xref: /libCEED/backends/ref/ceed-ref-operator.c (revision cae8b89ab4384ccb591c7143fd0ca8a192ac9d03) 
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 int CeedOperatorDestroy_Ref(CeedOperator op) {
20   int ierr;
21   CeedOperator_Ref *impl;
22   ierr = CeedOperatorGetData(op, (void *)&impl); CeedChk(ierr);
23 
24   for (CeedInt i=0; i<impl->numein+impl->numeout; i++) {
25     ierr = CeedVectorDestroy(&impl->evecs[i]); CeedChk(ierr);
26   }
27   ierr = CeedFree(&impl->evecs); CeedChk(ierr);
28   ierr = CeedFree(&impl->edata); CeedChk(ierr);
29   ierr = CeedFree(&impl->inputstate); CeedChk(ierr);
30 
31   for (CeedInt i=0; i<impl->numein; i++) {
32     ierr = CeedVectorDestroy(&impl->evecsin[i]); CeedChk(ierr);
33     ierr = CeedVectorDestroy(&impl->qvecsin[i]); CeedChk(ierr);
34   }
35   ierr = CeedFree(&impl->evecsin); CeedChk(ierr);
36   ierr = CeedFree(&impl->qvecsin); CeedChk(ierr);
37 
38   for (CeedInt i=0; i<impl->numeout; i++) {
39     ierr = CeedVectorDestroy(&impl->evecsout[i]); CeedChk(ierr);
40     ierr = CeedVectorDestroy(&impl->qvecsout[i]); CeedChk(ierr);
41   }
42   ierr = CeedFree(&impl->evecsout); CeedChk(ierr);
43   ierr = CeedFree(&impl->qvecsout); CeedChk(ierr);
44 
45   ierr = CeedFree(&impl); CeedChk(ierr);
46   return 0;
47 }
48 
49 /*
50   Setup infields or outfields
51  */
52 static int CeedOperatorSetupFields_Ref(CeedQFunction qf, CeedOperator op,
53                                        bool inOrOut,
54                                        CeedVector *fullevecs, CeedVector *evecs,
55                                        CeedVector *qvecs, CeedInt starte,
56                                        CeedInt numfields, CeedInt Q) {
57   CeedInt dim, ierr, size, P;
58   Ceed ceed;
59   ierr = CeedOperatorGetCeed(op, &ceed); CeedChk(ierr);
60   CeedBasis basis;
61   CeedElemRestriction Erestrict;
62   CeedOperatorField *opfields;
63   CeedQFunctionField *qffields;
64   if (inOrOut) {
65     ierr = CeedOperatorGetFields(op, NULL, &opfields); CeedChk(ierr);
66     ierr = CeedQFunctionGetFields(qf, NULL, &qffields); CeedChk(ierr);
67   } else {
68     ierr = CeedOperatorGetFields(op, &opfields, NULL); CeedChk(ierr);
69     ierr = CeedQFunctionGetFields(qf, &qffields, NULL); CeedChk(ierr);
70   }
71 
72   // Loop over fields
73   for (CeedInt i=0; i<numfields; i++) {
74     CeedEvalMode emode;
75     ierr = CeedQFunctionFieldGetEvalMode(qffields[i], &emode); CeedChk(ierr);
76 
77     if (emode != CEED_EVAL_WEIGHT) {
78       ierr = CeedOperatorFieldGetElemRestriction(opfields[i], &Erestrict);
79       CeedChk(ierr);
80       ierr = CeedElemRestrictionCreateVector(Erestrict, NULL,
81                                              &fullevecs[i+starte]);
82       CeedChk(ierr);
83     }
84 
85     switch(emode) {
86     case CEED_EVAL_NONE:
87       ierr = CeedQFunctionFieldGetSize(qffields[i], &size); CeedChk(ierr);
88       ierr = CeedVectorCreate(ceed, Q*size, &qvecs[i]); CeedChk(ierr);
89       break;
90     case CEED_EVAL_INTERP:
91       ierr = CeedQFunctionFieldGetSize(qffields[i], &size); CeedChk(ierr);
92       ierr = CeedElemRestrictionGetElementSize(Erestrict, &P);
93       CeedChk(ierr);
94       ierr = CeedVectorCreate(ceed, P*size, &evecs[i]); CeedChk(ierr);
95       ierr = CeedVectorCreate(ceed, Q*size, &qvecs[i]); CeedChk(ierr);
96       break;
97     case CEED_EVAL_GRAD:
98       ierr = CeedOperatorFieldGetBasis(opfields[i], &basis); CeedChk(ierr);
99       ierr = CeedQFunctionFieldGetSize(qffields[i], &size); CeedChk(ierr);
100       ierr = CeedBasisGetDimension(basis, &dim); CeedChk(ierr);
101       ierr = CeedElemRestrictionGetElementSize(Erestrict, &P);
102       CeedChk(ierr);
103       ierr = CeedVectorCreate(ceed, P*size/dim, &evecs[i]); CeedChk(ierr);
104       ierr = CeedVectorCreate(ceed, Q*size, &qvecs[i]); CeedChk(ierr);
105       break;
106     case CEED_EVAL_WEIGHT: // Only on input fields
107       ierr = CeedOperatorFieldGetBasis(opfields[i], &basis); CeedChk(ierr);
108       ierr = CeedVectorCreate(ceed, Q, &qvecs[i]); CeedChk(ierr);
109       ierr = CeedBasisApply(basis, 1, CEED_NOTRANSPOSE, CEED_EVAL_WEIGHT,
110                             CEED_VECTOR_NONE, qvecs[i]); CeedChk(ierr);
111       break;
112     case CEED_EVAL_DIV:
113       break; // Not implemented
114     case CEED_EVAL_CURL:
115       break; // Not implemented
116     }
117   }
118   return 0;
119 }
120 
121 /*
122   CeedOperator needs to connect all the named fields (be they active or passive)
123   to the named inputs and outputs of its CeedQFunction.
124  */
125 static int CeedOperatorSetup_Ref(CeedOperator op) {
126   int ierr;
127   bool setupdone;
128   ierr = CeedOperatorGetSetupStatus(op, &setupdone); CeedChk(ierr);
129   if (setupdone) return 0;
130   Ceed ceed;
131   ierr = CeedOperatorGetCeed(op, &ceed); CeedChk(ierr);
132   CeedOperator_Ref *impl;
133   ierr = CeedOperatorGetData(op, (void *)&impl); CeedChk(ierr);
134   CeedQFunction qf;
135   ierr = CeedOperatorGetQFunction(op, &qf); CeedChk(ierr);
136   CeedInt Q, numinputfields, numoutputfields;
137   ierr = CeedOperatorGetNumQuadraturePoints(op, &Q); CeedChk(ierr);
138   ierr = CeedQFunctionGetIdentityStatus(qf, &impl->identityqf); CeedChk(ierr);
139   ierr = CeedQFunctionGetNumArgs(qf, &numinputfields, &numoutputfields);
140   CeedChk(ierr);
141   CeedOperatorField *opinputfields, *opoutputfields;
142   ierr = CeedOperatorGetFields(op, &opinputfields, &opoutputfields);
143   CeedChk(ierr);
144   CeedQFunctionField *qfinputfields, *qfoutputfields;
145   ierr = CeedQFunctionGetFields(qf, &qfinputfields, &qfoutputfields);
146   CeedChk(ierr);
147 
148   // Allocate
149   ierr = CeedCalloc(numinputfields + numoutputfields, &impl->evecs);
150   CeedChk(ierr);
151   ierr = CeedCalloc(numinputfields + numoutputfields, &impl->edata);
152   CeedChk(ierr);
153 
154   ierr = CeedCalloc(16, &impl->inputstate); CeedChk(ierr);
155   ierr = CeedCalloc(16, &impl->evecsin); CeedChk(ierr);
156   ierr = CeedCalloc(16, &impl->evecsout); CeedChk(ierr);
157   ierr = CeedCalloc(16, &impl->qvecsin); CeedChk(ierr);
158   ierr = CeedCalloc(16, &impl->qvecsout); CeedChk(ierr);
159 
160   impl->numein = numinputfields; impl->numeout = numoutputfields;
161 
162   // Set up infield and outfield evecs and qvecs
163   // Infields
164   ierr = CeedOperatorSetupFields_Ref(qf, op, 0, impl->evecs,
165                                      impl->evecsin, impl->qvecsin, 0,
166                                      numinputfields, Q);
167   CeedChk(ierr);
168   // Outfields
169   ierr = CeedOperatorSetupFields_Ref(qf, op, 1, impl->evecs,
170                                      impl->evecsout, impl->qvecsout,
171                                      numinputfields, numoutputfields, Q);
172   CeedChk(ierr);
173 
174   // Identity QFunctions
175   if (impl->identityqf) {
176     CeedEvalMode inmode, outmode;
177     CeedQFunctionField *infields, *outfields;
178     ierr = CeedQFunctionGetFields(qf, &infields, &outfields); CeedChk(ierr);
179 
180     for (CeedInt i=0; i<numinputfields; i++) {
181       ierr = CeedQFunctionFieldGetEvalMode(infields[i], &inmode);
182       CeedChk(ierr);
183       ierr = CeedQFunctionFieldGetEvalMode(outfields[i], &outmode);
184       CeedChk(ierr);
185 
186       ierr = CeedVectorDestroy(&impl->qvecsout[i]); CeedChk(ierr);
187       impl->qvecsout[i] = impl->qvecsin[i];
188       ierr = CeedVectorAddReference(impl->qvecsin[i]); CeedChk(ierr);
189     }
190   }
191 
192   ierr = CeedOperatorSetSetupDone(op); CeedChk(ierr);
193 
194   return 0;
195 }
196 
197 // Setup Input fields
198 static inline int CeedOperatorSetupInputs_Ref(CeedInt numinputfields,
199     CeedQFunctionField *qfinputfields, CeedOperatorField *opinputfields,
200     CeedVector invec, const bool skipactive, CeedOperator_Ref *impl,
201     CeedRequest *request) {
202   CeedInt ierr;
203   CeedEvalMode emode;
204   CeedVector vec;
205   CeedElemRestriction Erestrict;
206   CeedTransposeMode lmode;
207   uint64_t state;
208 
209   for (CeedInt i=0; i<numinputfields; i++) {
210     // Get input vector
211     ierr = CeedOperatorFieldGetVector(opinputfields[i], &vec); CeedChk(ierr);
212     if (vec == CEED_VECTOR_ACTIVE) {
213       if (skipactive)
214         continue;
215       else
216         vec = invec;
217     }
218 
219     ierr = CeedQFunctionFieldGetEvalMode(qfinputfields[i], &emode);
220     CeedChk(ierr);
221     // Restrict and Evec
222     if (emode == CEED_EVAL_WEIGHT) { // Skip
223     } else {
224       // Restrict
225       ierr = CeedVectorGetState(vec, &state); CeedChk(ierr);
226       // Skip restriction if input is unchanged
227       if (state != impl->inputstate[i] || vec == invec) {
228         ierr = CeedOperatorFieldGetElemRestriction(opinputfields[i], &Erestrict);
229         CeedChk(ierr);
230         ierr = CeedOperatorFieldGetLMode(opinputfields[i], &lmode);
231         CeedChk(ierr);
232         ierr = CeedElemRestrictionApply(Erestrict, CEED_NOTRANSPOSE,
233                                         lmode, vec, impl->evecs[i],
234                                         request); CeedChk(ierr);
235         impl->inputstate[i] = state;
236       }
237       // Get evec
238       ierr = CeedVectorGetArrayRead(impl->evecs[i], CEED_MEM_HOST,
239                                     (const CeedScalar **) &impl->edata[i]);
240       CeedChk(ierr);
241     }
242   }
243   return 0;
244 }
245 
246 // Input basis action
247 static inline int CeedOperatorInputBasis_Ref(CeedInt e, CeedInt Q,
248     CeedQFunctionField *qfinputfields, CeedOperatorField *opinputfields,
249     CeedInt numinputfields, const bool skipactive, CeedOperator_Ref *impl) {
250   CeedInt ierr;
251   CeedInt dim, elemsize, size;
252   CeedElemRestriction Erestrict;
253   CeedEvalMode emode;
254   CeedBasis basis;
255 
256   for (CeedInt i=0; i<numinputfields; i++) {
257     // Skip active input
258     if (skipactive) {
259       CeedVector vec;
260       ierr = CeedOperatorFieldGetVector(opinputfields[i], &vec); CeedChk(ierr);
261       if (vec == CEED_VECTOR_ACTIVE)
262         continue;
263     }
264     // Get elemsize, emode, size
265     ierr = CeedOperatorFieldGetElemRestriction(opinputfields[i], &Erestrict);
266     CeedChk(ierr);
267     ierr = CeedElemRestrictionGetElementSize(Erestrict, &elemsize);
268     CeedChk(ierr);
269     ierr = CeedQFunctionFieldGetEvalMode(qfinputfields[i], &emode);
270     CeedChk(ierr);
271     ierr = CeedQFunctionFieldGetSize(qfinputfields[i], &size); CeedChk(ierr);
272     // Basis action
273     switch(emode) {
274     case CEED_EVAL_NONE:
275       ierr = CeedVectorSetArray(impl->qvecsin[i], CEED_MEM_HOST,
276                                 CEED_USE_POINTER,
277                                 &impl->edata[i][e*Q*size]); CeedChk(ierr);
278       break;
279     case CEED_EVAL_INTERP:
280       ierr = CeedOperatorFieldGetBasis(opinputfields[i], &basis); CeedChk(ierr);
281       ierr = CeedVectorSetArray(impl->evecsin[i], CEED_MEM_HOST,
282                                 CEED_USE_POINTER,
283                                 &impl->edata[i][e*elemsize*size]);
284       CeedChk(ierr);
285       ierr = CeedBasisApply(basis, 1, CEED_NOTRANSPOSE,
286                             CEED_EVAL_INTERP, impl->evecsin[i],
287                             impl->qvecsin[i]); CeedChk(ierr);
288       break;
289     case CEED_EVAL_GRAD:
290       ierr = CeedOperatorFieldGetBasis(opinputfields[i], &basis); CeedChk(ierr);
291       ierr = CeedBasisGetDimension(basis, &dim); CeedChk(ierr);
292       ierr = CeedVectorSetArray(impl->evecsin[i], CEED_MEM_HOST,
293                                 CEED_USE_POINTER,
294                                 &impl->edata[i][e*elemsize*size/dim]);
295       CeedChk(ierr);
296       ierr = CeedBasisApply(basis, 1, CEED_NOTRANSPOSE,
297                             CEED_EVAL_GRAD, impl->evecsin[i],
298                             impl->qvecsin[i]); CeedChk(ierr);
299       break;
300     case CEED_EVAL_WEIGHT:
301       break;  // No action
302     case CEED_EVAL_DIV:
303     case CEED_EVAL_CURL: {
304       // LCOV_EXCL_START
305       ierr = CeedOperatorFieldGetBasis(opinputfields[i], &basis);
306       CeedChk(ierr);
307       Ceed ceed;
308       ierr = CeedBasisGetCeed(basis, &ceed); CeedChk(ierr);
309       return CeedError(ceed, 1, "Ceed evaluation mode not implemented");
310       // LCOV_EXCL_STOP
311       break; // Not implemented
312     }
313     }
314   }
315   return 0;
316 }
317 
318 // Output basis action
319 static inline int CeedOperatorOutputBasis_Ref(CeedInt e, CeedInt Q,
320     CeedQFunctionField *qfoutputfields, CeedOperatorField *opoutputfields,
321     CeedInt numinputfields, CeedInt numoutputfields, CeedOperator op,
322     CeedOperator_Ref *impl) {
323   CeedInt ierr;
324   CeedInt dim, elemsize, size;
325   CeedElemRestriction Erestrict;
326   CeedEvalMode emode;
327   CeedBasis basis;
328 
329   for (CeedInt i=0; i<numoutputfields; i++) {
330     // Get elemsize, emode, size
331     ierr = CeedOperatorFieldGetElemRestriction(opoutputfields[i], &Erestrict);
332     CeedChk(ierr);
333     ierr = CeedElemRestrictionGetElementSize(Erestrict, &elemsize);
334     CeedChk(ierr);
335     ierr = CeedQFunctionFieldGetEvalMode(qfoutputfields[i], &emode);
336     CeedChk(ierr);
337     ierr = CeedQFunctionFieldGetSize(qfoutputfields[i], &size); CeedChk(ierr);
338     // Basis action
339     switch(emode) {
340     case CEED_EVAL_NONE:
341       break; // No action
342     case CEED_EVAL_INTERP:
343       ierr = CeedOperatorFieldGetBasis(opoutputfields[i], &basis);
344       CeedChk(ierr);
345       ierr = CeedVectorSetArray(impl->evecsout[i], CEED_MEM_HOST,
346                                 CEED_USE_POINTER,
347                                 &impl->edata[i + numinputfields][e*elemsize*size]);
348       CeedChk(ierr);
349       ierr = CeedBasisApply(basis, 1, CEED_TRANSPOSE,
350                             CEED_EVAL_INTERP, impl->qvecsout[i],
351                             impl->evecsout[i]); CeedChk(ierr);
352       break;
353     case CEED_EVAL_GRAD:
354       ierr = CeedOperatorFieldGetBasis(opoutputfields[i], &basis);
355       CeedChk(ierr);
356       ierr = CeedBasisGetDimension(basis, &dim); CeedChk(ierr);
357       ierr = CeedVectorSetArray(impl->evecsout[i], CEED_MEM_HOST,
358                                 CEED_USE_POINTER,
359                                 &impl->edata[i + numinputfields][e*elemsize*size/dim]);
360       CeedChk(ierr);
361       ierr = CeedBasisApply(basis, 1, CEED_TRANSPOSE,
362                             CEED_EVAL_GRAD, impl->qvecsout[i],
363                             impl->evecsout[i]); CeedChk(ierr);
364       break;
365     case CEED_EVAL_WEIGHT: {
366       // LCOV_EXCL_START
367       Ceed ceed;
368       ierr = CeedOperatorGetCeed(op, &ceed); CeedChk(ierr);
369       return CeedError(ceed, 1, "CEED_EVAL_WEIGHT cannot be an output "
370                        "evaluation mode");
371       // LCOV_EXCL_STOP
372       break; // Should not occur
373     }
374     case CEED_EVAL_DIV:
375     case CEED_EVAL_CURL: {
376       // LCOV_EXCL_START
377       Ceed ceed;
378       ierr = CeedOperatorGetCeed(op, &ceed); CeedChk(ierr);
379       return CeedError(ceed, 1, "Ceed evaluation mode not implemented");
380       // LCOV_EXCL_STOP
381       break; // Not implemented
382     }
383     }
384   }
385   return 0;
386 }
387 
388 // Restore Inputs
389 static inline int CeedOperatorRestoreInputs_Ref(CeedInt numinputfields,
390     CeedQFunctionField *qfinputfields, CeedOperatorField *opinputfields,
391     const bool skipactive, CeedOperator_Ref *impl) {
392   CeedInt ierr;
393   CeedEvalMode emode;
394 
395   for (CeedInt i=0; i<numinputfields; i++) {
396     // Skip active inputs
397     if (skipactive) {
398       CeedVector vec;
399       ierr = CeedOperatorFieldGetVector(opinputfields[i], &vec); CeedChk(ierr);
400       if (vec == CEED_VECTOR_ACTIVE)
401         continue;
402     }
403     // Restore input
404     ierr = CeedQFunctionFieldGetEvalMode(qfinputfields[i], &emode);
405     CeedChk(ierr);
406     if (emode == CEED_EVAL_WEIGHT) { // Skip
407     } else {
408       ierr = CeedVectorRestoreArrayRead(impl->evecs[i],
409                                         (const CeedScalar **) &impl->edata[i]);
410       CeedChk(ierr);
411     }
412   }
413   return 0;
414 }
415 
416 // Apply Operator
417 static int CeedOperatorApply_Ref(CeedOperator op, CeedVector invec,
418                                  CeedVector outvec, CeedRequest *request) {
419   int ierr;
420   CeedOperator_Ref *impl;
421   ierr = CeedOperatorGetData(op, (void *)&impl); CeedChk(ierr);
422   CeedQFunction qf;
423   ierr = CeedOperatorGetQFunction(op, &qf); CeedChk(ierr);
424   CeedInt Q, numelements, numinputfields, numoutputfields, size;
425   ierr = CeedOperatorGetNumQuadraturePoints(op, &Q); CeedChk(ierr);
426   ierr = CeedOperatorGetNumElements(op, &numelements); CeedChk(ierr);
427   ierr= CeedQFunctionGetNumArgs(qf, &numinputfields, &numoutputfields);
428   CeedChk(ierr);
429   CeedTransposeMode lmode;
430   CeedOperatorField *opinputfields, *opoutputfields;
431   ierr = CeedOperatorGetFields(op, &opinputfields, &opoutputfields);
432   CeedChk(ierr);
433   CeedQFunctionField *qfinputfields, *qfoutputfields;
434   ierr = CeedQFunctionGetFields(qf, &qfinputfields, &qfoutputfields);
435   CeedChk(ierr);
436   CeedEvalMode emode;
437   CeedVector vec;
438   CeedElemRestriction Erestrict;
439 
440   // Setup
441   ierr = CeedOperatorSetup_Ref(op); CeedChk(ierr);
442 
443   // Input Evecs and Restriction
444   ierr = CeedOperatorSetupInputs_Ref(numinputfields, qfinputfields,
445                                      opinputfields, invec, false, impl,
446                                      request); CeedChk(ierr);
447 
448   // Output Evecs
449   for (CeedInt i=0; i<numoutputfields; i++) {
450     ierr = CeedVectorGetArray(impl->evecs[i+impl->numein], CEED_MEM_HOST,
451                               &impl->edata[i + numinputfields]); CeedChk(ierr);
452   }
453 
454   // Loop through elements
455   for (CeedInt e=0; e<numelements; e++) {
456     // Output pointers
457     for (CeedInt i=0; i<numoutputfields; i++) {
458       ierr = CeedQFunctionFieldGetEvalMode(qfoutputfields[i], &emode);
459       CeedChk(ierr);
460       if (emode == CEED_EVAL_NONE) {
461         ierr = CeedQFunctionFieldGetSize(qfoutputfields[i], &size);
462         CeedChk(ierr);
463         ierr = CeedVectorSetArray(impl->qvecsout[i], CEED_MEM_HOST,
464                                   CEED_USE_POINTER,
465                                   &impl->edata[i + numinputfields][e*Q*size]);
466         CeedChk(ierr);
467       }
468     }
469 
470     // Input basis apply
471     ierr = CeedOperatorInputBasis_Ref(e, Q, qfinputfields, opinputfields,
472                                       numinputfields, false, impl);
473     CeedChk(ierr);
474 
475     // Q function
476     if (!impl->identityqf) {
477       ierr = CeedQFunctionApply(qf, Q, impl->qvecsin, impl->qvecsout);
478       CeedChk(ierr);
479     }
480 
481     // Output basis apply
482     ierr = CeedOperatorOutputBasis_Ref(e, Q, qfoutputfields, opoutputfields,
483                                        numinputfields, numoutputfields, op, impl);
484     CeedChk(ierr);
485   }
486 
487   // Output restriction
488   for (CeedInt i=0; i<numoutputfields; i++) {
489     // Restore evec
490     ierr = CeedVectorRestoreArray(impl->evecs[i+impl->numein],
491                                   &impl->edata[i + numinputfields]);
492     CeedChk(ierr);
493     // Get output vector
494     ierr = CeedOperatorFieldGetVector(opoutputfields[i], &vec); CeedChk(ierr);
495     // Active
496     if (vec == CEED_VECTOR_ACTIVE)
497       vec = outvec;
498     // Restrict
499     ierr = CeedOperatorFieldGetElemRestriction(opoutputfields[i], &Erestrict);
500     CeedChk(ierr);
501     ierr = CeedOperatorFieldGetLMode(opoutputfields[i], &lmode); CeedChk(ierr);
502     ierr = CeedElemRestrictionApply(Erestrict, CEED_TRANSPOSE,
503                                     lmode, impl->evecs[i+impl->numein], vec,
504                                     request); CeedChk(ierr);
505   }
506 
507   // Restore input arrays
508   ierr = CeedOperatorRestoreInputs_Ref(numinputfields, qfinputfields,
509                                        opinputfields, false, impl);
510   CeedChk(ierr);
511 
512   return 0;
513 }
514 
515 // Composite operators
516 static int CeedCompositeOperatorApply_Ref(CeedOperator op, CeedVector invec,
517     CeedVector outvec,
518     CeedRequest *request) {
519   int ierr;
520   CeedInt numsub;
521   CeedOperator *suboperators;
522   ierr = CeedOperatorGetNumSub(op, &numsub); CeedChk(ierr);
523   ierr = CeedOperatorGetSubList(op, &suboperators); CeedChk(ierr);
524 
525   for (CeedInt i=0; i<numsub; i++) {
526     ierr = CeedOperatorApplyAdd(suboperators[i], invec, outvec, request);
527     CeedChk(ierr);
528   }
529 
530   return 0;
531 }
532 
533 // Assemble Linear QFunction
534 static int CeedOperatorAssembleLinearQFunction_Ref(CeedOperator op,
535     CeedVector *assembled, CeedElemRestriction *rstr, CeedRequest *request) {
536   int ierr;
537   CeedOperator_Ref *impl;
538   ierr = CeedOperatorGetData(op, (void *)&impl); CeedChk(ierr);
539   CeedQFunction qf;
540   ierr = CeedOperatorGetQFunction(op, &qf); CeedChk(ierr);
541   CeedInt Q, numelements, numinputfields, numoutputfields, size;
542   ierr = CeedOperatorGetNumQuadraturePoints(op, &Q); CeedChk(ierr);
543   ierr = CeedOperatorGetNumElements(op, &numelements); CeedChk(ierr);
544   ierr= CeedQFunctionGetNumArgs(qf, &numinputfields, &numoutputfields);
545   CeedChk(ierr);
546   CeedOperatorField *opinputfields, *opoutputfields;
547   ierr = CeedOperatorGetFields(op, &opinputfields, &opoutputfields);
548   CeedChk(ierr);
549   CeedQFunctionField *qfinputfields, *qfoutputfields;
550   ierr = CeedQFunctionGetFields(qf, &qfinputfields, &qfoutputfields);
551   CeedChk(ierr);
552   CeedVector vec;
553   CeedInt numactivein = 0, numactiveout = 0;
554   CeedVector *activein = NULL;
555   CeedScalar *a, *tmp;
556   Ceed ceed, ceedparent;
557   ierr = CeedOperatorGetCeed(op, &ceed); CeedChk(ierr);
558   ierr = CeedGetOperatorFallbackParentCeed(ceed, &ceedparent); CeedChk(ierr);
559   ceedparent = ceedparent ? ceedparent : ceed;
560 
561   // Setup
562   ierr = CeedOperatorSetup_Ref(op); CeedChk(ierr);
563 
564   // Check for identity
565   if (impl->identityqf)
566     // LCOV_EXCL_START
567     return CeedError(ceed, 1, "Assembling identity qfunctions not supported");
568   // LCOV_EXCL_STOP
569 
570   // Input Evecs and Restriction
571   ierr = CeedOperatorSetupInputs_Ref(numinputfields, qfinputfields,
572                                      opinputfields, NULL, true, impl, request);
573   CeedChk(ierr);
574 
575   // Count number of active input fields
576   for (CeedInt i=0; i<numinputfields; i++) {
577     // Get input vector
578     ierr = CeedOperatorFieldGetVector(opinputfields[i], &vec); CeedChk(ierr);
579     // Check if active input
580     if (vec == CEED_VECTOR_ACTIVE) {
581       ierr = CeedQFunctionFieldGetSize(qfinputfields[i], &size); CeedChk(ierr);
582       ierr = CeedVectorSetValue(impl->qvecsin[i], 0.0); CeedChk(ierr);
583       ierr = CeedVectorGetArray(impl->qvecsin[i], CEED_MEM_HOST, &tmp);
584       CeedChk(ierr);
585       ierr = CeedRealloc(numactivein + size, &activein); CeedChk(ierr);
586       for (CeedInt field=0; field<size; field++) {
587         ierr = CeedVectorCreate(ceed, Q, &activein[numactivein+field]);
588         CeedChk(ierr);
589         ierr = CeedVectorSetArray(activein[numactivein+field], CEED_MEM_HOST,
590                                   CEED_USE_POINTER, &tmp[field*Q]);
591         CeedChk(ierr);
592       }
593       numactivein += size;
594       ierr = CeedVectorRestoreArray(impl->qvecsin[i], &tmp); CeedChk(ierr);
595     }
596   }
597 
598   // Count number of active output fields
599   for (CeedInt i=0; i<numoutputfields; i++) {
600     // Get output vector
601     ierr = CeedOperatorFieldGetVector(opoutputfields[i], &vec); CeedChk(ierr);
602     // Check if active output
603     if (vec == CEED_VECTOR_ACTIVE) {
604       ierr = CeedQFunctionFieldGetSize(qfoutputfields[i], &size); CeedChk(ierr);
605       numactiveout += size;
606     }
607   }
608 
609   // Check sizes
610   if (!numactivein || !numactiveout)
611     // LCOV_EXCL_START
612     return CeedError(ceed, 1, "Cannot assemble QFunction without active inputs "
613                      "and outputs");
614   // LCOV_EXCL_STOP
615 
616   // Create output restriction
617   ierr = CeedElemRestrictionCreateIdentity(ceedparent, numelements, Q,
618          numelements*Q, numactivein*numactiveout, rstr); CeedChk(ierr);
619   // Create assembled vector
620   ierr = CeedVectorCreate(ceedparent, numelements*Q*numactivein*numactiveout,
621                           assembled); CeedChk(ierr);
622   ierr = CeedVectorSetValue(*assembled, 0.0); CeedChk(ierr);
623   ierr = CeedVectorGetArray(*assembled, CEED_MEM_HOST, &a); CeedChk(ierr);
624 
625   // Loop through elements
626   for (CeedInt e=0; e<numelements; e++) {
627     // Input basis apply
628     ierr = CeedOperatorInputBasis_Ref(e, Q, qfinputfields, opinputfields,
629                                       numinputfields, true, impl);
630     CeedChk(ierr);
631 
632     // Assemble QFunction
633     for (CeedInt in=0; in<numactivein; in++) {
634       // Set Inputs
635       ierr = CeedVectorSetValue(activein[in], 1.0); CeedChk(ierr);
636       if (numactivein > 1) {
637         ierr = CeedVectorSetValue(activein[(in+numactivein-1)%numactivein],
638                                   0.0); CeedChk(ierr);
639       }
640       // Set Outputs
641       for (CeedInt out=0; out<numoutputfields; out++) {
642         // Get output vector
643         ierr = CeedOperatorFieldGetVector(opoutputfields[out], &vec);
644         CeedChk(ierr);
645         // Check if active output
646         if (vec == CEED_VECTOR_ACTIVE) {
647           CeedVectorSetArray(impl->qvecsout[out], CEED_MEM_HOST,
648                              CEED_USE_POINTER, a); CeedChk(ierr);
649           ierr = CeedQFunctionFieldGetSize(qfoutputfields[out], &size);
650           CeedChk(ierr);
651           a += size*Q; // Advance the pointer by the size of the output
652         }
653       }
654       // Apply QFunction
655       ierr = CeedQFunctionApply(qf, Q, impl->qvecsin, impl->qvecsout);
656       CeedChk(ierr);
657     }
658   }
659 
660   // Un-set output Qvecs to prevent accidental overwrite of Assembled
661   for (CeedInt out=0; out<numoutputfields; out++) {
662     // Get output vector
663     ierr = CeedOperatorFieldGetVector(opoutputfields[out], &vec);
664     CeedChk(ierr);
665     // Check if active output
666     if (vec == CEED_VECTOR_ACTIVE) {
667       CeedVectorSetArray(impl->qvecsout[out], CEED_MEM_HOST, CEED_COPY_VALUES,
668                          NULL); CeedChk(ierr);
669     }
670   }
671 
672   // Restore input arrays
673   ierr = CeedOperatorRestoreInputs_Ref(numinputfields, qfinputfields,
674                                        opinputfields, true, impl);
675   CeedChk(ierr);
676 
677   // Restore output
678   ierr = CeedVectorRestoreArray(*assembled, &a); CeedChk(ierr);
679 
680   // Cleanup
681   for (CeedInt i=0; i<numactivein; i++) {
682     ierr = CeedVectorDestroy(&activein[i]); CeedChk(ierr);
683   }
684   ierr = CeedFree(&activein); CeedChk(ierr);
685 
686   return 0;
687 }
688 
689 int CeedOperatorCreate_Ref(CeedOperator op) {
690   int ierr;
691   Ceed ceed;
692   ierr = CeedOperatorGetCeed(op, &ceed); CeedChk(ierr);
693   CeedOperator_Ref *impl;
694 
695   ierr = CeedCalloc(1, &impl); CeedChk(ierr);
696   ierr = CeedOperatorSetData(op, (void *)&impl); CeedChk(ierr);
697 
698   ierr = CeedSetBackendFunction(ceed, "Operator", op, "AssembleLinearQFunction",
699                                 CeedOperatorAssembleLinearQFunction_Ref);
700   CeedChk(ierr);
701   ierr = CeedSetBackendFunction(ceed, "Operator", op, "ApplyAdd",
702                                 CeedOperatorApply_Ref); CeedChk(ierr);
703   ierr = CeedSetBackendFunction(ceed, "Operator", op, "Destroy",
704                                 CeedOperatorDestroy_Ref); CeedChk(ierr);
705   return 0;
706 }
707 
708 int CeedCompositeOperatorCreate_Ref(CeedOperator op) {
709   int ierr;
710   Ceed ceed;
711   ierr = CeedOperatorGetCeed(op, &ceed); CeedChk(ierr);
712 
713   ierr = CeedSetBackendFunction(ceed, "Operator", op, "ApplyAdd",
714                                 CeedCompositeOperatorApply_Ref); CeedChk(ierr);
715   return 0;
716 }
717