xref: /libCEED/backends/ref/ceed-ref-restriction.c (revision 4d2a38eef5ff52550a65501d135c766add2f50f7)
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-ref.h"
18 
19 static inline int CeedElemRestrictionApply_Ref_Core(CeedElemRestriction r,
20     const CeedInt blksize, CeedInt start, CeedInt stop, CeedTransposeMode tmode,
21     CeedTransposeMode lmode, CeedVector u, CeedVector v, CeedRequest *request) {
22   int ierr;
23   CeedElemRestriction_Ref *impl;
24   ierr = CeedElemRestrictionGetData(r, (void *)&impl); CeedChk(ierr);;
25   const CeedScalar *uu;
26   CeedScalar *vv;
27   CeedInt nelem, elemsize, nnodes, ncomp, voffset;
28   ierr = CeedElemRestrictionGetNumElements(r, &nelem); CeedChk(ierr);
29   ierr = CeedElemRestrictionGetElementSize(r, &elemsize); CeedChk(ierr);
30   ierr = CeedElemRestrictionGetNumNodes(r, &nnodes); CeedChk(ierr);
31   ierr = CeedElemRestrictionGetNumComponents(r, &ncomp); CeedChk(ierr);
32   voffset = start*blksize*elemsize*ncomp;
33 
34   ierr = CeedVectorGetArrayRead(u, CEED_MEM_HOST, &uu); CeedChk(ierr);
35   ierr = CeedVectorGetArray(v, CEED_MEM_HOST, &vv); CeedChk(ierr);
36   // Restriction from lvector to evector
37   // Perform: v = r * u
38   if (tmode == CEED_NOTRANSPOSE) {
39     // No indices provided, Identity Restriction
40     if (!impl->indices) {
41       for (CeedInt e = start*blksize; e < stop*blksize; e+=blksize)
42         for (CeedInt j = 0; j < blksize; j++)
43           for (CeedInt k = 0; k < ncomp*elemsize; k++)
44             vv[e*elemsize*ncomp + k*blksize + j - voffset]
45               = uu[CeedIntMin(e+j,nelem-1)*ncomp*elemsize + k];
46     } else {
47       // Indices provided, standard or blocked restriction
48       // vv has shape [elemsize, ncomp, nelem], row-major
49       // uu has shape [nnodes, ncomp]
50       for (CeedInt e = start*blksize; e < stop*blksize; e+=blksize)
51         for (CeedInt d = 0; d < ncomp; d++)
52           for (CeedInt i = 0; i < elemsize*blksize; i++)
53             vv[i+elemsize*(d*blksize+ncomp*e) - voffset]
54               = uu[lmode == CEED_NOTRANSPOSE
55                          ? impl->indices[i+elemsize*e]+nnodes*d
56                          : d+ncomp*impl->indices[i+elemsize*e]];
57     }
58   } else {
59     // Restriction from evector to lvector
60     // Performing v += r^T * u
61     // No indices provided, Identity Restriction
62     if (!impl->indices) {
63       for (CeedInt e = start*blksize; e < stop*blksize; e+=blksize)
64         for (CeedInt j = 0; j < CeedIntMin(blksize, nelem-e); j++)
65           for (CeedInt k = 0; k < ncomp*elemsize; k++)
66             vv[(e+j)*ncomp*elemsize + k]
67             += uu[e*elemsize*ncomp + k*blksize + j - voffset];
68     } else {
69       // Indices provided, standard or blocked restriction
70       // uu has shape [elemsize, ncomp, nelem]
71       // vv has shape [nnodes, ncomp]
72       for (CeedInt e = start*blksize; e < stop*blksize; e+=blksize) {
73         for (CeedInt d = 0; d < ncomp; d++)
74           for (CeedInt i = 0; i < elemsize*blksize; i+=blksize)
75             // Iteration bound set to discard padding elements
76             for (CeedInt j = i; j < i+CeedIntMin(blksize, nelem-e); j++)
77               vv[lmode == CEED_NOTRANSPOSE
78                        ? impl->indices[j+e*elemsize]+nnodes*d
79                        : d+ncomp*impl->indices[j+e*elemsize]]
80               += uu[j+elemsize*(d*blksize+ncomp*e) - voffset];
81       }
82     }
83   }
84   ierr = CeedVectorRestoreArrayRead(u, &uu); CeedChk(ierr);
85   ierr = CeedVectorRestoreArray(v, &vv); CeedChk(ierr);
86   if (request != CEED_REQUEST_IMMEDIATE && request != CEED_REQUEST_ORDERED)
87     *request = NULL;
88   return 0;
89 }
90 
91 static int CeedElemRestrictionApply_Ref_Core_1(CeedElemRestriction r,
92     CeedInt start, CeedInt stop, CeedTransposeMode tmode,
93     CeedTransposeMode lmode, CeedVector u, CeedVector v, CeedRequest *request) {
94   return  CeedElemRestrictionApply_Ref_Core(r, 1, start, stop, tmode, lmode, u,
95            v, request);
96 }
97 
98 static int CeedElemRestrictionApply_Ref_Core_8(CeedElemRestriction r,
99     CeedInt start, CeedInt stop, CeedTransposeMode tmode,
100     CeedTransposeMode lmode, CeedVector u, CeedVector v, CeedRequest *request) {
101   return  CeedElemRestrictionApply_Ref_Core(r, 8, start, stop, tmode, lmode, u,
102            v, request);
103 }
104 
105 static int CeedElemRestrictionApply_Ref(CeedElemRestriction r,
106                                         CeedTransposeMode tmode,
107                                         CeedTransposeMode lmode, CeedVector u,
108                                         CeedVector v, CeedRequest *request) {
109   int ierr;
110   CeedInt numblk, blksize;
111   ierr = CeedElemRestrictionGetNumBlocks(r, &numblk); CeedChk(ierr);
112   ierr = CeedElemRestrictionGetBlockSize(r, &blksize); CeedChk(ierr);
113 
114   if (blksize == 1)
115     return CeedElemRestrictionApply_Ref_Core_1(r, 0, numblk, tmode, lmode, u,
116            v, request);
117   else if (blksize == 8)
118     return CeedElemRestrictionApply_Ref_Core_8(r, 0, numblk, tmode, lmode, u,
119            v, request);
120   else
121     // LCOV_EXCL_START
122     return CeedElemRestrictionApply_Ref_Core(r, blksize, 0, numblk, tmode,
123            lmode, u, v, request);
124   // LCOV_EXCL_STOP
125 }
126 
127 static int CeedElemRestrictionApplyBlock_Ref(CeedElemRestriction r,
128     CeedInt block, CeedTransposeMode tmode, CeedTransposeMode lmode,
129     CeedVector u, CeedVector v, CeedRequest *request) {
130   int ierr;
131   CeedInt blksize;
132   ierr = CeedElemRestrictionGetBlockSize(r, &blksize); CeedChk(ierr);
133 
134   if (blksize == 1)
135     return CeedElemRestrictionApply_Ref_Core_1(r, block, block+1, tmode, lmode,
136            u, v, request);
137   else if (blksize == 8)
138     return CeedElemRestrictionApply_Ref_Core_8(r, block, block+1, tmode, lmode,
139            u, v, request);
140   else
141     // LCOV_EXCL_START
142     return CeedElemRestrictionApply_Ref_Core(r, blksize, block, block+1, tmode,
143            lmode, u, v, request);
144   // LCOV_EXCL_STOP
145 }
146 
147 static int CeedElemRestrictionDestroy_Ref(CeedElemRestriction r) {
148   int ierr;
149   CeedElemRestriction_Ref *impl;
150   ierr = CeedElemRestrictionGetData(r, (void *)&impl); CeedChk(ierr);
151 
152   ierr = CeedFree(&impl->indices_allocated); CeedChk(ierr);
153   ierr = CeedFree(&impl); CeedChk(ierr);
154   return 0;
155 }
156 
157 int CeedElemRestrictionCreate_Ref(CeedMemType mtype, CeedCopyMode cmode,
158                                   const CeedInt *indices, CeedElemRestriction r) {
159   int ierr;
160   CeedElemRestriction_Ref *impl;
161   CeedInt elemsize, nelem;
162   ierr = CeedElemRestrictionGetNumElements(r, &nelem); CeedChk(ierr);
163   ierr = CeedElemRestrictionGetElementSize(r, &elemsize); CeedChk(ierr);
164   Ceed ceed;
165   ierr = CeedElemRestrictionGetCeed(r, &ceed); CeedChk(ierr);
166 
167   if (mtype != CEED_MEM_HOST)
168     // LCOV_EXCL_START
169     return CeedError(ceed, 1, "Only MemType = HOST supported");
170   // LCOV_EXCL_STOP
171   ierr = CeedCalloc(1,&impl); CeedChk(ierr);
172   switch (cmode) {
173   case CEED_COPY_VALUES:
174     ierr = CeedMalloc(nelem*elemsize, &impl->indices_allocated);
175     CeedChk(ierr);
176     memcpy(impl->indices_allocated, indices,
177            nelem * elemsize * sizeof(indices[0]));
178     impl->indices = impl->indices_allocated;
179     break;
180   case CEED_OWN_POINTER:
181     impl->indices_allocated = (CeedInt *)indices;
182     impl->indices = impl->indices_allocated;
183     break;
184   case CEED_USE_POINTER:
185     impl->indices = indices;
186   }
187 
188   ierr = CeedElemRestrictionSetData(r, (void *)&impl); CeedChk(ierr);
189   ierr = CeedSetBackendFunction(ceed, "ElemRestriction", r, "Apply",
190                                 CeedElemRestrictionApply_Ref); CeedChk(ierr);
191   ierr = CeedSetBackendFunction(ceed, "ElemRestriction", r, "ApplyBlock",
192                                 CeedElemRestrictionApplyBlock_Ref);
193   CeedChk(ierr);
194   ierr = CeedSetBackendFunction(ceed, "ElemRestriction", r, "Destroy",
195                                 CeedElemRestrictionDestroy_Ref); CeedChk(ierr);
196   return 0;
197 }
198