xref: /libCEED/backends/cuda-ref/ceed-cuda-ref-operator.c (revision 392d940c90dcc80d2c8cd0455511b2e57938a796)
1 // Copyright (c) 2017-2024, Lawrence Livermore National Security, LLC and other CEED contributors.
2 // All Rights Reserved. See the top-level LICENSE and NOTICE files for details.
3 //
4 // SPDX-License-Identifier: BSD-2-Clause
5 //
6 // This file is part of CEED:  http://github.com/ceed
7 
8 #include <ceed.h>
9 #include <ceed/backend.h>
10 #include <ceed/jit-tools.h>
11 #include <assert.h>
12 #include <cuda.h>
13 #include <cuda_runtime.h>
14 #include <stdbool.h>
15 #include <string.h>
16 
17 #include "../cuda/ceed-cuda-common.h"
18 #include "../cuda/ceed-cuda-compile.h"
19 #include "ceed-cuda-ref.h"
20 
21 //------------------------------------------------------------------------------
22 // Destroy operator
23 //------------------------------------------------------------------------------
24 static int CeedOperatorDestroy_Cuda(CeedOperator op) {
25   CeedOperator_Cuda *impl;
26 
27   CeedCallBackend(CeedOperatorGetData(op, &impl));
28 
29   // Apply data
30   for (CeedInt i = 0; i < impl->num_inputs + impl->num_outputs; i++) {
31     CeedCallBackend(CeedVectorDestroy(&impl->e_vecs[i]));
32   }
33   CeedCallBackend(CeedFree(&impl->e_vecs));
34   CeedCallBackend(CeedFree(&impl->input_states));
35 
36   for (CeedInt i = 0; i < impl->num_inputs; i++) {
37     CeedCallBackend(CeedVectorDestroy(&impl->q_vecs_in[i]));
38   }
39   CeedCallBackend(CeedFree(&impl->q_vecs_in));
40 
41   for (CeedInt i = 0; i < impl->num_outputs; i++) {
42     CeedCallBackend(CeedVectorDestroy(&impl->q_vecs_out[i]));
43   }
44   CeedCallBackend(CeedFree(&impl->q_vecs_out));
45 
46   // QFunction assembly data
47   for (CeedInt i = 0; i < impl->num_active_in; i++) {
48     CeedCallBackend(CeedVectorDestroy(&impl->qf_active_in[i]));
49   }
50   CeedCallBackend(CeedFree(&impl->qf_active_in));
51 
52   // Diag data
53   if (impl->diag) {
54     Ceed ceed;
55 
56     CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
57     if (impl->diag->module) {
58       CeedCallCuda(ceed, cuModuleUnload(impl->diag->module));
59     }
60     if (impl->diag->module_point_block) {
61       CeedCallCuda(ceed, cuModuleUnload(impl->diag->module_point_block));
62     }
63     CeedCallCuda(ceed, cudaFree(impl->diag->d_eval_modes_in));
64     CeedCallCuda(ceed, cudaFree(impl->diag->d_eval_modes_out));
65     CeedCallCuda(ceed, cudaFree(impl->diag->d_identity));
66     CeedCallCuda(ceed, cudaFree(impl->diag->d_interp_in));
67     CeedCallCuda(ceed, cudaFree(impl->diag->d_interp_out));
68     CeedCallCuda(ceed, cudaFree(impl->diag->d_grad_in));
69     CeedCallCuda(ceed, cudaFree(impl->diag->d_grad_out));
70     CeedCallCuda(ceed, cudaFree(impl->diag->d_div_in));
71     CeedCallCuda(ceed, cudaFree(impl->diag->d_div_out));
72     CeedCallCuda(ceed, cudaFree(impl->diag->d_curl_in));
73     CeedCallCuda(ceed, cudaFree(impl->diag->d_curl_out));
74     CeedCallBackend(CeedElemRestrictionDestroy(&impl->diag->diag_rstr));
75     CeedCallBackend(CeedElemRestrictionDestroy(&impl->diag->point_block_diag_rstr));
76     CeedCallBackend(CeedVectorDestroy(&impl->diag->elem_diag));
77     CeedCallBackend(CeedVectorDestroy(&impl->diag->point_block_elem_diag));
78   }
79   CeedCallBackend(CeedFree(&impl->diag));
80 
81   if (impl->asmb) {
82     Ceed ceed;
83 
84     CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
85     CeedCallCuda(ceed, cuModuleUnload(impl->asmb->module));
86     CeedCallCuda(ceed, cudaFree(impl->asmb->d_B_in));
87     CeedCallCuda(ceed, cudaFree(impl->asmb->d_B_out));
88   }
89   CeedCallBackend(CeedFree(&impl->asmb));
90 
91   CeedCallBackend(CeedFree(&impl));
92   return CEED_ERROR_SUCCESS;
93 }
94 
95 //------------------------------------------------------------------------------
96 // Setup infields or outfields
97 //------------------------------------------------------------------------------
98 static int CeedOperatorSetupFields_Cuda(CeedQFunction qf, CeedOperator op, bool is_input, CeedVector *e_vecs, CeedVector *q_vecs, CeedInt start_e,
99                                         CeedInt num_fields, CeedInt Q, CeedInt num_elem) {
100   Ceed                ceed;
101   CeedQFunctionField *qf_fields;
102   CeedOperatorField  *op_fields;
103 
104   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
105   if (is_input) {
106     CeedCallBackend(CeedOperatorGetFields(op, NULL, &op_fields, NULL, NULL));
107     CeedCallBackend(CeedQFunctionGetFields(qf, NULL, &qf_fields, NULL, NULL));
108   } else {
109     CeedCallBackend(CeedOperatorGetFields(op, NULL, NULL, NULL, &op_fields));
110     CeedCallBackend(CeedQFunctionGetFields(qf, NULL, NULL, NULL, &qf_fields));
111   }
112 
113   // Loop over fields
114   for (CeedInt i = 0; i < num_fields; i++) {
115     bool         is_strided = false, skip_restriction = false;
116     CeedSize     q_size;
117     CeedInt      size;
118     CeedEvalMode eval_mode;
119     CeedBasis    basis;
120 
121     CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_fields[i], &eval_mode));
122     if (eval_mode != CEED_EVAL_WEIGHT) {
123       CeedElemRestriction elem_rstr;
124 
125       // Check whether this field can skip the element restriction:
126       // Must be passive input, with eval_mode NONE, and have a strided restriction with CEED_STRIDES_BACKEND.
127       CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_fields[i], &elem_rstr));
128 
129       // First, check whether the field is input or output:
130       if (is_input) {
131         CeedVector vec;
132 
133         // Check for passive input
134         CeedCallBackend(CeedOperatorFieldGetVector(op_fields[i], &vec));
135         if (vec != CEED_VECTOR_ACTIVE) {
136           // Check eval_mode
137           if (eval_mode == CEED_EVAL_NONE) {
138             // Check for strided restriction
139             CeedCallBackend(CeedElemRestrictionIsStrided(elem_rstr, &is_strided));
140             if (is_strided) {
141               // Check if vector is already in preferred backend ordering
142               CeedCallBackend(CeedElemRestrictionHasBackendStrides(elem_rstr, &skip_restriction));
143             }
144           }
145         }
146       }
147       if (skip_restriction) {
148         // We do not need an E-Vector, but will use the input field vector's data directly in the operator application.
149         e_vecs[i + start_e] = NULL;
150       } else {
151         CeedCallBackend(CeedElemRestrictionCreateVector(elem_rstr, NULL, &e_vecs[i + start_e]));
152       }
153     }
154 
155     switch (eval_mode) {
156       case CEED_EVAL_NONE:
157         CeedCallBackend(CeedQFunctionFieldGetSize(qf_fields[i], &size));
158         q_size = (CeedSize)num_elem * Q * size;
159         CeedCallBackend(CeedVectorCreate(ceed, q_size, &q_vecs[i]));
160         break;
161       case CEED_EVAL_INTERP:
162       case CEED_EVAL_GRAD:
163       case CEED_EVAL_DIV:
164       case CEED_EVAL_CURL:
165         CeedCallBackend(CeedQFunctionFieldGetSize(qf_fields[i], &size));
166         q_size = (CeedSize)num_elem * Q * size;
167         CeedCallBackend(CeedVectorCreate(ceed, q_size, &q_vecs[i]));
168         break;
169       case CEED_EVAL_WEIGHT:  // Only on input fields
170         CeedCallBackend(CeedOperatorFieldGetBasis(op_fields[i], &basis));
171         q_size = (CeedSize)num_elem * Q;
172         CeedCallBackend(CeedVectorCreate(ceed, q_size, &q_vecs[i]));
173         CeedCallBackend(CeedBasisApply(basis, num_elem, CEED_NOTRANSPOSE, CEED_EVAL_WEIGHT, CEED_VECTOR_NONE, q_vecs[i]));
174         break;
175     }
176   }
177   return CEED_ERROR_SUCCESS;
178 }
179 
180 //------------------------------------------------------------------------------
181 // CeedOperator needs to connect all the named fields (be they active or passive) to the named inputs and outputs of its CeedQFunction.
182 //------------------------------------------------------------------------------
183 static int CeedOperatorSetup_Cuda(CeedOperator op) {
184   Ceed                ceed;
185   bool                is_setup_done;
186   CeedInt             Q, num_elem, num_input_fields, num_output_fields;
187   CeedQFunctionField *qf_input_fields, *qf_output_fields;
188   CeedQFunction       qf;
189   CeedOperatorField  *op_input_fields, *op_output_fields;
190   CeedOperator_Cuda  *impl;
191 
192   CeedCallBackend(CeedOperatorIsSetupDone(op, &is_setup_done));
193   if (is_setup_done) return CEED_ERROR_SUCCESS;
194 
195   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
196   CeedCallBackend(CeedOperatorGetData(op, &impl));
197   CeedCallBackend(CeedOperatorGetQFunction(op, &qf));
198   CeedCallBackend(CeedOperatorGetNumQuadraturePoints(op, &Q));
199   CeedCallBackend(CeedOperatorGetNumElements(op, &num_elem));
200   CeedCallBackend(CeedOperatorGetFields(op, &num_input_fields, &op_input_fields, &num_output_fields, &op_output_fields));
201   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, &qf_input_fields, NULL, &qf_output_fields));
202 
203   // Allocate
204   CeedCallBackend(CeedCalloc(num_input_fields + num_output_fields, &impl->e_vecs));
205   CeedCallBackend(CeedCalloc(CEED_FIELD_MAX, &impl->input_states));
206   CeedCallBackend(CeedCalloc(CEED_FIELD_MAX, &impl->q_vecs_in));
207   CeedCallBackend(CeedCalloc(CEED_FIELD_MAX, &impl->q_vecs_out));
208   impl->num_inputs  = num_input_fields;
209   impl->num_outputs = num_output_fields;
210 
211   // Set up infield and outfield e_vecs and q_vecs
212   // Infields
213   CeedCallBackend(CeedOperatorSetupFields_Cuda(qf, op, true, impl->e_vecs, impl->q_vecs_in, 0, num_input_fields, Q, num_elem));
214   // Outfields
215   CeedCallBackend(CeedOperatorSetupFields_Cuda(qf, op, false, impl->e_vecs, impl->q_vecs_out, num_input_fields, num_output_fields, Q, num_elem));
216 
217   CeedCallBackend(CeedOperatorSetSetupDone(op));
218   return CEED_ERROR_SUCCESS;
219 }
220 
221 //------------------------------------------------------------------------------
222 // Setup Operator Inputs
223 //------------------------------------------------------------------------------
224 static inline int CeedOperatorSetupInputs_Cuda(CeedInt num_input_fields, CeedQFunctionField *qf_input_fields, CeedOperatorField *op_input_fields,
225                                                CeedVector in_vec, const bool skip_active, CeedScalar *e_data[2 * CEED_FIELD_MAX],
226                                                CeedOperator_Cuda *impl, CeedRequest *request) {
227   for (CeedInt i = 0; i < num_input_fields; i++) {
228     CeedEvalMode        eval_mode;
229     CeedVector          vec;
230     CeedElemRestriction elem_rstr;
231 
232     // Get input vector
233     CeedCallBackend(CeedOperatorFieldGetVector(op_input_fields[i], &vec));
234     if (vec == CEED_VECTOR_ACTIVE) {
235       if (skip_active) continue;
236       else vec = in_vec;
237     }
238 
239     CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_input_fields[i], &eval_mode));
240     if (eval_mode == CEED_EVAL_WEIGHT) {  // Skip
241     } else {
242       // Get input vector
243       CeedCallBackend(CeedOperatorFieldGetVector(op_input_fields[i], &vec));
244       // Get input element restriction
245       CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_input_fields[i], &elem_rstr));
246       if (vec == CEED_VECTOR_ACTIVE) vec = in_vec;
247       // Restrict, if necessary
248       if (!impl->e_vecs[i]) {
249         // No restriction for this field; read data directly from vec.
250         CeedCallBackend(CeedVectorGetArrayRead(vec, CEED_MEM_DEVICE, (const CeedScalar **)&e_data[i]));
251       } else {
252         uint64_t state;
253 
254         CeedCallBackend(CeedVectorGetState(vec, &state));
255         if (state != impl->input_states[i]) {
256           CeedCallBackend(CeedElemRestrictionApply(elem_rstr, CEED_NOTRANSPOSE, vec, impl->e_vecs[i], request));
257           impl->input_states[i] = state;
258         }
259         // Get evec
260         CeedCallBackend(CeedVectorGetArrayRead(impl->e_vecs[i], CEED_MEM_DEVICE, (const CeedScalar **)&e_data[i]));
261       }
262     }
263   }
264   return CEED_ERROR_SUCCESS;
265 }
266 
267 //------------------------------------------------------------------------------
268 // Input Basis Action
269 //------------------------------------------------------------------------------
270 static inline int CeedOperatorInputBasis_Cuda(CeedInt num_elem, CeedQFunctionField *qf_input_fields, CeedOperatorField *op_input_fields,
271                                               CeedInt num_input_fields, const bool skip_active, CeedScalar *e_data[2 * CEED_FIELD_MAX],
272                                               CeedOperator_Cuda *impl) {
273   for (CeedInt i = 0; i < num_input_fields; i++) {
274     CeedInt             elem_size, size;
275     CeedEvalMode        eval_mode;
276     CeedElemRestriction elem_rstr;
277     CeedBasis           basis;
278 
279     // Skip active input
280     if (skip_active) {
281       CeedVector vec;
282 
283       CeedCallBackend(CeedOperatorFieldGetVector(op_input_fields[i], &vec));
284       if (vec == CEED_VECTOR_ACTIVE) continue;
285     }
286     // Get elem_size, eval_mode, size
287     CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_input_fields[i], &elem_rstr));
288     CeedCallBackend(CeedElemRestrictionGetElementSize(elem_rstr, &elem_size));
289     CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_input_fields[i], &eval_mode));
290     CeedCallBackend(CeedQFunctionFieldGetSize(qf_input_fields[i], &size));
291     // Basis action
292     switch (eval_mode) {
293       case CEED_EVAL_NONE:
294         CeedCallBackend(CeedVectorSetArray(impl->q_vecs_in[i], CEED_MEM_DEVICE, CEED_USE_POINTER, e_data[i]));
295         break;
296       case CEED_EVAL_INTERP:
297       case CEED_EVAL_GRAD:
298       case CEED_EVAL_DIV:
299       case CEED_EVAL_CURL:
300         CeedCallBackend(CeedOperatorFieldGetBasis(op_input_fields[i], &basis));
301         CeedCallBackend(CeedBasisApply(basis, num_elem, CEED_NOTRANSPOSE, eval_mode, impl->e_vecs[i], impl->q_vecs_in[i]));
302         break;
303       case CEED_EVAL_WEIGHT:
304         break;  // No action
305     }
306   }
307   return CEED_ERROR_SUCCESS;
308 }
309 
310 //------------------------------------------------------------------------------
311 // Restore Input Vectors
312 //------------------------------------------------------------------------------
313 static inline int CeedOperatorRestoreInputs_Cuda(CeedInt num_input_fields, CeedQFunctionField *qf_input_fields, CeedOperatorField *op_input_fields,
314                                                  const bool skip_active, CeedScalar *e_data[2 * CEED_FIELD_MAX], CeedOperator_Cuda *impl) {
315   for (CeedInt i = 0; i < num_input_fields; i++) {
316     CeedEvalMode eval_mode;
317     CeedVector   vec;
318 
319     // Skip active input
320     if (skip_active) {
321       CeedCallBackend(CeedOperatorFieldGetVector(op_input_fields[i], &vec));
322       if (vec == CEED_VECTOR_ACTIVE) continue;
323     }
324     CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_input_fields[i], &eval_mode));
325     if (eval_mode == CEED_EVAL_WEIGHT) {  // Skip
326     } else {
327       if (!impl->e_vecs[i]) {  // This was a skip_restriction case
328         CeedCallBackend(CeedOperatorFieldGetVector(op_input_fields[i], &vec));
329         CeedCallBackend(CeedVectorRestoreArrayRead(vec, (const CeedScalar **)&e_data[i]));
330       } else {
331         CeedCallBackend(CeedVectorRestoreArrayRead(impl->e_vecs[i], (const CeedScalar **)&e_data[i]));
332       }
333     }
334   }
335   return CEED_ERROR_SUCCESS;
336 }
337 
338 //------------------------------------------------------------------------------
339 // Apply and add to output
340 //------------------------------------------------------------------------------
341 static int CeedOperatorApplyAdd_Cuda(CeedOperator op, CeedVector in_vec, CeedVector out_vec, CeedRequest *request) {
342   CeedInt             Q, num_elem, elem_size, num_input_fields, num_output_fields, size;
343   CeedScalar         *e_data[2 * CEED_FIELD_MAX] = {NULL};
344   CeedQFunctionField *qf_input_fields, *qf_output_fields;
345   CeedQFunction       qf;
346   CeedOperatorField  *op_input_fields, *op_output_fields;
347   CeedOperator_Cuda  *impl;
348 
349   CeedCallBackend(CeedOperatorGetData(op, &impl));
350   CeedCallBackend(CeedOperatorGetQFunction(op, &qf));
351   CeedCallBackend(CeedOperatorGetNumQuadraturePoints(op, &Q));
352   CeedCallBackend(CeedOperatorGetNumElements(op, &num_elem));
353   CeedCallBackend(CeedOperatorGetFields(op, &num_input_fields, &op_input_fields, &num_output_fields, &op_output_fields));
354   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, &qf_input_fields, NULL, &qf_output_fields));
355 
356   // Setup
357   CeedCallBackend(CeedOperatorSetup_Cuda(op));
358 
359   // Input Evecs and Restriction
360   CeedCallBackend(CeedOperatorSetupInputs_Cuda(num_input_fields, qf_input_fields, op_input_fields, in_vec, false, e_data, impl, request));
361 
362   // Input basis apply if needed
363   CeedCallBackend(CeedOperatorInputBasis_Cuda(num_elem, qf_input_fields, op_input_fields, num_input_fields, false, e_data, impl));
364 
365   // Output pointers, as necessary
366   for (CeedInt i = 0; i < num_output_fields; i++) {
367     CeedEvalMode eval_mode;
368 
369     CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_output_fields[i], &eval_mode));
370     if (eval_mode == CEED_EVAL_NONE) {
371       // Set the output Q-Vector to use the E-Vector data directly.
372       CeedCallBackend(CeedVectorGetArrayWrite(impl->e_vecs[i + impl->num_inputs], CEED_MEM_DEVICE, &e_data[i + num_input_fields]));
373       CeedCallBackend(CeedVectorSetArray(impl->q_vecs_out[i], CEED_MEM_DEVICE, CEED_USE_POINTER, e_data[i + num_input_fields]));
374     }
375   }
376 
377   // Q function
378   CeedCallBackend(CeedQFunctionApply(qf, num_elem * Q, impl->q_vecs_in, impl->q_vecs_out));
379 
380   // Output basis apply if needed
381   for (CeedInt i = 0; i < num_output_fields; i++) {
382     CeedEvalMode        eval_mode;
383     CeedElemRestriction elem_rstr;
384     CeedBasis           basis;
385 
386     // Get elem_size, eval_mode, size
387     CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_output_fields[i], &elem_rstr));
388     CeedCallBackend(CeedElemRestrictionGetElementSize(elem_rstr, &elem_size));
389     CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_output_fields[i], &eval_mode));
390     CeedCallBackend(CeedQFunctionFieldGetSize(qf_output_fields[i], &size));
391     // Basis action
392     switch (eval_mode) {
393       case CEED_EVAL_NONE:
394         break;  // No action
395       case CEED_EVAL_INTERP:
396       case CEED_EVAL_GRAD:
397       case CEED_EVAL_DIV:
398       case CEED_EVAL_CURL:
399         CeedCallBackend(CeedOperatorFieldGetBasis(op_output_fields[i], &basis));
400         CeedCallBackend(CeedBasisApply(basis, num_elem, CEED_TRANSPOSE, eval_mode, impl->q_vecs_out[i], impl->e_vecs[i + impl->num_inputs]));
401         break;
402       // LCOV_EXCL_START
403       case CEED_EVAL_WEIGHT: {
404         return CeedError(CeedOperatorReturnCeed(op), CEED_ERROR_BACKEND, "CEED_EVAL_WEIGHT cannot be an output evaluation mode");
405         // LCOV_EXCL_STOP
406       }
407     }
408   }
409 
410   // Output restriction
411   for (CeedInt i = 0; i < num_output_fields; i++) {
412     CeedEvalMode        eval_mode;
413     CeedVector          vec;
414     CeedElemRestriction elem_rstr;
415 
416     // Restore evec
417     CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_output_fields[i], &eval_mode));
418     if (eval_mode == CEED_EVAL_NONE) {
419       CeedCallBackend(CeedVectorRestoreArray(impl->e_vecs[i + impl->num_inputs], &e_data[i + num_input_fields]));
420     }
421     // Get output vector
422     CeedCallBackend(CeedOperatorFieldGetVector(op_output_fields[i], &vec));
423     // Restrict
424     CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_output_fields[i], &elem_rstr));
425     // Active
426     if (vec == CEED_VECTOR_ACTIVE) vec = out_vec;
427 
428     CeedCallBackend(CeedElemRestrictionApply(elem_rstr, CEED_TRANSPOSE, impl->e_vecs[i + impl->num_inputs], vec, request));
429   }
430 
431   // Restore input arrays
432   CeedCallBackend(CeedOperatorRestoreInputs_Cuda(num_input_fields, qf_input_fields, op_input_fields, false, e_data, impl));
433   return CEED_ERROR_SUCCESS;
434 }
435 
436 //------------------------------------------------------------------------------
437 // Linear QFunction Assembly Core
438 //------------------------------------------------------------------------------
439 static inline int CeedOperatorLinearAssembleQFunctionCore_Cuda(CeedOperator op, bool build_objects, CeedVector *assembled, CeedElemRestriction *rstr,
440                                                                CeedRequest *request) {
441   Ceed                ceed, ceed_parent;
442   CeedInt             num_active_in, num_active_out, Q, num_elem, num_input_fields, num_output_fields, size;
443   CeedScalar         *assembled_array, *e_data[2 * CEED_FIELD_MAX] = {NULL};
444   CeedVector         *active_inputs;
445   CeedQFunctionField *qf_input_fields, *qf_output_fields;
446   CeedQFunction       qf;
447   CeedOperatorField  *op_input_fields, *op_output_fields;
448   CeedOperator_Cuda  *impl;
449 
450   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
451   CeedCallBackend(CeedOperatorGetFallbackParentCeed(op, &ceed_parent));
452   CeedCallBackend(CeedOperatorGetData(op, &impl));
453   CeedCallBackend(CeedOperatorGetNumQuadraturePoints(op, &Q));
454   CeedCallBackend(CeedOperatorGetNumElements(op, &num_elem));
455   CeedCallBackend(CeedOperatorGetQFunction(op, &qf));
456   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, &qf_input_fields, NULL, &qf_output_fields));
457   CeedCallBackend(CeedOperatorGetFields(op, &num_input_fields, &op_input_fields, &num_output_fields, &op_output_fields));
458   active_inputs = impl->qf_active_in;
459   num_active_in = impl->num_active_in, num_active_out = impl->num_active_out;
460 
461   // Setup
462   CeedCallBackend(CeedOperatorSetup_Cuda(op));
463 
464   // Input Evecs and Restriction
465   CeedCallBackend(CeedOperatorSetupInputs_Cuda(num_input_fields, qf_input_fields, op_input_fields, NULL, true, e_data, impl, request));
466 
467   // Count number of active input fields
468   if (!num_active_in) {
469     for (CeedInt i = 0; i < num_input_fields; i++) {
470       CeedScalar *q_vec_array;
471       CeedVector  vec;
472 
473       // Get input vector
474       CeedCallBackend(CeedOperatorFieldGetVector(op_input_fields[i], &vec));
475       // Check if active input
476       if (vec == CEED_VECTOR_ACTIVE) {
477         CeedCallBackend(CeedQFunctionFieldGetSize(qf_input_fields[i], &size));
478         CeedCallBackend(CeedVectorSetValue(impl->q_vecs_in[i], 0.0));
479         CeedCallBackend(CeedVectorGetArray(impl->q_vecs_in[i], CEED_MEM_DEVICE, &q_vec_array));
480         CeedCallBackend(CeedRealloc(num_active_in + size, &active_inputs));
481         for (CeedInt field = 0; field < size; field++) {
482           CeedSize q_size = (CeedSize)Q * num_elem;
483 
484           CeedCallBackend(CeedVectorCreate(ceed, q_size, &active_inputs[num_active_in + field]));
485           CeedCallBackend(
486               CeedVectorSetArray(active_inputs[num_active_in + field], CEED_MEM_DEVICE, CEED_USE_POINTER, &q_vec_array[field * Q * num_elem]));
487         }
488         num_active_in += size;
489         CeedCallBackend(CeedVectorRestoreArray(impl->q_vecs_in[i], &q_vec_array));
490       }
491     }
492     impl->num_active_in = num_active_in;
493     impl->qf_active_in  = active_inputs;
494   }
495 
496   // Count number of active output fields
497   if (!num_active_out) {
498     for (CeedInt i = 0; i < num_output_fields; i++) {
499       CeedVector vec;
500 
501       // Get output vector
502       CeedCallBackend(CeedOperatorFieldGetVector(op_output_fields[i], &vec));
503       // Check if active output
504       if (vec == CEED_VECTOR_ACTIVE) {
505         CeedCallBackend(CeedQFunctionFieldGetSize(qf_output_fields[i], &size));
506         num_active_out += size;
507       }
508     }
509     impl->num_active_out = num_active_out;
510   }
511 
512   // Check sizes
513   CeedCheck(num_active_in > 0 && num_active_out > 0, ceed, CEED_ERROR_BACKEND, "Cannot assemble QFunction without active inputs and outputs");
514 
515   // Build objects if needed
516   if (build_objects) {
517     CeedSize l_size     = (CeedSize)num_elem * Q * num_active_in * num_active_out;
518     CeedInt  strides[3] = {1, num_elem * Q, Q}; /* *NOPAD* */
519 
520     // Create output restriction
521     CeedCallBackend(CeedElemRestrictionCreateStrided(ceed_parent, num_elem, Q, num_active_in * num_active_out,
522                                                      num_active_in * num_active_out * num_elem * Q, strides, rstr));
523     // Create assembled vector
524     CeedCallBackend(CeedVectorCreate(ceed_parent, l_size, assembled));
525   }
526   CeedCallBackend(CeedVectorSetValue(*assembled, 0.0));
527   CeedCallBackend(CeedVectorGetArray(*assembled, CEED_MEM_DEVICE, &assembled_array));
528 
529   // Input basis apply
530   CeedCallBackend(CeedOperatorInputBasis_Cuda(num_elem, qf_input_fields, op_input_fields, num_input_fields, true, e_data, impl));
531 
532   // Assemble QFunction
533   for (CeedInt in = 0; in < num_active_in; in++) {
534     // Set Inputs
535     CeedCallBackend(CeedVectorSetValue(active_inputs[in], 1.0));
536     if (num_active_in > 1) {
537       CeedCallBackend(CeedVectorSetValue(active_inputs[(in + num_active_in - 1) % num_active_in], 0.0));
538     }
539     // Set Outputs
540     for (CeedInt out = 0; out < num_output_fields; out++) {
541       CeedVector vec;
542 
543       // Get output vector
544       CeedCallBackend(CeedOperatorFieldGetVector(op_output_fields[out], &vec));
545       // Check if active output
546       if (vec == CEED_VECTOR_ACTIVE) {
547         CeedCallBackend(CeedVectorSetArray(impl->q_vecs_out[out], CEED_MEM_DEVICE, CEED_USE_POINTER, assembled_array));
548         CeedCallBackend(CeedQFunctionFieldGetSize(qf_output_fields[out], &size));
549         assembled_array += size * Q * num_elem;  // Advance the pointer by the size of the output
550       }
551     }
552     // Apply QFunction
553     CeedCallBackend(CeedQFunctionApply(qf, Q * num_elem, impl->q_vecs_in, impl->q_vecs_out));
554   }
555 
556   // Un-set output q_vecs to prevent accidental overwrite of Assembled
557   for (CeedInt out = 0; out < num_output_fields; out++) {
558     CeedVector vec;
559 
560     // Get output vector
561     CeedCallBackend(CeedOperatorFieldGetVector(op_output_fields[out], &vec));
562     // Check if active output
563     if (vec == CEED_VECTOR_ACTIVE) {
564       CeedCallBackend(CeedVectorTakeArray(impl->q_vecs_out[out], CEED_MEM_DEVICE, NULL));
565     }
566   }
567 
568   // Restore input arrays
569   CeedCallBackend(CeedOperatorRestoreInputs_Cuda(num_input_fields, qf_input_fields, op_input_fields, true, e_data, impl));
570 
571   // Restore output
572   CeedCallBackend(CeedVectorRestoreArray(*assembled, &assembled_array));
573   return CEED_ERROR_SUCCESS;
574 }
575 
576 //------------------------------------------------------------------------------
577 // Assemble Linear QFunction
578 //------------------------------------------------------------------------------
579 static int CeedOperatorLinearAssembleQFunction_Cuda(CeedOperator op, CeedVector *assembled, CeedElemRestriction *rstr, CeedRequest *request) {
580   return CeedOperatorLinearAssembleQFunctionCore_Cuda(op, true, assembled, rstr, request);
581 }
582 
583 //------------------------------------------------------------------------------
584 // Update Assembled Linear QFunction
585 //------------------------------------------------------------------------------
586 static int CeedOperatorLinearAssembleQFunctionUpdate_Cuda(CeedOperator op, CeedVector assembled, CeedElemRestriction rstr, CeedRequest *request) {
587   return CeedOperatorLinearAssembleQFunctionCore_Cuda(op, false, &assembled, &rstr, request);
588 }
589 
590 //------------------------------------------------------------------------------
591 // Assemble Diagonal Setup
592 //------------------------------------------------------------------------------
593 static inline int CeedOperatorAssembleDiagonalSetup_Cuda(CeedOperator op) {
594   Ceed                ceed;
595   CeedInt             num_input_fields, num_output_fields, num_eval_modes_in = 0, num_eval_modes_out = 0;
596   CeedInt             q_comp, num_nodes, num_qpts;
597   CeedEvalMode       *eval_modes_in = NULL, *eval_modes_out = NULL;
598   CeedBasis           basis_in = NULL, basis_out = NULL;
599   CeedQFunctionField *qf_fields;
600   CeedQFunction       qf;
601   CeedOperatorField  *op_fields;
602   CeedOperator_Cuda  *impl;
603 
604   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
605   CeedCallBackend(CeedOperatorGetQFunction(op, &qf));
606   CeedCallBackend(CeedQFunctionGetNumArgs(qf, &num_input_fields, &num_output_fields));
607 
608   // Determine active input basis
609   CeedCallBackend(CeedOperatorGetFields(op, NULL, &op_fields, NULL, NULL));
610   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, &qf_fields, NULL, NULL));
611   for (CeedInt i = 0; i < num_input_fields; i++) {
612     CeedVector vec;
613 
614     CeedCallBackend(CeedOperatorFieldGetVector(op_fields[i], &vec));
615     if (vec == CEED_VECTOR_ACTIVE) {
616       CeedBasis    basis;
617       CeedEvalMode eval_mode;
618 
619       CeedCallBackend(CeedOperatorFieldGetBasis(op_fields[i], &basis));
620       CeedCheck(!basis_in || basis_in == basis, ceed, CEED_ERROR_BACKEND,
621                 "Backend does not implement operator diagonal assembly with multiple active bases");
622       basis_in = basis;
623       CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_fields[i], &eval_mode));
624       CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis_in, eval_mode, &q_comp));
625       if (eval_mode != CEED_EVAL_WEIGHT) {
626         // q_comp = 1 if CEED_EVAL_NONE, CEED_EVAL_WEIGHT caught by QF assembly
627         CeedCallBackend(CeedRealloc(num_eval_modes_in + q_comp, &eval_modes_in));
628         for (CeedInt d = 0; d < q_comp; d++) eval_modes_in[num_eval_modes_in + d] = eval_mode;
629         num_eval_modes_in += q_comp;
630       }
631     }
632   }
633 
634   // Determine active output basis
635   CeedCallBackend(CeedOperatorGetFields(op, NULL, NULL, NULL, &op_fields));
636   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, NULL, NULL, &qf_fields));
637   for (CeedInt i = 0; i < num_output_fields; i++) {
638     CeedVector vec;
639 
640     CeedCallBackend(CeedOperatorFieldGetVector(op_fields[i], &vec));
641     if (vec == CEED_VECTOR_ACTIVE) {
642       CeedBasis    basis;
643       CeedEvalMode eval_mode;
644 
645       CeedCallBackend(CeedOperatorFieldGetBasis(op_fields[i], &basis));
646       CeedCheck(!basis_out || basis_out == basis, ceed, CEED_ERROR_BACKEND,
647                 "Backend does not implement operator diagonal assembly with multiple active bases");
648       basis_out = basis;
649       CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_fields[i], &eval_mode));
650       CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis_out, eval_mode, &q_comp));
651       if (eval_mode != CEED_EVAL_WEIGHT) {
652         // q_comp = 1 if CEED_EVAL_NONE, CEED_EVAL_WEIGHT caught by QF assembly
653         CeedCallBackend(CeedRealloc(num_eval_modes_out + q_comp, &eval_modes_out));
654         for (CeedInt d = 0; d < q_comp; d++) eval_modes_out[num_eval_modes_out + d] = eval_mode;
655         num_eval_modes_out += q_comp;
656       }
657     }
658   }
659 
660   // Operator data struct
661   CeedCallBackend(CeedOperatorGetData(op, &impl));
662   CeedCallBackend(CeedCalloc(1, &impl->diag));
663   CeedOperatorDiag_Cuda *diag = impl->diag;
664 
665   // Basis matrices
666   CeedCallBackend(CeedBasisGetNumNodes(basis_in, &num_nodes));
667   if (basis_in == CEED_BASIS_NONE) num_qpts = num_nodes;
668   else CeedCallBackend(CeedBasisGetNumQuadraturePoints(basis_in, &num_qpts));
669   const CeedInt interp_bytes     = num_nodes * num_qpts * sizeof(CeedScalar);
670   const CeedInt eval_modes_bytes = sizeof(CeedEvalMode);
671   bool          has_eval_none    = false;
672 
673   // CEED_EVAL_NONE
674   for (CeedInt i = 0; i < num_eval_modes_in; i++) has_eval_none = has_eval_none || (eval_modes_in[i] == CEED_EVAL_NONE);
675   for (CeedInt i = 0; i < num_eval_modes_out; i++) has_eval_none = has_eval_none || (eval_modes_out[i] == CEED_EVAL_NONE);
676   if (has_eval_none) {
677     CeedScalar *identity = NULL;
678 
679     CeedCallBackend(CeedCalloc(num_nodes * num_qpts, &identity));
680     for (CeedInt i = 0; i < (num_nodes < num_qpts ? num_nodes : num_qpts); i++) identity[i * num_nodes + i] = 1.0;
681     CeedCallCuda(ceed, cudaMalloc((void **)&diag->d_identity, interp_bytes));
682     CeedCallCuda(ceed, cudaMemcpy(diag->d_identity, identity, interp_bytes, cudaMemcpyHostToDevice));
683     CeedCallBackend(CeedFree(&identity));
684   }
685 
686   // CEED_EVAL_INTERP, CEED_EVAL_GRAD, CEED_EVAL_DIV, and CEED_EVAL_CURL
687   for (CeedInt in = 0; in < 2; in++) {
688     CeedFESpace fespace;
689     CeedBasis   basis = in ? basis_in : basis_out;
690 
691     CeedCallBackend(CeedBasisGetFESpace(basis, &fespace));
692     switch (fespace) {
693       case CEED_FE_SPACE_H1: {
694         CeedInt           q_comp_interp, q_comp_grad;
695         const CeedScalar *interp, *grad;
696         CeedScalar       *d_interp, *d_grad;
697 
698         CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis, CEED_EVAL_INTERP, &q_comp_interp));
699         CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis, CEED_EVAL_GRAD, &q_comp_grad));
700 
701         CeedCallBackend(CeedBasisGetInterp(basis, &interp));
702         CeedCallCuda(ceed, cudaMalloc((void **)&d_interp, interp_bytes * q_comp_interp));
703         CeedCallCuda(ceed, cudaMemcpy(d_interp, interp, interp_bytes * q_comp_interp, cudaMemcpyHostToDevice));
704         CeedCallBackend(CeedBasisGetGrad(basis, &grad));
705         CeedCallCuda(ceed, cudaMalloc((void **)&d_grad, interp_bytes * q_comp_grad));
706         CeedCallCuda(ceed, cudaMemcpy(d_grad, grad, interp_bytes * q_comp_grad, cudaMemcpyHostToDevice));
707         if (in) {
708           diag->d_interp_in = d_interp;
709           diag->d_grad_in   = d_grad;
710         } else {
711           diag->d_interp_out = d_interp;
712           diag->d_grad_out   = d_grad;
713         }
714       } break;
715       case CEED_FE_SPACE_HDIV: {
716         CeedInt           q_comp_interp, q_comp_div;
717         const CeedScalar *interp, *div;
718         CeedScalar       *d_interp, *d_div;
719 
720         CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis, CEED_EVAL_INTERP, &q_comp_interp));
721         CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis, CEED_EVAL_DIV, &q_comp_div));
722 
723         CeedCallBackend(CeedBasisGetInterp(basis, &interp));
724         CeedCallCuda(ceed, cudaMalloc((void **)&d_interp, interp_bytes * q_comp_interp));
725         CeedCallCuda(ceed, cudaMemcpy(d_interp, interp, interp_bytes * q_comp_interp, cudaMemcpyHostToDevice));
726         CeedCallBackend(CeedBasisGetDiv(basis, &div));
727         CeedCallCuda(ceed, cudaMalloc((void **)&d_div, interp_bytes * q_comp_div));
728         CeedCallCuda(ceed, cudaMemcpy(d_div, div, interp_bytes * q_comp_div, cudaMemcpyHostToDevice));
729         if (in) {
730           diag->d_interp_in = d_interp;
731           diag->d_div_in    = d_div;
732         } else {
733           diag->d_interp_out = d_interp;
734           diag->d_div_out    = d_div;
735         }
736       } break;
737       case CEED_FE_SPACE_HCURL: {
738         CeedInt           q_comp_interp, q_comp_curl;
739         const CeedScalar *interp, *curl;
740         CeedScalar       *d_interp, *d_curl;
741 
742         CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis, CEED_EVAL_INTERP, &q_comp_interp));
743         CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis, CEED_EVAL_CURL, &q_comp_curl));
744 
745         CeedCallBackend(CeedBasisGetInterp(basis, &interp));
746         CeedCallCuda(ceed, cudaMalloc((void **)&d_interp, interp_bytes * q_comp_interp));
747         CeedCallCuda(ceed, cudaMemcpy(d_interp, interp, interp_bytes * q_comp_interp, cudaMemcpyHostToDevice));
748         CeedCallBackend(CeedBasisGetCurl(basis, &curl));
749         CeedCallCuda(ceed, cudaMalloc((void **)&d_curl, interp_bytes * q_comp_curl));
750         CeedCallCuda(ceed, cudaMemcpy(d_curl, curl, interp_bytes * q_comp_curl, cudaMemcpyHostToDevice));
751         if (in) {
752           diag->d_interp_in = d_interp;
753           diag->d_curl_in   = d_curl;
754         } else {
755           diag->d_interp_out = d_interp;
756           diag->d_curl_out   = d_curl;
757         }
758       } break;
759     }
760   }
761 
762   // Arrays of eval_modes
763   CeedCallCuda(ceed, cudaMalloc((void **)&diag->d_eval_modes_in, num_eval_modes_in * eval_modes_bytes));
764   CeedCallCuda(ceed, cudaMemcpy(diag->d_eval_modes_in, eval_modes_in, num_eval_modes_in * eval_modes_bytes, cudaMemcpyHostToDevice));
765   CeedCallCuda(ceed, cudaMalloc((void **)&diag->d_eval_modes_out, num_eval_modes_out * eval_modes_bytes));
766   CeedCallCuda(ceed, cudaMemcpy(diag->d_eval_modes_out, eval_modes_out, num_eval_modes_out * eval_modes_bytes, cudaMemcpyHostToDevice));
767   CeedCallBackend(CeedFree(&eval_modes_in));
768   CeedCallBackend(CeedFree(&eval_modes_out));
769   return CEED_ERROR_SUCCESS;
770 }
771 
772 //------------------------------------------------------------------------------
773 // Assemble Diagonal Setup (Compilation)
774 //------------------------------------------------------------------------------
775 static inline int CeedOperatorAssembleDiagonalSetupCompile_Cuda(CeedOperator op, CeedInt use_ceedsize_idx, const bool is_point_block) {
776   Ceed                ceed;
777   char               *diagonal_kernel_source;
778   const char         *diagonal_kernel_path;
779   CeedInt             num_input_fields, num_output_fields, num_eval_modes_in = 0, num_eval_modes_out = 0;
780   CeedInt             num_comp, q_comp, num_nodes, num_qpts;
781   CeedBasis           basis_in = NULL, basis_out = NULL;
782   CeedQFunctionField *qf_fields;
783   CeedQFunction       qf;
784   CeedOperatorField  *op_fields;
785   CeedOperator_Cuda  *impl;
786 
787   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
788   CeedCallBackend(CeedOperatorGetQFunction(op, &qf));
789   CeedCallBackend(CeedQFunctionGetNumArgs(qf, &num_input_fields, &num_output_fields));
790 
791   // Determine active input basis
792   CeedCallBackend(CeedOperatorGetFields(op, NULL, &op_fields, NULL, NULL));
793   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, &qf_fields, NULL, NULL));
794   for (CeedInt i = 0; i < num_input_fields; i++) {
795     CeedVector vec;
796 
797     CeedCallBackend(CeedOperatorFieldGetVector(op_fields[i], &vec));
798     if (vec == CEED_VECTOR_ACTIVE) {
799       CeedEvalMode eval_mode;
800 
801       CeedCallBackend(CeedOperatorFieldGetBasis(op_fields[i], &basis_in));
802       CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_fields[i], &eval_mode));
803       CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis_in, eval_mode, &q_comp));
804       if (eval_mode != CEED_EVAL_WEIGHT) {
805         num_eval_modes_in += q_comp;
806       }
807     }
808   }
809 
810   // Determine active output basis
811   CeedCallBackend(CeedOperatorGetFields(op, NULL, NULL, NULL, &op_fields));
812   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, NULL, NULL, &qf_fields));
813   for (CeedInt i = 0; i < num_output_fields; i++) {
814     CeedVector vec;
815 
816     CeedCallBackend(CeedOperatorFieldGetVector(op_fields[i], &vec));
817     if (vec == CEED_VECTOR_ACTIVE) {
818       CeedEvalMode eval_mode;
819 
820       CeedCallBackend(CeedOperatorFieldGetBasis(op_fields[i], &basis_out));
821       CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_fields[i], &eval_mode));
822       CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis_out, eval_mode, &q_comp));
823       if (eval_mode != CEED_EVAL_WEIGHT) {
824         num_eval_modes_out += q_comp;
825       }
826     }
827   }
828 
829   // Operator data struct
830   CeedCallBackend(CeedOperatorGetData(op, &impl));
831   CeedOperatorDiag_Cuda *diag = impl->diag;
832 
833   // Assemble kernel
834   CUmodule *module          = is_point_block ? &diag->module_point_block : &diag->module;
835   CeedInt   elems_per_block = 1;
836   CeedCallBackend(CeedBasisGetNumNodes(basis_in, &num_nodes));
837   CeedCallBackend(CeedBasisGetNumComponents(basis_in, &num_comp));
838   if (basis_in == CEED_BASIS_NONE) num_qpts = num_nodes;
839   else CeedCallBackend(CeedBasisGetNumQuadraturePoints(basis_in, &num_qpts));
840   CeedCallBackend(CeedGetJitAbsolutePath(ceed, "ceed/jit-source/cuda/cuda-ref-operator-assemble-diagonal.h", &diagonal_kernel_path));
841   CeedDebug256(ceed, CEED_DEBUG_COLOR_SUCCESS, "----- Loading Diagonal Assembly Kernel Source -----\n");
842   CeedCallBackend(CeedLoadSourceToBuffer(ceed, diagonal_kernel_path, &diagonal_kernel_source));
843   CeedDebug256(ceed, CEED_DEBUG_COLOR_SUCCESS, "----- Loading Diagonal Assembly Source Complete! -----\n");
844   CeedCallCuda(ceed, CeedCompile_Cuda(ceed, diagonal_kernel_source, module, 8, "NUM_EVAL_MODES_IN", num_eval_modes_in, "NUM_EVAL_MODES_OUT",
845                                       num_eval_modes_out, "NUM_COMP", num_comp, "NUM_NODES", num_nodes, "NUM_QPTS", num_qpts, "USE_CEEDSIZE",
846                                       use_ceedsize_idx, "USE_POINT_BLOCK", is_point_block ? 1 : 0, "BLOCK_SIZE", num_nodes * elems_per_block));
847   CeedCallCuda(ceed, CeedGetKernel_Cuda(ceed, *module, "LinearDiagonal", is_point_block ? &diag->LinearPointBlock : &diag->LinearDiagonal));
848   CeedCallBackend(CeedFree(&diagonal_kernel_path));
849   CeedCallBackend(CeedFree(&diagonal_kernel_source));
850   return CEED_ERROR_SUCCESS;
851 }
852 
853 //------------------------------------------------------------------------------
854 // Assemble Diagonal Core
855 //------------------------------------------------------------------------------
856 static inline int CeedOperatorAssembleDiagonalCore_Cuda(CeedOperator op, CeedVector assembled, CeedRequest *request, const bool is_point_block) {
857   Ceed                ceed;
858   CeedInt             num_elem, num_nodes;
859   CeedScalar         *elem_diag_array;
860   const CeedScalar   *assembled_qf_array;
861   CeedVector          assembled_qf   = NULL, elem_diag;
862   CeedElemRestriction assembled_rstr = NULL, rstr_in, rstr_out, diag_rstr;
863   CeedOperator_Cuda  *impl;
864 
865   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
866   CeedCallBackend(CeedOperatorGetData(op, &impl));
867 
868   // Assemble QFunction
869   CeedCallBackend(CeedOperatorLinearAssembleQFunctionBuildOrUpdate(op, &assembled_qf, &assembled_rstr, request));
870   CeedCallBackend(CeedElemRestrictionDestroy(&assembled_rstr));
871   CeedCallBackend(CeedVectorGetArrayRead(assembled_qf, CEED_MEM_DEVICE, &assembled_qf_array));
872 
873   // Setup
874   if (!impl->diag) CeedCallBackend(CeedOperatorAssembleDiagonalSetup_Cuda(op));
875   CeedOperatorDiag_Cuda *diag = impl->diag;
876 
877   assert(diag != NULL);
878 
879   // Assemble kernel if needed
880   if ((!is_point_block && !diag->LinearDiagonal) || (is_point_block && !diag->LinearPointBlock)) {
881     CeedSize assembled_length, assembled_qf_length;
882     CeedInt  use_ceedsize_idx = 0;
883     CeedCallBackend(CeedVectorGetLength(assembled, &assembled_length));
884     CeedCallBackend(CeedVectorGetLength(assembled_qf, &assembled_qf_length));
885     if ((assembled_length > INT_MAX) || (assembled_qf_length > INT_MAX)) use_ceedsize_idx = 1;
886 
887     CeedCallBackend(CeedOperatorAssembleDiagonalSetupCompile_Cuda(op, use_ceedsize_idx, is_point_block));
888   }
889 
890   // Restriction and diagonal vector
891   CeedCallBackend(CeedOperatorGetActiveElemRestrictions(op, &rstr_in, &rstr_out));
892   CeedCheck(rstr_in == rstr_out, ceed, CEED_ERROR_BACKEND,
893             "Cannot assemble operator diagonal with different input and output active element restrictions");
894   if (!is_point_block && !diag->diag_rstr) {
895     CeedCallBackend(CeedElemRestrictionCreateUnsignedCopy(rstr_out, &diag->diag_rstr));
896     CeedCallBackend(CeedElemRestrictionCreateVector(diag->diag_rstr, NULL, &diag->elem_diag));
897   } else if (is_point_block && !diag->point_block_diag_rstr) {
898     CeedCallBackend(CeedOperatorCreateActivePointBlockRestriction(rstr_out, &diag->point_block_diag_rstr));
899     CeedCallBackend(CeedElemRestrictionCreateVector(diag->point_block_diag_rstr, NULL, &diag->point_block_elem_diag));
900   }
901   diag_rstr = is_point_block ? diag->point_block_diag_rstr : diag->diag_rstr;
902   elem_diag = is_point_block ? diag->point_block_elem_diag : diag->elem_diag;
903   CeedCallBackend(CeedVectorSetValue(elem_diag, 0.0));
904 
905   // Only assemble diagonal if the basis has nodes, otherwise inputs are null pointers
906   CeedCallBackend(CeedElemRestrictionGetElementSize(diag_rstr, &num_nodes));
907   if (num_nodes > 0) {
908     // Assemble element operator diagonals
909     CeedCallBackend(CeedElemRestrictionGetNumElements(diag_rstr, &num_elem));
910     CeedCallBackend(CeedVectorGetArray(elem_diag, CEED_MEM_DEVICE, &elem_diag_array));
911 
912     // Compute the diagonal of B^T D B
913     CeedInt elems_per_block = 1;
914     CeedInt grid            = CeedDivUpInt(num_elem, elems_per_block);
915     void   *args[]          = {(void *)&num_elem,      &diag->d_identity,       &diag->d_interp_in,  &diag->d_grad_in, &diag->d_div_in,
916                                &diag->d_curl_in,       &diag->d_interp_out,     &diag->d_grad_out,   &diag->d_div_out, &diag->d_curl_out,
917                                &diag->d_eval_modes_in, &diag->d_eval_modes_out, &assembled_qf_array, &elem_diag_array};
918 
919     if (is_point_block) {
920       CeedCallBackend(CeedRunKernelDim_Cuda(ceed, diag->LinearPointBlock, grid, num_nodes, 1, elems_per_block, args));
921     } else {
922       CeedCallBackend(CeedRunKernelDim_Cuda(ceed, diag->LinearDiagonal, grid, num_nodes, 1, elems_per_block, args));
923     }
924 
925     // Restore arrays
926     CeedCallBackend(CeedVectorRestoreArray(elem_diag, &elem_diag_array));
927     CeedCallBackend(CeedVectorRestoreArrayRead(assembled_qf, &assembled_qf_array));
928   }
929 
930   // Assemble local operator diagonal
931   CeedCallBackend(CeedElemRestrictionApply(diag_rstr, CEED_TRANSPOSE, elem_diag, assembled, request));
932 
933   // Cleanup
934   CeedCallBackend(CeedVectorDestroy(&assembled_qf));
935   return CEED_ERROR_SUCCESS;
936 }
937 
938 //------------------------------------------------------------------------------
939 // Assemble Linear Diagonal
940 //------------------------------------------------------------------------------
941 static int CeedOperatorLinearAssembleAddDiagonal_Cuda(CeedOperator op, CeedVector assembled, CeedRequest *request) {
942   CeedCallBackend(CeedOperatorAssembleDiagonalCore_Cuda(op, assembled, request, false));
943   return CEED_ERROR_SUCCESS;
944 }
945 
946 //------------------------------------------------------------------------------
947 // Assemble Linear Point Block Diagonal
948 //------------------------------------------------------------------------------
949 static int CeedOperatorLinearAssembleAddPointBlockDiagonal_Cuda(CeedOperator op, CeedVector assembled, CeedRequest *request) {
950   CeedCallBackend(CeedOperatorAssembleDiagonalCore_Cuda(op, assembled, request, true));
951   return CEED_ERROR_SUCCESS;
952 }
953 
954 //------------------------------------------------------------------------------
955 // Single Operator Assembly Setup
956 //------------------------------------------------------------------------------
957 static int CeedSingleOperatorAssembleSetup_Cuda(CeedOperator op, CeedInt use_ceedsize_idx) {
958   Ceed                ceed;
959   Ceed_Cuda          *cuda_data;
960   char               *assembly_kernel_source;
961   const char         *assembly_kernel_path;
962   CeedInt             num_input_fields, num_output_fields, num_eval_modes_in = 0, num_eval_modes_out = 0;
963   CeedInt             elem_size_in, num_qpts_in = 0, num_comp_in, elem_size_out, num_qpts_out, num_comp_out, q_comp;
964   CeedEvalMode       *eval_modes_in = NULL, *eval_modes_out = NULL;
965   CeedElemRestriction rstr_in = NULL, rstr_out = NULL;
966   CeedBasis           basis_in = NULL, basis_out = NULL;
967   CeedQFunctionField *qf_fields;
968   CeedQFunction       qf;
969   CeedOperatorField  *input_fields, *output_fields;
970   CeedOperator_Cuda  *impl;
971 
972   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
973   CeedCallBackend(CeedOperatorGetData(op, &impl));
974 
975   // Get intput and output fields
976   CeedCallBackend(CeedOperatorGetFields(op, &num_input_fields, &input_fields, &num_output_fields, &output_fields));
977 
978   // Determine active input basis eval mode
979   CeedCallBackend(CeedOperatorGetQFunction(op, &qf));
980   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, &qf_fields, NULL, NULL));
981   for (CeedInt i = 0; i < num_input_fields; i++) {
982     CeedVector vec;
983 
984     CeedCallBackend(CeedOperatorFieldGetVector(input_fields[i], &vec));
985     if (vec == CEED_VECTOR_ACTIVE) {
986       CeedBasis    basis;
987       CeedEvalMode eval_mode;
988 
989       CeedCallBackend(CeedOperatorFieldGetBasis(input_fields[i], &basis));
990       CeedCheck(!basis_in || basis_in == basis, ceed, CEED_ERROR_BACKEND, "Backend does not implement operator assembly with multiple active bases");
991       basis_in = basis;
992       CeedCallBackend(CeedOperatorFieldGetElemRestriction(input_fields[i], &rstr_in));
993       CeedCallBackend(CeedElemRestrictionGetElementSize(rstr_in, &elem_size_in));
994       if (basis_in == CEED_BASIS_NONE) num_qpts_in = elem_size_in;
995       else CeedCallBackend(CeedBasisGetNumQuadraturePoints(basis_in, &num_qpts_in));
996       CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_fields[i], &eval_mode));
997       CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis_in, eval_mode, &q_comp));
998       if (eval_mode != CEED_EVAL_WEIGHT) {
999         // q_comp = 1 if CEED_EVAL_NONE, CEED_EVAL_WEIGHT caught by QF Assembly
1000         CeedCallBackend(CeedRealloc(num_eval_modes_in + q_comp, &eval_modes_in));
1001         for (CeedInt d = 0; d < q_comp; d++) {
1002           eval_modes_in[num_eval_modes_in + d] = eval_mode;
1003         }
1004         num_eval_modes_in += q_comp;
1005       }
1006     }
1007   }
1008 
1009   // Determine active output basis; basis_out and rstr_out only used if same as input, TODO
1010   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, NULL, NULL, &qf_fields));
1011   for (CeedInt i = 0; i < num_output_fields; i++) {
1012     CeedVector vec;
1013 
1014     CeedCallBackend(CeedOperatorFieldGetVector(output_fields[i], &vec));
1015     if (vec == CEED_VECTOR_ACTIVE) {
1016       CeedBasis    basis;
1017       CeedEvalMode eval_mode;
1018 
1019       CeedCallBackend(CeedOperatorFieldGetBasis(output_fields[i], &basis));
1020       CeedCheck(!basis_out || basis_out == basis, ceed, CEED_ERROR_BACKEND,
1021                 "Backend does not implement operator assembly with multiple active bases");
1022       basis_out = basis;
1023       CeedCallBackend(CeedOperatorFieldGetElemRestriction(output_fields[i], &rstr_out));
1024       CeedCallBackend(CeedElemRestrictionGetElementSize(rstr_out, &elem_size_out));
1025       if (basis_out == CEED_BASIS_NONE) num_qpts_out = elem_size_out;
1026       else CeedCallBackend(CeedBasisGetNumQuadraturePoints(basis_out, &num_qpts_out));
1027       CeedCheck(num_qpts_in == num_qpts_out, ceed, CEED_ERROR_UNSUPPORTED,
1028                 "Active input and output bases must have the same number of quadrature points");
1029       CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_fields[i], &eval_mode));
1030       CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis_out, eval_mode, &q_comp));
1031       if (eval_mode != CEED_EVAL_WEIGHT) {
1032         // q_comp = 1 if CEED_EVAL_NONE, CEED_EVAL_WEIGHT caught by QF Assembly
1033         CeedCallBackend(CeedRealloc(num_eval_modes_out + q_comp, &eval_modes_out));
1034         for (CeedInt d = 0; d < q_comp; d++) {
1035           eval_modes_out[num_eval_modes_out + d] = eval_mode;
1036         }
1037         num_eval_modes_out += q_comp;
1038       }
1039     }
1040   }
1041   CeedCheck(num_eval_modes_in > 0 && num_eval_modes_out > 0, ceed, CEED_ERROR_UNSUPPORTED, "Cannot assemble operator without inputs/outputs");
1042 
1043   CeedCallBackend(CeedCalloc(1, &impl->asmb));
1044   CeedOperatorAssemble_Cuda *asmb = impl->asmb;
1045   asmb->elems_per_block           = 1;
1046   asmb->block_size_x              = elem_size_in;
1047   asmb->block_size_y              = elem_size_out;
1048 
1049   CeedCallBackend(CeedGetData(ceed, &cuda_data));
1050   bool fallback = asmb->block_size_x * asmb->block_size_y * asmb->elems_per_block > cuda_data->device_prop.maxThreadsPerBlock;
1051 
1052   if (fallback) {
1053     // Use fallback kernel with 1D threadblock
1054     asmb->block_size_y = 1;
1055   }
1056 
1057   // Compile kernels
1058   CeedCallBackend(CeedElemRestrictionGetNumComponents(rstr_in, &num_comp_in));
1059   CeedCallBackend(CeedElemRestrictionGetNumComponents(rstr_out, &num_comp_out));
1060   CeedCallBackend(CeedGetJitAbsolutePath(ceed, "ceed/jit-source/cuda/cuda-ref-operator-assemble.h", &assembly_kernel_path));
1061   CeedDebug256(ceed, CEED_DEBUG_COLOR_SUCCESS, "----- Loading Assembly Kernel Source -----\n");
1062   CeedCallBackend(CeedLoadSourceToBuffer(ceed, assembly_kernel_path, &assembly_kernel_source));
1063   CeedDebug256(ceed, CEED_DEBUG_COLOR_SUCCESS, "----- Loading Assembly Source Complete! -----\n");
1064   CeedCallBackend(CeedCompile_Cuda(ceed, assembly_kernel_source, &asmb->module, 10, "NUM_EVAL_MODES_IN", num_eval_modes_in, "NUM_EVAL_MODES_OUT",
1065                                    num_eval_modes_out, "NUM_COMP_IN", num_comp_in, "NUM_COMP_OUT", num_comp_out, "NUM_NODES_IN", elem_size_in,
1066                                    "NUM_NODES_OUT", elem_size_out, "NUM_QPTS", num_qpts_in, "BLOCK_SIZE",
1067                                    asmb->block_size_x * asmb->block_size_y * asmb->elems_per_block, "BLOCK_SIZE_Y", asmb->block_size_y,
1068                                    "USE_CEEDSIZE", use_ceedsize_idx));
1069   CeedCallBackend(CeedGetKernel_Cuda(ceed, asmb->module, "LinearAssemble", &asmb->LinearAssemble));
1070   CeedCallBackend(CeedFree(&assembly_kernel_path));
1071   CeedCallBackend(CeedFree(&assembly_kernel_source));
1072 
1073   // Load into B_in, in order that they will be used in eval_modes_in
1074   {
1075     const CeedInt in_bytes           = elem_size_in * num_qpts_in * num_eval_modes_in * sizeof(CeedScalar);
1076     CeedInt       d_in               = 0;
1077     CeedEvalMode  eval_modes_in_prev = CEED_EVAL_NONE;
1078     bool          has_eval_none      = false;
1079     CeedScalar   *identity           = NULL;
1080 
1081     for (CeedInt i = 0; i < num_eval_modes_in; i++) {
1082       has_eval_none = has_eval_none || (eval_modes_in[i] == CEED_EVAL_NONE);
1083     }
1084     if (has_eval_none) {
1085       CeedCallBackend(CeedCalloc(elem_size_in * num_qpts_in, &identity));
1086       for (CeedInt i = 0; i < (elem_size_in < num_qpts_in ? elem_size_in : num_qpts_in); i++) identity[i * elem_size_in + i] = 1.0;
1087     }
1088 
1089     CeedCallCuda(ceed, cudaMalloc((void **)&asmb->d_B_in, in_bytes));
1090     for (CeedInt i = 0; i < num_eval_modes_in; i++) {
1091       const CeedScalar *h_B_in;
1092 
1093       CeedCallBackend(CeedOperatorGetBasisPointer(basis_in, eval_modes_in[i], identity, &h_B_in));
1094       CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis_in, eval_modes_in[i], &q_comp));
1095       if (q_comp > 1) {
1096         if (i == 0 || eval_modes_in[i] != eval_modes_in_prev) d_in = 0;
1097         else h_B_in = &h_B_in[(++d_in) * elem_size_in * num_qpts_in];
1098       }
1099       eval_modes_in_prev = eval_modes_in[i];
1100 
1101       CeedCallCuda(ceed, cudaMemcpy(&asmb->d_B_in[i * elem_size_in * num_qpts_in], h_B_in, elem_size_in * num_qpts_in * sizeof(CeedScalar),
1102                                     cudaMemcpyHostToDevice));
1103     }
1104 
1105     if (identity) {
1106       CeedCallBackend(CeedFree(&identity));
1107     }
1108   }
1109 
1110   // Load into B_out, in order that they will be used in eval_modes_out
1111   {
1112     const CeedInt out_bytes           = elem_size_out * num_qpts_out * num_eval_modes_out * sizeof(CeedScalar);
1113     CeedInt       d_out               = 0;
1114     CeedEvalMode  eval_modes_out_prev = CEED_EVAL_NONE;
1115     bool          has_eval_none       = false;
1116     CeedScalar   *identity            = NULL;
1117 
1118     for (CeedInt i = 0; i < num_eval_modes_out; i++) {
1119       has_eval_none = has_eval_none || (eval_modes_out[i] == CEED_EVAL_NONE);
1120     }
1121     if (has_eval_none) {
1122       CeedCallBackend(CeedCalloc(elem_size_out * num_qpts_out, &identity));
1123       for (CeedInt i = 0; i < (elem_size_out < num_qpts_out ? elem_size_out : num_qpts_out); i++) identity[i * elem_size_out + i] = 1.0;
1124     }
1125 
1126     CeedCallCuda(ceed, cudaMalloc((void **)&asmb->d_B_out, out_bytes));
1127     for (CeedInt i = 0; i < num_eval_modes_out; i++) {
1128       const CeedScalar *h_B_out;
1129 
1130       CeedCallBackend(CeedOperatorGetBasisPointer(basis_out, eval_modes_out[i], identity, &h_B_out));
1131       CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis_out, eval_modes_out[i], &q_comp));
1132       if (q_comp > 1) {
1133         if (i == 0 || eval_modes_out[i] != eval_modes_out_prev) d_out = 0;
1134         else h_B_out = &h_B_out[(++d_out) * elem_size_out * num_qpts_out];
1135       }
1136       eval_modes_out_prev = eval_modes_out[i];
1137 
1138       CeedCallCuda(ceed, cudaMemcpy(&asmb->d_B_out[i * elem_size_out * num_qpts_out], h_B_out, elem_size_out * num_qpts_out * sizeof(CeedScalar),
1139                                     cudaMemcpyHostToDevice));
1140     }
1141 
1142     if (identity) {
1143       CeedCallBackend(CeedFree(&identity));
1144     }
1145   }
1146   return CEED_ERROR_SUCCESS;
1147 }
1148 
1149 //------------------------------------------------------------------------------
1150 // Assemble matrix data for COO matrix of assembled operator.
1151 // The sparsity pattern is set by CeedOperatorLinearAssembleSymbolic.
1152 //
1153 // Note that this (and other assembly routines) currently assume only one active input restriction/basis per operator (could have multiple basis eval
1154 // modes).
1155 // TODO: allow multiple active input restrictions/basis objects
1156 //------------------------------------------------------------------------------
1157 static int CeedSingleOperatorAssemble_Cuda(CeedOperator op, CeedInt offset, CeedVector values) {
1158   Ceed                ceed;
1159   CeedSize            values_length = 0, assembled_qf_length = 0;
1160   CeedInt             use_ceedsize_idx = 0, num_elem_in, num_elem_out, elem_size_in, elem_size_out;
1161   CeedScalar         *values_array;
1162   const CeedScalar   *assembled_qf_array;
1163   CeedVector          assembled_qf   = NULL;
1164   CeedElemRestriction assembled_rstr = NULL, rstr_in, rstr_out;
1165   CeedRestrictionType rstr_type_in, rstr_type_out;
1166   const bool         *orients_in = NULL, *orients_out = NULL;
1167   const CeedInt8     *curl_orients_in = NULL, *curl_orients_out = NULL;
1168   CeedOperator_Cuda  *impl;
1169 
1170   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
1171   CeedCallBackend(CeedOperatorGetData(op, &impl));
1172 
1173   // Assemble QFunction
1174   CeedCallBackend(CeedOperatorLinearAssembleQFunctionBuildOrUpdate(op, &assembled_qf, &assembled_rstr, CEED_REQUEST_IMMEDIATE));
1175   CeedCallBackend(CeedElemRestrictionDestroy(&assembled_rstr));
1176   CeedCallBackend(CeedVectorGetArrayRead(assembled_qf, CEED_MEM_DEVICE, &assembled_qf_array));
1177 
1178   CeedCallBackend(CeedVectorGetLength(values, &values_length));
1179   CeedCallBackend(CeedVectorGetLength(assembled_qf, &assembled_qf_length));
1180   if ((values_length > INT_MAX) || (assembled_qf_length > INT_MAX)) use_ceedsize_idx = 1;
1181 
1182   // Setup
1183   if (!impl->asmb) CeedCallBackend(CeedSingleOperatorAssembleSetup_Cuda(op, use_ceedsize_idx));
1184   CeedOperatorAssemble_Cuda *asmb = impl->asmb;
1185 
1186   assert(asmb != NULL);
1187 
1188   // Assemble element operator
1189   CeedCallBackend(CeedVectorGetArray(values, CEED_MEM_DEVICE, &values_array));
1190   values_array += offset;
1191 
1192   CeedCallBackend(CeedOperatorGetActiveElemRestrictions(op, &rstr_in, &rstr_out));
1193   CeedCallBackend(CeedElemRestrictionGetNumElements(rstr_in, &num_elem_in));
1194   CeedCallBackend(CeedElemRestrictionGetElementSize(rstr_in, &elem_size_in));
1195 
1196   CeedCallBackend(CeedElemRestrictionGetType(rstr_in, &rstr_type_in));
1197   if (rstr_type_in == CEED_RESTRICTION_ORIENTED) {
1198     CeedCallBackend(CeedElemRestrictionGetOrientations(rstr_in, CEED_MEM_DEVICE, &orients_in));
1199   } else if (rstr_type_in == CEED_RESTRICTION_CURL_ORIENTED) {
1200     CeedCallBackend(CeedElemRestrictionGetCurlOrientations(rstr_in, CEED_MEM_DEVICE, &curl_orients_in));
1201   }
1202 
1203   if (rstr_in != rstr_out) {
1204     CeedCallBackend(CeedElemRestrictionGetNumElements(rstr_out, &num_elem_out));
1205     CeedCheck(num_elem_in == num_elem_out, ceed, CEED_ERROR_UNSUPPORTED,
1206               "Active input and output operator restrictions must have the same number of elements");
1207     CeedCallBackend(CeedElemRestrictionGetElementSize(rstr_out, &elem_size_out));
1208 
1209     CeedCallBackend(CeedElemRestrictionGetType(rstr_out, &rstr_type_out));
1210     if (rstr_type_out == CEED_RESTRICTION_ORIENTED) {
1211       CeedCallBackend(CeedElemRestrictionGetOrientations(rstr_out, CEED_MEM_DEVICE, &orients_out));
1212     } else if (rstr_type_out == CEED_RESTRICTION_CURL_ORIENTED) {
1213       CeedCallBackend(CeedElemRestrictionGetCurlOrientations(rstr_out, CEED_MEM_DEVICE, &curl_orients_out));
1214     }
1215   } else {
1216     elem_size_out    = elem_size_in;
1217     orients_out      = orients_in;
1218     curl_orients_out = curl_orients_in;
1219   }
1220 
1221   // Compute B^T D B
1222   CeedInt shared_mem =
1223       ((curl_orients_in || curl_orients_out ? elem_size_in * elem_size_out : 0) + (curl_orients_in ? elem_size_in * asmb->block_size_y : 0)) *
1224       sizeof(CeedScalar);
1225   CeedInt grid   = CeedDivUpInt(num_elem_in, asmb->elems_per_block);
1226   void   *args[] = {(void *)&num_elem_in, &asmb->d_B_in,     &asmb->d_B_out,      &orients_in,  &curl_orients_in,
1227                     &orients_out,         &curl_orients_out, &assembled_qf_array, &values_array};
1228 
1229   CeedCallBackend(
1230       CeedRunKernelDimShared_Cuda(ceed, asmb->LinearAssemble, grid, asmb->block_size_x, asmb->block_size_y, asmb->elems_per_block, shared_mem, args));
1231 
1232   // Restore arrays
1233   CeedCallBackend(CeedVectorRestoreArray(values, &values_array));
1234   CeedCallBackend(CeedVectorRestoreArrayRead(assembled_qf, &assembled_qf_array));
1235 
1236   // Cleanup
1237   CeedCallBackend(CeedVectorDestroy(&assembled_qf));
1238   if (rstr_type_in == CEED_RESTRICTION_ORIENTED) {
1239     CeedCallBackend(CeedElemRestrictionRestoreOrientations(rstr_in, &orients_in));
1240   } else if (rstr_type_in == CEED_RESTRICTION_CURL_ORIENTED) {
1241     CeedCallBackend(CeedElemRestrictionRestoreCurlOrientations(rstr_in, &curl_orients_in));
1242   }
1243   if (rstr_in != rstr_out) {
1244     if (rstr_type_out == CEED_RESTRICTION_ORIENTED) {
1245       CeedCallBackend(CeedElemRestrictionRestoreOrientations(rstr_out, &orients_out));
1246     } else if (rstr_type_out == CEED_RESTRICTION_CURL_ORIENTED) {
1247       CeedCallBackend(CeedElemRestrictionRestoreCurlOrientations(rstr_out, &curl_orients_out));
1248     }
1249   }
1250   return CEED_ERROR_SUCCESS;
1251 }
1252 
1253 //------------------------------------------------------------------------------
1254 // Create operator
1255 //------------------------------------------------------------------------------
1256 int CeedOperatorCreate_Cuda(CeedOperator op) {
1257   Ceed               ceed;
1258   CeedOperator_Cuda *impl;
1259 
1260   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
1261   CeedCallBackend(CeedCalloc(1, &impl));
1262   CeedCallBackend(CeedOperatorSetData(op, impl));
1263 
1264   CeedCallBackend(CeedSetBackendFunction(ceed, "Operator", op, "LinearAssembleQFunction", CeedOperatorLinearAssembleQFunction_Cuda));
1265   CeedCallBackend(CeedSetBackendFunction(ceed, "Operator", op, "LinearAssembleQFunctionUpdate", CeedOperatorLinearAssembleQFunctionUpdate_Cuda));
1266   CeedCallBackend(CeedSetBackendFunction(ceed, "Operator", op, "LinearAssembleAddDiagonal", CeedOperatorLinearAssembleAddDiagonal_Cuda));
1267   CeedCallBackend(
1268       CeedSetBackendFunction(ceed, "Operator", op, "LinearAssembleAddPointBlockDiagonal", CeedOperatorLinearAssembleAddPointBlockDiagonal_Cuda));
1269   CeedCallBackend(CeedSetBackendFunction(ceed, "Operator", op, "LinearAssembleSingle", CeedSingleOperatorAssemble_Cuda));
1270   CeedCallBackend(CeedSetBackendFunction(ceed, "Operator", op, "ApplyAdd", CeedOperatorApplyAdd_Cuda));
1271   CeedCallBackend(CeedSetBackendFunction(ceed, "Operator", op, "Destroy", CeedOperatorDestroy_Cuda));
1272   return CEED_ERROR_SUCCESS;
1273 }
1274 
1275 //------------------------------------------------------------------------------
1276