xref: /libCEED/backends/ref/ceed-ref-restriction.c (revision 6dc8cd5c5ab7b9ace8a2e17a66e76b5ad2e7b49e)
1 // Copyright (c) 2017-2018, Lawrence Livermore National Security, LLC.
2 // Produced at the Lawrence Livermore National Laboratory. LLNL-CODE-734707.
3 // All Rights reserved. See files LICENSE and NOTICE for details.
4 //
5 // This file is part of CEED, a collection of benchmarks, miniapps, software
6 // libraries and APIs for efficient high-order finite element and spectral
7 // element discretizations for exascale applications. For more information and
8 // source code availability see http://github.com/ceed.
9 //
10 // The CEED research is supported by the Exascale Computing Project 17-SC-20-SC,
11 // a collaborative effort of two U.S. Department of Energy organizations (Office
12 // of Science and the National Nuclear Security Administration) responsible for
13 // the planning and preparation of a capable exascale ecosystem, including
14 // software, applications, hardware, advanced system engineering and early
15 // testbed platforms, in support of the nation's exascale computing imperative.
16 
17 #include <ceed-impl.h>
18 #include <string.h>
19 #include "ceed-ref.h"
20 
21 static int CeedElemRestrictionApply_Ref(CeedElemRestriction r,
22                                         CeedTransposeMode tmode, CeedInt ncomp,
23                                         CeedTransposeMode lmode, CeedVector u,
24                                         CeedVector v, CeedRequest *request) {
25   CeedElemRestriction_Ref *impl = r->data;
26   int ierr;
27   const CeedScalar *uu;
28   CeedScalar *vv;
29   CeedInt esize = r->nelem*r->elemsize;
30 
31   ierr = CeedVectorGetArrayRead(u, CEED_MEM_HOST, &uu); CeedChk(ierr);
32   ierr = CeedVectorGetArray(v, CEED_MEM_HOST, &vv); CeedChk(ierr);
33   if (tmode == CEED_NOTRANSPOSE) {
34     // Perform: v = r * u
35     if (ncomp == 1) {
36       for (CeedInt i=0; i<esize; i++) vv[i] = uu[impl->indices[i]];
37     } else {
38       // vv is (elemsize x ncomp x nelem), column-major
39       if (lmode == CEED_NOTRANSPOSE) { // u is (ndof x ncomp), column-major
40         for (CeedInt e = 0; e < r->nelem; e++)
41           for (CeedInt d = 0; d < ncomp; d++)
42             for (CeedInt i=0; i<r->elemsize; i++) {
43               vv[i+r->elemsize*(d+ncomp*e)] =
44                 uu[impl->indices[i+r->elemsize*e]+r->ndof*d];
45             }
46       } else { // u is (ncomp x ndof), column-major
47         for (CeedInt e = 0; e < r->nelem; e++)
48           for (CeedInt d = 0; d < ncomp; d++)
49             for (CeedInt i=0; i<r->elemsize; i++) {
50               vv[i+r->elemsize*(d+ncomp*e)] =
51                 uu[d+ncomp*impl->indices[i+r->elemsize*e]];
52             }
53       }
54     }
55   } else {
56     // Note: in transpose mode, we perform: v += r^t * u
57     if (ncomp == 1) {
58       for (CeedInt i=0; i<esize; i++) vv[impl->indices[i]] += uu[i];
59     } else {
60       // u is (elemsize x ncomp x nelem)
61       if (lmode == CEED_NOTRANSPOSE) { // vv is (ndof x ncomp), column-major
62         for (CeedInt e = 0; e < r->nelem; e++)
63           for (CeedInt d = 0; d < ncomp; d++)
64             for (CeedInt i=0; i<r->elemsize; i++) {
65               vv[impl->indices[i+r->elemsize*e]+r->ndof*d] +=
66                 uu[i+r->elemsize*(d+e*ncomp)];
67             }
68       } else { // vv is (ncomp x ndof), column-major
69         for (CeedInt e = 0; e < r->nelem; e++)
70           for (CeedInt d = 0; d < ncomp; d++)
71             for (CeedInt i=0; i<r->elemsize; i++) {
72               vv[d+ncomp*impl->indices[i+r->elemsize*e]] +=
73                 uu[i+r->elemsize*(d+e*ncomp)];
74             }
75       }
76     }
77   }
78   ierr = CeedVectorRestoreArrayRead(u, &uu); CeedChk(ierr);
79   ierr = CeedVectorRestoreArray(v, &vv); CeedChk(ierr);
80   if (request != CEED_REQUEST_IMMEDIATE && request != CEED_REQUEST_ORDERED)
81     *request = NULL;
82   return 0;
83 }
84 
85 static int CeedElemRestrictionDestroy_Ref(CeedElemRestriction r) {
86   CeedElemRestriction_Ref *impl = r->data;
87   int ierr;
88 
89   ierr = CeedFree(&impl->indices_allocated); CeedChk(ierr);
90   ierr = CeedFree(&r->data); CeedChk(ierr);
91   return 0;
92 }
93 
94 int CeedElemRestrictionCreate_Ref(CeedElemRestriction r,
95                                   CeedMemType mtype,
96                                   CeedCopyMode cmode, const CeedInt *indices) {
97   int ierr;
98   CeedElemRestriction_Ref *impl;
99 
100   if (mtype != CEED_MEM_HOST)
101     return CeedError(r->ceed, 1, "Only MemType = HOST supported");
102   ierr = CeedCalloc(1,&impl); CeedChk(ierr);
103   switch (cmode) {
104   case CEED_COPY_VALUES:
105     ierr = CeedMalloc(r->nelem*r->elemsize, &impl->indices_allocated);
106     CeedChk(ierr);
107     memcpy(impl->indices_allocated, indices,
108            r->nelem * r->elemsize * sizeof(indices[0]));
109     impl->indices = impl->indices_allocated;
110     break;
111   case CEED_OWN_POINTER:
112     impl->indices_allocated = (CeedInt *)indices;
113     impl->indices = impl->indices_allocated;
114     break;
115   case CEED_USE_POINTER:
116     impl->indices = indices;
117   }
118   r->data = impl;
119   r->Apply = CeedElemRestrictionApply_Ref;
120   r->Destroy = CeedElemRestrictionDestroy_Ref;
121   return 0;
122 }
123