    111:     VecGetSize(aij->lvec,&ec);
    112:   }

    114:   /* create two temporary Index sets for build scatter gather */
    115:   ISCreateGeneral(((PetscObject)mat)->comm,ec,garray,PETSC_COPY_VALUES,&from);

    117:   ISCreateStride(PETSC_COMM_SELF,ec,0,1,&to);

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

    123:   /* generate the scatter context */
    124:   if (aij->Mvctx_mpi1_flg) {
    125:     VecScatterDestroy(&aij->Mvctx_mpi1);
    126:     VecScatterCreate(gvec,from,aij->lvec,to,&aij->Mvctx_mpi1);
    127:     VecScatterSetType(aij->Mvctx_mpi1,VECSCATTERMPI1);
    128:     PetscLogObjectParent((PetscObject)mat,(PetscObject)aij->Mvctx_mpi1);
    129:   } else {
    130:     VecScatterDestroy(&aij->Mvctx);
    131:     VecScatterCreate(gvec,from,aij->lvec,to,&aij->Mvctx);
    132:     PetscLogObjectParent((PetscObject)mat,(PetscObject)aij->Mvctx);
    133:     PetscLogObjectParent((PetscObject)mat,(PetscObject)aij->lvec);
    134:     PetscLogObjectMemory((PetscObject)mat,(ec+1)*sizeof(PetscInt));
    135:   }
    136:   aij->garray = garray;

    138:   PetscLogObjectParent((PetscObject)mat,(PetscObject)from);
    139:   PetscLogObjectParent((PetscObject)mat,(PetscObject)to);

    141:   ISDestroy(&from);
    142:   ISDestroy(&to);
    143:   VecDestroy(&gvec);
    144:   return(0);
    145: }

    147: /*
    148:      Takes the local part of an already assembled MPIAIJ matrix
    149:    and disassembles it. This is to allow new nonzeros into the matrix
    150:    that require more communication in the matrix vector multiply.
    151:    Thus certain data-structures must be rebuilt.

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

    166:   /* free stuff related to matrix-vec multiply */
    167:   VecGetSize(aij->lvec,&ec); /* needed for PetscLogObjectMemory below */
    168:   VecDestroy(&aij->lvec);
    169:   if (aij->colmap) {
    170: #if defined(PETSC_USE_CTABLE)
    171:     PetscTableDestroy(&aij->colmap);
    172: #else
    173:     PetscFree(aij->colmap);
    174:     PetscLogObjectMemory((PetscObject)A,-aij->B->cmap->n*sizeof(PetscInt));
    175: #endif
    176:   }

    178:   /* make sure that B is assembled so we can access its values */
    179:   MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);
    180:   MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);

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

    193:   if (Baij->nonew >= 0) { /* Inherit insertion error options (if positive). */
    194:     ((Mat_SeqAIJ*)Bnew->data)->nonew = Baij->nonew;
    195:   }

    197:   /*
    198:    Ensure that B's nonzerostate is monotonically increasing.
    199:    Or should this follow the MatSetValues() loop to preserve B's nonzerstate across a MatDisAssemble() call?
    200:    */
    201:   Bnew->nonzerostate = B->nonzerostate;

    203:   PetscFree(nz);
    204:   for (i=0; i<m; i++) {
    205:     for (j=Baij->i[i]; j<Baij->i[i+1]; j++) {
    206:       col  = garray[Baij->j[ct]];
    207:       v    = Baij->a[ct++];
    208:       MatSetValues(Bnew,1,&i,1,&col,&v,B->insertmode);
    209:     }
    210:   }
    211:   PetscFree(aij->garray);
    212:   PetscLogObjectMemory((PetscObject)A,-ec*sizeof(PetscInt));
    213:   MatDestroy(&B);
    214:   PetscLogObjectParent((PetscObject)A,(PetscObject)Bnew);

    216:   aij->B           = Bnew;
    217:   A->was_assembled = PETSC_FALSE;
    218:   return(0);
    219: }

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

    223: static PetscInt *auglyrmapd = 0,*auglyrmapo = 0; /* mapping from the local ordering to the "diagonal" and "off-diagonal" parts of the local matrix */
    224: static Vec auglydd          = 0,auglyoo     = 0; /* work vectors used to scale the two parts of the local matrix */

    227: PetscErrorCode MatMPIAIJDiagonalScaleLocalSetUp(Mat inA,Vec scale)
    228: {
    229:   Mat_MPIAIJ     *ina = (Mat_MPIAIJ*) inA->data; /*access private part of matrix */
    231:   PetscInt       i,n,nt,cstart,cend,no,*garray = ina->garray,*lindices;
    232:   PetscInt       *r_rmapd,*r_rmapo;

    235:   MatGetOwnershipRange(inA,&cstart,&cend);
    236:   MatGetSize(ina->A,NULL,&n);
    237:   PetscCalloc1(inA->rmap->mapping->n+1,&r_rmapd);
    238:   nt   = 0;
    239:   for (i=0; i<inA->rmap->mapping->n; i++) {
    240:     if (inA->rmap->mapping->indices[i] >= cstart && inA->rmap->mapping->indices[i] < cend) {
    241:       nt++;
    242:       r_rmapd[i] = inA->rmap->mapping->indices[i] + 1;
    243:     }
    244:   }
    245:   if (nt != n) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Hmm nt %D n %D",nt,n);
    246:   PetscMalloc1(n+1,&auglyrmapd);
    247:   for (i=0; i<inA->rmap->mapping->n; i++) {
    248:     if (r_rmapd[i]) {
    249:       auglyrmapd[(r_rmapd[i]-1)-cstart] = i;
    250:     }
    251:   }
    252:   PetscFree(r_rmapd);
    253:   VecCreateSeq(PETSC_COMM_SELF,n,&auglydd);

    255:   PetscCalloc1(inA->cmap->N+1,&lindices);
    256:   for (i=0; i<ina->B->cmap->n; i++) {
    257:     lindices[garray[i]] = i+1;
    258:   }
    259:   no   = inA->rmap->mapping->n - nt;
    260:   PetscCalloc1(inA->rmap->mapping->n+1,&r_rmapo);
    261:   nt   = 0;
    262:   for (i=0; i<inA->rmap->mapping->n; i++) {
    263:     if (lindices[inA->rmap->mapping->indices[i]]) {
    264:       nt++;
    265:       r_rmapo[i] = lindices[inA->rmap->mapping->indices[i]];
    266:     }
    267:   }
    268:   if (nt > no) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Hmm nt %D no %D",nt,n);
    269:   PetscFree(lindices);
    270:   PetscMalloc1(nt+1,&auglyrmapo);
    271:   for (i=0; i<inA->rmap->mapping->n; i++) {
    272:     if (r_rmapo[i]) {
    273:       auglyrmapo[(r_rmapo[i]-1)] = i;
    274:     }
    275:   }
    276:   PetscFree(r_rmapo);
    277:   VecCreateSeq(PETSC_COMM_SELF,nt,&auglyoo);
    278:   return(0);
    279: }

    281: PetscErrorCode MatMPIAIJDiagonalScaleLocal(Mat A,Vec scale)
    282: {
    283:   /* This routine should really be abandoned as it duplicates MatDiagonalScaleLocal */

    287:   PetscTryMethod(A,"MatDiagonalScaleLocal_C",(Mat,Vec),(A,scale));
    288:   return(0);
    289: }

    291: PetscErrorCode  MatDiagonalScaleLocal_MPIAIJ(Mat A,Vec scale)
    292: {
    293:   Mat_MPIAIJ        *a = (Mat_MPIAIJ*) A->data; /*access private part of matrix */
    294:   PetscErrorCode    ierr;
    295:   PetscInt          n,i;
    296:   PetscScalar       *d,*o;
    297:   const PetscScalar *s;

    300:   if (!auglyrmapd) {
    301:     MatMPIAIJDiagonalScaleLocalSetUp(A,scale);
    302:   }

    304:   VecGetArrayRead(scale,&s);

    306:   VecGetLocalSize(auglydd,&n);
    307:   VecGetArray(auglydd,&d);
    308:   for (i=0; i<n; i++) {
    309:     d[i] = s[auglyrmapd[i]]; /* copy "diagonal" (true local) portion of scale into dd vector */
    310:   }
    311:   VecRestoreArray(auglydd,&d);
    312:   /* column scale "diagonal" portion of local matrix */
    313:   MatDiagonalScale(a->A,NULL,auglydd);

    315:   VecGetLocalSize(auglyoo,&n);
    316:   VecGetArray(auglyoo,&o);
    317:   for (i=0; i<n; i++) {
    318:     o[i] = s[auglyrmapo[i]]; /* copy "off-diagonal" portion of scale into oo vector */
    319:   }
    320:   VecRestoreArrayRead(scale,&s);
    321:   VecRestoreArray(auglyoo,&o);
    322:   /* column scale "off-diagonal" portion of local matrix */
    323:   MatDiagonalScale(a->B,NULL,auglyoo);
    324:   return(0);
    325: }