xref: /petsc/src/vec/is/sf/impls/basic/gather/sfgather.c (revision dd5b3ca66ca4de5e00e985c205d0f80060c552e8)
1*dd5b3ca6SJunchao Zhang #include <../src/vec/is/sf/impls/basic/gatherv/sfgatherv.h>
2*dd5b3ca6SJunchao Zhang 
3*dd5b3ca6SJunchao Zhang typedef PetscSFPack_Allgatherv PetscSFPack_Gather;
4*dd5b3ca6SJunchao Zhang #define PetscSFPackGet_Gather PetscSFPackGet_Allgatherv
5*dd5b3ca6SJunchao Zhang 
6*dd5b3ca6SJunchao Zhang /* Reuse the type. The difference is some fields (i.e., displs, recvcounts) are not used in Gather, which is not a big deal */
7*dd5b3ca6SJunchao Zhang typedef PetscSF_Allgatherv PetscSF_Gather;
8*dd5b3ca6SJunchao Zhang 
9*dd5b3ca6SJunchao Zhang PETSC_INTERN PetscErrorCode PetscSFBcastAndOpBegin_Gather(PetscSF sf,MPI_Datatype unit,const void *rootdata,void *leafdata,MPI_Op op)
10*dd5b3ca6SJunchao Zhang {
11*dd5b3ca6SJunchao Zhang   PetscErrorCode       ierr;
12*dd5b3ca6SJunchao Zhang   PetscSFPack_Gatherv  link;
13*dd5b3ca6SJunchao Zhang   PetscMPIInt          rank,sendcount;
14*dd5b3ca6SJunchao Zhang   MPI_Comm             comm;
15*dd5b3ca6SJunchao Zhang   void                 *recvbuf;
16*dd5b3ca6SJunchao Zhang 
17*dd5b3ca6SJunchao Zhang   PetscFunctionBegin;
18*dd5b3ca6SJunchao Zhang   ierr = PetscSFPackGet_Gatherv(sf,unit,rootdata,&link);CHKERRQ(ierr);
19*dd5b3ca6SJunchao Zhang   ierr = PetscObjectGetComm((PetscObject)sf,&comm);CHKERRQ(ierr);
20*dd5b3ca6SJunchao Zhang 
21*dd5b3ca6SJunchao Zhang   if (op == MPIU_REPLACE) {
22*dd5b3ca6SJunchao Zhang     recvbuf = leafdata;
23*dd5b3ca6SJunchao Zhang   } else {
24*dd5b3ca6SJunchao Zhang     ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
25*dd5b3ca6SJunchao Zhang     if (!link->leaf && !rank) {ierr = PetscMalloc(sf->nleaves*link->unitbytes,&link->leaf);CHKERRQ(ierr);}
26*dd5b3ca6SJunchao Zhang     recvbuf = link->leaf;
27*dd5b3ca6SJunchao Zhang   }
28*dd5b3ca6SJunchao Zhang 
29*dd5b3ca6SJunchao Zhang   ierr = PetscMPIIntCast(sf->nroots,&sendcount);CHKERRQ(ierr);
30*dd5b3ca6SJunchao Zhang   ierr = MPIU_Igather(rootdata,sendcount,unit,recvbuf,sendcount,unit,0/*rank 0*/,comm,&link->request);CHKERRQ(ierr);
31*dd5b3ca6SJunchao Zhang   PetscFunctionReturn(0);
32*dd5b3ca6SJunchao Zhang }
33*dd5b3ca6SJunchao Zhang 
34*dd5b3ca6SJunchao Zhang static PetscErrorCode PetscSFReduceBegin_Gather(PetscSF sf,MPI_Datatype unit,const void *leafdata,void *rootdata,MPI_Op op)
35*dd5b3ca6SJunchao Zhang {
36*dd5b3ca6SJunchao Zhang   PetscErrorCode       ierr;
37*dd5b3ca6SJunchao Zhang   PetscSFPack_Gatherv  link;
38*dd5b3ca6SJunchao Zhang   PetscMPIInt          recvcount;
39*dd5b3ca6SJunchao Zhang   MPI_Comm             comm;
40*dd5b3ca6SJunchao Zhang   void                 *recvbuf;
41*dd5b3ca6SJunchao Zhang 
42*dd5b3ca6SJunchao Zhang   PetscFunctionBegin;
43*dd5b3ca6SJunchao Zhang   ierr = PetscSFPackGet_Gatherv(sf,unit,leafdata,&link);CHKERRQ(ierr);
44*dd5b3ca6SJunchao Zhang   ierr = PetscObjectGetComm((PetscObject)sf,&comm);CHKERRQ(ierr);
45*dd5b3ca6SJunchao Zhang 
46*dd5b3ca6SJunchao Zhang   if (op == MPIU_REPLACE) {
47*dd5b3ca6SJunchao Zhang     recvbuf = rootdata;
48*dd5b3ca6SJunchao Zhang   } else {
49*dd5b3ca6SJunchao Zhang     if (!link->root) {ierr = PetscMalloc(sf->nroots*link->unitbytes,&link->root);CHKERRQ(ierr);}
50*dd5b3ca6SJunchao Zhang     recvbuf = link->root;
51*dd5b3ca6SJunchao Zhang   }
52*dd5b3ca6SJunchao Zhang 
53*dd5b3ca6SJunchao Zhang   ierr = PetscMPIIntCast(sf->nroots,&recvcount);CHKERRQ(ierr);
54*dd5b3ca6SJunchao Zhang   ierr = MPIU_Iscatter(leafdata,recvcount,unit,recvbuf,recvcount,unit,0/*rank 0*/,comm,&link->request);CHKERRQ(ierr);
55*dd5b3ca6SJunchao Zhang   PetscFunctionReturn(0);
56*dd5b3ca6SJunchao Zhang }
57*dd5b3ca6SJunchao Zhang 
58*dd5b3ca6SJunchao Zhang PETSC_INTERN PetscErrorCode PetscSFCreate_Gather(PetscSF sf)
59*dd5b3ca6SJunchao Zhang {
60*dd5b3ca6SJunchao Zhang   PetscErrorCode  ierr;
61*dd5b3ca6SJunchao Zhang   PetscSF_Gather  *dat = (PetscSF_Gather*)sf->data;
62*dd5b3ca6SJunchao Zhang 
63*dd5b3ca6SJunchao Zhang   PetscFunctionBegin;
64*dd5b3ca6SJunchao Zhang   /* Inherit from Allgatherv */
65*dd5b3ca6SJunchao Zhang   sf->ops->Reset           = PetscSFReset_Allgatherv;
66*dd5b3ca6SJunchao Zhang   sf->ops->Destroy         = PetscSFDestroy_Allgatherv;
67*dd5b3ca6SJunchao Zhang   sf->ops->GetGraph        = PetscSFGetGraph_Allgatherv;
68*dd5b3ca6SJunchao Zhang   sf->ops->GetRootRanks    = PetscSFGetRootRanks_Allgatherv;
69*dd5b3ca6SJunchao Zhang   sf->ops->GetLeafRanks    = PetscSFGetLeafRanks_Allgatherv;
70*dd5b3ca6SJunchao Zhang   sf->ops->BcastAndOpEnd   = PetscSFBcastAndOpEnd_Allgatherv;
71*dd5b3ca6SJunchao Zhang   sf->ops->ReduceEnd       = PetscSFReduceEnd_Allgatherv;
72*dd5b3ca6SJunchao Zhang   sf->ops->FetchAndOpEnd   = PetscSFFetchAndOpEnd_Allgatherv;
73*dd5b3ca6SJunchao Zhang   sf->ops->CreateLocalSF   = PetscSFCreateLocalSF_Allgatherv;
74*dd5b3ca6SJunchao Zhang 
75*dd5b3ca6SJunchao Zhang   /* Inherit from Gatherv */
76*dd5b3ca6SJunchao Zhang   sf->ops->FetchAndOpBegin = PetscSFFetchAndOpBegin_Gatherv;
77*dd5b3ca6SJunchao Zhang 
78*dd5b3ca6SJunchao Zhang   /* Gather stuff */
79*dd5b3ca6SJunchao Zhang   sf->ops->BcastAndOpBegin = PetscSFBcastAndOpBegin_Gather;
80*dd5b3ca6SJunchao Zhang   sf->ops->ReduceBegin     = PetscSFReduceBegin_Gather;
81*dd5b3ca6SJunchao Zhang 
82*dd5b3ca6SJunchao Zhang   ierr     = PetscNewLog(sf,&dat);CHKERRQ(ierr);
83*dd5b3ca6SJunchao Zhang   sf->data = (void*)dat;
84*dd5b3ca6SJunchao Zhang   PetscFunctionReturn(0);
85*dd5b3ca6SJunchao Zhang }
86*dd5b3ca6SJunchao Zhang 
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