xref: /libCEED/backends/cuda-ref/ceed-cuda-ref-operator.c (revision 8b0f73481df5f9f5ba2e5a396f0652e2438a7896)
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   CeedCallBackend(CeedFree(&impl->num_points));
31   CeedCallBackend(CeedFree(&impl->skip_rstr_in));
32   CeedCallBackend(CeedFree(&impl->skip_rstr_out));
33   CeedCallBackend(CeedFree(&impl->apply_add_basis_out));
34   CeedCallBackend(CeedFree(&impl->input_field_order));
35   CeedCallBackend(CeedFree(&impl->output_field_order));
36   CeedCallBackend(CeedFree(&impl->input_states));
37 
38   for (CeedInt i = 0; i < impl->num_inputs; i++) {
39     CeedCallBackend(CeedVectorDestroy(&impl->e_vecs_in[i]));
40     CeedCallBackend(CeedVectorDestroy(&impl->q_vecs_in[i]));
41   }
42   CeedCallBackend(CeedFree(&impl->e_vecs_in));
43   CeedCallBackend(CeedFree(&impl->q_vecs_in));
44 
45   for (CeedInt i = 0; i < impl->num_outputs; i++) {
46     CeedCallBackend(CeedVectorDestroy(&impl->e_vecs_out[i]));
47     CeedCallBackend(CeedVectorDestroy(&impl->q_vecs_out[i]));
48   }
49   CeedCallBackend(CeedFree(&impl->e_vecs_out));
50   CeedCallBackend(CeedFree(&impl->q_vecs_out));
51   CeedCallBackend(CeedVectorDestroy(&impl->point_coords_elem));
52 
53   // QFunction assembly data
54   for (CeedInt i = 0; i < impl->num_active_in; i++) {
55     CeedCallBackend(CeedVectorDestroy(&impl->qf_active_in[i]));
56   }
57   CeedCallBackend(CeedFree(&impl->qf_active_in));
58 
59   // Diag data
60   if (impl->diag) {
61     Ceed ceed;
62 
63     CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
64     if (impl->diag->module) {
65       CeedCallCuda(ceed, cuModuleUnload(impl->diag->module));
66     }
67     if (impl->diag->module_point_block) {
68       CeedCallCuda(ceed, cuModuleUnload(impl->diag->module_point_block));
69     }
70     CeedCallCuda(ceed, cudaFree(impl->diag->d_eval_modes_in));
71     CeedCallCuda(ceed, cudaFree(impl->diag->d_eval_modes_out));
72     CeedCallCuda(ceed, cudaFree(impl->diag->d_identity));
73     CeedCallCuda(ceed, cudaFree(impl->diag->d_interp_in));
74     CeedCallCuda(ceed, cudaFree(impl->diag->d_interp_out));
75     CeedCallCuda(ceed, cudaFree(impl->diag->d_grad_in));
76     CeedCallCuda(ceed, cudaFree(impl->diag->d_grad_out));
77     CeedCallCuda(ceed, cudaFree(impl->diag->d_div_in));
78     CeedCallCuda(ceed, cudaFree(impl->diag->d_div_out));
79     CeedCallCuda(ceed, cudaFree(impl->diag->d_curl_in));
80     CeedCallCuda(ceed, cudaFree(impl->diag->d_curl_out));
81     CeedCallBackend(CeedElemRestrictionDestroy(&impl->diag->diag_rstr));
82     CeedCallBackend(CeedElemRestrictionDestroy(&impl->diag->point_block_diag_rstr));
83     CeedCallBackend(CeedVectorDestroy(&impl->diag->elem_diag));
84     CeedCallBackend(CeedVectorDestroy(&impl->diag->point_block_elem_diag));
85   }
86   CeedCallBackend(CeedFree(&impl->diag));
87 
88   if (impl->asmb) {
89     Ceed ceed;
90 
91     CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
92     CeedCallCuda(ceed, cuModuleUnload(impl->asmb->module));
93     CeedCallCuda(ceed, cudaFree(impl->asmb->d_B_in));
94     CeedCallCuda(ceed, cudaFree(impl->asmb->d_B_out));
95   }
96   CeedCallBackend(CeedFree(&impl->asmb));
97 
98   CeedCallBackend(CeedFree(&impl));
99   return CEED_ERROR_SUCCESS;
100 }
101 
102 //------------------------------------------------------------------------------
103 // Setup infields or outfields
104 //------------------------------------------------------------------------------
105 static int CeedOperatorSetupFields_Cuda(CeedQFunction qf, CeedOperator op, bool is_input, bool is_at_points, bool *skip_rstr, bool *apply_add_basis,
106                                         CeedVector *e_vecs, CeedVector *q_vecs, CeedInt num_fields, CeedInt Q, CeedInt num_elem) {
107   Ceed                ceed;
108   CeedQFunctionField *qf_fields;
109   CeedOperatorField  *op_fields;
110 
111   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
112   if (is_input) {
113     CeedCallBackend(CeedOperatorGetFields(op, NULL, &op_fields, NULL, NULL));
114     CeedCallBackend(CeedQFunctionGetFields(qf, NULL, &qf_fields, NULL, NULL));
115   } else {
116     CeedCallBackend(CeedOperatorGetFields(op, NULL, NULL, NULL, &op_fields));
117     CeedCallBackend(CeedQFunctionGetFields(qf, NULL, NULL, NULL, &qf_fields));
118   }
119 
120   // Loop over fields
121   for (CeedInt i = 0; i < num_fields; i++) {
122     bool                is_active = false, is_strided = false, skip_e_vec = false;
123     CeedSize            q_size;
124     CeedInt             size;
125     CeedEvalMode        eval_mode;
126     CeedVector          l_vec;
127     CeedElemRestriction elem_rstr;
128 
129     // Check whether this field can skip the element restriction:
130     // Input CEED_VECTOR_ACTIVE
131     // Output CEED_VECTOR_ACTIVE without CEED_EVAL_NONE
132     // Input CEED_VECTOR_NONE with CEED_EVAL_WEIGHT
133     // Input passive vectorr with CEED_EVAL_NONE and strided restriction with CEED_STRIDES_BACKEND
134     CeedCallBackend(CeedOperatorFieldGetVector(op_fields[i], &l_vec));
135     is_active = l_vec == CEED_VECTOR_ACTIVE;
136     CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_fields[i], &elem_rstr));
137     CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_fields[i], &eval_mode));
138     skip_e_vec = (is_input && is_active) || (is_active && eval_mode != CEED_EVAL_NONE) || (eval_mode == CEED_EVAL_WEIGHT);
139     if (!skip_e_vec && is_input && !is_active && eval_mode == CEED_EVAL_NONE) {
140       CeedCallBackend(CeedElemRestrictionIsStrided(elem_rstr, &is_strided));
141       if (is_strided) CeedCallBackend(CeedElemRestrictionHasBackendStrides(elem_rstr, &skip_e_vec));
142     }
143     if (skip_e_vec) {
144       e_vecs[i] = NULL;
145     } else {
146       CeedCallBackend(CeedElemRestrictionCreateVector(elem_rstr, NULL, &e_vecs[i]));
147     }
148 
149     switch (eval_mode) {
150       case CEED_EVAL_NONE:
151       case CEED_EVAL_INTERP:
152       case CEED_EVAL_GRAD:
153       case CEED_EVAL_DIV:
154       case CEED_EVAL_CURL:
155         CeedCallBackend(CeedQFunctionFieldGetSize(qf_fields[i], &size));
156         q_size = (CeedSize)num_elem * (CeedSize)Q * (CeedSize)size;
157         CeedCallBackend(CeedVectorCreate(ceed, q_size, &q_vecs[i]));
158         break;
159       case CEED_EVAL_WEIGHT: {
160         CeedBasis basis;
161 
162         CeedCallBackend(CeedOperatorFieldGetBasis(op_fields[i], &basis));
163         q_size = (CeedSize)num_elem * (CeedSize)Q;
164         CeedCallBackend(CeedVectorCreate(ceed, q_size, &q_vecs[i]));
165         if (is_at_points) {
166           CeedInt num_points[num_elem];
167 
168           for (CeedInt i = 0; i < num_elem; i++) num_points[i] = Q;
169           CeedCallBackend(
170               CeedBasisApplyAtPoints(basis, num_elem, num_points, CEED_NOTRANSPOSE, CEED_EVAL_WEIGHT, CEED_VECTOR_NONE, CEED_VECTOR_NONE, q_vecs[i]));
171         } else {
172           CeedCallBackend(CeedBasisApply(basis, num_elem, CEED_NOTRANSPOSE, CEED_EVAL_WEIGHT, CEED_VECTOR_NONE, q_vecs[i]));
173         }
174         break;
175       }
176     }
177   }
178   // Drop duplicate restrictions
179   if (is_input) {
180     for (CeedInt i = 0; i < num_fields; i++) {
181       CeedVector          vec_i;
182       CeedElemRestriction rstr_i;
183 
184       CeedCallBackend(CeedOperatorFieldGetVector(op_fields[i], &vec_i));
185       CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_fields[i], &rstr_i));
186       for (CeedInt j = i + 1; j < num_fields; j++) {
187         CeedVector          vec_j;
188         CeedElemRestriction rstr_j;
189 
190         CeedCallBackend(CeedOperatorFieldGetVector(op_fields[j], &vec_j));
191         CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_fields[j], &rstr_j));
192         if (vec_i == vec_j && rstr_i == rstr_j) {
193           if (e_vecs[i]) CeedCallBackend(CeedVectorReferenceCopy(e_vecs[i], &e_vecs[j]));
194           skip_rstr[j] = true;
195         }
196       }
197     }
198   } else {
199     for (CeedInt i = num_fields - 1; i >= 0; i--) {
200       CeedVector          vec_i;
201       CeedElemRestriction rstr_i;
202 
203       CeedCallBackend(CeedOperatorFieldGetVector(op_fields[i], &vec_i));
204       CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_fields[i], &rstr_i));
205       for (CeedInt j = i - 1; j >= 0; j--) {
206         CeedVector          vec_j;
207         CeedElemRestriction rstr_j;
208 
209         CeedCallBackend(CeedOperatorFieldGetVector(op_fields[j], &vec_j));
210         CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_fields[j], &rstr_j));
211         if (vec_i == vec_j && rstr_i == rstr_j) {
212           if (e_vecs[i]) CeedCallBackend(CeedVectorReferenceCopy(e_vecs[i], &e_vecs[j]));
213           skip_rstr[j]       = true;
214           apply_add_basis[i] = true;
215         }
216       }
217     }
218   }
219   return CEED_ERROR_SUCCESS;
220 }
221 
222 //------------------------------------------------------------------------------
223 // CeedOperator needs to connect all the named fields (be they active or passive) to the named inputs and outputs of its CeedQFunction.
224 //------------------------------------------------------------------------------
225 static int CeedOperatorSetup_Cuda(CeedOperator op) {
226   Ceed                ceed;
227   bool                is_setup_done;
228   CeedInt             Q, num_elem, num_input_fields, num_output_fields;
229   CeedQFunctionField *qf_input_fields, *qf_output_fields;
230   CeedQFunction       qf;
231   CeedOperatorField  *op_input_fields, *op_output_fields;
232   CeedOperator_Cuda  *impl;
233 
234   CeedCallBackend(CeedOperatorIsSetupDone(op, &is_setup_done));
235   if (is_setup_done) return CEED_ERROR_SUCCESS;
236 
237   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
238   CeedCallBackend(CeedOperatorGetData(op, &impl));
239   CeedCallBackend(CeedOperatorGetQFunction(op, &qf));
240   CeedCallBackend(CeedOperatorGetNumQuadraturePoints(op, &Q));
241   CeedCallBackend(CeedOperatorGetNumElements(op, &num_elem));
242   CeedCallBackend(CeedOperatorGetFields(op, &num_input_fields, &op_input_fields, &num_output_fields, &op_output_fields));
243   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, &qf_input_fields, NULL, &qf_output_fields));
244 
245   // Allocate
246   CeedCallBackend(CeedCalloc(num_input_fields, &impl->e_vecs_in));
247   CeedCallBackend(CeedCalloc(num_output_fields, &impl->e_vecs_out));
248   CeedCallBackend(CeedCalloc(num_input_fields, &impl->skip_rstr_in));
249   CeedCallBackend(CeedCalloc(num_output_fields, &impl->skip_rstr_out));
250   CeedCallBackend(CeedCalloc(num_output_fields, &impl->apply_add_basis_out));
251   CeedCallBackend(CeedCalloc(num_input_fields, &impl->input_field_order));
252   CeedCallBackend(CeedCalloc(num_output_fields, &impl->output_field_order));
253   CeedCallBackend(CeedCalloc(num_input_fields, &impl->input_states));
254   CeedCallBackend(CeedCalloc(num_input_fields, &impl->q_vecs_in));
255   CeedCallBackend(CeedCalloc(num_output_fields, &impl->q_vecs_out));
256   impl->num_inputs  = num_input_fields;
257   impl->num_outputs = num_output_fields;
258 
259   // Set up infield and outfield e-vecs and q-vecs
260   CeedCallBackend(
261       CeedOperatorSetupFields_Cuda(qf, op, true, false, impl->skip_rstr_in, NULL, impl->e_vecs_in, impl->q_vecs_in, num_input_fields, Q, num_elem));
262   CeedCallBackend(CeedOperatorSetupFields_Cuda(qf, op, false, false, impl->skip_rstr_out, impl->apply_add_basis_out, impl->e_vecs_out,
263                                                impl->q_vecs_out, num_output_fields, Q, num_elem));
264 
265   // Reorder fields to allow reuse of buffers
266   impl->max_active_e_vec_len = 0;
267   {
268     bool    is_ordered[CEED_FIELD_MAX];
269     CeedInt curr_index = 0;
270 
271     for (CeedInt i = 0; i < num_input_fields; i++) is_ordered[i] = false;
272     for (CeedInt i = 0; i < num_input_fields; i++) {
273       CeedSize            e_vec_len_i;
274       CeedVector          vec_i;
275       CeedElemRestriction rstr_i;
276 
277       if (is_ordered[i]) continue;
278       is_ordered[i]                       = true;
279       impl->input_field_order[curr_index] = i;
280       curr_index++;
281       CeedCallBackend(CeedOperatorFieldGetVector(op_input_fields[i], &vec_i));
282       if (vec_i == CEED_VECTOR_NONE) continue;  // CEED_EVAL_WEIGHT
283       CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_input_fields[i], &rstr_i));
284       CeedCallBackend(CeedElemRestrictionGetEVectorSize(rstr_i, &e_vec_len_i));
285       impl->max_active_e_vec_len = e_vec_len_i > impl->max_active_e_vec_len ? e_vec_len_i : impl->max_active_e_vec_len;
286       for (CeedInt j = i + 1; j < num_input_fields; j++) {
287         CeedVector          vec_j;
288         CeedElemRestriction rstr_j;
289 
290         CeedCallBackend(CeedOperatorFieldGetVector(op_input_fields[j], &vec_j));
291         CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_input_fields[j], &rstr_j));
292         if (rstr_i == rstr_j && vec_i == vec_j) {
293           is_ordered[j]                       = true;
294           impl->input_field_order[curr_index] = j;
295           curr_index++;
296         }
297       }
298     }
299   }
300   {
301     bool    is_ordered[CEED_FIELD_MAX];
302     CeedInt curr_index = 0;
303 
304     for (CeedInt i = 0; i < num_output_fields; i++) is_ordered[i] = false;
305     for (CeedInt i = 0; i < num_output_fields; i++) {
306       CeedSize            e_vec_len_i;
307       CeedVector          vec_i;
308       CeedElemRestriction rstr_i;
309 
310       if (is_ordered[i]) continue;
311       is_ordered[i]                        = true;
312       impl->output_field_order[curr_index] = i;
313       curr_index++;
314       CeedCallBackend(CeedOperatorFieldGetVector(op_output_fields[i], &vec_i));
315       CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_output_fields[i], &rstr_i));
316       CeedCallBackend(CeedElemRestrictionGetEVectorSize(rstr_i, &e_vec_len_i));
317       impl->max_active_e_vec_len = e_vec_len_i > impl->max_active_e_vec_len ? e_vec_len_i : impl->max_active_e_vec_len;
318       for (CeedInt j = i + 1; j < num_output_fields; j++) {
319         CeedVector          vec_j;
320         CeedElemRestriction rstr_j;
321 
322         CeedCallBackend(CeedOperatorFieldGetVector(op_output_fields[j], &vec_j));
323         CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_output_fields[j], &rstr_j));
324         if (rstr_i == rstr_j && vec_i == vec_j) {
325           is_ordered[j]                        = true;
326           impl->output_field_order[curr_index] = j;
327           curr_index++;
328         }
329       }
330     }
331   }
332   CeedCallBackend(CeedOperatorSetSetupDone(op));
333   return CEED_ERROR_SUCCESS;
334 }
335 
336 //------------------------------------------------------------------------------
337 // Restrict Operator Inputs
338 //------------------------------------------------------------------------------
339 static inline int CeedOperatorInputRestrict_Cuda(CeedOperatorField op_input_field, CeedQFunctionField qf_input_field, CeedInt input_field,
340                                                  CeedVector in_vec, CeedVector active_e_vec, const bool skip_active, CeedOperator_Cuda *impl,
341                                                  CeedRequest *request) {
342   bool       is_active = false;
343   CeedVector l_vec, e_vec = impl->e_vecs_in[input_field];
344 
345   // Get input vector
346   CeedCallBackend(CeedOperatorFieldGetVector(op_input_field, &l_vec));
347   is_active = l_vec == CEED_VECTOR_ACTIVE;
348   if (is_active && skip_active) return CEED_ERROR_SUCCESS;
349   if (is_active) {
350     l_vec = in_vec;
351     if (!e_vec) e_vec = active_e_vec;
352   }
353 
354   // Restriction action
355   if (e_vec) {
356     // Restrict, if necessary
357     if (!impl->skip_rstr_in[input_field]) {
358       uint64_t state;
359 
360       CeedCallBackend(CeedVectorGetState(l_vec, &state));
361       if (is_active || state != impl->input_states[input_field]) {
362         CeedElemRestriction elem_rstr;
363 
364         CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_input_field, &elem_rstr));
365         CeedCallBackend(CeedElemRestrictionApply(elem_rstr, CEED_NOTRANSPOSE, l_vec, e_vec, request));
366       }
367       impl->input_states[input_field] = state;
368     }
369   }
370   return CEED_ERROR_SUCCESS;
371 }
372 
373 //------------------------------------------------------------------------------
374 // Input Basis Action
375 //------------------------------------------------------------------------------
376 static inline int CeedOperatorInputBasis_Cuda(CeedOperatorField op_input_field, CeedQFunctionField qf_input_field, CeedInt input_field,
377                                               CeedVector in_vec, CeedVector active_e_vec, CeedInt num_elem, const bool skip_active,
378                                               CeedOperator_Cuda *impl) {
379   bool         is_active = false;
380   CeedEvalMode eval_mode;
381   CeedVector   l_vec, e_vec = impl->e_vecs_in[input_field], q_vec = impl->q_vecs_in[input_field];
382 
383   // Skip active input
384   CeedCallBackend(CeedOperatorFieldGetVector(op_input_field, &l_vec));
385   is_active = l_vec == CEED_VECTOR_ACTIVE;
386   if (is_active && skip_active) return CEED_ERROR_SUCCESS;
387   if (is_active) {
388     l_vec = in_vec;
389     if (!e_vec) e_vec = active_e_vec;
390   }
391 
392   // Basis action
393   CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_input_field, &eval_mode));
394   switch (eval_mode) {
395     case CEED_EVAL_NONE: {
396       const CeedScalar *e_vec_array;
397 
398       if (e_vec) {
399         CeedCallBackend(CeedVectorGetArrayRead(e_vec, CEED_MEM_DEVICE, &e_vec_array));
400       } else {
401         CeedCallBackend(CeedVectorGetArrayRead(l_vec, CEED_MEM_DEVICE, &e_vec_array));
402       }
403       CeedCallBackend(CeedVectorSetArray(q_vec, CEED_MEM_DEVICE, CEED_USE_POINTER, (CeedScalar *)e_vec_array));
404       break;
405     }
406     case CEED_EVAL_INTERP:
407     case CEED_EVAL_GRAD:
408     case CEED_EVAL_DIV:
409     case CEED_EVAL_CURL: {
410       CeedBasis basis;
411 
412       CeedCallBackend(CeedOperatorFieldGetBasis(op_input_field, &basis));
413       CeedCallBackend(CeedBasisApply(basis, num_elem, CEED_NOTRANSPOSE, eval_mode, e_vec, q_vec));
414       break;
415     }
416     case CEED_EVAL_WEIGHT:
417       break;  // No action
418   }
419   return CEED_ERROR_SUCCESS;
420 }
421 
422 //------------------------------------------------------------------------------
423 // Restore Input Vectors
424 //------------------------------------------------------------------------------
425 static inline int CeedOperatorInputRestore_Cuda(CeedOperatorField op_input_field, CeedQFunctionField qf_input_field, CeedInt input_field,
426                                                 CeedVector in_vec, CeedVector active_e_vec, const bool skip_active, CeedOperator_Cuda *impl) {
427   bool         is_active = false;
428   CeedEvalMode eval_mode;
429   CeedVector   l_vec, e_vec = impl->e_vecs_in[input_field];
430 
431   // Skip active input
432   CeedCallBackend(CeedOperatorFieldGetVector(op_input_field, &l_vec));
433   is_active = l_vec == CEED_VECTOR_ACTIVE;
434   if (is_active && skip_active) return CEED_ERROR_SUCCESS;
435   if (is_active) {
436     l_vec = in_vec;
437     if (!e_vec) e_vec = active_e_vec;
438   }
439 
440   // Restore e-vec
441   CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_input_field, &eval_mode));
442   if (eval_mode == CEED_EVAL_NONE) {
443     const CeedScalar *e_vec_array;
444 
445     CeedCallBackend(CeedVectorTakeArray(impl->q_vecs_in[input_field], CEED_MEM_DEVICE, (CeedScalar **)&e_vec_array));
446     if (e_vec) {
447       CeedCallBackend(CeedVectorRestoreArrayRead(e_vec, &e_vec_array));
448     } else {
449       CeedCallBackend(CeedVectorRestoreArrayRead(l_vec, &e_vec_array));
450     }
451   }
452   return CEED_ERROR_SUCCESS;
453 }
454 
455 //------------------------------------------------------------------------------
456 // Apply and add to output
457 //------------------------------------------------------------------------------
458 static int CeedOperatorApplyAdd_Cuda(CeedOperator op, CeedVector in_vec, CeedVector out_vec, CeedRequest *request) {
459   CeedInt             Q, num_elem, num_input_fields, num_output_fields;
460   Ceed                ceed;
461   CeedVector          active_e_vec;
462   CeedQFunctionField *qf_input_fields, *qf_output_fields;
463   CeedQFunction       qf;
464   CeedOperatorField  *op_input_fields, *op_output_fields;
465   CeedOperator_Cuda  *impl;
466 
467   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
468   CeedCallBackend(CeedOperatorGetData(op, &impl));
469   CeedCallBackend(CeedOperatorGetQFunction(op, &qf));
470   CeedCallBackend(CeedOperatorGetNumQuadraturePoints(op, &Q));
471   CeedCallBackend(CeedOperatorGetNumElements(op, &num_elem));
472   CeedCallBackend(CeedOperatorGetFields(op, &num_input_fields, &op_input_fields, &num_output_fields, &op_output_fields));
473   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, &qf_input_fields, NULL, &qf_output_fields));
474 
475   // Setup
476   CeedCallBackend(CeedOperatorSetup_Cuda(op));
477 
478   // Work vector
479   CeedCallBackend(CeedGetWorkVector(ceed, impl->max_active_e_vec_len, &active_e_vec));
480 
481   // Process inputs
482   for (CeedInt i = 0; i < num_input_fields; i++) {
483     CeedInt field = impl->input_field_order[i];
484 
485     CeedCallBackend(
486         CeedOperatorInputRestrict_Cuda(op_input_fields[field], qf_input_fields[field], field, in_vec, active_e_vec, false, impl, request));
487     CeedCallBackend(CeedOperatorInputBasis_Cuda(op_input_fields[field], qf_input_fields[field], field, in_vec, active_e_vec, num_elem, false, impl));
488   }
489 
490   // Output pointers, as necessary
491   for (CeedInt i = 0; i < num_output_fields; i++) {
492     CeedEvalMode eval_mode;
493 
494     CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_output_fields[i], &eval_mode));
495     if (eval_mode == CEED_EVAL_NONE) {
496       CeedScalar *e_vec_array;
497 
498       CeedCallBackend(CeedVectorGetArrayWrite(impl->e_vecs_out[i], CEED_MEM_DEVICE, &e_vec_array));
499       CeedCallBackend(CeedVectorSetArray(impl->q_vecs_out[i], CEED_MEM_DEVICE, CEED_USE_POINTER, e_vec_array));
500     }
501   }
502 
503   // Q function
504   CeedCallBackend(CeedQFunctionApply(qf, num_elem * Q, impl->q_vecs_in, impl->q_vecs_out));
505 
506   // Restore input arrays
507   for (CeedInt i = 0; i < num_input_fields; i++) {
508     CeedCallBackend(CeedOperatorInputRestore_Cuda(op_input_fields[i], qf_input_fields[i], i, in_vec, active_e_vec, false, impl));
509   }
510 
511   // Output basis and restriction
512   for (CeedInt i = 0; i < num_output_fields; i++) {
513     bool                is_active = false;
514     CeedInt             field     = impl->output_field_order[i];
515     CeedEvalMode        eval_mode;
516     CeedVector          l_vec, e_vec = impl->e_vecs_out[field], q_vec = impl->q_vecs_out[field];
517     CeedElemRestriction elem_rstr;
518     CeedBasis           basis;
519 
520     // Output vector
521     CeedCallBackend(CeedOperatorFieldGetVector(op_output_fields[field], &l_vec));
522     is_active = l_vec == CEED_VECTOR_ACTIVE;
523     if (is_active) {
524       l_vec = out_vec;
525       if (!e_vec) e_vec = active_e_vec;
526     }
527 
528     // Basis action
529     CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_output_fields[field], &eval_mode));
530     switch (eval_mode) {
531       case CEED_EVAL_NONE:
532         break;  // No action
533       case CEED_EVAL_INTERP:
534       case CEED_EVAL_GRAD:
535       case CEED_EVAL_DIV:
536       case CEED_EVAL_CURL:
537         CeedCallBackend(CeedOperatorFieldGetBasis(op_output_fields[field], &basis));
538         if (impl->apply_add_basis_out[field]) {
539           CeedCallBackend(CeedBasisApplyAdd(basis, num_elem, CEED_TRANSPOSE, eval_mode, q_vec, e_vec));
540         } else {
541           CeedCallBackend(CeedBasisApply(basis, num_elem, CEED_TRANSPOSE, eval_mode, q_vec, e_vec));
542         }
543         break;
544       // LCOV_EXCL_START
545       case CEED_EVAL_WEIGHT: {
546         return CeedError(ceed, CEED_ERROR_BACKEND, "CEED_EVAL_WEIGHT cannot be an output evaluation mode");
547         // LCOV_EXCL_STOP
548       }
549     }
550 
551     // Restore evec
552     if (eval_mode == CEED_EVAL_NONE) {
553       CeedScalar *e_vec_array;
554 
555       CeedCallBackend(CeedVectorTakeArray(impl->q_vecs_out[i], CEED_MEM_DEVICE, &e_vec_array));
556       CeedCallBackend(CeedVectorRestoreArray(e_vec, &e_vec_array));
557     }
558 
559     // Restrict
560     if (impl->skip_rstr_out[field]) continue;
561     CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_output_fields[field], &elem_rstr));
562     CeedCallBackend(CeedElemRestrictionApply(elem_rstr, CEED_TRANSPOSE, e_vec, l_vec, request));
563   }
564 
565   // Return work vector
566   CeedCallBackend(CeedRestoreWorkVector(ceed, &active_e_vec));
567   return CEED_ERROR_SUCCESS;
568 }
569 
570 //------------------------------------------------------------------------------
571 // CeedOperator needs to connect all the named fields (be they active or passive) to the named inputs and outputs of its CeedQFunction.
572 //------------------------------------------------------------------------------
573 static int CeedOperatorSetupAtPoints_Cuda(CeedOperator op) {
574   Ceed                ceed;
575   bool                is_setup_done;
576   CeedInt             max_num_points = -1, num_elem, num_input_fields, num_output_fields;
577   CeedQFunctionField *qf_input_fields, *qf_output_fields;
578   CeedQFunction       qf;
579   CeedOperatorField  *op_input_fields, *op_output_fields;
580   CeedOperator_Cuda  *impl;
581 
582   CeedCallBackend(CeedOperatorIsSetupDone(op, &is_setup_done));
583   if (is_setup_done) return CEED_ERROR_SUCCESS;
584 
585   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
586   CeedCallBackend(CeedOperatorGetData(op, &impl));
587   CeedCallBackend(CeedOperatorGetQFunction(op, &qf));
588   CeedCallBackend(CeedOperatorGetNumElements(op, &num_elem));
589   CeedCallBackend(CeedOperatorGetFields(op, &num_input_fields, &op_input_fields, &num_output_fields, &op_output_fields));
590   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, &qf_input_fields, NULL, &qf_output_fields));
591   {
592     CeedElemRestriction rstr_points = NULL;
593 
594     CeedCallBackend(CeedOperatorAtPointsGetPoints(op, &rstr_points, NULL));
595     CeedCallBackend(CeedElemRestrictionGetMaxPointsInElement(rstr_points, &max_num_points));
596     CeedCallBackend(CeedCalloc(num_elem, &impl->num_points));
597     for (CeedInt e = 0; e < num_elem; e++) {
598       CeedInt num_points_elem;
599 
600       CeedCallBackend(CeedElemRestrictionGetNumPointsInElement(rstr_points, e, &num_points_elem));
601       impl->num_points[e] = num_points_elem;
602     }
603     CeedCallBackend(CeedElemRestrictionDestroy(&rstr_points));
604   }
605   impl->max_num_points = max_num_points;
606 
607   // Allocate
608   CeedCallBackend(CeedCalloc(num_input_fields, &impl->e_vecs_in));
609   CeedCallBackend(CeedCalloc(num_output_fields, &impl->e_vecs_out));
610   CeedCallBackend(CeedCalloc(num_input_fields, &impl->skip_rstr_in));
611   CeedCallBackend(CeedCalloc(num_output_fields, &impl->skip_rstr_out));
612   CeedCallBackend(CeedCalloc(num_output_fields, &impl->apply_add_basis_out));
613   CeedCallBackend(CeedCalloc(num_input_fields, &impl->input_field_order));
614   CeedCallBackend(CeedCalloc(num_output_fields, &impl->output_field_order));
615   CeedCallBackend(CeedCalloc(num_input_fields, &impl->input_states));
616   CeedCallBackend(CeedCalloc(num_input_fields, &impl->q_vecs_in));
617   CeedCallBackend(CeedCalloc(num_output_fields, &impl->q_vecs_out));
618   impl->num_inputs  = num_input_fields;
619   impl->num_outputs = num_output_fields;
620 
621   // Set up infield and outfield e-vecs and q-vecs
622   CeedCallBackend(CeedOperatorSetupFields_Cuda(qf, op, true, true, impl->skip_rstr_in, NULL, impl->e_vecs_in, impl->q_vecs_in, num_input_fields,
623                                                max_num_points, num_elem));
624   CeedCallBackend(CeedOperatorSetupFields_Cuda(qf, op, false, true, impl->skip_rstr_out, impl->apply_add_basis_out, impl->e_vecs_out,
625                                                impl->q_vecs_out, num_output_fields, max_num_points, num_elem));
626 
627   // Reorder fields to allow reuse of buffers
628   impl->max_active_e_vec_len = 0;
629   {
630     bool    is_ordered[CEED_FIELD_MAX];
631     CeedInt curr_index = 0;
632 
633     for (CeedInt i = 0; i < num_input_fields; i++) is_ordered[i] = false;
634     for (CeedInt i = 0; i < num_input_fields; i++) {
635       CeedSize            e_vec_len_i;
636       CeedVector          vec_i;
637       CeedElemRestriction rstr_i;
638 
639       if (is_ordered[i]) continue;
640       is_ordered[i]                       = true;
641       impl->input_field_order[curr_index] = i;
642       curr_index++;
643       CeedCallBackend(CeedOperatorFieldGetVector(op_input_fields[i], &vec_i));
644       if (vec_i == CEED_VECTOR_NONE) continue;  // CEED_EVAL_WEIGHT
645       CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_input_fields[i], &rstr_i));
646       CeedCallBackend(CeedElemRestrictionGetEVectorSize(rstr_i, &e_vec_len_i));
647       impl->max_active_e_vec_len = e_vec_len_i > impl->max_active_e_vec_len ? e_vec_len_i : impl->max_active_e_vec_len;
648       for (CeedInt j = i + 1; j < num_input_fields; j++) {
649         CeedVector          vec_j;
650         CeedElemRestriction rstr_j;
651 
652         CeedCallBackend(CeedOperatorFieldGetVector(op_input_fields[j], &vec_j));
653         CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_input_fields[j], &rstr_j));
654         if (rstr_i == rstr_j && vec_i == vec_j) {
655           is_ordered[j]                       = true;
656           impl->input_field_order[curr_index] = j;
657           curr_index++;
658         }
659       }
660     }
661   }
662   {
663     bool    is_ordered[CEED_FIELD_MAX];
664     CeedInt curr_index = 0;
665 
666     for (CeedInt i = 0; i < num_output_fields; i++) is_ordered[i] = false;
667     for (CeedInt i = 0; i < num_output_fields; i++) {
668       CeedSize            e_vec_len_i;
669       CeedVector          vec_i;
670       CeedElemRestriction rstr_i;
671 
672       if (is_ordered[i]) continue;
673       is_ordered[i]                        = true;
674       impl->output_field_order[curr_index] = i;
675       curr_index++;
676       CeedCallBackend(CeedOperatorFieldGetVector(op_output_fields[i], &vec_i));
677       CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_output_fields[i], &rstr_i));
678       CeedCallBackend(CeedElemRestrictionGetEVectorSize(rstr_i, &e_vec_len_i));
679       impl->max_active_e_vec_len = e_vec_len_i > impl->max_active_e_vec_len ? e_vec_len_i : impl->max_active_e_vec_len;
680       for (CeedInt j = i + 1; j < num_output_fields; j++) {
681         CeedVector          vec_j;
682         CeedElemRestriction rstr_j;
683 
684         CeedCallBackend(CeedOperatorFieldGetVector(op_output_fields[j], &vec_j));
685         CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_output_fields[j], &rstr_j));
686         if (rstr_i == rstr_j && vec_i == vec_j) {
687           is_ordered[j]                        = true;
688           impl->output_field_order[curr_index] = j;
689           curr_index++;
690         }
691       }
692     }
693   }
694 
695   CeedCallBackend(CeedOperatorSetSetupDone(op));
696   return CEED_ERROR_SUCCESS;
697 }
698 
699 //------------------------------------------------------------------------------
700 // Input Basis Action AtPoints
701 //------------------------------------------------------------------------------
702 static inline int CeedOperatorInputBasisAtPoints_Cuda(CeedOperatorField op_input_field, CeedQFunctionField qf_input_field, CeedInt input_field,
703                                                       CeedVector in_vec, CeedVector active_e_vec, CeedInt num_elem, const CeedInt *num_points,
704                                                       const bool skip_active, CeedOperator_Cuda *impl) {
705   bool         is_active = false;
706   CeedEvalMode eval_mode;
707   CeedVector   l_vec, e_vec = impl->e_vecs_in[input_field], q_vec = impl->q_vecs_in[input_field];
708 
709   // Skip active input
710   CeedCallBackend(CeedOperatorFieldGetVector(op_input_field, &l_vec));
711   is_active = l_vec == CEED_VECTOR_ACTIVE;
712   if (is_active && skip_active) return CEED_ERROR_SUCCESS;
713   if (is_active) {
714     l_vec = in_vec;
715     if (!e_vec) e_vec = active_e_vec;
716   }
717 
718   // Basis action
719   CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_input_field, &eval_mode));
720   switch (eval_mode) {
721     case CEED_EVAL_NONE: {
722       const CeedScalar *e_vec_array;
723 
724       if (e_vec) {
725         CeedCallBackend(CeedVectorGetArrayRead(e_vec, CEED_MEM_DEVICE, &e_vec_array));
726       } else {
727         CeedCallBackend(CeedVectorGetArrayRead(l_vec, CEED_MEM_DEVICE, &e_vec_array));
728       }
729       CeedCallBackend(CeedVectorSetArray(q_vec, CEED_MEM_DEVICE, CEED_USE_POINTER, (CeedScalar *)e_vec_array));
730       break;
731     }
732     case CEED_EVAL_INTERP:
733     case CEED_EVAL_GRAD:
734     case CEED_EVAL_DIV:
735     case CEED_EVAL_CURL: {
736       CeedBasis basis;
737 
738       CeedCallBackend(CeedOperatorFieldGetBasis(op_input_field, &basis));
739       CeedCallBackend(CeedBasisApplyAtPoints(basis, num_elem, num_points, CEED_NOTRANSPOSE, eval_mode, impl->point_coords_elem, e_vec, q_vec));
740       break;
741     }
742     case CEED_EVAL_WEIGHT:
743       break;  // No action
744   }
745   return CEED_ERROR_SUCCESS;
746 }
747 
748 //------------------------------------------------------------------------------
749 // Apply and add to output AtPoints
750 //------------------------------------------------------------------------------
751 static int CeedOperatorApplyAddAtPoints_Cuda(CeedOperator op, CeedVector in_vec, CeedVector out_vec, CeedRequest *request) {
752   CeedInt             max_num_points, *num_points, num_elem, num_input_fields, num_output_fields;
753   Ceed                ceed;
754   CeedVector          active_e_vec;
755   CeedQFunctionField *qf_input_fields, *qf_output_fields;
756   CeedQFunction       qf;
757   CeedOperatorField  *op_input_fields, *op_output_fields;
758   CeedOperator_Cuda  *impl;
759 
760   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
761   CeedCallBackend(CeedOperatorGetData(op, &impl));
762   CeedCallBackend(CeedOperatorGetQFunction(op, &qf));
763   CeedCallBackend(CeedOperatorGetNumElements(op, &num_elem));
764   CeedCallBackend(CeedOperatorGetFields(op, &num_input_fields, &op_input_fields, &num_output_fields, &op_output_fields));
765   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, &qf_input_fields, NULL, &qf_output_fields));
766 
767   // Setup
768   CeedCallBackend(CeedOperatorSetupAtPoints_Cuda(op));
769   num_points     = impl->num_points;
770   max_num_points = impl->max_num_points;
771 
772   // Work vector
773   CeedCallBackend(CeedGetWorkVector(ceed, impl->max_active_e_vec_len, &active_e_vec));
774 
775   // Get point coordinates
776   if (!impl->point_coords_elem) {
777     CeedVector          point_coords = NULL;
778     CeedElemRestriction rstr_points  = NULL;
779 
780     CeedCallBackend(CeedOperatorAtPointsGetPoints(op, &rstr_points, &point_coords));
781     CeedCallBackend(CeedElemRestrictionCreateVector(rstr_points, NULL, &impl->point_coords_elem));
782     CeedCallBackend(CeedElemRestrictionApply(rstr_points, CEED_NOTRANSPOSE, point_coords, impl->point_coords_elem, request));
783     CeedCallBackend(CeedVectorDestroy(&point_coords));
784     CeedCallBackend(CeedElemRestrictionDestroy(&rstr_points));
785   }
786 
787   // Process inputs
788   for (CeedInt i = 0; i < num_input_fields; i++) {
789     CeedInt field = impl->input_field_order[i];
790 
791     CeedCallBackend(
792         CeedOperatorInputRestrict_Cuda(op_input_fields[field], qf_input_fields[field], field, in_vec, active_e_vec, false, impl, request));
793     CeedCallBackend(CeedOperatorInputBasisAtPoints_Cuda(op_input_fields[field], qf_input_fields[field], field, in_vec, active_e_vec, num_elem,
794                                                         num_points, false, impl));
795   }
796 
797   // Output pointers, as necessary
798   for (CeedInt i = 0; i < num_output_fields; i++) {
799     CeedEvalMode eval_mode;
800 
801     CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_output_fields[i], &eval_mode));
802     if (eval_mode == CEED_EVAL_NONE) {
803       CeedScalar *e_vec_array;
804 
805       CeedCallBackend(CeedVectorGetArrayWrite(impl->e_vecs_out[i], CEED_MEM_DEVICE, &e_vec_array));
806       CeedCallBackend(CeedVectorSetArray(impl->q_vecs_out[i], CEED_MEM_DEVICE, CEED_USE_POINTER, e_vec_array));
807     }
808   }
809 
810   // Q function
811   CeedCallBackend(CeedQFunctionApply(qf, num_elem * max_num_points, impl->q_vecs_in, impl->q_vecs_out));
812 
813   // Restore input arrays
814   for (CeedInt i = 0; i < num_input_fields; i++) {
815     CeedCallBackend(CeedOperatorInputRestore_Cuda(op_input_fields[i], qf_input_fields[i], i, in_vec, active_e_vec, false, impl));
816   }
817 
818   // Output basis and restriction
819   for (CeedInt i = 0; i < num_output_fields; i++) {
820     bool                is_active = false;
821     CeedInt             field     = impl->output_field_order[i];
822     CeedEvalMode        eval_mode;
823     CeedVector          l_vec, e_vec = impl->e_vecs_out[field], q_vec = impl->q_vecs_out[field];
824     CeedElemRestriction elem_rstr;
825     CeedBasis           basis;
826 
827     // Output vector
828     CeedCallBackend(CeedOperatorFieldGetVector(op_output_fields[field], &l_vec));
829     is_active = l_vec == CEED_VECTOR_ACTIVE;
830     if (is_active) {
831       l_vec = out_vec;
832       if (!e_vec) e_vec = active_e_vec;
833     }
834 
835     // Basis action
836     CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_output_fields[field], &eval_mode));
837     switch (eval_mode) {
838       case CEED_EVAL_NONE:
839         break;  // No action
840       case CEED_EVAL_INTERP:
841       case CEED_EVAL_GRAD:
842       case CEED_EVAL_DIV:
843       case CEED_EVAL_CURL:
844         CeedCallBackend(CeedOperatorFieldGetBasis(op_output_fields[field], &basis));
845         if (impl->apply_add_basis_out[field]) {
846           CeedCallBackend(CeedBasisApplyAddAtPoints(basis, num_elem, num_points, CEED_TRANSPOSE, eval_mode, impl->point_coords_elem, q_vec, e_vec));
847         } else {
848           CeedCallBackend(CeedBasisApplyAtPoints(basis, num_elem, num_points, CEED_TRANSPOSE, eval_mode, impl->point_coords_elem, q_vec, e_vec));
849         }
850         break;
851       // LCOV_EXCL_START
852       case CEED_EVAL_WEIGHT: {
853         return CeedError(ceed, CEED_ERROR_BACKEND, "CEED_EVAL_WEIGHT cannot be an output evaluation mode");
854         // LCOV_EXCL_STOP
855       }
856     }
857 
858     // Restore evec
859     if (eval_mode == CEED_EVAL_NONE) {
860       CeedScalar *e_vec_array;
861 
862       CeedCallBackend(CeedVectorTakeArray(impl->q_vecs_out[i], CEED_MEM_DEVICE, &e_vec_array));
863       CeedCallBackend(CeedVectorRestoreArray(e_vec, &e_vec_array));
864     }
865 
866     // Restrict
867     if (impl->skip_rstr_out[field]) continue;
868     CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_output_fields[field], &elem_rstr));
869     CeedCallBackend(CeedElemRestrictionApply(elem_rstr, CEED_TRANSPOSE, e_vec, l_vec, request));
870   }
871 
872   // Restore work vector
873   CeedCallBackend(CeedRestoreWorkVector(ceed, &active_e_vec));
874   return CEED_ERROR_SUCCESS;
875 }
876 
877 //------------------------------------------------------------------------------
878 // Linear QFunction Assembly Core
879 //------------------------------------------------------------------------------
880 static inline int CeedOperatorLinearAssembleQFunctionCore_Cuda(CeedOperator op, bool build_objects, CeedVector *assembled, CeedElemRestriction *rstr,
881                                                                CeedRequest *request) {
882   Ceed                ceed, ceed_parent;
883   CeedInt             num_active_in, num_active_out, Q, num_elem, num_input_fields, num_output_fields, size;
884   CeedScalar         *assembled_array;
885   CeedVector         *active_inputs;
886   CeedQFunctionField *qf_input_fields, *qf_output_fields;
887   CeedQFunction       qf;
888   CeedOperatorField  *op_input_fields, *op_output_fields;
889   CeedOperator_Cuda  *impl;
890 
891   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
892   CeedCallBackend(CeedOperatorGetFallbackParentCeed(op, &ceed_parent));
893   CeedCallBackend(CeedOperatorGetData(op, &impl));
894   CeedCallBackend(CeedOperatorGetNumQuadraturePoints(op, &Q));
895   CeedCallBackend(CeedOperatorGetNumElements(op, &num_elem));
896   CeedCallBackend(CeedOperatorGetQFunction(op, &qf));
897   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, &qf_input_fields, NULL, &qf_output_fields));
898   CeedCallBackend(CeedOperatorGetFields(op, &num_input_fields, &op_input_fields, &num_output_fields, &op_output_fields));
899   active_inputs = impl->qf_active_in;
900   num_active_in = impl->num_active_in, num_active_out = impl->num_active_out;
901 
902   // Setup
903   CeedCallBackend(CeedOperatorSetup_Cuda(op));
904 
905   // Process inputs
906   for (CeedInt i = 0; i < num_input_fields; i++) {
907     CeedCallBackend(CeedOperatorInputRestrict_Cuda(op_input_fields[i], qf_input_fields[i], i, NULL, NULL, true, impl, request));
908     CeedCallBackend(CeedOperatorInputBasis_Cuda(op_input_fields[i], qf_input_fields[i], i, NULL, NULL, num_elem, true, impl));
909   }
910 
911   // Count number of active input fields
912   if (!num_active_in) {
913     for (CeedInt i = 0; i < num_input_fields; i++) {
914       CeedScalar *q_vec_array;
915       CeedVector  l_vec;
916 
917       // Check if active input
918       CeedCallBackend(CeedOperatorFieldGetVector(op_input_fields[i], &l_vec));
919       if (l_vec == CEED_VECTOR_ACTIVE) {
920         CeedCallBackend(CeedQFunctionFieldGetSize(qf_input_fields[i], &size));
921         CeedCallBackend(CeedVectorSetValue(impl->q_vecs_in[i], 0.0));
922         CeedCallBackend(CeedVectorGetArray(impl->q_vecs_in[i], CEED_MEM_DEVICE, &q_vec_array));
923         CeedCallBackend(CeedRealloc(num_active_in + size, &active_inputs));
924         for (CeedInt field = 0; field < size; field++) {
925           CeedSize q_size = (CeedSize)Q * num_elem;
926 
927           CeedCallBackend(CeedVectorCreate(ceed, q_size, &active_inputs[num_active_in + field]));
928           CeedCallBackend(
929               CeedVectorSetArray(active_inputs[num_active_in + field], CEED_MEM_DEVICE, CEED_USE_POINTER, &q_vec_array[field * Q * num_elem]));
930         }
931         num_active_in += size;
932         CeedCallBackend(CeedVectorRestoreArray(impl->q_vecs_in[i], &q_vec_array));
933       }
934     }
935     impl->num_active_in = num_active_in;
936     impl->qf_active_in  = active_inputs;
937   }
938 
939   // Count number of active output fields
940   if (!num_active_out) {
941     for (CeedInt i = 0; i < num_output_fields; i++) {
942       CeedVector l_vec;
943 
944       // Check if active output
945       CeedCallBackend(CeedOperatorFieldGetVector(op_output_fields[i], &l_vec));
946       if (l_vec == CEED_VECTOR_ACTIVE) {
947         CeedCallBackend(CeedQFunctionFieldGetSize(qf_output_fields[i], &size));
948         num_active_out += size;
949       }
950     }
951     impl->num_active_out = num_active_out;
952   }
953 
954   // Check sizes
955   CeedCheck(num_active_in > 0 && num_active_out > 0, ceed, CEED_ERROR_BACKEND, "Cannot assemble QFunction without active inputs and outputs");
956 
957   // Build objects if needed
958   if (build_objects) {
959     CeedSize l_size     = (CeedSize)num_elem * Q * num_active_in * num_active_out;
960     CeedInt  strides[3] = {1, num_elem * Q, Q}; /* *NOPAD* */
961 
962     // Create output restriction
963     CeedCallBackend(CeedElemRestrictionCreateStrided(ceed_parent, num_elem, Q, num_active_in * num_active_out,
964                                                      (CeedSize)num_active_in * (CeedSize)num_active_out * (CeedSize)num_elem * (CeedSize)Q, strides,
965                                                      rstr));
966     // Create assembled vector
967     CeedCallBackend(CeedVectorCreate(ceed_parent, l_size, assembled));
968   }
969   CeedCallBackend(CeedVectorSetValue(*assembled, 0.0));
970   CeedCallBackend(CeedVectorGetArray(*assembled, CEED_MEM_DEVICE, &assembled_array));
971 
972   // Assemble QFunction
973   for (CeedInt in = 0; in < num_active_in; in++) {
974     // Set Inputs
975     CeedCallBackend(CeedVectorSetValue(active_inputs[in], 1.0));
976     if (num_active_in > 1) {
977       CeedCallBackend(CeedVectorSetValue(active_inputs[(in + num_active_in - 1) % num_active_in], 0.0));
978     }
979     // Set Outputs
980     for (CeedInt out = 0; out < num_output_fields; out++) {
981       CeedVector l_vec;
982 
983       // Get output vector
984       CeedCallBackend(CeedOperatorFieldGetVector(op_output_fields[out], &l_vec));
985       // Check if active output
986       if (l_vec == CEED_VECTOR_ACTIVE) {
987         CeedCallBackend(CeedVectorSetArray(impl->q_vecs_out[out], CEED_MEM_DEVICE, CEED_USE_POINTER, assembled_array));
988         CeedCallBackend(CeedQFunctionFieldGetSize(qf_output_fields[out], &size));
989         assembled_array += size * Q * num_elem;  // Advance the pointer by the size of the output
990       }
991     }
992     // Apply QFunction
993     CeedCallBackend(CeedQFunctionApply(qf, Q * num_elem, impl->q_vecs_in, impl->q_vecs_out));
994   }
995 
996   // Un-set output q-vecs to prevent accidental overwrite of Assembled
997   for (CeedInt out = 0; out < num_output_fields; out++) {
998     CeedVector l_vec;
999 
1000     CeedCallBackend(CeedOperatorFieldGetVector(op_output_fields[out], &l_vec));
1001     if (l_vec == CEED_VECTOR_ACTIVE) {
1002       CeedCallBackend(CeedVectorTakeArray(impl->q_vecs_out[out], CEED_MEM_DEVICE, NULL));
1003     }
1004   }
1005 
1006   // Restore input arrays
1007   for (CeedInt i = 0; i < num_input_fields; i++) {
1008     CeedCallBackend(CeedOperatorInputRestore_Cuda(op_input_fields[i], qf_input_fields[i], i, NULL, NULL, true, impl));
1009   }
1010 
1011   // Restore output
1012   CeedCallBackend(CeedVectorRestoreArray(*assembled, &assembled_array));
1013   return CEED_ERROR_SUCCESS;
1014 }
1015 
1016 //------------------------------------------------------------------------------
1017 // Assemble Linear QFunction
1018 //------------------------------------------------------------------------------
1019 static int CeedOperatorLinearAssembleQFunction_Cuda(CeedOperator op, CeedVector *assembled, CeedElemRestriction *rstr, CeedRequest *request) {
1020   return CeedOperatorLinearAssembleQFunctionCore_Cuda(op, true, assembled, rstr, request);
1021 }
1022 
1023 //------------------------------------------------------------------------------
1024 // Update Assembled Linear QFunction
1025 //------------------------------------------------------------------------------
1026 static int CeedOperatorLinearAssembleQFunctionUpdate_Cuda(CeedOperator op, CeedVector assembled, CeedElemRestriction rstr, CeedRequest *request) {
1027   return CeedOperatorLinearAssembleQFunctionCore_Cuda(op, false, &assembled, &rstr, request);
1028 }
1029 
1030 //------------------------------------------------------------------------------
1031 // Assemble Diagonal Setup
1032 //------------------------------------------------------------------------------
1033 static inline int CeedOperatorAssembleDiagonalSetup_Cuda(CeedOperator op) {
1034   Ceed                ceed;
1035   CeedInt             num_input_fields, num_output_fields, num_eval_modes_in = 0, num_eval_modes_out = 0;
1036   CeedInt             q_comp, num_nodes, num_qpts;
1037   CeedEvalMode       *eval_modes_in = NULL, *eval_modes_out = NULL;
1038   CeedBasis           basis_in = NULL, basis_out = NULL;
1039   CeedQFunctionField *qf_fields;
1040   CeedQFunction       qf;
1041   CeedOperatorField  *op_fields;
1042   CeedOperator_Cuda  *impl;
1043 
1044   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
1045   CeedCallBackend(CeedOperatorGetQFunction(op, &qf));
1046   CeedCallBackend(CeedQFunctionGetNumArgs(qf, &num_input_fields, &num_output_fields));
1047 
1048   // Determine active input basis
1049   CeedCallBackend(CeedOperatorGetFields(op, NULL, &op_fields, NULL, NULL));
1050   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, &qf_fields, NULL, NULL));
1051   for (CeedInt i = 0; i < num_input_fields; i++) {
1052     CeedVector vec;
1053 
1054     CeedCallBackend(CeedOperatorFieldGetVector(op_fields[i], &vec));
1055     if (vec == CEED_VECTOR_ACTIVE) {
1056       CeedBasis    basis;
1057       CeedEvalMode eval_mode;
1058 
1059       CeedCallBackend(CeedOperatorFieldGetBasis(op_fields[i], &basis));
1060       CeedCheck(!basis_in || basis_in == basis, ceed, CEED_ERROR_BACKEND,
1061                 "Backend does not implement operator diagonal assembly with multiple active bases");
1062       basis_in = basis;
1063       CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_fields[i], &eval_mode));
1064       CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis_in, eval_mode, &q_comp));
1065       if (eval_mode != CEED_EVAL_WEIGHT) {
1066         // q_comp = 1 if CEED_EVAL_NONE, CEED_EVAL_WEIGHT caught by QF assembly
1067         CeedCallBackend(CeedRealloc(num_eval_modes_in + q_comp, &eval_modes_in));
1068         for (CeedInt d = 0; d < q_comp; d++) eval_modes_in[num_eval_modes_in + d] = eval_mode;
1069         num_eval_modes_in += q_comp;
1070       }
1071     }
1072   }
1073 
1074   // Determine active output basis
1075   CeedCallBackend(CeedOperatorGetFields(op, NULL, NULL, NULL, &op_fields));
1076   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, NULL, NULL, &qf_fields));
1077   for (CeedInt i = 0; i < num_output_fields; i++) {
1078     CeedVector vec;
1079 
1080     CeedCallBackend(CeedOperatorFieldGetVector(op_fields[i], &vec));
1081     if (vec == CEED_VECTOR_ACTIVE) {
1082       CeedBasis    basis;
1083       CeedEvalMode eval_mode;
1084 
1085       CeedCallBackend(CeedOperatorFieldGetBasis(op_fields[i], &basis));
1086       CeedCheck(!basis_out || basis_out == basis, ceed, CEED_ERROR_BACKEND,
1087                 "Backend does not implement operator diagonal assembly with multiple active bases");
1088       basis_out = basis;
1089       CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_fields[i], &eval_mode));
1090       CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis_out, eval_mode, &q_comp));
1091       if (eval_mode != CEED_EVAL_WEIGHT) {
1092         // q_comp = 1 if CEED_EVAL_NONE, CEED_EVAL_WEIGHT caught by QF assembly
1093         CeedCallBackend(CeedRealloc(num_eval_modes_out + q_comp, &eval_modes_out));
1094         for (CeedInt d = 0; d < q_comp; d++) eval_modes_out[num_eval_modes_out + d] = eval_mode;
1095         num_eval_modes_out += q_comp;
1096       }
1097     }
1098   }
1099 
1100   // Operator data struct
1101   CeedCallBackend(CeedOperatorGetData(op, &impl));
1102   CeedCallBackend(CeedCalloc(1, &impl->diag));
1103   CeedOperatorDiag_Cuda *diag = impl->diag;
1104 
1105   // Basis matrices
1106   CeedCallBackend(CeedBasisGetNumNodes(basis_in, &num_nodes));
1107   if (basis_in == CEED_BASIS_NONE) num_qpts = num_nodes;
1108   else CeedCallBackend(CeedBasisGetNumQuadraturePoints(basis_in, &num_qpts));
1109   const CeedInt interp_bytes     = num_nodes * num_qpts * sizeof(CeedScalar);
1110   const CeedInt eval_modes_bytes = sizeof(CeedEvalMode);
1111   bool          has_eval_none    = false;
1112 
1113   // CEED_EVAL_NONE
1114   for (CeedInt i = 0; i < num_eval_modes_in; i++) has_eval_none = has_eval_none || (eval_modes_in[i] == CEED_EVAL_NONE);
1115   for (CeedInt i = 0; i < num_eval_modes_out; i++) has_eval_none = has_eval_none || (eval_modes_out[i] == CEED_EVAL_NONE);
1116   if (has_eval_none) {
1117     CeedScalar *identity = NULL;
1118 
1119     CeedCallBackend(CeedCalloc(num_nodes * num_qpts, &identity));
1120     for (CeedInt i = 0; i < (num_nodes < num_qpts ? num_nodes : num_qpts); i++) identity[i * num_nodes + i] = 1.0;
1121     CeedCallCuda(ceed, cudaMalloc((void **)&diag->d_identity, interp_bytes));
1122     CeedCallCuda(ceed, cudaMemcpy(diag->d_identity, identity, interp_bytes, cudaMemcpyHostToDevice));
1123     CeedCallBackend(CeedFree(&identity));
1124   }
1125 
1126   // CEED_EVAL_INTERP, CEED_EVAL_GRAD, CEED_EVAL_DIV, and CEED_EVAL_CURL
1127   for (CeedInt in = 0; in < 2; in++) {
1128     CeedFESpace fespace;
1129     CeedBasis   basis = in ? basis_in : basis_out;
1130 
1131     CeedCallBackend(CeedBasisGetFESpace(basis, &fespace));
1132     switch (fespace) {
1133       case CEED_FE_SPACE_H1: {
1134         CeedInt           q_comp_interp, q_comp_grad;
1135         const CeedScalar *interp, *grad;
1136         CeedScalar       *d_interp, *d_grad;
1137 
1138         CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis, CEED_EVAL_INTERP, &q_comp_interp));
1139         CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis, CEED_EVAL_GRAD, &q_comp_grad));
1140 
1141         CeedCallBackend(CeedBasisGetInterp(basis, &interp));
1142         CeedCallCuda(ceed, cudaMalloc((void **)&d_interp, interp_bytes * q_comp_interp));
1143         CeedCallCuda(ceed, cudaMemcpy(d_interp, interp, interp_bytes * q_comp_interp, cudaMemcpyHostToDevice));
1144         CeedCallBackend(CeedBasisGetGrad(basis, &grad));
1145         CeedCallCuda(ceed, cudaMalloc((void **)&d_grad, interp_bytes * q_comp_grad));
1146         CeedCallCuda(ceed, cudaMemcpy(d_grad, grad, interp_bytes * q_comp_grad, cudaMemcpyHostToDevice));
1147         if (in) {
1148           diag->d_interp_in = d_interp;
1149           diag->d_grad_in   = d_grad;
1150         } else {
1151           diag->d_interp_out = d_interp;
1152           diag->d_grad_out   = d_grad;
1153         }
1154       } break;
1155       case CEED_FE_SPACE_HDIV: {
1156         CeedInt           q_comp_interp, q_comp_div;
1157         const CeedScalar *interp, *div;
1158         CeedScalar       *d_interp, *d_div;
1159 
1160         CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis, CEED_EVAL_INTERP, &q_comp_interp));
1161         CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis, CEED_EVAL_DIV, &q_comp_div));
1162 
1163         CeedCallBackend(CeedBasisGetInterp(basis, &interp));
1164         CeedCallCuda(ceed, cudaMalloc((void **)&d_interp, interp_bytes * q_comp_interp));
1165         CeedCallCuda(ceed, cudaMemcpy(d_interp, interp, interp_bytes * q_comp_interp, cudaMemcpyHostToDevice));
1166         CeedCallBackend(CeedBasisGetDiv(basis, &div));
1167         CeedCallCuda(ceed, cudaMalloc((void **)&d_div, interp_bytes * q_comp_div));
1168         CeedCallCuda(ceed, cudaMemcpy(d_div, div, interp_bytes * q_comp_div, cudaMemcpyHostToDevice));
1169         if (in) {
1170           diag->d_interp_in = d_interp;
1171           diag->d_div_in    = d_div;
1172         } else {
1173           diag->d_interp_out = d_interp;
1174           diag->d_div_out    = d_div;
1175         }
1176       } break;
1177       case CEED_FE_SPACE_HCURL: {
1178         CeedInt           q_comp_interp, q_comp_curl;
1179         const CeedScalar *interp, *curl;
1180         CeedScalar       *d_interp, *d_curl;
1181 
1182         CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis, CEED_EVAL_INTERP, &q_comp_interp));
1183         CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis, CEED_EVAL_CURL, &q_comp_curl));
1184 
1185         CeedCallBackend(CeedBasisGetInterp(basis, &interp));
1186         CeedCallCuda(ceed, cudaMalloc((void **)&d_interp, interp_bytes * q_comp_interp));
1187         CeedCallCuda(ceed, cudaMemcpy(d_interp, interp, interp_bytes * q_comp_interp, cudaMemcpyHostToDevice));
1188         CeedCallBackend(CeedBasisGetCurl(basis, &curl));
1189         CeedCallCuda(ceed, cudaMalloc((void **)&d_curl, interp_bytes * q_comp_curl));
1190         CeedCallCuda(ceed, cudaMemcpy(d_curl, curl, interp_bytes * q_comp_curl, cudaMemcpyHostToDevice));
1191         if (in) {
1192           diag->d_interp_in = d_interp;
1193           diag->d_curl_in   = d_curl;
1194         } else {
1195           diag->d_interp_out = d_interp;
1196           diag->d_curl_out   = d_curl;
1197         }
1198       } break;
1199     }
1200   }
1201 
1202   // Arrays of eval_modes
1203   CeedCallCuda(ceed, cudaMalloc((void **)&diag->d_eval_modes_in, num_eval_modes_in * eval_modes_bytes));
1204   CeedCallCuda(ceed, cudaMemcpy(diag->d_eval_modes_in, eval_modes_in, num_eval_modes_in * eval_modes_bytes, cudaMemcpyHostToDevice));
1205   CeedCallCuda(ceed, cudaMalloc((void **)&diag->d_eval_modes_out, num_eval_modes_out * eval_modes_bytes));
1206   CeedCallCuda(ceed, cudaMemcpy(diag->d_eval_modes_out, eval_modes_out, num_eval_modes_out * eval_modes_bytes, cudaMemcpyHostToDevice));
1207   CeedCallBackend(CeedFree(&eval_modes_in));
1208   CeedCallBackend(CeedFree(&eval_modes_out));
1209   return CEED_ERROR_SUCCESS;
1210 }
1211 
1212 //------------------------------------------------------------------------------
1213 // Assemble Diagonal Setup (Compilation)
1214 //------------------------------------------------------------------------------
1215 static inline int CeedOperatorAssembleDiagonalSetupCompile_Cuda(CeedOperator op, CeedInt use_ceedsize_idx, const bool is_point_block) {
1216   Ceed                ceed;
1217   char               *diagonal_kernel_source;
1218   const char         *diagonal_kernel_path;
1219   CeedInt             num_input_fields, num_output_fields, num_eval_modes_in = 0, num_eval_modes_out = 0;
1220   CeedInt             num_comp, q_comp, num_nodes, num_qpts;
1221   CeedBasis           basis_in = NULL, basis_out = NULL;
1222   CeedQFunctionField *qf_fields;
1223   CeedQFunction       qf;
1224   CeedOperatorField  *op_fields;
1225   CeedOperator_Cuda  *impl;
1226 
1227   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
1228   CeedCallBackend(CeedOperatorGetQFunction(op, &qf));
1229   CeedCallBackend(CeedQFunctionGetNumArgs(qf, &num_input_fields, &num_output_fields));
1230 
1231   // Determine active input basis
1232   CeedCallBackend(CeedOperatorGetFields(op, NULL, &op_fields, NULL, NULL));
1233   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, &qf_fields, NULL, NULL));
1234   for (CeedInt i = 0; i < num_input_fields; i++) {
1235     CeedVector vec;
1236 
1237     CeedCallBackend(CeedOperatorFieldGetVector(op_fields[i], &vec));
1238     if (vec == CEED_VECTOR_ACTIVE) {
1239       CeedEvalMode eval_mode;
1240 
1241       CeedCallBackend(CeedOperatorFieldGetBasis(op_fields[i], &basis_in));
1242       CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_fields[i], &eval_mode));
1243       CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis_in, eval_mode, &q_comp));
1244       if (eval_mode != CEED_EVAL_WEIGHT) {
1245         num_eval_modes_in += q_comp;
1246       }
1247     }
1248   }
1249 
1250   // Determine active output basis
1251   CeedCallBackend(CeedOperatorGetFields(op, NULL, NULL, NULL, &op_fields));
1252   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, NULL, NULL, &qf_fields));
1253   for (CeedInt i = 0; i < num_output_fields; i++) {
1254     CeedVector vec;
1255 
1256     CeedCallBackend(CeedOperatorFieldGetVector(op_fields[i], &vec));
1257     if (vec == CEED_VECTOR_ACTIVE) {
1258       CeedEvalMode eval_mode;
1259 
1260       CeedCallBackend(CeedOperatorFieldGetBasis(op_fields[i], &basis_out));
1261       CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_fields[i], &eval_mode));
1262       CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis_out, eval_mode, &q_comp));
1263       if (eval_mode != CEED_EVAL_WEIGHT) {
1264         num_eval_modes_out += q_comp;
1265       }
1266     }
1267   }
1268 
1269   // Operator data struct
1270   CeedCallBackend(CeedOperatorGetData(op, &impl));
1271   CeedOperatorDiag_Cuda *diag = impl->diag;
1272 
1273   // Assemble kernel
1274   CUmodule *module          = is_point_block ? &diag->module_point_block : &diag->module;
1275   CeedInt   elems_per_block = 1;
1276   CeedCallBackend(CeedBasisGetNumNodes(basis_in, &num_nodes));
1277   CeedCallBackend(CeedBasisGetNumComponents(basis_in, &num_comp));
1278   if (basis_in == CEED_BASIS_NONE) num_qpts = num_nodes;
1279   else CeedCallBackend(CeedBasisGetNumQuadraturePoints(basis_in, &num_qpts));
1280   CeedCallBackend(CeedGetJitAbsolutePath(ceed, "ceed/jit-source/cuda/cuda-ref-operator-assemble-diagonal.h", &diagonal_kernel_path));
1281   CeedDebug256(ceed, CEED_DEBUG_COLOR_SUCCESS, "----- Loading Diagonal Assembly Kernel Source -----\n");
1282   CeedCallBackend(CeedLoadSourceToBuffer(ceed, diagonal_kernel_path, &diagonal_kernel_source));
1283   CeedDebug256(ceed, CEED_DEBUG_COLOR_SUCCESS, "----- Loading Diagonal Assembly Source Complete! -----\n");
1284   CeedCallCuda(ceed, CeedCompile_Cuda(ceed, diagonal_kernel_source, module, 8, "NUM_EVAL_MODES_IN", num_eval_modes_in, "NUM_EVAL_MODES_OUT",
1285                                       num_eval_modes_out, "NUM_COMP", num_comp, "NUM_NODES", num_nodes, "NUM_QPTS", num_qpts, "USE_CEEDSIZE",
1286                                       use_ceedsize_idx, "USE_POINT_BLOCK", is_point_block ? 1 : 0, "BLOCK_SIZE", num_nodes * elems_per_block));
1287   CeedCallCuda(ceed, CeedGetKernel_Cuda(ceed, *module, "LinearDiagonal", is_point_block ? &diag->LinearPointBlock : &diag->LinearDiagonal));
1288   CeedCallBackend(CeedFree(&diagonal_kernel_path));
1289   CeedCallBackend(CeedFree(&diagonal_kernel_source));
1290   return CEED_ERROR_SUCCESS;
1291 }
1292 
1293 //------------------------------------------------------------------------------
1294 // Assemble Diagonal Core
1295 //------------------------------------------------------------------------------
1296 static inline int CeedOperatorAssembleDiagonalCore_Cuda(CeedOperator op, CeedVector assembled, CeedRequest *request, const bool is_point_block) {
1297   Ceed                ceed;
1298   CeedInt             num_elem, num_nodes;
1299   CeedScalar         *elem_diag_array;
1300   const CeedScalar   *assembled_qf_array;
1301   CeedVector          assembled_qf   = NULL, elem_diag;
1302   CeedElemRestriction assembled_rstr = NULL, rstr_in, rstr_out, diag_rstr;
1303   CeedOperator_Cuda  *impl;
1304 
1305   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
1306   CeedCallBackend(CeedOperatorGetData(op, &impl));
1307 
1308   // Assemble QFunction
1309   CeedCallBackend(CeedOperatorLinearAssembleQFunctionBuildOrUpdate(op, &assembled_qf, &assembled_rstr, request));
1310   CeedCallBackend(CeedElemRestrictionDestroy(&assembled_rstr));
1311   CeedCallBackend(CeedVectorGetArrayRead(assembled_qf, CEED_MEM_DEVICE, &assembled_qf_array));
1312 
1313   // Setup
1314   if (!impl->diag) CeedCallBackend(CeedOperatorAssembleDiagonalSetup_Cuda(op));
1315   CeedOperatorDiag_Cuda *diag = impl->diag;
1316 
1317   assert(diag != NULL);
1318 
1319   // Assemble kernel if needed
1320   if ((!is_point_block && !diag->LinearDiagonal) || (is_point_block && !diag->LinearPointBlock)) {
1321     CeedSize assembled_length, assembled_qf_length;
1322     CeedInt  use_ceedsize_idx = 0;
1323     CeedCallBackend(CeedVectorGetLength(assembled, &assembled_length));
1324     CeedCallBackend(CeedVectorGetLength(assembled_qf, &assembled_qf_length));
1325     if ((assembled_length > INT_MAX) || (assembled_qf_length > INT_MAX)) use_ceedsize_idx = 1;
1326 
1327     CeedCallBackend(CeedOperatorAssembleDiagonalSetupCompile_Cuda(op, use_ceedsize_idx, is_point_block));
1328   }
1329 
1330   // Restriction and diagonal vector
1331   CeedCallBackend(CeedOperatorGetActiveElemRestrictions(op, &rstr_in, &rstr_out));
1332   CeedCheck(rstr_in == rstr_out, ceed, CEED_ERROR_BACKEND,
1333             "Cannot assemble operator diagonal with different input and output active element restrictions");
1334   if (!is_point_block && !diag->diag_rstr) {
1335     CeedCallBackend(CeedElemRestrictionCreateUnsignedCopy(rstr_out, &diag->diag_rstr));
1336     CeedCallBackend(CeedElemRestrictionCreateVector(diag->diag_rstr, NULL, &diag->elem_diag));
1337   } else if (is_point_block && !diag->point_block_diag_rstr) {
1338     CeedCallBackend(CeedOperatorCreateActivePointBlockRestriction(rstr_out, &diag->point_block_diag_rstr));
1339     CeedCallBackend(CeedElemRestrictionCreateVector(diag->point_block_diag_rstr, NULL, &diag->point_block_elem_diag));
1340   }
1341   diag_rstr = is_point_block ? diag->point_block_diag_rstr : diag->diag_rstr;
1342   elem_diag = is_point_block ? diag->point_block_elem_diag : diag->elem_diag;
1343   CeedCallBackend(CeedVectorSetValue(elem_diag, 0.0));
1344 
1345   // Only assemble diagonal if the basis has nodes, otherwise inputs are null pointers
1346   CeedCallBackend(CeedElemRestrictionGetElementSize(diag_rstr, &num_nodes));
1347   if (num_nodes > 0) {
1348     // Assemble element operator diagonals
1349     CeedCallBackend(CeedElemRestrictionGetNumElements(diag_rstr, &num_elem));
1350     CeedCallBackend(CeedVectorGetArray(elem_diag, CEED_MEM_DEVICE, &elem_diag_array));
1351 
1352     // Compute the diagonal of B^T D B
1353     CeedInt elems_per_block = 1;
1354     CeedInt grid            = CeedDivUpInt(num_elem, elems_per_block);
1355     void   *args[]          = {(void *)&num_elem,      &diag->d_identity,       &diag->d_interp_in,  &diag->d_grad_in, &diag->d_div_in,
1356                                &diag->d_curl_in,       &diag->d_interp_out,     &diag->d_grad_out,   &diag->d_div_out, &diag->d_curl_out,
1357                                &diag->d_eval_modes_in, &diag->d_eval_modes_out, &assembled_qf_array, &elem_diag_array};
1358 
1359     if (is_point_block) {
1360       CeedCallBackend(CeedRunKernelDim_Cuda(ceed, diag->LinearPointBlock, grid, num_nodes, 1, elems_per_block, args));
1361     } else {
1362       CeedCallBackend(CeedRunKernelDim_Cuda(ceed, diag->LinearDiagonal, grid, num_nodes, 1, elems_per_block, args));
1363     }
1364 
1365     // Restore arrays
1366     CeedCallBackend(CeedVectorRestoreArray(elem_diag, &elem_diag_array));
1367     CeedCallBackend(CeedVectorRestoreArrayRead(assembled_qf, &assembled_qf_array));
1368   }
1369 
1370   // Assemble local operator diagonal
1371   CeedCallBackend(CeedElemRestrictionApply(diag_rstr, CEED_TRANSPOSE, elem_diag, assembled, request));
1372 
1373   // Cleanup
1374   CeedCallBackend(CeedVectorDestroy(&assembled_qf));
1375   return CEED_ERROR_SUCCESS;
1376 }
1377 
1378 //------------------------------------------------------------------------------
1379 // Assemble Linear Diagonal
1380 //------------------------------------------------------------------------------
1381 static int CeedOperatorLinearAssembleAddDiagonal_Cuda(CeedOperator op, CeedVector assembled, CeedRequest *request) {
1382   CeedCallBackend(CeedOperatorAssembleDiagonalCore_Cuda(op, assembled, request, false));
1383   return CEED_ERROR_SUCCESS;
1384 }
1385 
1386 //------------------------------------------------------------------------------
1387 // Assemble Linear Point Block Diagonal
1388 //------------------------------------------------------------------------------
1389 static int CeedOperatorLinearAssembleAddPointBlockDiagonal_Cuda(CeedOperator op, CeedVector assembled, CeedRequest *request) {
1390   CeedCallBackend(CeedOperatorAssembleDiagonalCore_Cuda(op, assembled, request, true));
1391   return CEED_ERROR_SUCCESS;
1392 }
1393 
1394 //------------------------------------------------------------------------------
1395 // Single Operator Assembly Setup
1396 //------------------------------------------------------------------------------
1397 static int CeedSingleOperatorAssembleSetup_Cuda(CeedOperator op, CeedInt use_ceedsize_idx) {
1398   Ceed                ceed;
1399   Ceed_Cuda          *cuda_data;
1400   char               *assembly_kernel_source;
1401   const char         *assembly_kernel_path;
1402   CeedInt             num_input_fields, num_output_fields, num_eval_modes_in = 0, num_eval_modes_out = 0;
1403   CeedInt             elem_size_in, num_qpts_in = 0, num_comp_in, elem_size_out, num_qpts_out, num_comp_out, q_comp;
1404   CeedEvalMode       *eval_modes_in = NULL, *eval_modes_out = NULL;
1405   CeedElemRestriction rstr_in = NULL, rstr_out = NULL;
1406   CeedBasis           basis_in = NULL, basis_out = NULL;
1407   CeedQFunctionField *qf_fields;
1408   CeedQFunction       qf;
1409   CeedOperatorField  *input_fields, *output_fields;
1410   CeedOperator_Cuda  *impl;
1411 
1412   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
1413   CeedCallBackend(CeedOperatorGetData(op, &impl));
1414 
1415   // Get intput and output fields
1416   CeedCallBackend(CeedOperatorGetFields(op, &num_input_fields, &input_fields, &num_output_fields, &output_fields));
1417 
1418   // Determine active input basis eval mode
1419   CeedCallBackend(CeedOperatorGetQFunction(op, &qf));
1420   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, &qf_fields, NULL, NULL));
1421   for (CeedInt i = 0; i < num_input_fields; i++) {
1422     CeedVector vec;
1423 
1424     CeedCallBackend(CeedOperatorFieldGetVector(input_fields[i], &vec));
1425     if (vec == CEED_VECTOR_ACTIVE) {
1426       CeedBasis    basis;
1427       CeedEvalMode eval_mode;
1428 
1429       CeedCallBackend(CeedOperatorFieldGetBasis(input_fields[i], &basis));
1430       CeedCheck(!basis_in || basis_in == basis, ceed, CEED_ERROR_BACKEND, "Backend does not implement operator assembly with multiple active bases");
1431       basis_in = basis;
1432       CeedCallBackend(CeedOperatorFieldGetElemRestriction(input_fields[i], &rstr_in));
1433       CeedCallBackend(CeedElemRestrictionGetElementSize(rstr_in, &elem_size_in));
1434       if (basis_in == CEED_BASIS_NONE) num_qpts_in = elem_size_in;
1435       else CeedCallBackend(CeedBasisGetNumQuadraturePoints(basis_in, &num_qpts_in));
1436       CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_fields[i], &eval_mode));
1437       CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis_in, eval_mode, &q_comp));
1438       if (eval_mode != CEED_EVAL_WEIGHT) {
1439         // q_comp = 1 if CEED_EVAL_NONE, CEED_EVAL_WEIGHT caught by QF Assembly
1440         CeedCallBackend(CeedRealloc(num_eval_modes_in + q_comp, &eval_modes_in));
1441         for (CeedInt d = 0; d < q_comp; d++) {
1442           eval_modes_in[num_eval_modes_in + d] = eval_mode;
1443         }
1444         num_eval_modes_in += q_comp;
1445       }
1446     }
1447   }
1448 
1449   // Determine active output basis; basis_out and rstr_out only used if same as input, TODO
1450   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, NULL, NULL, &qf_fields));
1451   for (CeedInt i = 0; i < num_output_fields; i++) {
1452     CeedVector vec;
1453 
1454     CeedCallBackend(CeedOperatorFieldGetVector(output_fields[i], &vec));
1455     if (vec == CEED_VECTOR_ACTIVE) {
1456       CeedBasis    basis;
1457       CeedEvalMode eval_mode;
1458 
1459       CeedCallBackend(CeedOperatorFieldGetBasis(output_fields[i], &basis));
1460       CeedCheck(!basis_out || basis_out == basis, ceed, CEED_ERROR_BACKEND,
1461                 "Backend does not implement operator assembly with multiple active bases");
1462       basis_out = basis;
1463       CeedCallBackend(CeedOperatorFieldGetElemRestriction(output_fields[i], &rstr_out));
1464       CeedCallBackend(CeedElemRestrictionGetElementSize(rstr_out, &elem_size_out));
1465       if (basis_out == CEED_BASIS_NONE) num_qpts_out = elem_size_out;
1466       else CeedCallBackend(CeedBasisGetNumQuadraturePoints(basis_out, &num_qpts_out));
1467       CeedCheck(num_qpts_in == num_qpts_out, ceed, CEED_ERROR_UNSUPPORTED,
1468                 "Active input and output bases must have the same number of quadrature points");
1469       CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_fields[i], &eval_mode));
1470       CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis_out, eval_mode, &q_comp));
1471       if (eval_mode != CEED_EVAL_WEIGHT) {
1472         // q_comp = 1 if CEED_EVAL_NONE, CEED_EVAL_WEIGHT caught by QF Assembly
1473         CeedCallBackend(CeedRealloc(num_eval_modes_out + q_comp, &eval_modes_out));
1474         for (CeedInt d = 0; d < q_comp; d++) {
1475           eval_modes_out[num_eval_modes_out + d] = eval_mode;
1476         }
1477         num_eval_modes_out += q_comp;
1478       }
1479     }
1480   }
1481   CeedCheck(num_eval_modes_in > 0 && num_eval_modes_out > 0, ceed, CEED_ERROR_UNSUPPORTED, "Cannot assemble operator without inputs/outputs");
1482 
1483   CeedCallBackend(CeedCalloc(1, &impl->asmb));
1484   CeedOperatorAssemble_Cuda *asmb = impl->asmb;
1485   asmb->elems_per_block           = 1;
1486   asmb->block_size_x              = elem_size_in;
1487   asmb->block_size_y              = elem_size_out;
1488 
1489   CeedCallBackend(CeedGetData(ceed, &cuda_data));
1490   bool fallback = asmb->block_size_x * asmb->block_size_y * asmb->elems_per_block > cuda_data->device_prop.maxThreadsPerBlock;
1491 
1492   if (fallback) {
1493     // Use fallback kernel with 1D threadblock
1494     asmb->block_size_y = 1;
1495   }
1496 
1497   // Compile kernels
1498   CeedCallBackend(CeedElemRestrictionGetNumComponents(rstr_in, &num_comp_in));
1499   CeedCallBackend(CeedElemRestrictionGetNumComponents(rstr_out, &num_comp_out));
1500   CeedCallBackend(CeedGetJitAbsolutePath(ceed, "ceed/jit-source/cuda/cuda-ref-operator-assemble.h", &assembly_kernel_path));
1501   CeedDebug256(ceed, CEED_DEBUG_COLOR_SUCCESS, "----- Loading Assembly Kernel Source -----\n");
1502   CeedCallBackend(CeedLoadSourceToBuffer(ceed, assembly_kernel_path, &assembly_kernel_source));
1503   CeedDebug256(ceed, CEED_DEBUG_COLOR_SUCCESS, "----- Loading Assembly Source Complete! -----\n");
1504   CeedCallBackend(CeedCompile_Cuda(ceed, assembly_kernel_source, &asmb->module, 10, "NUM_EVAL_MODES_IN", num_eval_modes_in, "NUM_EVAL_MODES_OUT",
1505                                    num_eval_modes_out, "NUM_COMP_IN", num_comp_in, "NUM_COMP_OUT", num_comp_out, "NUM_NODES_IN", elem_size_in,
1506                                    "NUM_NODES_OUT", elem_size_out, "NUM_QPTS", num_qpts_in, "BLOCK_SIZE",
1507                                    asmb->block_size_x * asmb->block_size_y * asmb->elems_per_block, "BLOCK_SIZE_Y", asmb->block_size_y,
1508                                    "USE_CEEDSIZE", use_ceedsize_idx));
1509   CeedCallBackend(CeedGetKernel_Cuda(ceed, asmb->module, "LinearAssemble", &asmb->LinearAssemble));
1510   CeedCallBackend(CeedFree(&assembly_kernel_path));
1511   CeedCallBackend(CeedFree(&assembly_kernel_source));
1512 
1513   // Load into B_in, in order that they will be used in eval_modes_in
1514   {
1515     const CeedInt in_bytes           = elem_size_in * num_qpts_in * num_eval_modes_in * sizeof(CeedScalar);
1516     CeedInt       d_in               = 0;
1517     CeedEvalMode  eval_modes_in_prev = CEED_EVAL_NONE;
1518     bool          has_eval_none      = false;
1519     CeedScalar   *identity           = NULL;
1520 
1521     for (CeedInt i = 0; i < num_eval_modes_in; i++) {
1522       has_eval_none = has_eval_none || (eval_modes_in[i] == CEED_EVAL_NONE);
1523     }
1524     if (has_eval_none) {
1525       CeedCallBackend(CeedCalloc(elem_size_in * num_qpts_in, &identity));
1526       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;
1527     }
1528 
1529     CeedCallCuda(ceed, cudaMalloc((void **)&asmb->d_B_in, in_bytes));
1530     for (CeedInt i = 0; i < num_eval_modes_in; i++) {
1531       const CeedScalar *h_B_in;
1532 
1533       CeedCallBackend(CeedOperatorGetBasisPointer(basis_in, eval_modes_in[i], identity, &h_B_in));
1534       CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis_in, eval_modes_in[i], &q_comp));
1535       if (q_comp > 1) {
1536         if (i == 0 || eval_modes_in[i] != eval_modes_in_prev) d_in = 0;
1537         else h_B_in = &h_B_in[(++d_in) * elem_size_in * num_qpts_in];
1538       }
1539       eval_modes_in_prev = eval_modes_in[i];
1540 
1541       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),
1542                                     cudaMemcpyHostToDevice));
1543     }
1544 
1545     if (identity) {
1546       CeedCallBackend(CeedFree(&identity));
1547     }
1548   }
1549   CeedCallBackend(CeedFree(&eval_modes_in));
1550 
1551   // Load into B_out, in order that they will be used in eval_modes_out
1552   {
1553     const CeedInt out_bytes           = elem_size_out * num_qpts_out * num_eval_modes_out * sizeof(CeedScalar);
1554     CeedInt       d_out               = 0;
1555     CeedEvalMode  eval_modes_out_prev = CEED_EVAL_NONE;
1556     bool          has_eval_none       = false;
1557     CeedScalar   *identity            = NULL;
1558 
1559     for (CeedInt i = 0; i < num_eval_modes_out; i++) {
1560       has_eval_none = has_eval_none || (eval_modes_out[i] == CEED_EVAL_NONE);
1561     }
1562     if (has_eval_none) {
1563       CeedCallBackend(CeedCalloc(elem_size_out * num_qpts_out, &identity));
1564       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;
1565     }
1566 
1567     CeedCallCuda(ceed, cudaMalloc((void **)&asmb->d_B_out, out_bytes));
1568     for (CeedInt i = 0; i < num_eval_modes_out; i++) {
1569       const CeedScalar *h_B_out;
1570 
1571       CeedCallBackend(CeedOperatorGetBasisPointer(basis_out, eval_modes_out[i], identity, &h_B_out));
1572       CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis_out, eval_modes_out[i], &q_comp));
1573       if (q_comp > 1) {
1574         if (i == 0 || eval_modes_out[i] != eval_modes_out_prev) d_out = 0;
1575         else h_B_out = &h_B_out[(++d_out) * elem_size_out * num_qpts_out];
1576       }
1577       eval_modes_out_prev = eval_modes_out[i];
1578 
1579       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),
1580                                     cudaMemcpyHostToDevice));
1581     }
1582 
1583     if (identity) {
1584       CeedCallBackend(CeedFree(&identity));
1585     }
1586   }
1587   CeedCallBackend(CeedFree(&eval_modes_out));
1588   return CEED_ERROR_SUCCESS;
1589 }
1590 
1591 //------------------------------------------------------------------------------
1592 // Assemble matrix data for COO matrix of assembled operator.
1593 // The sparsity pattern is set by CeedOperatorLinearAssembleSymbolic.
1594 //
1595 // Note that this (and other assembly routines) currently assume only one active input restriction/basis per operator
1596 // (could have multiple basis eval modes).
1597 // TODO: allow multiple active input restrictions/basis objects
1598 //------------------------------------------------------------------------------
1599 static int CeedSingleOperatorAssemble_Cuda(CeedOperator op, CeedInt offset, CeedVector values) {
1600   Ceed                ceed;
1601   CeedSize            values_length = 0, assembled_qf_length = 0;
1602   CeedInt             use_ceedsize_idx = 0, num_elem_in, num_elem_out, elem_size_in, elem_size_out;
1603   CeedScalar         *values_array;
1604   const CeedScalar   *assembled_qf_array;
1605   CeedVector          assembled_qf   = NULL;
1606   CeedElemRestriction assembled_rstr = NULL, rstr_in, rstr_out;
1607   CeedRestrictionType rstr_type_in, rstr_type_out;
1608   const bool         *orients_in = NULL, *orients_out = NULL;
1609   const CeedInt8     *curl_orients_in = NULL, *curl_orients_out = NULL;
1610   CeedOperator_Cuda  *impl;
1611 
1612   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
1613   CeedCallBackend(CeedOperatorGetData(op, &impl));
1614 
1615   // Assemble QFunction
1616   CeedCallBackend(CeedOperatorLinearAssembleQFunctionBuildOrUpdate(op, &assembled_qf, &assembled_rstr, CEED_REQUEST_IMMEDIATE));
1617   CeedCallBackend(CeedElemRestrictionDestroy(&assembled_rstr));
1618   CeedCallBackend(CeedVectorGetArrayRead(assembled_qf, CEED_MEM_DEVICE, &assembled_qf_array));
1619 
1620   CeedCallBackend(CeedVectorGetLength(values, &values_length));
1621   CeedCallBackend(CeedVectorGetLength(assembled_qf, &assembled_qf_length));
1622   if ((values_length > INT_MAX) || (assembled_qf_length > INT_MAX)) use_ceedsize_idx = 1;
1623 
1624   // Setup
1625   if (!impl->asmb) CeedCallBackend(CeedSingleOperatorAssembleSetup_Cuda(op, use_ceedsize_idx));
1626   CeedOperatorAssemble_Cuda *asmb = impl->asmb;
1627 
1628   assert(asmb != NULL);
1629 
1630   // Assemble element operator
1631   CeedCallBackend(CeedVectorGetArray(values, CEED_MEM_DEVICE, &values_array));
1632   values_array += offset;
1633 
1634   CeedCallBackend(CeedOperatorGetActiveElemRestrictions(op, &rstr_in, &rstr_out));
1635   CeedCallBackend(CeedElemRestrictionGetNumElements(rstr_in, &num_elem_in));
1636   CeedCallBackend(CeedElemRestrictionGetElementSize(rstr_in, &elem_size_in));
1637 
1638   CeedCallBackend(CeedElemRestrictionGetType(rstr_in, &rstr_type_in));
1639   if (rstr_type_in == CEED_RESTRICTION_ORIENTED) {
1640     CeedCallBackend(CeedElemRestrictionGetOrientations(rstr_in, CEED_MEM_DEVICE, &orients_in));
1641   } else if (rstr_type_in == CEED_RESTRICTION_CURL_ORIENTED) {
1642     CeedCallBackend(CeedElemRestrictionGetCurlOrientations(rstr_in, CEED_MEM_DEVICE, &curl_orients_in));
1643   }
1644 
1645   if (rstr_in != rstr_out) {
1646     CeedCallBackend(CeedElemRestrictionGetNumElements(rstr_out, &num_elem_out));
1647     CeedCheck(num_elem_in == num_elem_out, ceed, CEED_ERROR_UNSUPPORTED,
1648               "Active input and output operator restrictions must have the same number of elements");
1649     CeedCallBackend(CeedElemRestrictionGetElementSize(rstr_out, &elem_size_out));
1650 
1651     CeedCallBackend(CeedElemRestrictionGetType(rstr_out, &rstr_type_out));
1652     if (rstr_type_out == CEED_RESTRICTION_ORIENTED) {
1653       CeedCallBackend(CeedElemRestrictionGetOrientations(rstr_out, CEED_MEM_DEVICE, &orients_out));
1654     } else if (rstr_type_out == CEED_RESTRICTION_CURL_ORIENTED) {
1655       CeedCallBackend(CeedElemRestrictionGetCurlOrientations(rstr_out, CEED_MEM_DEVICE, &curl_orients_out));
1656     }
1657   } else {
1658     elem_size_out    = elem_size_in;
1659     orients_out      = orients_in;
1660     curl_orients_out = curl_orients_in;
1661   }
1662 
1663   // Compute B^T D B
1664   CeedInt shared_mem =
1665       ((curl_orients_in || curl_orients_out ? elem_size_in * elem_size_out : 0) + (curl_orients_in ? elem_size_in * asmb->block_size_y : 0)) *
1666       sizeof(CeedScalar);
1667   CeedInt grid   = CeedDivUpInt(num_elem_in, asmb->elems_per_block);
1668   void   *args[] = {(void *)&num_elem_in, &asmb->d_B_in,     &asmb->d_B_out,      &orients_in,  &curl_orients_in,
1669                     &orients_out,         &curl_orients_out, &assembled_qf_array, &values_array};
1670 
1671   CeedCallBackend(
1672       CeedRunKernelDimShared_Cuda(ceed, asmb->LinearAssemble, grid, asmb->block_size_x, asmb->block_size_y, asmb->elems_per_block, shared_mem, args));
1673 
1674   // Restore arrays
1675   CeedCallBackend(CeedVectorRestoreArray(values, &values_array));
1676   CeedCallBackend(CeedVectorRestoreArrayRead(assembled_qf, &assembled_qf_array));
1677 
1678   // Cleanup
1679   CeedCallBackend(CeedVectorDestroy(&assembled_qf));
1680   if (rstr_type_in == CEED_RESTRICTION_ORIENTED) {
1681     CeedCallBackend(CeedElemRestrictionRestoreOrientations(rstr_in, &orients_in));
1682   } else if (rstr_type_in == CEED_RESTRICTION_CURL_ORIENTED) {
1683     CeedCallBackend(CeedElemRestrictionRestoreCurlOrientations(rstr_in, &curl_orients_in));
1684   }
1685   if (rstr_in != rstr_out) {
1686     if (rstr_type_out == CEED_RESTRICTION_ORIENTED) {
1687       CeedCallBackend(CeedElemRestrictionRestoreOrientations(rstr_out, &orients_out));
1688     } else if (rstr_type_out == CEED_RESTRICTION_CURL_ORIENTED) {
1689       CeedCallBackend(CeedElemRestrictionRestoreCurlOrientations(rstr_out, &curl_orients_out));
1690     }
1691   }
1692   return CEED_ERROR_SUCCESS;
1693 }
1694 
1695 //------------------------------------------------------------------------------
1696 // Assemble Linear QFunction AtPoints
1697 //------------------------------------------------------------------------------
1698 static int CeedOperatorLinearAssembleQFunctionAtPoints_Cuda(CeedOperator op, CeedVector *assembled, CeedElemRestriction *rstr, CeedRequest *request) {
1699   return CeedError(CeedOperatorReturnCeed(op), CEED_ERROR_BACKEND, "Backend does not implement CeedOperatorLinearAssembleQFunction");
1700 }
1701 
1702 //------------------------------------------------------------------------------
1703 // Assemble Linear Diagonal AtPoints
1704 //------------------------------------------------------------------------------
1705 static int CeedOperatorLinearAssembleAddDiagonalAtPoints_Cuda(CeedOperator op, CeedVector assembled, CeedRequest *request) {
1706   CeedInt             max_num_points, *num_points, num_elem, num_input_fields, num_output_fields;
1707   Ceed                ceed;
1708   CeedVector          active_e_vec_in, active_e_vec_out;
1709   CeedQFunctionField *qf_input_fields, *qf_output_fields;
1710   CeedQFunction       qf;
1711   CeedOperatorField  *op_input_fields, *op_output_fields;
1712   CeedOperator_Cuda  *impl;
1713 
1714   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
1715   CeedCallBackend(CeedOperatorGetData(op, &impl));
1716   CeedCallBackend(CeedOperatorGetQFunction(op, &qf));
1717   CeedCallBackend(CeedOperatorGetNumElements(op, &num_elem));
1718   CeedCallBackend(CeedOperatorGetFields(op, &num_input_fields, &op_input_fields, &num_output_fields, &op_output_fields));
1719   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, &qf_input_fields, NULL, &qf_output_fields));
1720 
1721   // Setup
1722   CeedCallBackend(CeedOperatorSetupAtPoints_Cuda(op));
1723   num_points     = impl->num_points;
1724   max_num_points = impl->max_num_points;
1725 
1726   // Work vector
1727   CeedCallBackend(CeedGetWorkVector(ceed, impl->max_active_e_vec_len, &active_e_vec_in));
1728   CeedCallBackend(CeedGetWorkVector(ceed, impl->max_active_e_vec_len, &active_e_vec_out));
1729   {
1730     CeedSize length_in, length_out;
1731 
1732     CeedCallBackend(CeedVectorGetLength(active_e_vec_in, &length_in));
1733     CeedCallBackend(CeedVectorGetLength(active_e_vec_out, &length_out));
1734     // Need input e_vec to be longer
1735     if (length_in < length_out) {
1736       CeedVector temp = active_e_vec_in;
1737 
1738       active_e_vec_in  = active_e_vec_out;
1739       active_e_vec_out = temp;
1740     }
1741   }
1742 
1743   // Get point coordinates
1744   if (!impl->point_coords_elem) {
1745     CeedVector          point_coords = NULL;
1746     CeedElemRestriction rstr_points  = NULL;
1747 
1748     CeedCallBackend(CeedOperatorAtPointsGetPoints(op, &rstr_points, &point_coords));
1749     CeedCallBackend(CeedElemRestrictionCreateVector(rstr_points, NULL, &impl->point_coords_elem));
1750     CeedCallBackend(CeedElemRestrictionApply(rstr_points, CEED_NOTRANSPOSE, point_coords, impl->point_coords_elem, request));
1751     CeedCallBackend(CeedVectorDestroy(&point_coords));
1752     CeedCallBackend(CeedElemRestrictionDestroy(&rstr_points));
1753   }
1754 
1755   // Process inputs
1756   for (CeedInt i = 0; i < num_input_fields; i++) {
1757     CeedCallBackend(CeedOperatorInputRestrict_Cuda(op_input_fields[i], qf_input_fields[i], i, NULL, NULL, true, impl, request));
1758     CeedCallBackend(CeedOperatorInputBasisAtPoints_Cuda(op_input_fields[i], qf_input_fields[i], i, NULL, NULL, num_elem, num_points, true, impl));
1759   }
1760 
1761   // Clear active input Qvecs
1762   for (CeedInt i = 0; i < num_input_fields; i++) {
1763     CeedVector vec;
1764 
1765     CeedCallBackend(CeedOperatorFieldGetVector(op_input_fields[i], &vec));
1766     if (vec != CEED_VECTOR_ACTIVE) continue;
1767     CeedCallBackend(CeedVectorSetValue(impl->q_vecs_in[i], 0.0));
1768   }
1769 
1770   // Output pointers, as necessary
1771   for (CeedInt i = 0; i < num_output_fields; i++) {
1772     CeedEvalMode eval_mode;
1773 
1774     CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_output_fields[i], &eval_mode));
1775     if (eval_mode == CEED_EVAL_NONE) {
1776       CeedScalar *e_vec_array;
1777 
1778       CeedCallBackend(CeedVectorGetArrayWrite(impl->e_vecs_out[i], CEED_MEM_DEVICE, &e_vec_array));
1779       CeedCallBackend(CeedVectorSetArray(impl->q_vecs_out[i], CEED_MEM_DEVICE, CEED_USE_POINTER, e_vec_array));
1780     }
1781   }
1782 
1783   // Loop over active fields
1784   for (CeedInt i = 0; i < num_input_fields; i++) {
1785     bool                is_active_at_points = true;
1786     CeedInt             elem_size = 1, num_comp_active = 1, e_vec_size = 0;
1787     CeedRestrictionType rstr_type;
1788     CeedVector          l_vec;
1789     CeedElemRestriction elem_rstr;
1790 
1791     CeedCallBackend(CeedOperatorFieldGetVector(op_input_fields[i], &l_vec));
1792     // -- Skip non-active input
1793     if (l_vec != CEED_VECTOR_ACTIVE) continue;
1794 
1795     // -- Get active restriction type
1796     CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_input_fields[i], &elem_rstr));
1797     CeedCallBackend(CeedElemRestrictionGetType(elem_rstr, &rstr_type));
1798     is_active_at_points = rstr_type == CEED_RESTRICTION_POINTS;
1799     if (!is_active_at_points) CeedCallBackend(CeedElemRestrictionGetElementSize(elem_rstr, &elem_size));
1800     else elem_size = max_num_points;
1801     CeedCallBackend(CeedElemRestrictionGetNumComponents(elem_rstr, &num_comp_active));
1802 
1803     e_vec_size = elem_size * num_comp_active;
1804     for (CeedInt s = 0; s < e_vec_size; s++) {
1805       bool         is_active_input = false;
1806       CeedEvalMode eval_mode;
1807       CeedVector   l_vec, q_vec = impl->q_vecs_in[i];
1808       CeedBasis    basis;
1809 
1810       CeedCallBackend(CeedOperatorFieldGetVector(op_input_fields[i], &l_vec));
1811       // Skip non-active input
1812       is_active_input = l_vec == CEED_VECTOR_ACTIVE;
1813       if (!is_active_input) continue;
1814 
1815       // Update unit vector
1816       if (s == 0) CeedCallBackend(CeedVectorSetValue(active_e_vec_in, 0.0));
1817       else CeedCallBackend(CeedVectorSetValueStrided(active_e_vec_in, s - 1, e_vec_size, 0.0));
1818       CeedCallBackend(CeedVectorSetValueStrided(active_e_vec_in, s, e_vec_size, 1.0));
1819 
1820       // Basis action
1821       CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_input_fields[i], &eval_mode));
1822       switch (eval_mode) {
1823         case CEED_EVAL_NONE: {
1824           const CeedScalar *e_vec_array;
1825 
1826           CeedCallBackend(CeedVectorGetArrayRead(active_e_vec_in, CEED_MEM_DEVICE, &e_vec_array));
1827           CeedCallBackend(CeedVectorSetArray(q_vec, CEED_MEM_DEVICE, CEED_USE_POINTER, (CeedScalar *)e_vec_array));
1828           break;
1829         }
1830         case CEED_EVAL_INTERP:
1831         case CEED_EVAL_GRAD:
1832         case CEED_EVAL_DIV:
1833         case CEED_EVAL_CURL:
1834           CeedCallBackend(CeedOperatorFieldGetBasis(op_input_fields[i], &basis));
1835           CeedCallBackend(
1836               CeedBasisApplyAtPoints(basis, num_elem, num_points, CEED_NOTRANSPOSE, eval_mode, impl->point_coords_elem, active_e_vec_in, q_vec));
1837           break;
1838         case CEED_EVAL_WEIGHT:
1839           break;  // No action
1840       }
1841 
1842       // Q function
1843       CeedCallBackend(CeedQFunctionApply(qf, num_elem * max_num_points, impl->q_vecs_in, impl->q_vecs_out));
1844 
1845       // Output basis apply if needed
1846       for (CeedInt j = 0; j < num_output_fields; j++) {
1847         bool                is_active_output = false;
1848         CeedInt             elem_size        = 0;
1849         CeedRestrictionType rstr_type;
1850         CeedEvalMode        eval_mode;
1851         CeedVector          l_vec, e_vec = impl->e_vecs_out[j], q_vec = impl->q_vecs_out[j];
1852         CeedElemRestriction elem_rstr;
1853         CeedBasis           basis;
1854 
1855         CeedCallBackend(CeedOperatorFieldGetVector(op_output_fields[j], &l_vec));
1856         // ---- Skip non-active output
1857         is_active_output = l_vec == CEED_VECTOR_ACTIVE;
1858         if (!is_active_output) continue;
1859         if (!e_vec) e_vec = active_e_vec_out;
1860 
1861         // ---- Check if elem size matches
1862         CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_output_fields[j], &elem_rstr));
1863         CeedCallBackend(CeedElemRestrictionGetType(elem_rstr, &rstr_type));
1864         if (is_active_at_points && rstr_type != CEED_RESTRICTION_POINTS) continue;
1865         if (rstr_type == CEED_RESTRICTION_POINTS) {
1866           CeedCallBackend(CeedElemRestrictionGetMaxPointsInElement(elem_rstr, &elem_size));
1867         } else {
1868           CeedCallBackend(CeedElemRestrictionGetElementSize(elem_rstr, &elem_size));
1869         }
1870         {
1871           CeedInt num_comp = 0;
1872 
1873           CeedCallBackend(CeedElemRestrictionGetNumComponents(elem_rstr, &num_comp));
1874           if (e_vec_size != num_comp * elem_size) continue;
1875         }
1876 
1877         // Basis action
1878         CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_output_fields[j], &eval_mode));
1879         switch (eval_mode) {
1880           case CEED_EVAL_NONE: {
1881             CeedScalar *e_vec_array;
1882 
1883             CeedCallBackend(CeedVectorTakeArray(q_vec, CEED_MEM_DEVICE, &e_vec_array));
1884             CeedCallBackend(CeedVectorRestoreArray(e_vec, &e_vec_array));
1885             break;
1886           }
1887           case CEED_EVAL_INTERP:
1888           case CEED_EVAL_GRAD:
1889           case CEED_EVAL_DIV:
1890           case CEED_EVAL_CURL:
1891             CeedCallBackend(CeedOperatorFieldGetBasis(op_output_fields[j], &basis));
1892             CeedCallBackend(CeedBasisApplyAtPoints(basis, num_elem, num_points, CEED_TRANSPOSE, eval_mode, impl->point_coords_elem, q_vec, e_vec));
1893             break;
1894           // LCOV_EXCL_START
1895           case CEED_EVAL_WEIGHT: {
1896             return CeedError(CeedOperatorReturnCeed(op), CEED_ERROR_BACKEND, "CEED_EVAL_WEIGHT cannot be an output evaluation mode");
1897             // LCOV_EXCL_STOP
1898           }
1899         }
1900 
1901         // Mask output e-vec
1902         CeedCallBackend(CeedVectorPointwiseMult(e_vec, active_e_vec_in, e_vec));
1903 
1904         // Restrict
1905         CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_output_fields[j], &elem_rstr));
1906         CeedCallBackend(CeedElemRestrictionApply(elem_rstr, CEED_TRANSPOSE, e_vec, assembled, request));
1907 
1908         // Reset q_vec for
1909         if (eval_mode == CEED_EVAL_NONE) {
1910           CeedScalar *e_vec_array;
1911 
1912           CeedCallBackend(CeedVectorGetArrayWrite(e_vec, CEED_MEM_DEVICE, &e_vec_array));
1913           CeedCallBackend(CeedVectorSetArray(q_vec, CEED_MEM_DEVICE, CEED_USE_POINTER, e_vec_array));
1914         }
1915       }
1916 
1917       // Reset vec
1918       if (s == e_vec_size - 1 && i != num_input_fields - 1) CeedCallBackend(CeedVectorSetValue(q_vec, 0.0));
1919     }
1920   }
1921 
1922   // Restore CEED_EVAL_NONE
1923   for (CeedInt i = 0; i < num_output_fields; i++) {
1924     CeedEvalMode eval_mode;
1925 
1926     // Get eval_mode
1927     CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_output_fields[i], &eval_mode));
1928 
1929     // Restore evec
1930     CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_output_fields[i], &eval_mode));
1931     if (eval_mode == CEED_EVAL_NONE) {
1932       CeedScalar *e_vec_array;
1933 
1934       CeedCallBackend(CeedVectorTakeArray(impl->q_vecs_in[i], CEED_MEM_DEVICE, &e_vec_array));
1935       CeedCallBackend(CeedVectorRestoreArray(impl->e_vecs_in[i], &e_vec_array));
1936     }
1937   }
1938 
1939   // Restore input arrays
1940   for (CeedInt i = 0; i < num_input_fields; i++) {
1941     CeedCallBackend(CeedOperatorInputRestore_Cuda(op_input_fields[i], qf_input_fields[i], i, NULL, NULL, true, impl));
1942   }
1943 
1944   // Restore work vector
1945   CeedCallBackend(CeedRestoreWorkVector(ceed, &active_e_vec_in));
1946   CeedCallBackend(CeedRestoreWorkVector(ceed, &active_e_vec_out));
1947   return CEED_ERROR_SUCCESS;
1948 }
1949 
1950 //------------------------------------------------------------------------------
1951 // Create operator
1952 //------------------------------------------------------------------------------
1953 int CeedOperatorCreate_Cuda(CeedOperator op) {
1954   Ceed               ceed;
1955   CeedOperator_Cuda *impl;
1956 
1957   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
1958   CeedCallBackend(CeedCalloc(1, &impl));
1959   CeedCallBackend(CeedOperatorSetData(op, impl));
1960 
1961   CeedCallBackend(CeedSetBackendFunction(ceed, "Operator", op, "LinearAssembleQFunction", CeedOperatorLinearAssembleQFunction_Cuda));
1962   CeedCallBackend(CeedSetBackendFunction(ceed, "Operator", op, "LinearAssembleQFunctionUpdate", CeedOperatorLinearAssembleQFunctionUpdate_Cuda));
1963   CeedCallBackend(CeedSetBackendFunction(ceed, "Operator", op, "LinearAssembleAddDiagonal", CeedOperatorLinearAssembleAddDiagonal_Cuda));
1964   CeedCallBackend(
1965       CeedSetBackendFunction(ceed, "Operator", op, "LinearAssembleAddPointBlockDiagonal", CeedOperatorLinearAssembleAddPointBlockDiagonal_Cuda));
1966   CeedCallBackend(CeedSetBackendFunction(ceed, "Operator", op, "LinearAssembleSingle", CeedSingleOperatorAssemble_Cuda));
1967   CeedCallBackend(CeedSetBackendFunction(ceed, "Operator", op, "ApplyAdd", CeedOperatorApplyAdd_Cuda));
1968   CeedCallBackend(CeedSetBackendFunction(ceed, "Operator", op, "Destroy", CeedOperatorDestroy_Cuda));
1969   return CEED_ERROR_SUCCESS;
1970 }
1971 
1972 //------------------------------------------------------------------------------
1973 // Create operator AtPoints
1974 //------------------------------------------------------------------------------
1975 int CeedOperatorCreateAtPoints_Cuda(CeedOperator op) {
1976   Ceed               ceed;
1977   CeedOperator_Cuda *impl;
1978 
1979   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
1980   CeedCallBackend(CeedCalloc(1, &impl));
1981   CeedCallBackend(CeedOperatorSetData(op, impl));
1982 
1983   CeedCallBackend(CeedSetBackendFunction(ceed, "Operator", op, "LinearAssembleQFunction", CeedOperatorLinearAssembleQFunctionAtPoints_Cuda));
1984   CeedCallBackend(CeedSetBackendFunction(ceed, "Operator", op, "LinearAssembleAddDiagonal", CeedOperatorLinearAssembleAddDiagonalAtPoints_Cuda));
1985   CeedCallBackend(CeedSetBackendFunction(ceed, "Operator", op, "ApplyAdd", CeedOperatorApplyAddAtPoints_Cuda));
1986   CeedCallBackend(CeedSetBackendFunction(ceed, "Operator", op, "Destroy", CeedOperatorDestroy_Cuda));
1987   return CEED_ERROR_SUCCESS;
1988 }
1989 
1990 //------------------------------------------------------------------------------
1991