xref: /libCEED/backends/ref/ceed-ref-restriction.c (revision 5f2ab5aea732eb0ddc28708ef0797ec66b11b897)
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           }
43         }
44       }
45     } else if (ncomp == 1) {
46       for (CeedInt i = 0; i<esize; i++) vv[i] = uu[impl->indices[i]];
47     } else {
48       // vv is (elemsize x ncomp x nelem), column-major
49       if (lmode == CEED_NOTRANSPOSE) { // u is (ndof x ncomp), column-major
50         for (CeedInt e = 0; e < nblk*blksize; e++)
51           for (CeedInt d = 0; d < ncomp; d++)
52             for (CeedInt i = 0; i < r->elemsize; i++) {
53               vv[i+r->elemsize*(d+ncomp*e)] =
54                 uu[impl->indices[i+r->elemsize*e]+r->ndof*d];
55             }
56       } else { // u is (ncomp x ndof), column-major
57         for (CeedInt e = 0; e < r->nblk*blksize; e++) {
58           for (CeedInt d = 0; d < ncomp; d++) {
59             for (CeedInt i = 0; i < r->elemsize; i++) {
60               vv[i+r->elemsize*(d+ncomp*e)] =
61                 uu[d+ncomp*impl->indices[i+r->elemsize*e]];
62             }
63           }
64         }
65       }
66     }
67   } else {
68     // Note: in transpose mode, we perform: v += r^t * u
69     esize = (nblk - 1)*blksize*elemsize;
70     if (!impl->indices) {
71       for (CeedInt e = 0; e < nblk*blksize; e+=blksize) {
72         CeedInt maxj = ((e<(nblk-1)*blksize)||!(r->nelem%blksize))?blksize:r->nelem%blksize;
73         for (CeedInt j = 0; j < maxj; j++) {
74           for (CeedInt k = 0; k < ncomp*elemsize; k++) {
75             vv[(e + j)*ncomp*elemsize + k] += uu[e*ncomp*elemsize + k*blksize + j];
76           }
77         }
78       }
79     } else if (ncomp == 1) {
80       for (CeedInt i = 0; i < esize; i++) vv[impl->indices[i]] += uu[i];
81       CeedInt nlastelems = (r->nelem%blksize)?r->nelem%blksize:blksize;
82       CeedInt shift = (nblk - 1)*blksize*elemsize;
83       for (CeedInt i = 0; i < blksize*elemsize; i++) {
84         if ((i % blksize) < nlastelems) {
85           vv[impl->indices[shift + i]] += uu[shift + i];
86         }
87       }
88     } else {
89       // u is (elemsize x ncomp x nelem)
90       if (lmode == CEED_NOTRANSPOSE) { // vv is (ndof x ncomp), column-major
91         for (CeedInt e = 0; e < r->nelem; e++) {
92           for (CeedInt d = 0; d < ncomp; d++) {
93             for (CeedInt i = 0; i < elemsize; i++) {
94               vv[impl->indices[i+elemsize*e]+r->ndof*d] +=
95                 uu[i+elemsize*(d+e*ncomp)];
96             }
97           }
98         }
99       } else { // vv is (ncomp x ndof), column-major
100         for (CeedInt e = 0; e < r->nelem; e++) {
101           for (CeedInt d = 0; d < ncomp; d++) {
102             for (CeedInt i = 0; i < elemsize; i++) {
103               vv[d+ncomp*impl->indices[i+elemsize*e]] +=
104                 uu[i+r->elemsize*(d+e*ncomp)];
105             }
106           }
107         }
108       }
109     }
110   }
111   ierr = CeedVectorRestoreArrayRead(u, &uu); CeedChk(ierr);
112   ierr = CeedVectorRestoreArray(v, &vv); CeedChk(ierr);
113   if (request != CEED_REQUEST_IMMEDIATE && request != CEED_REQUEST_ORDERED)
114     *request = NULL;
115   return 0;
116 }
117 
118 static int CeedElemRestrictionDestroy_Ref(CeedElemRestriction r) {
119   CeedElemRestriction_Ref *impl = r->data;
120   int ierr;
121 
122   ierr = CeedFree(&impl->indices_allocated); CeedChk(ierr);
123   ierr = CeedFree(&r->data); CeedChk(ierr);
124   return 0;
125 }
126 
127 int CeedElemRestrictionCreate_Ref(CeedElemRestriction r,
128                                   CeedMemType mtype,
129                                   CeedCopyMode cmode, const CeedInt *indices) {
130   int ierr;
131   CeedElemRestriction_Ref *impl;
132 
133   if (mtype != CEED_MEM_HOST)
134     return CeedError(r->ceed, 1, "Only MemType = HOST supported");
135   ierr = CeedCalloc(1,&impl); CeedChk(ierr);
136   switch (cmode) {
137   case CEED_COPY_VALUES:
138     ierr = CeedMalloc(r->nelem*r->elemsize, &impl->indices_allocated);
139     CeedChk(ierr);
140     memcpy(impl->indices_allocated, indices,
141            r->nelem * r->elemsize * sizeof(indices[0]));
142     impl->indices = impl->indices_allocated;
143     break;
144   case CEED_OWN_POINTER:
145     impl->indices_allocated = (CeedInt *)indices;
146     impl->indices = impl->indices_allocated;
147     break;
148   case CEED_USE_POINTER:
149     impl->indices = indices;
150   }
151   r->data = impl;
152   r->Apply = CeedElemRestrictionApply_Ref;
153   r->Destroy = CeedElemRestrictionDestroy_Ref;
154   return 0;
155 }
156