xref: /libCEED/rust/libceed-sys/c-src/backends/ref/ceed-ref-restriction.c (revision 7fe495dce79ea51a5ec2e0980c38a0f44563dade)
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,
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 nblk = r->nblk, blksize = r->blksize, elemsize = r->elemsize,
30           ncomp=r->ncomp;
31 
32   ierr = CeedVectorGetArrayRead(u, CEED_MEM_HOST, &uu); CeedChk(ierr);
33   ierr = CeedVectorGetArray(v, CEED_MEM_HOST, &vv); CeedChk(ierr);
34   if (tmode == CEED_NOTRANSPOSE) {
35     // Perform: v = r * u
36     if (!impl->indices) {
37       for (CeedInt e = 0; e < nblk*blksize; e+=blksize)
38         for (CeedInt j = 0; j < blksize; j++)
39           for (CeedInt k = 0; k < ncomp*elemsize; k++)
40             vv[e*elemsize*ncomp + k*blksize + j] =
41               uu[CeedIntMin(e+j,r->nelem-1)*ncomp*elemsize + k];
42     } else {
43       // vv is (elemsize x ncomp x nelem), column-major
44       if (lmode == CEED_NOTRANSPOSE) { // u is (ndof x ncomp), column-major
45         for (CeedInt e = 0; e < nblk*blksize; e++)
46           for (CeedInt d = 0; d < ncomp; d++)
47             for (CeedInt i = 0; i < r->elemsize; i++)
48               vv[i+r->elemsize*(d+ncomp*e)] =
49                 uu[impl->indices[i+r->elemsize*e]+r->ndof*d];
50       } else { // u is (ncomp x ndof), column-major
51         for (CeedInt e = 0; e < nblk*blksize; e++)
52           for (CeedInt d = 0; d < ncomp; d++)
53             for (CeedInt i = 0; i < r->elemsize; i++)
54               vv[i+r->elemsize*(d+ncomp*e)] =
55                 uu[d+ncomp*impl->indices[i+r->elemsize*e]];
56       }
57     }
58   } else {
59     // Note: in transpose mode, we perform: v += r^t * u
60     if (!impl->indices) {
61       for (CeedInt e = 0; e < nblk*blksize; e+=blksize) {
62         CeedInt maxj = ((e<(nblk-1)*blksize)
63                         ||!(r->nelem%blksize))?blksize:r->nelem%blksize;
64         for (CeedInt j = 0; j < maxj; j++)
65           for (CeedInt k = 0; k < ncomp*elemsize; k++)
66             vv[(e+j)*ncomp*elemsize + k] += uu[e*elemsize*ncomp + k*blksize + j];
67       }
68     } else {
69       // u is (elemsize x ncomp x nelem)
70       if (lmode == CEED_NOTRANSPOSE) { // vv is (ndof x ncomp), column-major
71         for (CeedInt e = 0; e < nblk; e++) {
72           CeedInt nblkelems = ((e==nblk-1)&&(r->nelem%blksize))?r->nelem%blksize:blksize;
73           for (CeedInt d = 0; d < ncomp; d++)
74             for (CeedInt i = 0; i < elemsize*blksize; i++)
75               if ((i%blksize)<nblkelems) vv[impl->indices[i+e*blksize*elemsize]+r->ndof*d] +=
76                   uu[i+elemsize*(d+e*blksize*ncomp)];
77         }
78       } else { // vv is (ncomp x ndof), column-major
79         for (CeedInt e = 0; e < nblk; e++) {
80           CeedInt nblkelems = ((e==nblk-1)&&(r->nelem%blksize))?r->nelem%blksize:blksize;
81           for (CeedInt d = 0; d < ncomp; d++)
82             for (CeedInt i = 0; i < elemsize*blksize; i++)
83               if ((i%blksize)<nblkelems)  vv[d+ncomp*impl->indices[i+e*blksize*elemsize]] +=
84                   uu[i+r->elemsize*(d+e*blksize*ncomp)];
85         }
86       }
87     }
88   }
89   ierr = CeedVectorRestoreArrayRead(u, &uu); CeedChk(ierr);
90   ierr = CeedVectorRestoreArray(v, &vv); CeedChk(ierr);
91   if (request != CEED_REQUEST_IMMEDIATE && request != CEED_REQUEST_ORDERED)
92     *request = NULL;
93   return 0;
94 }
95 
96 static int CeedElemRestrictionDestroy_Ref(CeedElemRestriction r) {
97   CeedElemRestriction_Ref *impl = r->data;
98   int ierr;
99 
100   ierr = CeedFree(&impl->indices_allocated); CeedChk(ierr);
101   ierr = CeedFree(&r->data); CeedChk(ierr);
102   return 0;
103 }
104 
105 int CeedElemRestrictionCreate_Ref(CeedElemRestriction r,
106                                   CeedMemType mtype,
107                                   CeedCopyMode cmode, const CeedInt *indices) {
108   int ierr;
109   CeedElemRestriction_Ref *impl;
110 
111   if (mtype != CEED_MEM_HOST)
112     return CeedError(r->ceed, 1, "Only MemType = HOST supported");
113   ierr = CeedCalloc(1,&impl); CeedChk(ierr);
114   switch (cmode) {
115   case CEED_COPY_VALUES:
116     ierr = CeedMalloc(r->nelem*r->elemsize, &impl->indices_allocated);
117     CeedChk(ierr);
118     memcpy(impl->indices_allocated, indices,
119            r->nelem * r->elemsize * sizeof(indices[0]));
120     impl->indices = impl->indices_allocated;
121     break;
122   case CEED_OWN_POINTER:
123     impl->indices_allocated = (CeedInt *)indices;
124     impl->indices = impl->indices_allocated;
125     break;
126   case CEED_USE_POINTER:
127     impl->indices = indices;
128   }
129   r->data = impl;
130   r->Apply = CeedElemRestrictionApply_Ref;
131   r->Destroy = CeedElemRestrictionDestroy_Ref;
132   return 0;
133 }
134