xref: /petsc/src/vec/is/sf/impls/basic/gather/sfgather.c (revision 855db38d8495605a5e3dcabe2b88744316163d08)
1dd5b3ca6SJunchao Zhang #include <../src/vec/is/sf/impls/basic/gatherv/sfgatherv.h>
2dd5b3ca6SJunchao Zhang 
3dd5b3ca6SJunchao Zhang #define PetscSFPackGet_Gather PetscSFPackGet_Allgatherv
4dd5b3ca6SJunchao Zhang 
5dd5b3ca6SJunchao Zhang /* Reuse the type. The difference is some fields (i.e., displs, recvcounts) are not used in Gather, which is not a big deal */
6dd5b3ca6SJunchao Zhang typedef PetscSF_Allgatherv PetscSF_Gather;
7dd5b3ca6SJunchao Zhang 
8eb02082bSJunchao Zhang PETSC_INTERN PetscErrorCode PetscSFBcastAndOpBegin_Gather(PetscSF sf,MPI_Datatype unit,PetscMemType rootmtype,const void *rootdata,PetscMemType leafmtype,void *leafdata,MPI_Op op)
9dd5b3ca6SJunchao Zhang {
10dd5b3ca6SJunchao Zhang   PetscErrorCode       ierr;
11eb02082bSJunchao Zhang   PetscSFPack          link;
12*855db38dSJunchao Zhang   PetscMPIInt          sendcount;
13dd5b3ca6SJunchao Zhang   MPI_Comm             comm;
14*855db38dSJunchao Zhang   const void           *rootbuf_mpi; /* buffer used by MPI */
15*855db38dSJunchao Zhang   void                 *leafbuf_mpi;
16*855db38dSJunchao Zhang   PetscMemType         rootmtype_mpi,leafmtype_mpi;
17dd5b3ca6SJunchao Zhang 
18dd5b3ca6SJunchao Zhang   PetscFunctionBegin;
19eb02082bSJunchao Zhang   ierr = PetscSFPackGet_Gather(sf,unit,rootmtype,rootdata,leafmtype,leafdata,&link);CHKERRQ(ierr);
20dd5b3ca6SJunchao Zhang   ierr = PetscObjectGetComm((PetscObject)sf,&comm);CHKERRQ(ierr);
21dd5b3ca6SJunchao Zhang   ierr = PetscMPIIntCast(sf->nroots,&sendcount);CHKERRQ(ierr);
22*855db38dSJunchao Zhang   ierr = PetscSFBcastPrepareMPIBuffers_Allgatherv(sf,link,op,&rootmtype_mpi,&rootbuf_mpi,&leafmtype_mpi,&leafbuf_mpi);CHKERRQ(ierr);
23*855db38dSJunchao Zhang   ierr = MPIU_Igather(rootbuf_mpi,sendcount,unit,leafbuf_mpi,sendcount,unit,0/*rank 0*/,comm,link->rootreqs[PETSCSF_ROOT2LEAF_BCAST][rootmtype_mpi]);CHKERRQ(ierr);
24dd5b3ca6SJunchao Zhang   PetscFunctionReturn(0);
25dd5b3ca6SJunchao Zhang }
26dd5b3ca6SJunchao Zhang 
27eb02082bSJunchao Zhang static PetscErrorCode PetscSFReduceBegin_Gather(PetscSF sf,MPI_Datatype unit,PetscMemType leafmtype,const void *leafdata,PetscMemType rootmtype,void *rootdata,MPI_Op op)
28dd5b3ca6SJunchao Zhang {
29dd5b3ca6SJunchao Zhang   PetscErrorCode       ierr;
30eb02082bSJunchao Zhang   PetscSFPack          link;
31dd5b3ca6SJunchao Zhang   PetscMPIInt          recvcount;
32dd5b3ca6SJunchao Zhang   MPI_Comm             comm;
33*855db38dSJunchao Zhang   const void           *leafbuf_mpi;
34*855db38dSJunchao Zhang   void                 *rootbuf_mpi;
35*855db38dSJunchao Zhang   PetscMemType         leafmtype_mpi,rootmtype_mpi;
36dd5b3ca6SJunchao Zhang 
37dd5b3ca6SJunchao Zhang   PetscFunctionBegin;
38eb02082bSJunchao Zhang   ierr = PetscSFPackGet_Gather(sf,unit,rootmtype,rootdata,leafmtype,leafdata,&link);CHKERRQ(ierr);
39dd5b3ca6SJunchao Zhang   ierr = PetscObjectGetComm((PetscObject)sf,&comm);CHKERRQ(ierr);
40dd5b3ca6SJunchao Zhang   ierr = PetscMPIIntCast(sf->nroots,&recvcount);CHKERRQ(ierr);
41*855db38dSJunchao Zhang   ierr = PetscSFReducePrepareMPIBuffers_Gatherv(sf,link,op,&rootmtype_mpi,&rootbuf_mpi,&leafmtype_mpi,&leafbuf_mpi);CHKERRQ(ierr);
42*855db38dSJunchao Zhang   ierr = MPIU_Iscatter(leafbuf_mpi,recvcount,unit,rootbuf_mpi,recvcount,unit,0/*rank 0*/,comm,link->rootreqs[PETSCSF_LEAF2ROOT_REDUCE][rootmtype_mpi]);CHKERRQ(ierr);
43dd5b3ca6SJunchao Zhang   PetscFunctionReturn(0);
44dd5b3ca6SJunchao Zhang }
45dd5b3ca6SJunchao Zhang 
46dd5b3ca6SJunchao Zhang PETSC_INTERN PetscErrorCode PetscSFCreate_Gather(PetscSF sf)
47dd5b3ca6SJunchao Zhang {
48dd5b3ca6SJunchao Zhang   PetscErrorCode  ierr;
49dd5b3ca6SJunchao Zhang   PetscSF_Gather  *dat = (PetscSF_Gather*)sf->data;
50dd5b3ca6SJunchao Zhang 
51dd5b3ca6SJunchao Zhang   PetscFunctionBegin;
52dd5b3ca6SJunchao Zhang   /* Inherit from Allgatherv */
53dd5b3ca6SJunchao Zhang   sf->ops->Reset           = PetscSFReset_Allgatherv;
54dd5b3ca6SJunchao Zhang   sf->ops->Destroy         = PetscSFDestroy_Allgatherv;
55dd5b3ca6SJunchao Zhang   sf->ops->GetGraph        = PetscSFGetGraph_Allgatherv;
56dd5b3ca6SJunchao Zhang   sf->ops->GetRootRanks    = PetscSFGetRootRanks_Allgatherv;
57dd5b3ca6SJunchao Zhang   sf->ops->GetLeafRanks    = PetscSFGetLeafRanks_Allgatherv;
58dd5b3ca6SJunchao Zhang   sf->ops->BcastAndOpEnd   = PetscSFBcastAndOpEnd_Allgatherv;
59dd5b3ca6SJunchao Zhang   sf->ops->ReduceEnd       = PetscSFReduceEnd_Allgatherv;
60dd5b3ca6SJunchao Zhang   sf->ops->FetchAndOpEnd   = PetscSFFetchAndOpEnd_Allgatherv;
61dd5b3ca6SJunchao Zhang   sf->ops->CreateLocalSF   = PetscSFCreateLocalSF_Allgatherv;
62dd5b3ca6SJunchao Zhang 
63dd5b3ca6SJunchao Zhang   /* Inherit from Gatherv */
64dd5b3ca6SJunchao Zhang   sf->ops->FetchAndOpBegin = PetscSFFetchAndOpBegin_Gatherv;
65dd5b3ca6SJunchao Zhang 
66dd5b3ca6SJunchao Zhang   /* Gather stuff */
67dd5b3ca6SJunchao Zhang   sf->ops->BcastAndOpBegin = PetscSFBcastAndOpBegin_Gather;
68dd5b3ca6SJunchao Zhang   sf->ops->ReduceBegin     = PetscSFReduceBegin_Gather;
69dd5b3ca6SJunchao Zhang 
70dd5b3ca6SJunchao Zhang   ierr     = PetscNewLog(sf,&dat);CHKERRQ(ierr);
71dd5b3ca6SJunchao Zhang   sf->data = (void*)dat;
72dd5b3ca6SJunchao Zhang   PetscFunctionReturn(0);
73dd5b3ca6SJunchao Zhang }
74dd5b3ca6SJunchao Zhang 
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