xref: /libCEED/rust/libceed-sys/c-src/backends/ref/ceed-ref-restriction.c (revision 170d5e7106681a99f11609ba4d34f66fd5013a1d)
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           esize = nblk*blksize*elemsize, 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 if (ncomp == 1) {
43       for (CeedInt i = 0; i<esize; i++) vv[i] = uu[impl->indices[i]];
44     } else {
45       // vv is (elemsize x ncomp x nelem), column-major
46       if (lmode == CEED_NOTRANSPOSE) { // u is (ndof x ncomp), column-major
47         for (CeedInt e = 0; e < nblk*blksize; 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[impl->indices[i+r->elemsize*e]+r->ndof*d];
52       } else { // u is (ncomp x ndof), column-major
53         for (CeedInt e = 0; e < r->nblk*blksize; e++)
54           for (CeedInt d = 0; d < ncomp; d++)
55             for (CeedInt i = 0; i < r->elemsize; i++)
56               vv[i+r->elemsize*(d+ncomp*e)] =
57                 uu[d+ncomp*impl->indices[i+r->elemsize*e]];
58       }
59     }
60   } else {
61     // Note: in transpose mode, we perform: v += r^t * u
62     esize = (nblk - 1)*blksize*elemsize;
63     if (!impl->indices) {
64       for (CeedInt e = 0; e < nblk*blksize; e+=blksize) {
65         CeedInt maxj = ((e<(nblk-1)*blksize)
66                         ||!(r->nelem%blksize))?blksize:r->nelem%blksize;
67         for (CeedInt j = 0; j < maxj; j++)
68           for (CeedInt k = 0; k < ncomp*elemsize; k++)
69             vv[(e + j)*ncomp*elemsize + k] += uu[e*ncomp*elemsize + k*blksize + j];
70       }
71     } else if (ncomp == 1) {
72       for (CeedInt i = 0; i < esize; i++) vv[impl->indices[i]] += uu[i];
73       CeedInt nlastelems = (r->nelem%blksize)?r->nelem%blksize:blksize;
74       CeedInt shift = (nblk - 1)*blksize*elemsize;
75       for (CeedInt i = 0; i < blksize*elemsize; i++)
76         if ((i % blksize) < nlastelems)
77           vv[impl->indices[shift + i]] += uu[shift + i];
78     } else {
79       // u is (elemsize x ncomp x nelem)
80       if (lmode == CEED_NOTRANSPOSE) { // vv is (ndof x ncomp), column-major
81         for (CeedInt e = 0; e < r->nelem; e++)
82           for (CeedInt d = 0; d < ncomp; d++)
83             for (CeedInt i = 0; i < elemsize; i++)
84               vv[impl->indices[i+elemsize*e]+r->ndof*d] +=
85                 uu[i+elemsize*(d+e*ncomp)];
86       } else { // vv is (ncomp x ndof), column-major
87         for (CeedInt e = 0; e < r->nelem; e++)
88           for (CeedInt d = 0; d < ncomp; d++)
89             for (CeedInt i = 0; i < elemsize; i++)
90               vv[d+ncomp*impl->indices[i+elemsize*e]] +=
91                 uu[i+r->elemsize*(d+e*ncomp)];
92       }
93     }
94   }
95   ierr = CeedVectorRestoreArrayRead(u, &uu); CeedChk(ierr);
96   ierr = CeedVectorRestoreArray(v, &vv); CeedChk(ierr);
97   if (request != CEED_REQUEST_IMMEDIATE && request != CEED_REQUEST_ORDERED)
98     *request = NULL;
99   return 0;
100 }
101 
102 static int CeedElemRestrictionDestroy_Ref(CeedElemRestriction r) {
103   CeedElemRestriction_Ref *impl = r->data;
104   int ierr;
105 
106   ierr = CeedFree(&impl->indices_allocated); CeedChk(ierr);
107   ierr = CeedFree(&r->data); CeedChk(ierr);
108   return 0;
109 }
110 
111 int CeedElemRestrictionCreate_Ref(CeedElemRestriction r,
112                                   CeedMemType mtype,
113                                   CeedCopyMode cmode, const CeedInt *indices) {
114   int ierr;
115   CeedElemRestriction_Ref *impl;
116 
117   if (mtype != CEED_MEM_HOST)
118     return CeedError(r->ceed, 1, "Only MemType = HOST supported");
119   ierr = CeedCalloc(1,&impl); CeedChk(ierr);
120   switch (cmode) {
121   case CEED_COPY_VALUES:
122     ierr = CeedMalloc(r->nelem*r->elemsize, &impl->indices_allocated);
123     CeedChk(ierr);
124     memcpy(impl->indices_allocated, indices,
125            r->nelem * r->elemsize * sizeof(indices[0]));
126     impl->indices = impl->indices_allocated;
127     break;
128   case CEED_OWN_POINTER:
129     impl->indices_allocated = (CeedInt *)indices;
130     impl->indices = impl->indices_allocated;
131     break;
132   case CEED_USE_POINTER:
133     impl->indices = indices;
134   }
135   r->data = impl;
136   r->Apply = CeedElemRestrictionApply_Ref;
137   r->Destroy = CeedElemRestrictionDestroy_Ref;
138   return 0;
139 }
140