xref: /petsc/src/vec/is/sf/impls/basic/gather/sfgather.c (revision ad227fea26420e7a31ef041a9fa1418814d171a8)
1dd5b3ca6SJunchao Zhang #include <../src/vec/is/sf/impls/basic/gatherv/sfgatherv.h>
2cd620004SJunchao Zhang #include <../src/vec/is/sf/impls/basic/allgather/sfallgather.h>
3dd5b3ca6SJunchao Zhang 
4dd5b3ca6SJunchao Zhang /* Reuse the type. The difference is some fields (i.e., displs, recvcounts) are not used in Gather, which is not a big deal */
5dd5b3ca6SJunchao Zhang typedef PetscSF_Allgatherv PetscSF_Gather;
6dd5b3ca6SJunchao Zhang 
7*ad227feaSJunchao Zhang PETSC_INTERN PetscErrorCode PetscSFBcastBegin_Gather(PetscSF sf,MPI_Datatype unit,PetscMemType rootmtype,const void *rootdata,PetscMemType leafmtype,void *leafdata,MPI_Op op)
8dd5b3ca6SJunchao Zhang {
9dd5b3ca6SJunchao Zhang   PetscErrorCode       ierr;
10cd620004SJunchao Zhang   PetscSFLink          link;
11855db38dSJunchao Zhang   PetscMPIInt          sendcount;
12dd5b3ca6SJunchao Zhang   MPI_Comm             comm;
13cd620004SJunchao Zhang   void                 *rootbuf = NULL,*leafbuf = NULL;
14cd620004SJunchao Zhang   MPI_Request          *req;
15dd5b3ca6SJunchao Zhang 
16dd5b3ca6SJunchao Zhang   PetscFunctionBegin;
17cd620004SJunchao Zhang   ierr = PetscSFLinkCreate(sf,unit,rootmtype,rootdata,leafmtype,leafdata,op,PETSCSF_BCAST,&link);CHKERRQ(ierr);
18cd620004SJunchao Zhang   ierr = PetscSFLinkPackRootData(sf,link,PETSCSF_REMOTE,rootdata);CHKERRQ(ierr);
19dd5b3ca6SJunchao Zhang   ierr = PetscObjectGetComm((PetscObject)sf,&comm);CHKERRQ(ierr);
20dd5b3ca6SJunchao Zhang   ierr = PetscMPIIntCast(sf->nroots,&sendcount);CHKERRQ(ierr);
21cd620004SJunchao Zhang   ierr = PetscSFLinkGetMPIBuffersAndRequests(sf,link,PETSCSF_ROOT2LEAF,&rootbuf,&leafbuf,&req,NULL);CHKERRQ(ierr);
22cd620004SJunchao Zhang   ierr = MPIU_Igather(rootbuf,sendcount,unit,leafbuf,sendcount,unit,0/*rank 0*/,comm,req);CHKERRQ(ierr);
23dd5b3ca6SJunchao Zhang   PetscFunctionReturn(0);
24dd5b3ca6SJunchao Zhang }
25dd5b3ca6SJunchao Zhang 
26eb02082bSJunchao Zhang static PetscErrorCode PetscSFReduceBegin_Gather(PetscSF sf,MPI_Datatype unit,PetscMemType leafmtype,const void *leafdata,PetscMemType rootmtype,void *rootdata,MPI_Op op)
27dd5b3ca6SJunchao Zhang {
28dd5b3ca6SJunchao Zhang   PetscErrorCode       ierr;
29cd620004SJunchao Zhang   PetscSFLink          link;
30dd5b3ca6SJunchao Zhang   PetscMPIInt          recvcount;
31dd5b3ca6SJunchao Zhang   MPI_Comm             comm;
32cd620004SJunchao Zhang   void                 *rootbuf = NULL,*leafbuf = NULL;
33cd620004SJunchao Zhang   MPI_Request          *req;
34dd5b3ca6SJunchao Zhang 
35dd5b3ca6SJunchao Zhang   PetscFunctionBegin;
36cd620004SJunchao Zhang   ierr = PetscSFLinkCreate(sf,unit,rootmtype,rootdata,leafmtype,leafdata,op,PETSCSF_REDUCE,&link);CHKERRQ(ierr);
37cd620004SJunchao Zhang   ierr = PetscSFLinkPackLeafData(sf,link,PETSCSF_REMOTE,leafdata);CHKERRQ(ierr);
38dd5b3ca6SJunchao Zhang   ierr = PetscObjectGetComm((PetscObject)sf,&comm);CHKERRQ(ierr);
39dd5b3ca6SJunchao Zhang   ierr = PetscMPIIntCast(sf->nroots,&recvcount);CHKERRQ(ierr);
40cd620004SJunchao Zhang   ierr = PetscSFLinkGetMPIBuffersAndRequests(sf,link,PETSCSF_LEAF2ROOT,&rootbuf,&leafbuf,&req,NULL);CHKERRQ(ierr);
41cd620004SJunchao Zhang   ierr = MPIU_Iscatter(leafbuf,recvcount,unit,rootbuf,recvcount,unit,0/*rank 0*/,comm,req);CHKERRQ(ierr);
42dd5b3ca6SJunchao Zhang   PetscFunctionReturn(0);
43dd5b3ca6SJunchao Zhang }
44dd5b3ca6SJunchao Zhang 
45dd5b3ca6SJunchao Zhang PETSC_INTERN PetscErrorCode PetscSFCreate_Gather(PetscSF sf)
46dd5b3ca6SJunchao Zhang {
47dd5b3ca6SJunchao Zhang   PetscErrorCode  ierr;
48dd5b3ca6SJunchao Zhang   PetscSF_Gather  *dat = (PetscSF_Gather*)sf->data;
49dd5b3ca6SJunchao Zhang 
50dd5b3ca6SJunchao Zhang   PetscFunctionBegin;
51*ad227feaSJunchao Zhang   sf->ops->BcastEnd        = PetscSFBcastEnd_Basic;
52cd620004SJunchao Zhang   sf->ops->ReduceEnd       = PetscSFReduceEnd_Basic;
53cd620004SJunchao Zhang 
54dd5b3ca6SJunchao Zhang   /* Inherit from Allgatherv */
55dd5b3ca6SJunchao Zhang   sf->ops->Reset           = PetscSFReset_Allgatherv;
56dd5b3ca6SJunchao Zhang   sf->ops->Destroy         = PetscSFDestroy_Allgatherv;
57dd5b3ca6SJunchao Zhang   sf->ops->GetGraph        = PetscSFGetGraph_Allgatherv;
58dd5b3ca6SJunchao Zhang   sf->ops->GetRootRanks    = PetscSFGetRootRanks_Allgatherv;
59dd5b3ca6SJunchao Zhang   sf->ops->GetLeafRanks    = PetscSFGetLeafRanks_Allgatherv;
60dd5b3ca6SJunchao Zhang   sf->ops->FetchAndOpEnd   = PetscSFFetchAndOpEnd_Allgatherv;
61dd5b3ca6SJunchao Zhang   sf->ops->CreateLocalSF   = PetscSFCreateLocalSF_Allgatherv;
62dd5b3ca6SJunchao Zhang 
63cd620004SJunchao Zhang   /* Inherit from Allgather */
64cd620004SJunchao Zhang   sf->ops->SetUp           = PetscSFSetUp_Allgather;
65cd620004SJunchao Zhang 
66dd5b3ca6SJunchao Zhang   /* Inherit from Gatherv */
67dd5b3ca6SJunchao Zhang   sf->ops->FetchAndOpBegin = PetscSFFetchAndOpBegin_Gatherv;
68dd5b3ca6SJunchao Zhang 
69dd5b3ca6SJunchao Zhang   /* Gather stuff */
70*ad227feaSJunchao Zhang   sf->ops->BcastBegin      = PetscSFBcastBegin_Gather;
71dd5b3ca6SJunchao Zhang   sf->ops->ReduceBegin     = PetscSFReduceBegin_Gather;
72dd5b3ca6SJunchao Zhang 
73dd5b3ca6SJunchao Zhang   ierr     = PetscNewLog(sf,&dat);CHKERRQ(ierr);
74dd5b3ca6SJunchao Zhang   sf->data = (void*)dat;
75dd5b3ca6SJunchao Zhang   PetscFunctionReturn(0);
76dd5b3ca6SJunchao Zhang }
77dd5b3ca6SJunchao Zhang 
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