xref: /libCEED/backends/cuda-ref/ceed-cuda-ref-operator.c (revision 43e13fee434cb91795700b4c22c1d8174b8fa174)
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   for (CeedInt i = 0; i < impl->num_inputs + impl->num_outputs; i++) {
35     CeedCallBackend(CeedVectorDestroy(&impl->e_vecs[i]));
36   }
37   CeedCallBackend(CeedFree(&impl->e_vecs));
38   CeedCallBackend(CeedFree(&impl->input_states));
39 
40   for (CeedInt i = 0; i < impl->num_inputs; i++) {
41     CeedCallBackend(CeedVectorDestroy(&impl->q_vecs_in[i]));
42   }
43   CeedCallBackend(CeedFree(&impl->q_vecs_in));
44 
45   for (CeedInt i = 0; i < impl->num_outputs; i++) {
46     CeedCallBackend(CeedVectorDestroy(&impl->q_vecs_out[i]));
47   }
48   CeedCallBackend(CeedFree(&impl->q_vecs_out));
49   CeedCallBackend(CeedVectorDestroy(&impl->point_coords_elem));
50 
51   // QFunction assembly data
52   for (CeedInt i = 0; i < impl->num_active_in; i++) {
53     CeedCallBackend(CeedVectorDestroy(&impl->qf_active_in[i]));
54   }
55   CeedCallBackend(CeedFree(&impl->qf_active_in));
56 
57   // Diag data
58   if (impl->diag) {
59     Ceed ceed;
60 
61     CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
62     if (impl->diag->module) {
63       CeedCallCuda(ceed, cuModuleUnload(impl->diag->module));
64     }
65     if (impl->diag->module_point_block) {
66       CeedCallCuda(ceed, cuModuleUnload(impl->diag->module_point_block));
67     }
68     CeedCallCuda(ceed, cudaFree(impl->diag->d_eval_modes_in));
69     CeedCallCuda(ceed, cudaFree(impl->diag->d_eval_modes_out));
70     CeedCallCuda(ceed, cudaFree(impl->diag->d_identity));
71     CeedCallCuda(ceed, cudaFree(impl->diag->d_interp_in));
72     CeedCallCuda(ceed, cudaFree(impl->diag->d_interp_out));
73     CeedCallCuda(ceed, cudaFree(impl->diag->d_grad_in));
74     CeedCallCuda(ceed, cudaFree(impl->diag->d_grad_out));
75     CeedCallCuda(ceed, cudaFree(impl->diag->d_div_in));
76     CeedCallCuda(ceed, cudaFree(impl->diag->d_div_out));
77     CeedCallCuda(ceed, cudaFree(impl->diag->d_curl_in));
78     CeedCallCuda(ceed, cudaFree(impl->diag->d_curl_out));
79     CeedCallBackend(CeedElemRestrictionDestroy(&impl->diag->diag_rstr));
80     CeedCallBackend(CeedElemRestrictionDestroy(&impl->diag->point_block_diag_rstr));
81     CeedCallBackend(CeedVectorDestroy(&impl->diag->elem_diag));
82     CeedCallBackend(CeedVectorDestroy(&impl->diag->point_block_elem_diag));
83   }
84   CeedCallBackend(CeedFree(&impl->diag));
85 
86   if (impl->asmb) {
87     Ceed ceed;
88 
89     CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
90     CeedCallCuda(ceed, cuModuleUnload(impl->asmb->module));
91     CeedCallCuda(ceed, cudaFree(impl->asmb->d_B_in));
92     CeedCallCuda(ceed, cudaFree(impl->asmb->d_B_out));
93   }
94   CeedCallBackend(CeedFree(&impl->asmb));
95 
96   CeedCallBackend(CeedFree(&impl));
97   return CEED_ERROR_SUCCESS;
98 }
99 
100 //------------------------------------------------------------------------------
101 // Setup infields or outfields
102 //------------------------------------------------------------------------------
103 static int CeedOperatorSetupFields_Cuda(CeedQFunction qf, CeedOperator op, bool is_input, bool is_at_points, bool *skip_rstr, bool *apply_add_basis,
104                                         CeedVector *e_vecs, CeedVector *q_vecs, CeedInt start_e, CeedInt num_fields, CeedInt Q, CeedInt num_elem) {
105   Ceed                ceed;
106   CeedQFunctionField *qf_fields;
107   CeedOperatorField  *op_fields;
108 
109   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
110   if (is_input) {
111     CeedCallBackend(CeedOperatorGetFields(op, NULL, &op_fields, NULL, NULL));
112     CeedCallBackend(CeedQFunctionGetFields(qf, NULL, &qf_fields, NULL, NULL));
113   } else {
114     CeedCallBackend(CeedOperatorGetFields(op, NULL, NULL, NULL, &op_fields));
115     CeedCallBackend(CeedQFunctionGetFields(qf, NULL, NULL, NULL, &qf_fields));
116   }
117 
118   // Loop over fields
119   for (CeedInt i = 0; i < num_fields; i++) {
120     bool         is_strided = false, skip_restriction = false;
121     CeedSize     q_size;
122     CeedInt      size;
123     CeedEvalMode eval_mode;
124     CeedBasis    basis;
125 
126     CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_fields[i], &eval_mode));
127     if (eval_mode != CEED_EVAL_WEIGHT) {
128       CeedElemRestriction elem_rstr;
129 
130       // Check whether this field can skip the element restriction:
131       // Must be passive input, with eval_mode NONE, and have a strided restriction with CEED_STRIDES_BACKEND.
132       CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_fields[i], &elem_rstr));
133 
134       // First, check whether the field is input or output:
135       if (is_input) {
136         CeedVector vec;
137 
138         // Check for passive input
139         CeedCallBackend(CeedOperatorFieldGetVector(op_fields[i], &vec));
140         if (vec != CEED_VECTOR_ACTIVE) {
141           // Check eval_mode
142           if (eval_mode == CEED_EVAL_NONE) {
143             // Check for strided restriction
144             CeedCallBackend(CeedElemRestrictionIsStrided(elem_rstr, &is_strided));
145             if (is_strided) {
146               // Check if vector is already in preferred backend ordering
147               CeedCallBackend(CeedElemRestrictionHasBackendStrides(elem_rstr, &skip_restriction));
148             }
149           }
150         }
151       }
152       if (skip_restriction) {
153         // We do not need an E-Vector, but will use the input field vector's data directly in the operator application.
154         e_vecs[i + start_e] = NULL;
155       } else {
156         CeedCallBackend(CeedElemRestrictionCreateVector(elem_rstr, NULL, &e_vecs[i + start_e]));
157       }
158     }
159 
160     switch (eval_mode) {
161       case CEED_EVAL_NONE:
162         CeedCallBackend(CeedQFunctionFieldGetSize(qf_fields[i], &size));
163         q_size = (CeedSize)num_elem * Q * size;
164         CeedCallBackend(CeedVectorCreate(ceed, q_size, &q_vecs[i]));
165         break;
166       case CEED_EVAL_INTERP:
167       case CEED_EVAL_GRAD:
168       case CEED_EVAL_DIV:
169       case CEED_EVAL_CURL:
170         CeedCallBackend(CeedQFunctionFieldGetSize(qf_fields[i], &size));
171         q_size = (CeedSize)num_elem * Q * size;
172         CeedCallBackend(CeedVectorCreate(ceed, q_size, &q_vecs[i]));
173         break;
174       case CEED_EVAL_WEIGHT:  // Only on input fields
175         CeedCallBackend(CeedOperatorFieldGetBasis(op_fields[i], &basis));
176         q_size = (CeedSize)num_elem * Q;
177         CeedCallBackend(CeedVectorCreate(ceed, q_size, &q_vecs[i]));
178         if (is_at_points) {
179           CeedInt num_points[num_elem];
180 
181           for (CeedInt i = 0; i < num_elem; i++) num_points[i] = Q;
182           CeedCallBackend(
183               CeedBasisApplyAtPoints(basis, num_elem, num_points, CEED_NOTRANSPOSE, CEED_EVAL_WEIGHT, CEED_VECTOR_NONE, CEED_VECTOR_NONE, q_vecs[i]));
184         } else {
185           CeedCallBackend(CeedBasisApply(basis, num_elem, CEED_NOTRANSPOSE, CEED_EVAL_WEIGHT, CEED_VECTOR_NONE, q_vecs[i]));
186         }
187         break;
188     }
189   }
190   // Drop duplicate restrictions
191   if (is_input) {
192     for (CeedInt i = 0; i < num_fields; i++) {
193       CeedVector          vec_i;
194       CeedElemRestriction rstr_i;
195 
196       CeedCallBackend(CeedOperatorFieldGetVector(op_fields[i], &vec_i));
197       CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_fields[i], &rstr_i));
198       for (CeedInt j = i + 1; j < num_fields; j++) {
199         CeedVector          vec_j;
200         CeedElemRestriction rstr_j;
201 
202         CeedCallBackend(CeedOperatorFieldGetVector(op_fields[j], &vec_j));
203         CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_fields[j], &rstr_j));
204         if (vec_i == vec_j && rstr_i == rstr_j) {
205           CeedCallBackend(CeedVectorReferenceCopy(e_vecs[i + start_e], &e_vecs[j + start_e]));
206           skip_rstr[j] = true;
207         }
208       }
209     }
210   } else {
211     for (CeedInt i = num_fields - 1; i >= 0; i--) {
212       CeedVector          vec_i;
213       CeedElemRestriction rstr_i;
214 
215       CeedCallBackend(CeedOperatorFieldGetVector(op_fields[i], &vec_i));
216       CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_fields[i], &rstr_i));
217       for (CeedInt j = i - 1; j >= 0; j--) {
218         CeedVector          vec_j;
219         CeedElemRestriction rstr_j;
220 
221         CeedCallBackend(CeedOperatorFieldGetVector(op_fields[j], &vec_j));
222         CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_fields[j], &rstr_j));
223         if (vec_i == vec_j && rstr_i == rstr_j) {
224           CeedCallBackend(CeedVectorReferenceCopy(e_vecs[i + start_e], &e_vecs[j + start_e]));
225           skip_rstr[j]       = true;
226           apply_add_basis[i] = true;
227         }
228       }
229     }
230   }
231   return CEED_ERROR_SUCCESS;
232 }
233 
234 //------------------------------------------------------------------------------
235 // CeedOperator needs to connect all the named fields (be they active or passive) to the named inputs and outputs of its CeedQFunction.
236 //------------------------------------------------------------------------------
237 static int CeedOperatorSetup_Cuda(CeedOperator op) {
238   Ceed                ceed;
239   bool                is_setup_done;
240   CeedInt             Q, num_elem, num_input_fields, num_output_fields;
241   CeedQFunctionField *qf_input_fields, *qf_output_fields;
242   CeedQFunction       qf;
243   CeedOperatorField  *op_input_fields, *op_output_fields;
244   CeedOperator_Cuda  *impl;
245 
246   CeedCallBackend(CeedOperatorIsSetupDone(op, &is_setup_done));
247   if (is_setup_done) return CEED_ERROR_SUCCESS;
248 
249   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
250   CeedCallBackend(CeedOperatorGetData(op, &impl));
251   CeedCallBackend(CeedOperatorGetQFunction(op, &qf));
252   CeedCallBackend(CeedOperatorGetNumQuadraturePoints(op, &Q));
253   CeedCallBackend(CeedOperatorGetNumElements(op, &num_elem));
254   CeedCallBackend(CeedOperatorGetFields(op, &num_input_fields, &op_input_fields, &num_output_fields, &op_output_fields));
255   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, &qf_input_fields, NULL, &qf_output_fields));
256 
257   // Allocate
258   CeedCallBackend(CeedCalloc(num_input_fields + num_output_fields, &impl->e_vecs));
259   CeedCallBackend(CeedCalloc(CEED_FIELD_MAX, &impl->skip_rstr_in));
260   CeedCallBackend(CeedCalloc(CEED_FIELD_MAX, &impl->skip_rstr_out));
261   CeedCallBackend(CeedCalloc(CEED_FIELD_MAX, &impl->apply_add_basis_out));
262   CeedCallBackend(CeedCalloc(CEED_FIELD_MAX, &impl->input_states));
263   CeedCallBackend(CeedCalloc(CEED_FIELD_MAX, &impl->q_vecs_in));
264   CeedCallBackend(CeedCalloc(CEED_FIELD_MAX, &impl->q_vecs_out));
265   impl->num_inputs  = num_input_fields;
266   impl->num_outputs = num_output_fields;
267 
268   // Set up infield and outfield e-vecs and q-vecs
269   // Infields
270   CeedCallBackend(
271       CeedOperatorSetupFields_Cuda(qf, op, true, false, impl->skip_rstr_in, NULL, impl->e_vecs, impl->q_vecs_in, 0, num_input_fields, Q, num_elem));
272   // Outfields
273   CeedCallBackend(CeedOperatorSetupFields_Cuda(qf, op, false, false, impl->skip_rstr_out, impl->apply_add_basis_out, impl->e_vecs, impl->q_vecs_out,
274                                                num_input_fields, num_output_fields, Q, num_elem));
275 
276   // Reuse active e-vecs where able
277   {
278     CeedInt              num_used  = 0;
279     CeedElemRestriction *rstr_used = NULL;
280 
281     for (CeedInt i = 0; i < num_input_fields; i++) {
282       bool                is_used = false;
283       CeedVector          vec_i;
284       CeedElemRestriction rstr_i;
285 
286       CeedCallBackend(CeedOperatorFieldGetVector(op_input_fields[i], &vec_i));
287       if (vec_i != CEED_VECTOR_ACTIVE) continue;
288       CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_input_fields[i], &rstr_i));
289       for (CeedInt j = 0; j < num_used; j++) {
290         if (rstr_i == rstr_used[i]) is_used = true;
291       }
292       if (is_used) continue;
293       num_used++;
294       if (num_used == 1) CeedCallBackend(CeedCalloc(num_used, &rstr_used));
295       else CeedCallBackend(CeedRealloc(num_used, &rstr_used));
296       rstr_used[num_used - 1] = rstr_i;
297       for (CeedInt j = num_output_fields - 1; j >= 0; j--) {
298         CeedEvalMode        eval_mode;
299         CeedVector          vec_j;
300         CeedElemRestriction rstr_j;
301 
302         CeedCallBackend(CeedOperatorFieldGetVector(op_output_fields[j], &vec_j));
303         if (vec_j != CEED_VECTOR_ACTIVE) continue;
304         CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_output_fields[j], &eval_mode));
305         if (eval_mode == CEED_EVAL_NONE) continue;
306         CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_output_fields[j], &rstr_j));
307         if (rstr_i == rstr_j) {
308           CeedCallBackend(CeedVectorReferenceCopy(impl->e_vecs[i], &impl->e_vecs[j + impl->num_inputs]));
309         }
310       }
311     }
312     CeedCallBackend(CeedFree(&rstr_used));
313   }
314   impl->has_shared_e_vecs = true;
315   CeedCallBackend(CeedOperatorSetSetupDone(op));
316   return CEED_ERROR_SUCCESS;
317 }
318 
319 //------------------------------------------------------------------------------
320 // Restrict Operator Inputs
321 //------------------------------------------------------------------------------
322 static inline int CeedOperatorInputRestrict_Cuda(CeedOperatorField op_input_field, CeedQFunctionField qf_input_field, CeedInt input_field,
323                                                  CeedVector in_vec, const bool skip_active, CeedScalar **e_data, CeedOperator_Cuda *impl,
324                                                  CeedRequest *request) {
325   CeedEvalMode        eval_mode;
326   CeedVector          vec;
327   CeedElemRestriction elem_rstr;
328 
329   // Get input vector
330   CeedCallBackend(CeedOperatorFieldGetVector(op_input_field, &vec));
331   if (vec == CEED_VECTOR_ACTIVE) {
332     if (skip_active) return CEED_ERROR_SUCCESS;
333     else vec = in_vec;
334   }
335 
336   // Restriction action
337   CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_input_field, &eval_mode));
338   if (eval_mode == CEED_EVAL_WEIGHT) {  // Skip
339   } else {
340     // Get input vector
341     CeedCallBackend(CeedOperatorFieldGetVector(op_input_field, &vec));
342     // Get input element restriction
343     CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_input_field, &elem_rstr));
344     if (vec == CEED_VECTOR_ACTIVE) vec = in_vec;
345     // Restrict, if necessary
346     if (!impl->e_vecs[input_field]) {
347       // No restriction for this field; read data directly from vec.
348       CeedCallBackend(CeedVectorGetArrayRead(vec, CEED_MEM_DEVICE, (const CeedScalar **)e_data));
349     } else {
350       uint64_t state;
351 
352       CeedCallBackend(CeedVectorGetState(vec, &state));
353       if ((state != impl->input_states[input_field] || vec == in_vec) && !impl->skip_rstr_in[input_field]) {
354         CeedCallBackend(CeedElemRestrictionApply(elem_rstr, CEED_NOTRANSPOSE, vec, impl->e_vecs[input_field], request));
355       }
356       impl->input_states[input_field] = state;
357       // Get evec
358       CeedCallBackend(CeedVectorGetArrayRead(impl->e_vecs[input_field], CEED_MEM_DEVICE, (const CeedScalar **)e_data));
359     }
360   }
361   return CEED_ERROR_SUCCESS;
362 }
363 
364 //------------------------------------------------------------------------------
365 // Input Basis Action
366 //------------------------------------------------------------------------------
367 static inline int CeedOperatorInputBasis_Cuda(CeedOperatorField op_input_field, CeedQFunctionField qf_input_field, CeedInt input_field,
368                                               CeedInt num_elem, const bool skip_active, CeedScalar *e_data, CeedOperator_Cuda *impl) {
369   CeedEvalMode eval_mode;
370 
371   // Skip active input
372   if (skip_active) {
373     CeedVector vec;
374 
375     CeedCallBackend(CeedOperatorFieldGetVector(op_input_field, &vec));
376     if (vec == CEED_VECTOR_ACTIVE) return CEED_ERROR_SUCCESS;
377   }
378 
379   // Basis action
380   CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_input_field, &eval_mode));
381   switch (eval_mode) {
382     case CEED_EVAL_NONE:
383       CeedCallBackend(CeedVectorSetArray(impl->q_vecs_in[input_field], CEED_MEM_DEVICE, CEED_USE_POINTER, e_data));
384       break;
385     case CEED_EVAL_INTERP:
386     case CEED_EVAL_GRAD:
387     case CEED_EVAL_DIV:
388     case CEED_EVAL_CURL: {
389       CeedBasis basis;
390 
391       CeedCallBackend(CeedOperatorFieldGetBasis(op_input_field, &basis));
392       CeedCallBackend(CeedBasisApply(basis, num_elem, CEED_NOTRANSPOSE, eval_mode, impl->e_vecs[input_field], impl->q_vecs_in[input_field]));
393       break;
394     }
395     case CEED_EVAL_WEIGHT:
396       break;  // No action
397   }
398   return CEED_ERROR_SUCCESS;
399 }
400 
401 //------------------------------------------------------------------------------
402 // Restore Input Vectors
403 //------------------------------------------------------------------------------
404 static inline int CeedOperatorInputRestore_Cuda(CeedOperatorField op_input_field, CeedQFunctionField qf_input_field, CeedInt input_field,
405                                                 const bool skip_active, CeedScalar **e_data, CeedOperator_Cuda *impl) {
406   CeedEvalMode eval_mode;
407   CeedVector   vec;
408 
409   // Skip active input
410   if (skip_active) {
411     CeedCallBackend(CeedOperatorFieldGetVector(op_input_field, &vec));
412     if (vec == CEED_VECTOR_ACTIVE) return CEED_ERROR_SUCCESS;
413   }
414 
415   // Restore e-vec
416   CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_input_field, &eval_mode));
417   if (eval_mode == CEED_EVAL_WEIGHT) {  // Skip
418   } else {
419     if (!impl->e_vecs[input_field]) {  // This was a skip_restriction case
420       CeedCallBackend(CeedOperatorFieldGetVector(op_input_field, &vec));
421       CeedCallBackend(CeedVectorRestoreArrayRead(vec, (const CeedScalar **)e_data));
422     } else {
423       CeedCallBackend(CeedVectorRestoreArrayRead(impl->e_vecs[input_field], (const CeedScalar **)e_data));
424     }
425   }
426   return CEED_ERROR_SUCCESS;
427 }
428 
429 //------------------------------------------------------------------------------
430 // Apply and add to output
431 //------------------------------------------------------------------------------
432 static int CeedOperatorApplyAdd_Cuda(CeedOperator op, CeedVector in_vec, CeedVector out_vec, CeedRequest *request) {
433   CeedInt             Q, num_elem, elem_size, num_input_fields, num_output_fields, size;
434   CeedScalar         *e_data[2 * CEED_FIELD_MAX] = {NULL};
435   CeedQFunctionField *qf_input_fields, *qf_output_fields;
436   CeedQFunction       qf;
437   CeedOperatorField  *op_input_fields, *op_output_fields;
438   CeedOperator_Cuda  *impl;
439 
440   CeedCallBackend(CeedOperatorGetData(op, &impl));
441   CeedCallBackend(CeedOperatorGetQFunction(op, &qf));
442   CeedCallBackend(CeedOperatorGetNumQuadraturePoints(op, &Q));
443   CeedCallBackend(CeedOperatorGetNumElements(op, &num_elem));
444   CeedCallBackend(CeedOperatorGetFields(op, &num_input_fields, &op_input_fields, &num_output_fields, &op_output_fields));
445   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, &qf_input_fields, NULL, &qf_output_fields));
446 
447   // Setup
448   CeedCallBackend(CeedOperatorSetup_Cuda(op));
449 
450   // Process inputs
451   for (CeedInt i = 0; i < num_input_fields; i++) {
452     CeedCallBackend(CeedOperatorInputRestrict_Cuda(op_input_fields[i], qf_input_fields[i], i, in_vec, false, &e_data[i], impl, request));
453     CeedCallBackend(CeedOperatorInputBasis_Cuda(op_input_fields[i], qf_input_fields[i], i, num_elem, false, e_data[i], impl));
454   }
455 
456   // Output pointers, as necessary
457   for (CeedInt i = 0; i < num_output_fields; i++) {
458     CeedEvalMode eval_mode;
459 
460     CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_output_fields[i], &eval_mode));
461     if (eval_mode == CEED_EVAL_NONE) {
462       // Set the output Q-Vector to use the E-Vector data directly.
463       CeedCallBackend(CeedVectorGetArrayWrite(impl->e_vecs[i + impl->num_inputs], CEED_MEM_DEVICE, &e_data[i + num_input_fields]));
464       CeedCallBackend(CeedVectorSetArray(impl->q_vecs_out[i], CEED_MEM_DEVICE, CEED_USE_POINTER, e_data[i + num_input_fields]));
465     }
466   }
467 
468   // Q function
469   CeedCallBackend(CeedQFunctionApply(qf, num_elem * Q, impl->q_vecs_in, impl->q_vecs_out));
470 
471   // Restore input arrays
472   for (CeedInt i = 0; i < num_input_fields; i++) {
473     CeedCallBackend(CeedOperatorInputRestore_Cuda(op_input_fields[i], qf_input_fields[i], i, false, &e_data[i], impl));
474   }
475 
476   // Output basis apply if needed
477   for (CeedInt i = 0; i < num_output_fields; i++) {
478     CeedEvalMode        eval_mode;
479     CeedElemRestriction elem_rstr;
480     CeedBasis           basis;
481 
482     // Get elem_size, eval_mode, size
483     CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_output_fields[i], &elem_rstr));
484     CeedCallBackend(CeedElemRestrictionGetElementSize(elem_rstr, &elem_size));
485     CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_output_fields[i], &eval_mode));
486     CeedCallBackend(CeedQFunctionFieldGetSize(qf_output_fields[i], &size));
487     // Basis action
488     switch (eval_mode) {
489       case CEED_EVAL_NONE:
490         break;  // No action
491       case CEED_EVAL_INTERP:
492       case CEED_EVAL_GRAD:
493       case CEED_EVAL_DIV:
494       case CEED_EVAL_CURL:
495         CeedCallBackend(CeedOperatorFieldGetBasis(op_output_fields[i], &basis));
496         if (impl->apply_add_basis_out[i]) {
497           CeedCallBackend(CeedBasisApplyAdd(basis, num_elem, CEED_TRANSPOSE, eval_mode, impl->q_vecs_out[i], impl->e_vecs[i + impl->num_inputs]));
498         } else {
499           CeedCallBackend(CeedBasisApply(basis, num_elem, CEED_TRANSPOSE, eval_mode, impl->q_vecs_out[i], impl->e_vecs[i + impl->num_inputs]));
500         }
501         break;
502       // LCOV_EXCL_START
503       case CEED_EVAL_WEIGHT: {
504         return CeedError(CeedOperatorReturnCeed(op), CEED_ERROR_BACKEND, "CEED_EVAL_WEIGHT cannot be an output evaluation mode");
505         // LCOV_EXCL_STOP
506       }
507     }
508   }
509 
510   // Output restriction
511   for (CeedInt i = 0; i < num_output_fields; i++) {
512     CeedEvalMode        eval_mode;
513     CeedVector          vec;
514     CeedElemRestriction elem_rstr;
515 
516     // Restore evec
517     CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_output_fields[i], &eval_mode));
518     if (eval_mode == CEED_EVAL_NONE) {
519       CeedCallBackend(CeedVectorRestoreArray(impl->e_vecs[i + impl->num_inputs], &e_data[i + num_input_fields]));
520     }
521     if (impl->skip_rstr_out[i]) continue;
522     // Get output vector
523     CeedCallBackend(CeedOperatorFieldGetVector(op_output_fields[i], &vec));
524     // Restrict
525     CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_output_fields[i], &elem_rstr));
526     // Active
527     if (vec == CEED_VECTOR_ACTIVE) vec = out_vec;
528 
529     CeedCallBackend(CeedElemRestrictionApply(elem_rstr, CEED_TRANSPOSE, impl->e_vecs[i + impl->num_inputs], vec, request));
530   }
531   return CEED_ERROR_SUCCESS;
532 }
533 
534 //------------------------------------------------------------------------------
535 // CeedOperator needs to connect all the named fields (be they active or passive) to the named inputs and outputs of its CeedQFunction.
536 //------------------------------------------------------------------------------
537 static int CeedOperatorSetupAtPoints_Cuda(CeedOperator op) {
538   Ceed                ceed;
539   bool                is_setup_done;
540   CeedInt             max_num_points = -1, num_elem, num_input_fields, num_output_fields;
541   CeedQFunctionField *qf_input_fields, *qf_output_fields;
542   CeedQFunction       qf;
543   CeedOperatorField  *op_input_fields, *op_output_fields;
544   CeedOperator_Cuda  *impl;
545 
546   CeedCallBackend(CeedOperatorIsSetupDone(op, &is_setup_done));
547   if (is_setup_done) return CEED_ERROR_SUCCESS;
548 
549   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
550   CeedCallBackend(CeedOperatorGetData(op, &impl));
551   CeedCallBackend(CeedOperatorGetQFunction(op, &qf));
552   CeedCallBackend(CeedOperatorGetNumElements(op, &num_elem));
553   CeedCallBackend(CeedOperatorGetFields(op, &num_input_fields, &op_input_fields, &num_output_fields, &op_output_fields));
554   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, &qf_input_fields, NULL, &qf_output_fields));
555   {
556     CeedElemRestriction rstr_points = NULL;
557 
558     CeedCallBackend(CeedOperatorAtPointsGetPoints(op, &rstr_points, NULL));
559     CeedCallBackend(CeedElemRestrictionGetMaxPointsInElement(rstr_points, &max_num_points));
560     CeedCallBackend(CeedCalloc(num_elem, &impl->num_points));
561     for (CeedInt e = 0; e < num_elem; e++) {
562       CeedInt num_points_elem;
563 
564       CeedCallBackend(CeedElemRestrictionGetNumPointsInElement(rstr_points, e, &num_points_elem));
565       impl->num_points[e] = num_points_elem;
566     }
567   }
568   impl->max_num_points = max_num_points;
569 
570   // Allocate
571   CeedCallBackend(CeedCalloc(num_input_fields + num_output_fields, &impl->e_vecs));
572   CeedCallBackend(CeedCalloc(CEED_FIELD_MAX, &impl->skip_rstr_in));
573   CeedCallBackend(CeedCalloc(CEED_FIELD_MAX, &impl->skip_rstr_out));
574   CeedCallBackend(CeedCalloc(CEED_FIELD_MAX, &impl->apply_add_basis_out));
575   CeedCallBackend(CeedCalloc(CEED_FIELD_MAX, &impl->input_states));
576   CeedCallBackend(CeedCalloc(CEED_FIELD_MAX, &impl->q_vecs_in));
577   CeedCallBackend(CeedCalloc(CEED_FIELD_MAX, &impl->q_vecs_out));
578   impl->num_inputs  = num_input_fields;
579   impl->num_outputs = num_output_fields;
580 
581   // Set up infield and outfield e-vecs and q-vecs
582   // Infields
583   CeedCallBackend(CeedOperatorSetupFields_Cuda(qf, op, true, true, impl->skip_rstr_in, NULL, impl->e_vecs, impl->q_vecs_in, 0, num_input_fields,
584                                                max_num_points, num_elem));
585   // Outfields
586   CeedCallBackend(CeedOperatorSetupFields_Cuda(qf, op, false, true, impl->skip_rstr_out, impl->apply_add_basis_out, impl->e_vecs, impl->q_vecs_out,
587                                                num_input_fields, num_output_fields, max_num_points, num_elem));
588 
589   // Reuse active e-vecs where able
590   {
591     CeedInt              num_used  = 0;
592     CeedElemRestriction *rstr_used = NULL;
593 
594     for (CeedInt i = 0; i < num_input_fields; i++) {
595       bool                is_used = false;
596       CeedVector          vec_i;
597       CeedElemRestriction rstr_i;
598 
599       CeedCallBackend(CeedOperatorFieldGetVector(op_input_fields[i], &vec_i));
600       if (vec_i != CEED_VECTOR_ACTIVE) continue;
601       CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_input_fields[i], &rstr_i));
602       for (CeedInt j = 0; j < num_used; j++) {
603         if (rstr_i == rstr_used[i]) is_used = true;
604       }
605       if (is_used) continue;
606       num_used++;
607       if (num_used == 1) CeedCallBackend(CeedCalloc(num_used, &rstr_used));
608       else CeedCallBackend(CeedRealloc(num_used, &rstr_used));
609       rstr_used[num_used - 1] = rstr_i;
610       for (CeedInt j = num_output_fields - 1; j >= 0; j--) {
611         CeedEvalMode        eval_mode;
612         CeedVector          vec_j;
613         CeedElemRestriction rstr_j;
614 
615         CeedCallBackend(CeedOperatorFieldGetVector(op_output_fields[j], &vec_j));
616         if (vec_j != CEED_VECTOR_ACTIVE) continue;
617         CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_output_fields[j], &eval_mode));
618         if (eval_mode == CEED_EVAL_NONE) continue;
619         CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_output_fields[j], &rstr_j));
620         if (rstr_i == rstr_j) {
621           CeedCallBackend(CeedVectorReferenceCopy(impl->e_vecs[i], &impl->e_vecs[j + impl->num_inputs]));
622         }
623       }
624     }
625     CeedCallBackend(CeedFree(&rstr_used));
626   }
627   impl->has_shared_e_vecs = true;
628   CeedCallBackend(CeedOperatorSetSetupDone(op));
629   return CEED_ERROR_SUCCESS;
630 }
631 
632 //------------------------------------------------------------------------------
633 // Input Basis Action AtPoints
634 //------------------------------------------------------------------------------
635 static inline int CeedOperatorInputBasisAtPoints_Cuda(CeedOperatorField op_input_field, CeedQFunctionField qf_input_field, CeedInt input_field,
636                                                       CeedInt num_elem, const CeedInt *num_points, const bool skip_active, CeedScalar *e_data,
637                                                       CeedOperator_Cuda *impl) {
638   CeedEvalMode eval_mode;
639 
640   // Skip active input
641   if (skip_active) {
642     CeedVector vec;
643 
644     CeedCallBackend(CeedOperatorFieldGetVector(op_input_field, &vec));
645     if (vec == CEED_VECTOR_ACTIVE) return CEED_ERROR_SUCCESS;
646   }
647 
648   // Basis action
649   CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_input_field, &eval_mode));
650   switch (eval_mode) {
651     case CEED_EVAL_NONE:
652       CeedCallBackend(CeedVectorSetArray(impl->q_vecs_in[input_field], CEED_MEM_DEVICE, CEED_USE_POINTER, e_data));
653       break;
654     case CEED_EVAL_INTERP:
655     case CEED_EVAL_GRAD:
656     case CEED_EVAL_DIV:
657     case CEED_EVAL_CURL: {
658       CeedBasis basis;
659 
660       CeedCallBackend(CeedOperatorFieldGetBasis(op_input_field, &basis));
661       CeedCallBackend(CeedBasisApplyAtPoints(basis, num_elem, num_points, CEED_NOTRANSPOSE, eval_mode, impl->point_coords_elem,
662                                              impl->e_vecs[input_field], impl->q_vecs_in[input_field]));
663       break;
664     }
665     case CEED_EVAL_WEIGHT:
666       break;  // No action
667   }
668   return CEED_ERROR_SUCCESS;
669 }
670 
671 //------------------------------------------------------------------------------
672 // Apply and add to output AtPoints
673 //------------------------------------------------------------------------------
674 static int CeedOperatorApplyAddAtPoints_Cuda(CeedOperator op, CeedVector in_vec, CeedVector out_vec, CeedRequest *request) {
675   CeedInt             max_num_points, *num_points, num_elem, elem_size, num_input_fields, num_output_fields, size;
676   CeedScalar         *e_data[2 * CEED_FIELD_MAX] = {NULL};
677   CeedQFunctionField *qf_input_fields, *qf_output_fields;
678   CeedQFunction       qf;
679   CeedOperatorField  *op_input_fields, *op_output_fields;
680   CeedOperator_Cuda  *impl;
681 
682   CeedCallBackend(CeedOperatorGetData(op, &impl));
683   CeedCallBackend(CeedOperatorGetQFunction(op, &qf));
684   CeedCallBackend(CeedOperatorGetNumElements(op, &num_elem));
685   CeedCallBackend(CeedOperatorGetFields(op, &num_input_fields, &op_input_fields, &num_output_fields, &op_output_fields));
686   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, &qf_input_fields, NULL, &qf_output_fields));
687 
688   // Setup
689   CeedCallBackend(CeedOperatorSetupAtPoints_Cuda(op));
690   num_points     = impl->num_points;
691   max_num_points = impl->max_num_points;
692 
693   // Get point coordinates
694   if (!impl->point_coords_elem) {
695     CeedVector          point_coords = NULL;
696     CeedElemRestriction rstr_points  = NULL;
697 
698     CeedCallBackend(CeedOperatorAtPointsGetPoints(op, &rstr_points, &point_coords));
699     CeedCallBackend(CeedElemRestrictionCreateVector(rstr_points, NULL, &impl->point_coords_elem));
700     CeedCallBackend(CeedElemRestrictionApply(rstr_points, CEED_NOTRANSPOSE, point_coords, impl->point_coords_elem, request));
701   }
702 
703   // Process inputs
704   for (CeedInt i = 0; i < num_input_fields; i++) {
705     CeedCallBackend(CeedOperatorInputRestrict_Cuda(op_input_fields[i], qf_input_fields[i], i, in_vec, false, &e_data[i], impl, request));
706     CeedCallBackend(CeedOperatorInputBasisAtPoints_Cuda(op_input_fields[i], qf_input_fields[i], i, num_elem, num_points, false, e_data[i], impl));
707   }
708 
709   // Output pointers, as necessary
710   for (CeedInt i = 0; i < num_output_fields; i++) {
711     CeedEvalMode eval_mode;
712 
713     CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_output_fields[i], &eval_mode));
714     if (eval_mode == CEED_EVAL_NONE) {
715       // Set the output Q-Vector to use the E-Vector data directly.
716       CeedCallBackend(CeedVectorGetArrayWrite(impl->e_vecs[i + impl->num_inputs], CEED_MEM_DEVICE, &e_data[i + num_input_fields]));
717       CeedCallBackend(CeedVectorSetArray(impl->q_vecs_out[i], CEED_MEM_DEVICE, CEED_USE_POINTER, e_data[i + num_input_fields]));
718     }
719   }
720 
721   // Q function
722   CeedCallBackend(CeedQFunctionApply(qf, num_elem * max_num_points, impl->q_vecs_in, impl->q_vecs_out));
723 
724   // Restore input arrays
725   for (CeedInt i = 0; i < num_input_fields; i++) {
726     CeedCallBackend(CeedOperatorInputRestore_Cuda(op_input_fields[i], qf_input_fields[i], i, false, &e_data[i], impl));
727   }
728 
729   // Output basis apply if needed
730   for (CeedInt i = 0; i < num_output_fields; i++) {
731     CeedEvalMode        eval_mode;
732     CeedElemRestriction elem_rstr;
733     CeedBasis           basis;
734 
735     // Get elem_size, eval_mode, size
736     CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_output_fields[i], &elem_rstr));
737     CeedCallBackend(CeedElemRestrictionGetElementSize(elem_rstr, &elem_size));
738     CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_output_fields[i], &eval_mode));
739     CeedCallBackend(CeedQFunctionFieldGetSize(qf_output_fields[i], &size));
740     // Basis action
741     switch (eval_mode) {
742       case CEED_EVAL_NONE:
743         break;  // No action
744       case CEED_EVAL_INTERP:
745       case CEED_EVAL_GRAD:
746       case CEED_EVAL_DIV:
747       case CEED_EVAL_CURL:
748         CeedCallBackend(CeedOperatorFieldGetBasis(op_output_fields[i], &basis));
749         if (impl->apply_add_basis_out[i]) {
750           CeedCallBackend(CeedBasisApplyAddAtPoints(basis, num_elem, num_points, CEED_TRANSPOSE, eval_mode, impl->point_coords_elem,
751                                                     impl->q_vecs_out[i], impl->e_vecs[i + impl->num_inputs]));
752         } else {
753           CeedCallBackend(CeedBasisApplyAtPoints(basis, num_elem, num_points, CEED_TRANSPOSE, eval_mode, impl->point_coords_elem, impl->q_vecs_out[i],
754                                                  impl->e_vecs[i + impl->num_inputs]));
755         }
756         break;
757       // LCOV_EXCL_START
758       case CEED_EVAL_WEIGHT: {
759         return CeedError(CeedOperatorReturnCeed(op), CEED_ERROR_BACKEND, "CEED_EVAL_WEIGHT cannot be an output evaluation mode");
760         // LCOV_EXCL_STOP
761       }
762     }
763   }
764 
765   // Output restriction
766   for (CeedInt i = 0; i < num_output_fields; i++) {
767     CeedEvalMode        eval_mode;
768     CeedVector          vec;
769     CeedElemRestriction elem_rstr;
770 
771     // Restore evec
772     CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_output_fields[i], &eval_mode));
773     if (eval_mode == CEED_EVAL_NONE) {
774       CeedCallBackend(CeedVectorRestoreArray(impl->e_vecs[i + impl->num_inputs], &e_data[i + num_input_fields]));
775     }
776     if (impl->skip_rstr_out[i]) continue;
777     // Get output vector
778     CeedCallBackend(CeedOperatorFieldGetVector(op_output_fields[i], &vec));
779     // Restrict
780     CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_output_fields[i], &elem_rstr));
781     // Active
782     if (vec == CEED_VECTOR_ACTIVE) vec = out_vec;
783 
784     CeedCallBackend(CeedElemRestrictionApply(elem_rstr, CEED_TRANSPOSE, impl->e_vecs[i + impl->num_inputs], vec, request));
785   }
786   return CEED_ERROR_SUCCESS;
787 }
788 
789 //------------------------------------------------------------------------------
790 // Linear QFunction Assembly Core
791 //------------------------------------------------------------------------------
792 static inline int CeedOperatorLinearAssembleQFunctionCore_Cuda(CeedOperator op, bool build_objects, CeedVector *assembled, CeedElemRestriction *rstr,
793                                                                CeedRequest *request) {
794   Ceed                ceed, ceed_parent;
795   CeedInt             num_active_in, num_active_out, Q, num_elem, num_input_fields, num_output_fields, size;
796   CeedScalar         *assembled_array, *e_data[2 * CEED_FIELD_MAX] = {NULL};
797   CeedVector         *active_inputs;
798   CeedQFunctionField *qf_input_fields, *qf_output_fields;
799   CeedQFunction       qf;
800   CeedOperatorField  *op_input_fields, *op_output_fields;
801   CeedOperator_Cuda  *impl;
802 
803   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
804   CeedCallBackend(CeedOperatorGetFallbackParentCeed(op, &ceed_parent));
805   CeedCallBackend(CeedOperatorGetData(op, &impl));
806   CeedCallBackend(CeedOperatorGetNumQuadraturePoints(op, &Q));
807   CeedCallBackend(CeedOperatorGetNumElements(op, &num_elem));
808   CeedCallBackend(CeedOperatorGetQFunction(op, &qf));
809   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, &qf_input_fields, NULL, &qf_output_fields));
810   CeedCallBackend(CeedOperatorGetFields(op, &num_input_fields, &op_input_fields, &num_output_fields, &op_output_fields));
811   active_inputs = impl->qf_active_in;
812   num_active_in = impl->num_active_in, num_active_out = impl->num_active_out;
813 
814   // Setup
815   CeedCallBackend(CeedOperatorSetup_Cuda(op));
816 
817   // Input Evecs and Restriction
818   for (CeedInt i = 0; i < num_input_fields; i++) {
819     CeedCallBackend(CeedOperatorInputRestrict_Cuda(op_input_fields[i], qf_input_fields[i], i, NULL, true, &e_data[i], impl, request));
820   }
821 
822   // Count number of active input fields
823   if (!num_active_in) {
824     for (CeedInt i = 0; i < num_input_fields; i++) {
825       CeedScalar *q_vec_array;
826       CeedVector  vec;
827 
828       // Get input vector
829       CeedCallBackend(CeedOperatorFieldGetVector(op_input_fields[i], &vec));
830       // Check if active input
831       if (vec == CEED_VECTOR_ACTIVE) {
832         CeedCallBackend(CeedQFunctionFieldGetSize(qf_input_fields[i], &size));
833         CeedCallBackend(CeedVectorSetValue(impl->q_vecs_in[i], 0.0));
834         CeedCallBackend(CeedVectorGetArray(impl->q_vecs_in[i], CEED_MEM_DEVICE, &q_vec_array));
835         CeedCallBackend(CeedRealloc(num_active_in + size, &active_inputs));
836         for (CeedInt field = 0; field < size; field++) {
837           CeedSize q_size = (CeedSize)Q * num_elem;
838 
839           CeedCallBackend(CeedVectorCreate(ceed, q_size, &active_inputs[num_active_in + field]));
840           CeedCallBackend(
841               CeedVectorSetArray(active_inputs[num_active_in + field], CEED_MEM_DEVICE, CEED_USE_POINTER, &q_vec_array[field * Q * num_elem]));
842         }
843         num_active_in += size;
844         CeedCallBackend(CeedVectorRestoreArray(impl->q_vecs_in[i], &q_vec_array));
845       }
846     }
847     impl->num_active_in = num_active_in;
848     impl->qf_active_in  = active_inputs;
849   }
850 
851   // Count number of active output fields
852   if (!num_active_out) {
853     for (CeedInt i = 0; i < num_output_fields; i++) {
854       CeedVector vec;
855 
856       // Get output vector
857       CeedCallBackend(CeedOperatorFieldGetVector(op_output_fields[i], &vec));
858       // Check if active output
859       if (vec == CEED_VECTOR_ACTIVE) {
860         CeedCallBackend(CeedQFunctionFieldGetSize(qf_output_fields[i], &size));
861         num_active_out += size;
862       }
863     }
864     impl->num_active_out = num_active_out;
865   }
866 
867   // Check sizes
868   CeedCheck(num_active_in > 0 && num_active_out > 0, ceed, CEED_ERROR_BACKEND, "Cannot assemble QFunction without active inputs and outputs");
869 
870   // Build objects if needed
871   if (build_objects) {
872     CeedSize l_size     = (CeedSize)num_elem * Q * num_active_in * num_active_out;
873     CeedInt  strides[3] = {1, num_elem * Q, Q}; /* *NOPAD* */
874 
875     // Create output restriction
876     CeedCallBackend(CeedElemRestrictionCreateStrided(ceed_parent, num_elem, Q, num_active_in * num_active_out,
877                                                      (CeedSize)num_active_in * (CeedSize)num_active_out * (CeedSize)num_elem * (CeedSize)Q, strides,
878                                                      rstr));
879     // Create assembled vector
880     CeedCallBackend(CeedVectorCreate(ceed_parent, l_size, assembled));
881   }
882   CeedCallBackend(CeedVectorSetValue(*assembled, 0.0));
883   CeedCallBackend(CeedVectorGetArray(*assembled, CEED_MEM_DEVICE, &assembled_array));
884 
885   // Input basis apply
886   for (CeedInt i = 0; i < num_input_fields; i++) {
887     CeedCallBackend(CeedOperatorInputBasis_Cuda(op_input_fields[i], qf_input_fields[i], i, num_elem, true, e_data[i], impl));
888   }
889 
890   // Assemble QFunction
891   for (CeedInt in = 0; in < num_active_in; in++) {
892     // Set Inputs
893     CeedCallBackend(CeedVectorSetValue(active_inputs[in], 1.0));
894     if (num_active_in > 1) {
895       CeedCallBackend(CeedVectorSetValue(active_inputs[(in + num_active_in - 1) % num_active_in], 0.0));
896     }
897     // Set Outputs
898     for (CeedInt out = 0; out < num_output_fields; out++) {
899       CeedVector vec;
900 
901       // Get output vector
902       CeedCallBackend(CeedOperatorFieldGetVector(op_output_fields[out], &vec));
903       // Check if active output
904       if (vec == CEED_VECTOR_ACTIVE) {
905         CeedCallBackend(CeedVectorSetArray(impl->q_vecs_out[out], CEED_MEM_DEVICE, CEED_USE_POINTER, assembled_array));
906         CeedCallBackend(CeedQFunctionFieldGetSize(qf_output_fields[out], &size));
907         assembled_array += size * Q * num_elem;  // Advance the pointer by the size of the output
908       }
909     }
910     // Apply QFunction
911     CeedCallBackend(CeedQFunctionApply(qf, Q * num_elem, impl->q_vecs_in, impl->q_vecs_out));
912   }
913 
914   // Un-set output q-vecs to prevent accidental overwrite of Assembled
915   for (CeedInt out = 0; out < num_output_fields; out++) {
916     CeedVector vec;
917 
918     // Get output vector
919     CeedCallBackend(CeedOperatorFieldGetVector(op_output_fields[out], &vec));
920     // Check if active output
921     if (vec == CEED_VECTOR_ACTIVE) {
922       CeedCallBackend(CeedVectorTakeArray(impl->q_vecs_out[out], CEED_MEM_DEVICE, NULL));
923     }
924   }
925 
926   // Restore input arrays
927   for (CeedInt i = 0; i < num_input_fields; i++) {
928     CeedCallBackend(CeedOperatorInputRestore_Cuda(op_input_fields[i], qf_input_fields[i], i, true, &e_data[i], impl));
929   }
930 
931   // Restore output
932   CeedCallBackend(CeedVectorRestoreArray(*assembled, &assembled_array));
933   return CEED_ERROR_SUCCESS;
934 }
935 
936 //------------------------------------------------------------------------------
937 // Assemble Linear QFunction
938 //------------------------------------------------------------------------------
939 static int CeedOperatorLinearAssembleQFunction_Cuda(CeedOperator op, CeedVector *assembled, CeedElemRestriction *rstr, CeedRequest *request) {
940   return CeedOperatorLinearAssembleQFunctionCore_Cuda(op, true, assembled, rstr, request);
941 }
942 
943 //------------------------------------------------------------------------------
944 // Update Assembled Linear QFunction
945 //------------------------------------------------------------------------------
946 static int CeedOperatorLinearAssembleQFunctionUpdate_Cuda(CeedOperator op, CeedVector assembled, CeedElemRestriction rstr, CeedRequest *request) {
947   return CeedOperatorLinearAssembleQFunctionCore_Cuda(op, false, &assembled, &rstr, request);
948 }
949 
950 //------------------------------------------------------------------------------
951 // Assemble Diagonal Setup
952 //------------------------------------------------------------------------------
953 static inline int CeedOperatorAssembleDiagonalSetup_Cuda(CeedOperator op) {
954   Ceed                ceed;
955   CeedInt             num_input_fields, num_output_fields, num_eval_modes_in = 0, num_eval_modes_out = 0;
956   CeedInt             q_comp, num_nodes, num_qpts;
957   CeedEvalMode       *eval_modes_in = NULL, *eval_modes_out = NULL;
958   CeedBasis           basis_in = NULL, basis_out = NULL;
959   CeedQFunctionField *qf_fields;
960   CeedQFunction       qf;
961   CeedOperatorField  *op_fields;
962   CeedOperator_Cuda  *impl;
963 
964   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
965   CeedCallBackend(CeedOperatorGetQFunction(op, &qf));
966   CeedCallBackend(CeedQFunctionGetNumArgs(qf, &num_input_fields, &num_output_fields));
967 
968   // Determine active input basis
969   CeedCallBackend(CeedOperatorGetFields(op, NULL, &op_fields, NULL, NULL));
970   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, &qf_fields, NULL, NULL));
971   for (CeedInt i = 0; i < num_input_fields; i++) {
972     CeedVector vec;
973 
974     CeedCallBackend(CeedOperatorFieldGetVector(op_fields[i], &vec));
975     if (vec == CEED_VECTOR_ACTIVE) {
976       CeedBasis    basis;
977       CeedEvalMode eval_mode;
978 
979       CeedCallBackend(CeedOperatorFieldGetBasis(op_fields[i], &basis));
980       CeedCheck(!basis_in || basis_in == basis, ceed, CEED_ERROR_BACKEND,
981                 "Backend does not implement operator diagonal assembly with multiple active bases");
982       basis_in = basis;
983       CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_fields[i], &eval_mode));
984       CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis_in, eval_mode, &q_comp));
985       if (eval_mode != CEED_EVAL_WEIGHT) {
986         // q_comp = 1 if CEED_EVAL_NONE, CEED_EVAL_WEIGHT caught by QF assembly
987         CeedCallBackend(CeedRealloc(num_eval_modes_in + q_comp, &eval_modes_in));
988         for (CeedInt d = 0; d < q_comp; d++) eval_modes_in[num_eval_modes_in + d] = eval_mode;
989         num_eval_modes_in += q_comp;
990       }
991     }
992   }
993 
994   // Determine active output basis
995   CeedCallBackend(CeedOperatorGetFields(op, NULL, NULL, NULL, &op_fields));
996   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, NULL, NULL, &qf_fields));
997   for (CeedInt i = 0; i < num_output_fields; i++) {
998     CeedVector vec;
999 
1000     CeedCallBackend(CeedOperatorFieldGetVector(op_fields[i], &vec));
1001     if (vec == CEED_VECTOR_ACTIVE) {
1002       CeedBasis    basis;
1003       CeedEvalMode eval_mode;
1004 
1005       CeedCallBackend(CeedOperatorFieldGetBasis(op_fields[i], &basis));
1006       CeedCheck(!basis_out || basis_out == basis, ceed, CEED_ERROR_BACKEND,
1007                 "Backend does not implement operator diagonal assembly with multiple active bases");
1008       basis_out = basis;
1009       CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_fields[i], &eval_mode));
1010       CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis_out, eval_mode, &q_comp));
1011       if (eval_mode != CEED_EVAL_WEIGHT) {
1012         // q_comp = 1 if CEED_EVAL_NONE, CEED_EVAL_WEIGHT caught by QF assembly
1013         CeedCallBackend(CeedRealloc(num_eval_modes_out + q_comp, &eval_modes_out));
1014         for (CeedInt d = 0; d < q_comp; d++) eval_modes_out[num_eval_modes_out + d] = eval_mode;
1015         num_eval_modes_out += q_comp;
1016       }
1017     }
1018   }
1019 
1020   // Operator data struct
1021   CeedCallBackend(CeedOperatorGetData(op, &impl));
1022   CeedCallBackend(CeedCalloc(1, &impl->diag));
1023   CeedOperatorDiag_Cuda *diag = impl->diag;
1024 
1025   // Basis matrices
1026   CeedCallBackend(CeedBasisGetNumNodes(basis_in, &num_nodes));
1027   if (basis_in == CEED_BASIS_NONE) num_qpts = num_nodes;
1028   else CeedCallBackend(CeedBasisGetNumQuadraturePoints(basis_in, &num_qpts));
1029   const CeedInt interp_bytes     = num_nodes * num_qpts * sizeof(CeedScalar);
1030   const CeedInt eval_modes_bytes = sizeof(CeedEvalMode);
1031   bool          has_eval_none    = false;
1032 
1033   // CEED_EVAL_NONE
1034   for (CeedInt i = 0; i < num_eval_modes_in; i++) has_eval_none = has_eval_none || (eval_modes_in[i] == CEED_EVAL_NONE);
1035   for (CeedInt i = 0; i < num_eval_modes_out; i++) has_eval_none = has_eval_none || (eval_modes_out[i] == CEED_EVAL_NONE);
1036   if (has_eval_none) {
1037     CeedScalar *identity = NULL;
1038 
1039     CeedCallBackend(CeedCalloc(num_nodes * num_qpts, &identity));
1040     for (CeedInt i = 0; i < (num_nodes < num_qpts ? num_nodes : num_qpts); i++) identity[i * num_nodes + i] = 1.0;
1041     CeedCallCuda(ceed, cudaMalloc((void **)&diag->d_identity, interp_bytes));
1042     CeedCallCuda(ceed, cudaMemcpy(diag->d_identity, identity, interp_bytes, cudaMemcpyHostToDevice));
1043     CeedCallBackend(CeedFree(&identity));
1044   }
1045 
1046   // CEED_EVAL_INTERP, CEED_EVAL_GRAD, CEED_EVAL_DIV, and CEED_EVAL_CURL
1047   for (CeedInt in = 0; in < 2; in++) {
1048     CeedFESpace fespace;
1049     CeedBasis   basis = in ? basis_in : basis_out;
1050 
1051     CeedCallBackend(CeedBasisGetFESpace(basis, &fespace));
1052     switch (fespace) {
1053       case CEED_FE_SPACE_H1: {
1054         CeedInt           q_comp_interp, q_comp_grad;
1055         const CeedScalar *interp, *grad;
1056         CeedScalar       *d_interp, *d_grad;
1057 
1058         CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis, CEED_EVAL_INTERP, &q_comp_interp));
1059         CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis, CEED_EVAL_GRAD, &q_comp_grad));
1060 
1061         CeedCallBackend(CeedBasisGetInterp(basis, &interp));
1062         CeedCallCuda(ceed, cudaMalloc((void **)&d_interp, interp_bytes * q_comp_interp));
1063         CeedCallCuda(ceed, cudaMemcpy(d_interp, interp, interp_bytes * q_comp_interp, cudaMemcpyHostToDevice));
1064         CeedCallBackend(CeedBasisGetGrad(basis, &grad));
1065         CeedCallCuda(ceed, cudaMalloc((void **)&d_grad, interp_bytes * q_comp_grad));
1066         CeedCallCuda(ceed, cudaMemcpy(d_grad, grad, interp_bytes * q_comp_grad, cudaMemcpyHostToDevice));
1067         if (in) {
1068           diag->d_interp_in = d_interp;
1069           diag->d_grad_in   = d_grad;
1070         } else {
1071           diag->d_interp_out = d_interp;
1072           diag->d_grad_out   = d_grad;
1073         }
1074       } break;
1075       case CEED_FE_SPACE_HDIV: {
1076         CeedInt           q_comp_interp, q_comp_div;
1077         const CeedScalar *interp, *div;
1078         CeedScalar       *d_interp, *d_div;
1079 
1080         CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis, CEED_EVAL_INTERP, &q_comp_interp));
1081         CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis, CEED_EVAL_DIV, &q_comp_div));
1082 
1083         CeedCallBackend(CeedBasisGetInterp(basis, &interp));
1084         CeedCallCuda(ceed, cudaMalloc((void **)&d_interp, interp_bytes * q_comp_interp));
1085         CeedCallCuda(ceed, cudaMemcpy(d_interp, interp, interp_bytes * q_comp_interp, cudaMemcpyHostToDevice));
1086         CeedCallBackend(CeedBasisGetDiv(basis, &div));
1087         CeedCallCuda(ceed, cudaMalloc((void **)&d_div, interp_bytes * q_comp_div));
1088         CeedCallCuda(ceed, cudaMemcpy(d_div, div, interp_bytes * q_comp_div, cudaMemcpyHostToDevice));
1089         if (in) {
1090           diag->d_interp_in = d_interp;
1091           diag->d_div_in    = d_div;
1092         } else {
1093           diag->d_interp_out = d_interp;
1094           diag->d_div_out    = d_div;
1095         }
1096       } break;
1097       case CEED_FE_SPACE_HCURL: {
1098         CeedInt           q_comp_interp, q_comp_curl;
1099         const CeedScalar *interp, *curl;
1100         CeedScalar       *d_interp, *d_curl;
1101 
1102         CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis, CEED_EVAL_INTERP, &q_comp_interp));
1103         CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis, CEED_EVAL_CURL, &q_comp_curl));
1104 
1105         CeedCallBackend(CeedBasisGetInterp(basis, &interp));
1106         CeedCallCuda(ceed, cudaMalloc((void **)&d_interp, interp_bytes * q_comp_interp));
1107         CeedCallCuda(ceed, cudaMemcpy(d_interp, interp, interp_bytes * q_comp_interp, cudaMemcpyHostToDevice));
1108         CeedCallBackend(CeedBasisGetCurl(basis, &curl));
1109         CeedCallCuda(ceed, cudaMalloc((void **)&d_curl, interp_bytes * q_comp_curl));
1110         CeedCallCuda(ceed, cudaMemcpy(d_curl, curl, interp_bytes * q_comp_curl, cudaMemcpyHostToDevice));
1111         if (in) {
1112           diag->d_interp_in = d_interp;
1113           diag->d_curl_in   = d_curl;
1114         } else {
1115           diag->d_interp_out = d_interp;
1116           diag->d_curl_out   = d_curl;
1117         }
1118       } break;
1119     }
1120   }
1121 
1122   // Arrays of eval_modes
1123   CeedCallCuda(ceed, cudaMalloc((void **)&diag->d_eval_modes_in, num_eval_modes_in * eval_modes_bytes));
1124   CeedCallCuda(ceed, cudaMemcpy(diag->d_eval_modes_in, eval_modes_in, num_eval_modes_in * eval_modes_bytes, cudaMemcpyHostToDevice));
1125   CeedCallCuda(ceed, cudaMalloc((void **)&diag->d_eval_modes_out, num_eval_modes_out * eval_modes_bytes));
1126   CeedCallCuda(ceed, cudaMemcpy(diag->d_eval_modes_out, eval_modes_out, num_eval_modes_out * eval_modes_bytes, cudaMemcpyHostToDevice));
1127   CeedCallBackend(CeedFree(&eval_modes_in));
1128   CeedCallBackend(CeedFree(&eval_modes_out));
1129   return CEED_ERROR_SUCCESS;
1130 }
1131 
1132 //------------------------------------------------------------------------------
1133 // Assemble Diagonal Setup (Compilation)
1134 //------------------------------------------------------------------------------
1135 static inline int CeedOperatorAssembleDiagonalSetupCompile_Cuda(CeedOperator op, CeedInt use_ceedsize_idx, const bool is_point_block) {
1136   Ceed                ceed;
1137   char               *diagonal_kernel_source;
1138   const char         *diagonal_kernel_path;
1139   CeedInt             num_input_fields, num_output_fields, num_eval_modes_in = 0, num_eval_modes_out = 0;
1140   CeedInt             num_comp, q_comp, num_nodes, num_qpts;
1141   CeedBasis           basis_in = NULL, basis_out = NULL;
1142   CeedQFunctionField *qf_fields;
1143   CeedQFunction       qf;
1144   CeedOperatorField  *op_fields;
1145   CeedOperator_Cuda  *impl;
1146 
1147   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
1148   CeedCallBackend(CeedOperatorGetQFunction(op, &qf));
1149   CeedCallBackend(CeedQFunctionGetNumArgs(qf, &num_input_fields, &num_output_fields));
1150 
1151   // Determine active input basis
1152   CeedCallBackend(CeedOperatorGetFields(op, NULL, &op_fields, NULL, NULL));
1153   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, &qf_fields, NULL, NULL));
1154   for (CeedInt i = 0; i < num_input_fields; i++) {
1155     CeedVector vec;
1156 
1157     CeedCallBackend(CeedOperatorFieldGetVector(op_fields[i], &vec));
1158     if (vec == CEED_VECTOR_ACTIVE) {
1159       CeedEvalMode eval_mode;
1160 
1161       CeedCallBackend(CeedOperatorFieldGetBasis(op_fields[i], &basis_in));
1162       CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_fields[i], &eval_mode));
1163       CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis_in, eval_mode, &q_comp));
1164       if (eval_mode != CEED_EVAL_WEIGHT) {
1165         num_eval_modes_in += q_comp;
1166       }
1167     }
1168   }
1169 
1170   // Determine active output basis
1171   CeedCallBackend(CeedOperatorGetFields(op, NULL, NULL, NULL, &op_fields));
1172   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, NULL, NULL, &qf_fields));
1173   for (CeedInt i = 0; i < num_output_fields; i++) {
1174     CeedVector vec;
1175 
1176     CeedCallBackend(CeedOperatorFieldGetVector(op_fields[i], &vec));
1177     if (vec == CEED_VECTOR_ACTIVE) {
1178       CeedEvalMode eval_mode;
1179 
1180       CeedCallBackend(CeedOperatorFieldGetBasis(op_fields[i], &basis_out));
1181       CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_fields[i], &eval_mode));
1182       CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis_out, eval_mode, &q_comp));
1183       if (eval_mode != CEED_EVAL_WEIGHT) {
1184         num_eval_modes_out += q_comp;
1185       }
1186     }
1187   }
1188 
1189   // Operator data struct
1190   CeedCallBackend(CeedOperatorGetData(op, &impl));
1191   CeedOperatorDiag_Cuda *diag = impl->diag;
1192 
1193   // Assemble kernel
1194   CUmodule *module          = is_point_block ? &diag->module_point_block : &diag->module;
1195   CeedInt   elems_per_block = 1;
1196   CeedCallBackend(CeedBasisGetNumNodes(basis_in, &num_nodes));
1197   CeedCallBackend(CeedBasisGetNumComponents(basis_in, &num_comp));
1198   if (basis_in == CEED_BASIS_NONE) num_qpts = num_nodes;
1199   else CeedCallBackend(CeedBasisGetNumQuadraturePoints(basis_in, &num_qpts));
1200   CeedCallBackend(CeedGetJitAbsolutePath(ceed, "ceed/jit-source/cuda/cuda-ref-operator-assemble-diagonal.h", &diagonal_kernel_path));
1201   CeedDebug256(ceed, CEED_DEBUG_COLOR_SUCCESS, "----- Loading Diagonal Assembly Kernel Source -----\n");
1202   CeedCallBackend(CeedLoadSourceToBuffer(ceed, diagonal_kernel_path, &diagonal_kernel_source));
1203   CeedDebug256(ceed, CEED_DEBUG_COLOR_SUCCESS, "----- Loading Diagonal Assembly Source Complete! -----\n");
1204   CeedCallCuda(ceed, CeedCompile_Cuda(ceed, diagonal_kernel_source, module, 8, "NUM_EVAL_MODES_IN", num_eval_modes_in, "NUM_EVAL_MODES_OUT",
1205                                       num_eval_modes_out, "NUM_COMP", num_comp, "NUM_NODES", num_nodes, "NUM_QPTS", num_qpts, "USE_CEEDSIZE",
1206                                       use_ceedsize_idx, "USE_POINT_BLOCK", is_point_block ? 1 : 0, "BLOCK_SIZE", num_nodes * elems_per_block));
1207   CeedCallCuda(ceed, CeedGetKernel_Cuda(ceed, *module, "LinearDiagonal", is_point_block ? &diag->LinearPointBlock : &diag->LinearDiagonal));
1208   CeedCallBackend(CeedFree(&diagonal_kernel_path));
1209   CeedCallBackend(CeedFree(&diagonal_kernel_source));
1210   return CEED_ERROR_SUCCESS;
1211 }
1212 
1213 //------------------------------------------------------------------------------
1214 // Assemble Diagonal Core
1215 //------------------------------------------------------------------------------
1216 static inline int CeedOperatorAssembleDiagonalCore_Cuda(CeedOperator op, CeedVector assembled, CeedRequest *request, const bool is_point_block) {
1217   Ceed                ceed;
1218   CeedInt             num_elem, num_nodes;
1219   CeedScalar         *elem_diag_array;
1220   const CeedScalar   *assembled_qf_array;
1221   CeedVector          assembled_qf   = NULL, elem_diag;
1222   CeedElemRestriction assembled_rstr = NULL, rstr_in, rstr_out, diag_rstr;
1223   CeedOperator_Cuda  *impl;
1224 
1225   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
1226   CeedCallBackend(CeedOperatorGetData(op, &impl));
1227 
1228   // Assemble QFunction
1229   CeedCallBackend(CeedOperatorLinearAssembleQFunctionBuildOrUpdate(op, &assembled_qf, &assembled_rstr, request));
1230   CeedCallBackend(CeedElemRestrictionDestroy(&assembled_rstr));
1231   CeedCallBackend(CeedVectorGetArrayRead(assembled_qf, CEED_MEM_DEVICE, &assembled_qf_array));
1232 
1233   // Setup
1234   if (!impl->diag) CeedCallBackend(CeedOperatorAssembleDiagonalSetup_Cuda(op));
1235   CeedOperatorDiag_Cuda *diag = impl->diag;
1236 
1237   assert(diag != NULL);
1238 
1239   // Assemble kernel if needed
1240   if ((!is_point_block && !diag->LinearDiagonal) || (is_point_block && !diag->LinearPointBlock)) {
1241     CeedSize assembled_length, assembled_qf_length;
1242     CeedInt  use_ceedsize_idx = 0;
1243     CeedCallBackend(CeedVectorGetLength(assembled, &assembled_length));
1244     CeedCallBackend(CeedVectorGetLength(assembled_qf, &assembled_qf_length));
1245     if ((assembled_length > INT_MAX) || (assembled_qf_length > INT_MAX)) use_ceedsize_idx = 1;
1246 
1247     CeedCallBackend(CeedOperatorAssembleDiagonalSetupCompile_Cuda(op, use_ceedsize_idx, is_point_block));
1248   }
1249 
1250   // Restriction and diagonal vector
1251   CeedCallBackend(CeedOperatorGetActiveElemRestrictions(op, &rstr_in, &rstr_out));
1252   CeedCheck(rstr_in == rstr_out, ceed, CEED_ERROR_BACKEND,
1253             "Cannot assemble operator diagonal with different input and output active element restrictions");
1254   if (!is_point_block && !diag->diag_rstr) {
1255     CeedCallBackend(CeedElemRestrictionCreateUnsignedCopy(rstr_out, &diag->diag_rstr));
1256     CeedCallBackend(CeedElemRestrictionCreateVector(diag->diag_rstr, NULL, &diag->elem_diag));
1257   } else if (is_point_block && !diag->point_block_diag_rstr) {
1258     CeedCallBackend(CeedOperatorCreateActivePointBlockRestriction(rstr_out, &diag->point_block_diag_rstr));
1259     CeedCallBackend(CeedElemRestrictionCreateVector(diag->point_block_diag_rstr, NULL, &diag->point_block_elem_diag));
1260   }
1261   diag_rstr = is_point_block ? diag->point_block_diag_rstr : diag->diag_rstr;
1262   elem_diag = is_point_block ? diag->point_block_elem_diag : diag->elem_diag;
1263   CeedCallBackend(CeedVectorSetValue(elem_diag, 0.0));
1264 
1265   // Only assemble diagonal if the basis has nodes, otherwise inputs are null pointers
1266   CeedCallBackend(CeedElemRestrictionGetElementSize(diag_rstr, &num_nodes));
1267   if (num_nodes > 0) {
1268     // Assemble element operator diagonals
1269     CeedCallBackend(CeedElemRestrictionGetNumElements(diag_rstr, &num_elem));
1270     CeedCallBackend(CeedVectorGetArray(elem_diag, CEED_MEM_DEVICE, &elem_diag_array));
1271 
1272     // Compute the diagonal of B^T D B
1273     CeedInt elems_per_block = 1;
1274     CeedInt grid            = CeedDivUpInt(num_elem, elems_per_block);
1275     void   *args[]          = {(void *)&num_elem,      &diag->d_identity,       &diag->d_interp_in,  &diag->d_grad_in, &diag->d_div_in,
1276                                &diag->d_curl_in,       &diag->d_interp_out,     &diag->d_grad_out,   &diag->d_div_out, &diag->d_curl_out,
1277                                &diag->d_eval_modes_in, &diag->d_eval_modes_out, &assembled_qf_array, &elem_diag_array};
1278 
1279     if (is_point_block) {
1280       CeedCallBackend(CeedRunKernelDim_Cuda(ceed, diag->LinearPointBlock, grid, num_nodes, 1, elems_per_block, args));
1281     } else {
1282       CeedCallBackend(CeedRunKernelDim_Cuda(ceed, diag->LinearDiagonal, grid, num_nodes, 1, elems_per_block, args));
1283     }
1284 
1285     // Restore arrays
1286     CeedCallBackend(CeedVectorRestoreArray(elem_diag, &elem_diag_array));
1287     CeedCallBackend(CeedVectorRestoreArrayRead(assembled_qf, &assembled_qf_array));
1288   }
1289 
1290   // Assemble local operator diagonal
1291   CeedCallBackend(CeedElemRestrictionApply(diag_rstr, CEED_TRANSPOSE, elem_diag, assembled, request));
1292 
1293   // Cleanup
1294   CeedCallBackend(CeedVectorDestroy(&assembled_qf));
1295   return CEED_ERROR_SUCCESS;
1296 }
1297 
1298 //------------------------------------------------------------------------------
1299 // Assemble Linear Diagonal
1300 //------------------------------------------------------------------------------
1301 static int CeedOperatorLinearAssembleAddDiagonal_Cuda(CeedOperator op, CeedVector assembled, CeedRequest *request) {
1302   CeedCallBackend(CeedOperatorAssembleDiagonalCore_Cuda(op, assembled, request, false));
1303   return CEED_ERROR_SUCCESS;
1304 }
1305 
1306 //------------------------------------------------------------------------------
1307 // Assemble Linear Point Block Diagonal
1308 //------------------------------------------------------------------------------
1309 static int CeedOperatorLinearAssembleAddPointBlockDiagonal_Cuda(CeedOperator op, CeedVector assembled, CeedRequest *request) {
1310   CeedCallBackend(CeedOperatorAssembleDiagonalCore_Cuda(op, assembled, request, true));
1311   return CEED_ERROR_SUCCESS;
1312 }
1313 
1314 //------------------------------------------------------------------------------
1315 // Single Operator Assembly Setup
1316 //------------------------------------------------------------------------------
1317 static int CeedSingleOperatorAssembleSetup_Cuda(CeedOperator op, CeedInt use_ceedsize_idx) {
1318   Ceed                ceed;
1319   Ceed_Cuda          *cuda_data;
1320   char               *assembly_kernel_source;
1321   const char         *assembly_kernel_path;
1322   CeedInt             num_input_fields, num_output_fields, num_eval_modes_in = 0, num_eval_modes_out = 0;
1323   CeedInt             elem_size_in, num_qpts_in = 0, num_comp_in, elem_size_out, num_qpts_out, num_comp_out, q_comp;
1324   CeedEvalMode       *eval_modes_in = NULL, *eval_modes_out = NULL;
1325   CeedElemRestriction rstr_in = NULL, rstr_out = NULL;
1326   CeedBasis           basis_in = NULL, basis_out = NULL;
1327   CeedQFunctionField *qf_fields;
1328   CeedQFunction       qf;
1329   CeedOperatorField  *input_fields, *output_fields;
1330   CeedOperator_Cuda  *impl;
1331 
1332   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
1333   CeedCallBackend(CeedOperatorGetData(op, &impl));
1334 
1335   // Get intput and output fields
1336   CeedCallBackend(CeedOperatorGetFields(op, &num_input_fields, &input_fields, &num_output_fields, &output_fields));
1337 
1338   // Determine active input basis eval mode
1339   CeedCallBackend(CeedOperatorGetQFunction(op, &qf));
1340   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, &qf_fields, NULL, NULL));
1341   for (CeedInt i = 0; i < num_input_fields; i++) {
1342     CeedVector vec;
1343 
1344     CeedCallBackend(CeedOperatorFieldGetVector(input_fields[i], &vec));
1345     if (vec == CEED_VECTOR_ACTIVE) {
1346       CeedBasis    basis;
1347       CeedEvalMode eval_mode;
1348 
1349       CeedCallBackend(CeedOperatorFieldGetBasis(input_fields[i], &basis));
1350       CeedCheck(!basis_in || basis_in == basis, ceed, CEED_ERROR_BACKEND, "Backend does not implement operator assembly with multiple active bases");
1351       basis_in = basis;
1352       CeedCallBackend(CeedOperatorFieldGetElemRestriction(input_fields[i], &rstr_in));
1353       CeedCallBackend(CeedElemRestrictionGetElementSize(rstr_in, &elem_size_in));
1354       if (basis_in == CEED_BASIS_NONE) num_qpts_in = elem_size_in;
1355       else CeedCallBackend(CeedBasisGetNumQuadraturePoints(basis_in, &num_qpts_in));
1356       CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_fields[i], &eval_mode));
1357       CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis_in, eval_mode, &q_comp));
1358       if (eval_mode != CEED_EVAL_WEIGHT) {
1359         // q_comp = 1 if CEED_EVAL_NONE, CEED_EVAL_WEIGHT caught by QF Assembly
1360         CeedCallBackend(CeedRealloc(num_eval_modes_in + q_comp, &eval_modes_in));
1361         for (CeedInt d = 0; d < q_comp; d++) {
1362           eval_modes_in[num_eval_modes_in + d] = eval_mode;
1363         }
1364         num_eval_modes_in += q_comp;
1365       }
1366     }
1367   }
1368 
1369   // Determine active output basis; basis_out and rstr_out only used if same as input, TODO
1370   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, NULL, NULL, &qf_fields));
1371   for (CeedInt i = 0; i < num_output_fields; i++) {
1372     CeedVector vec;
1373 
1374     CeedCallBackend(CeedOperatorFieldGetVector(output_fields[i], &vec));
1375     if (vec == CEED_VECTOR_ACTIVE) {
1376       CeedBasis    basis;
1377       CeedEvalMode eval_mode;
1378 
1379       CeedCallBackend(CeedOperatorFieldGetBasis(output_fields[i], &basis));
1380       CeedCheck(!basis_out || basis_out == basis, ceed, CEED_ERROR_BACKEND,
1381                 "Backend does not implement operator assembly with multiple active bases");
1382       basis_out = basis;
1383       CeedCallBackend(CeedOperatorFieldGetElemRestriction(output_fields[i], &rstr_out));
1384       CeedCallBackend(CeedElemRestrictionGetElementSize(rstr_out, &elem_size_out));
1385       if (basis_out == CEED_BASIS_NONE) num_qpts_out = elem_size_out;
1386       else CeedCallBackend(CeedBasisGetNumQuadraturePoints(basis_out, &num_qpts_out));
1387       CeedCheck(num_qpts_in == num_qpts_out, ceed, CEED_ERROR_UNSUPPORTED,
1388                 "Active input and output bases must have the same number of quadrature points");
1389       CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_fields[i], &eval_mode));
1390       CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis_out, eval_mode, &q_comp));
1391       if (eval_mode != CEED_EVAL_WEIGHT) {
1392         // q_comp = 1 if CEED_EVAL_NONE, CEED_EVAL_WEIGHT caught by QF Assembly
1393         CeedCallBackend(CeedRealloc(num_eval_modes_out + q_comp, &eval_modes_out));
1394         for (CeedInt d = 0; d < q_comp; d++) {
1395           eval_modes_out[num_eval_modes_out + d] = eval_mode;
1396         }
1397         num_eval_modes_out += q_comp;
1398       }
1399     }
1400   }
1401   CeedCheck(num_eval_modes_in > 0 && num_eval_modes_out > 0, ceed, CEED_ERROR_UNSUPPORTED, "Cannot assemble operator without inputs/outputs");
1402 
1403   CeedCallBackend(CeedCalloc(1, &impl->asmb));
1404   CeedOperatorAssemble_Cuda *asmb = impl->asmb;
1405   asmb->elems_per_block           = 1;
1406   asmb->block_size_x              = elem_size_in;
1407   asmb->block_size_y              = elem_size_out;
1408 
1409   CeedCallBackend(CeedGetData(ceed, &cuda_data));
1410   bool fallback = asmb->block_size_x * asmb->block_size_y * asmb->elems_per_block > cuda_data->device_prop.maxThreadsPerBlock;
1411 
1412   if (fallback) {
1413     // Use fallback kernel with 1D threadblock
1414     asmb->block_size_y = 1;
1415   }
1416 
1417   // Compile kernels
1418   CeedCallBackend(CeedElemRestrictionGetNumComponents(rstr_in, &num_comp_in));
1419   CeedCallBackend(CeedElemRestrictionGetNumComponents(rstr_out, &num_comp_out));
1420   CeedCallBackend(CeedGetJitAbsolutePath(ceed, "ceed/jit-source/cuda/cuda-ref-operator-assemble.h", &assembly_kernel_path));
1421   CeedDebug256(ceed, CEED_DEBUG_COLOR_SUCCESS, "----- Loading Assembly Kernel Source -----\n");
1422   CeedCallBackend(CeedLoadSourceToBuffer(ceed, assembly_kernel_path, &assembly_kernel_source));
1423   CeedDebug256(ceed, CEED_DEBUG_COLOR_SUCCESS, "----- Loading Assembly Source Complete! -----\n");
1424   CeedCallBackend(CeedCompile_Cuda(ceed, assembly_kernel_source, &asmb->module, 10, "NUM_EVAL_MODES_IN", num_eval_modes_in, "NUM_EVAL_MODES_OUT",
1425                                    num_eval_modes_out, "NUM_COMP_IN", num_comp_in, "NUM_COMP_OUT", num_comp_out, "NUM_NODES_IN", elem_size_in,
1426                                    "NUM_NODES_OUT", elem_size_out, "NUM_QPTS", num_qpts_in, "BLOCK_SIZE",
1427                                    asmb->block_size_x * asmb->block_size_y * asmb->elems_per_block, "BLOCK_SIZE_Y", asmb->block_size_y,
1428                                    "USE_CEEDSIZE", use_ceedsize_idx));
1429   CeedCallBackend(CeedGetKernel_Cuda(ceed, asmb->module, "LinearAssemble", &asmb->LinearAssemble));
1430   CeedCallBackend(CeedFree(&assembly_kernel_path));
1431   CeedCallBackend(CeedFree(&assembly_kernel_source));
1432 
1433   // Load into B_in, in order that they will be used in eval_modes_in
1434   {
1435     const CeedInt in_bytes           = elem_size_in * num_qpts_in * num_eval_modes_in * sizeof(CeedScalar);
1436     CeedInt       d_in               = 0;
1437     CeedEvalMode  eval_modes_in_prev = CEED_EVAL_NONE;
1438     bool          has_eval_none      = false;
1439     CeedScalar   *identity           = NULL;
1440 
1441     for (CeedInt i = 0; i < num_eval_modes_in; i++) {
1442       has_eval_none = has_eval_none || (eval_modes_in[i] == CEED_EVAL_NONE);
1443     }
1444     if (has_eval_none) {
1445       CeedCallBackend(CeedCalloc(elem_size_in * num_qpts_in, &identity));
1446       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;
1447     }
1448 
1449     CeedCallCuda(ceed, cudaMalloc((void **)&asmb->d_B_in, in_bytes));
1450     for (CeedInt i = 0; i < num_eval_modes_in; i++) {
1451       const CeedScalar *h_B_in;
1452 
1453       CeedCallBackend(CeedOperatorGetBasisPointer(basis_in, eval_modes_in[i], identity, &h_B_in));
1454       CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis_in, eval_modes_in[i], &q_comp));
1455       if (q_comp > 1) {
1456         if (i == 0 || eval_modes_in[i] != eval_modes_in_prev) d_in = 0;
1457         else h_B_in = &h_B_in[(++d_in) * elem_size_in * num_qpts_in];
1458       }
1459       eval_modes_in_prev = eval_modes_in[i];
1460 
1461       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),
1462                                     cudaMemcpyHostToDevice));
1463     }
1464 
1465     if (identity) {
1466       CeedCallBackend(CeedFree(&identity));
1467     }
1468   }
1469 
1470   // Load into B_out, in order that they will be used in eval_modes_out
1471   {
1472     const CeedInt out_bytes           = elem_size_out * num_qpts_out * num_eval_modes_out * sizeof(CeedScalar);
1473     CeedInt       d_out               = 0;
1474     CeedEvalMode  eval_modes_out_prev = CEED_EVAL_NONE;
1475     bool          has_eval_none       = false;
1476     CeedScalar   *identity            = NULL;
1477 
1478     for (CeedInt i = 0; i < num_eval_modes_out; i++) {
1479       has_eval_none = has_eval_none || (eval_modes_out[i] == CEED_EVAL_NONE);
1480     }
1481     if (has_eval_none) {
1482       CeedCallBackend(CeedCalloc(elem_size_out * num_qpts_out, &identity));
1483       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;
1484     }
1485 
1486     CeedCallCuda(ceed, cudaMalloc((void **)&asmb->d_B_out, out_bytes));
1487     for (CeedInt i = 0; i < num_eval_modes_out; i++) {
1488       const CeedScalar *h_B_out;
1489 
1490       CeedCallBackend(CeedOperatorGetBasisPointer(basis_out, eval_modes_out[i], identity, &h_B_out));
1491       CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis_out, eval_modes_out[i], &q_comp));
1492       if (q_comp > 1) {
1493         if (i == 0 || eval_modes_out[i] != eval_modes_out_prev) d_out = 0;
1494         else h_B_out = &h_B_out[(++d_out) * elem_size_out * num_qpts_out];
1495       }
1496       eval_modes_out_prev = eval_modes_out[i];
1497 
1498       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),
1499                                     cudaMemcpyHostToDevice));
1500     }
1501 
1502     if (identity) {
1503       CeedCallBackend(CeedFree(&identity));
1504     }
1505   }
1506   return CEED_ERROR_SUCCESS;
1507 }
1508 
1509 //------------------------------------------------------------------------------
1510 // Assemble matrix data for COO matrix of assembled operator.
1511 // The sparsity pattern is set by CeedOperatorLinearAssembleSymbolic.
1512 //
1513 // Note that this (and other assembly routines) currently assume only one active input restriction/basis per operator (could have multiple basis eval
1514 // modes).
1515 // TODO: allow multiple active input restrictions/basis objects
1516 //------------------------------------------------------------------------------
1517 static int CeedSingleOperatorAssemble_Cuda(CeedOperator op, CeedInt offset, CeedVector values) {
1518   Ceed                ceed;
1519   CeedSize            values_length = 0, assembled_qf_length = 0;
1520   CeedInt             use_ceedsize_idx = 0, num_elem_in, num_elem_out, elem_size_in, elem_size_out;
1521   CeedScalar         *values_array;
1522   const CeedScalar   *assembled_qf_array;
1523   CeedVector          assembled_qf   = NULL;
1524   CeedElemRestriction assembled_rstr = NULL, rstr_in, rstr_out;
1525   CeedRestrictionType rstr_type_in, rstr_type_out;
1526   const bool         *orients_in = NULL, *orients_out = NULL;
1527   const CeedInt8     *curl_orients_in = NULL, *curl_orients_out = NULL;
1528   CeedOperator_Cuda  *impl;
1529 
1530   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
1531   CeedCallBackend(CeedOperatorGetData(op, &impl));
1532 
1533   // Assemble QFunction
1534   CeedCallBackend(CeedOperatorLinearAssembleQFunctionBuildOrUpdate(op, &assembled_qf, &assembled_rstr, CEED_REQUEST_IMMEDIATE));
1535   CeedCallBackend(CeedElemRestrictionDestroy(&assembled_rstr));
1536   CeedCallBackend(CeedVectorGetArrayRead(assembled_qf, CEED_MEM_DEVICE, &assembled_qf_array));
1537 
1538   CeedCallBackend(CeedVectorGetLength(values, &values_length));
1539   CeedCallBackend(CeedVectorGetLength(assembled_qf, &assembled_qf_length));
1540   if ((values_length > INT_MAX) || (assembled_qf_length > INT_MAX)) use_ceedsize_idx = 1;
1541 
1542   // Setup
1543   if (!impl->asmb) CeedCallBackend(CeedSingleOperatorAssembleSetup_Cuda(op, use_ceedsize_idx));
1544   CeedOperatorAssemble_Cuda *asmb = impl->asmb;
1545 
1546   assert(asmb != NULL);
1547 
1548   // Assemble element operator
1549   CeedCallBackend(CeedVectorGetArray(values, CEED_MEM_DEVICE, &values_array));
1550   values_array += offset;
1551 
1552   CeedCallBackend(CeedOperatorGetActiveElemRestrictions(op, &rstr_in, &rstr_out));
1553   CeedCallBackend(CeedElemRestrictionGetNumElements(rstr_in, &num_elem_in));
1554   CeedCallBackend(CeedElemRestrictionGetElementSize(rstr_in, &elem_size_in));
1555 
1556   CeedCallBackend(CeedElemRestrictionGetType(rstr_in, &rstr_type_in));
1557   if (rstr_type_in == CEED_RESTRICTION_ORIENTED) {
1558     CeedCallBackend(CeedElemRestrictionGetOrientations(rstr_in, CEED_MEM_DEVICE, &orients_in));
1559   } else if (rstr_type_in == CEED_RESTRICTION_CURL_ORIENTED) {
1560     CeedCallBackend(CeedElemRestrictionGetCurlOrientations(rstr_in, CEED_MEM_DEVICE, &curl_orients_in));
1561   }
1562 
1563   if (rstr_in != rstr_out) {
1564     CeedCallBackend(CeedElemRestrictionGetNumElements(rstr_out, &num_elem_out));
1565     CeedCheck(num_elem_in == num_elem_out, ceed, CEED_ERROR_UNSUPPORTED,
1566               "Active input and output operator restrictions must have the same number of elements");
1567     CeedCallBackend(CeedElemRestrictionGetElementSize(rstr_out, &elem_size_out));
1568 
1569     CeedCallBackend(CeedElemRestrictionGetType(rstr_out, &rstr_type_out));
1570     if (rstr_type_out == CEED_RESTRICTION_ORIENTED) {
1571       CeedCallBackend(CeedElemRestrictionGetOrientations(rstr_out, CEED_MEM_DEVICE, &orients_out));
1572     } else if (rstr_type_out == CEED_RESTRICTION_CURL_ORIENTED) {
1573       CeedCallBackend(CeedElemRestrictionGetCurlOrientations(rstr_out, CEED_MEM_DEVICE, &curl_orients_out));
1574     }
1575   } else {
1576     elem_size_out    = elem_size_in;
1577     orients_out      = orients_in;
1578     curl_orients_out = curl_orients_in;
1579   }
1580 
1581   // Compute B^T D B
1582   CeedInt shared_mem =
1583       ((curl_orients_in || curl_orients_out ? elem_size_in * elem_size_out : 0) + (curl_orients_in ? elem_size_in * asmb->block_size_y : 0)) *
1584       sizeof(CeedScalar);
1585   CeedInt grid   = CeedDivUpInt(num_elem_in, asmb->elems_per_block);
1586   void   *args[] = {(void *)&num_elem_in, &asmb->d_B_in,     &asmb->d_B_out,      &orients_in,  &curl_orients_in,
1587                     &orients_out,         &curl_orients_out, &assembled_qf_array, &values_array};
1588 
1589   CeedCallBackend(
1590       CeedRunKernelDimShared_Cuda(ceed, asmb->LinearAssemble, grid, asmb->block_size_x, asmb->block_size_y, asmb->elems_per_block, shared_mem, args));
1591 
1592   // Restore arrays
1593   CeedCallBackend(CeedVectorRestoreArray(values, &values_array));
1594   CeedCallBackend(CeedVectorRestoreArrayRead(assembled_qf, &assembled_qf_array));
1595 
1596   // Cleanup
1597   CeedCallBackend(CeedVectorDestroy(&assembled_qf));
1598   if (rstr_type_in == CEED_RESTRICTION_ORIENTED) {
1599     CeedCallBackend(CeedElemRestrictionRestoreOrientations(rstr_in, &orients_in));
1600   } else if (rstr_type_in == CEED_RESTRICTION_CURL_ORIENTED) {
1601     CeedCallBackend(CeedElemRestrictionRestoreCurlOrientations(rstr_in, &curl_orients_in));
1602   }
1603   if (rstr_in != rstr_out) {
1604     if (rstr_type_out == CEED_RESTRICTION_ORIENTED) {
1605       CeedCallBackend(CeedElemRestrictionRestoreOrientations(rstr_out, &orients_out));
1606     } else if (rstr_type_out == CEED_RESTRICTION_CURL_ORIENTED) {
1607       CeedCallBackend(CeedElemRestrictionRestoreCurlOrientations(rstr_out, &curl_orients_out));
1608     }
1609   }
1610   return CEED_ERROR_SUCCESS;
1611 }
1612 
1613 //------------------------------------------------------------------------------
1614 // Assemble Linear QFunction AtPoints
1615 //------------------------------------------------------------------------------
1616 static int CeedOperatorLinearAssembleQFunctionAtPoints_Cuda(CeedOperator op, CeedVector *assembled, CeedElemRestriction *rstr, CeedRequest *request) {
1617   return CeedError(CeedOperatorReturnCeed(op), CEED_ERROR_BACKEND, "Backend does not implement CeedOperatorLinearAssembleQFunction");
1618 }
1619 
1620 //------------------------------------------------------------------------------
1621 // Assemble Linear Diagonal AtPoints
1622 //------------------------------------------------------------------------------
1623 static int CeedOperatorLinearAssembleAddDiagonalAtPoints_Cuda(CeedOperator op, CeedVector assembled, CeedRequest *request) {
1624   CeedInt             max_num_points, *num_points, num_elem, num_input_fields, num_output_fields;
1625   CeedScalar         *e_data[2 * CEED_FIELD_MAX] = {NULL};
1626   CeedQFunctionField *qf_input_fields, *qf_output_fields;
1627   CeedQFunction       qf;
1628   CeedOperatorField  *op_input_fields, *op_output_fields;
1629   CeedOperator_Cuda  *impl;
1630 
1631   CeedCallBackend(CeedOperatorGetData(op, &impl));
1632   CeedCallBackend(CeedOperatorGetQFunction(op, &qf));
1633   CeedCallBackend(CeedOperatorGetNumElements(op, &num_elem));
1634   CeedCallBackend(CeedOperatorGetFields(op, &num_input_fields, &op_input_fields, &num_output_fields, &op_output_fields));
1635   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, &qf_input_fields, NULL, &qf_output_fields));
1636 
1637   // Setup
1638   CeedCallBackend(CeedOperatorSetupAtPoints_Cuda(op));
1639   num_points     = impl->num_points;
1640   max_num_points = impl->max_num_points;
1641 
1642   // Create separate output e-vecs
1643   if (impl->has_shared_e_vecs) {
1644     for (CeedInt i = 0; i < impl->num_outputs; i++) {
1645       CeedCallBackend(CeedVectorDestroy(&impl->q_vecs_out[i]));
1646       CeedCallBackend(CeedVectorDestroy(&impl->e_vecs[impl->num_inputs + i]));
1647     }
1648     CeedCallBackend(CeedOperatorSetupFields_Cuda(qf, op, false, true, impl->skip_rstr_out, impl->apply_add_basis_out, impl->e_vecs, impl->q_vecs_out,
1649                                                  num_input_fields, num_output_fields, max_num_points, num_elem));
1650   }
1651   impl->has_shared_e_vecs = false;
1652 
1653   // Get point coordinates
1654   if (!impl->point_coords_elem) {
1655     CeedVector          point_coords = NULL;
1656     CeedElemRestriction rstr_points  = NULL;
1657 
1658     CeedCallBackend(CeedOperatorAtPointsGetPoints(op, &rstr_points, &point_coords));
1659     CeedCallBackend(CeedElemRestrictionCreateVector(rstr_points, NULL, &impl->point_coords_elem));
1660     CeedCallBackend(CeedElemRestrictionApply(rstr_points, CEED_NOTRANSPOSE, point_coords, impl->point_coords_elem, request));
1661   }
1662 
1663   // Input Evecs and Restriction
1664   for (CeedInt i = 0; i < num_input_fields; i++) {
1665     CeedCallBackend(CeedOperatorInputRestrict_Cuda(op_input_fields[i], qf_input_fields[i], i, NULL, true, &e_data[i], impl, request));
1666   }
1667 
1668   // Clear active input Qvecs
1669   for (CeedInt i = 0; i < num_input_fields; i++) {
1670     CeedVector vec;
1671 
1672     CeedCallBackend(CeedOperatorFieldGetVector(op_input_fields[i], &vec));
1673     if (vec != CEED_VECTOR_ACTIVE) continue;
1674     CeedCallBackend(CeedVectorSetValue(impl->q_vecs_in[i], 0.0));
1675   }
1676 
1677   // Input basis apply if needed
1678   for (CeedInt i = 0; i < num_input_fields; i++) {
1679     CeedCallBackend(CeedOperatorInputBasisAtPoints_Cuda(op_input_fields[i], qf_input_fields[i], i, num_elem, num_points, true, e_data[i], impl));
1680   }
1681 
1682   // Output pointers, as necessary
1683   for (CeedInt i = 0; i < num_output_fields; i++) {
1684     CeedEvalMode eval_mode;
1685 
1686     CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_output_fields[i], &eval_mode));
1687     if (eval_mode == CEED_EVAL_NONE) {
1688       // Set the output Q-Vector to use the E-Vector data directly.
1689       CeedCallBackend(CeedVectorGetArrayWrite(impl->e_vecs[i + impl->num_inputs], CEED_MEM_DEVICE, &e_data[i + num_input_fields]));
1690       CeedCallBackend(CeedVectorSetArray(impl->q_vecs_out[i], CEED_MEM_DEVICE, CEED_USE_POINTER, e_data[i + num_input_fields]));
1691     }
1692   }
1693 
1694   // Loop over active fields
1695   for (CeedInt i = 0; i < num_input_fields; i++) {
1696     bool                is_active_at_points = true;
1697     CeedInt             elem_size = 1, num_comp_active = 1, e_vec_size = 0;
1698     CeedRestrictionType rstr_type;
1699     CeedVector          vec;
1700     CeedElemRestriction elem_rstr;
1701 
1702     CeedCallBackend(CeedOperatorFieldGetVector(op_input_fields[i], &vec));
1703     // -- Skip non-active input
1704     if (vec != CEED_VECTOR_ACTIVE) continue;
1705 
1706     // -- Get active restriction type
1707     CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_input_fields[i], &elem_rstr));
1708     CeedCallBackend(CeedElemRestrictionGetType(elem_rstr, &rstr_type));
1709     is_active_at_points = rstr_type == CEED_RESTRICTION_POINTS;
1710     if (!is_active_at_points) CeedCallBackend(CeedElemRestrictionGetElementSize(elem_rstr, &elem_size));
1711     else elem_size = max_num_points;
1712     CeedCallBackend(CeedElemRestrictionGetNumComponents(elem_rstr, &num_comp_active));
1713 
1714     e_vec_size = elem_size * num_comp_active;
1715     for (CeedInt s = 0; s < e_vec_size; s++) {
1716       bool         is_active_input = false;
1717       CeedEvalMode eval_mode;
1718       CeedVector   vec;
1719       CeedBasis    basis;
1720 
1721       CeedCallBackend(CeedOperatorFieldGetVector(op_input_fields[i], &vec));
1722       // Skip non-active input
1723       is_active_input = vec == CEED_VECTOR_ACTIVE;
1724       if (!is_active_input) continue;
1725 
1726       // Update unit vector
1727       if (s == 0) CeedCallBackend(CeedVectorSetValue(impl->e_vecs[i], 0.0));
1728       else CeedCallBackend(CeedVectorSetValueStrided(impl->e_vecs[i], s - 1, e_vec_size, 0.0));
1729       CeedCallBackend(CeedVectorSetValueStrided(impl->e_vecs[i], s, e_vec_size, 1.0));
1730 
1731       // Basis action
1732       CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_input_fields[i], &eval_mode));
1733       switch (eval_mode) {
1734         case CEED_EVAL_NONE:
1735           CeedCallBackend(CeedVectorSetArray(impl->q_vecs_in[i], CEED_MEM_DEVICE, CEED_USE_POINTER, e_data[i]));
1736           break;
1737         case CEED_EVAL_INTERP:
1738         case CEED_EVAL_GRAD:
1739         case CEED_EVAL_DIV:
1740         case CEED_EVAL_CURL:
1741           CeedCallBackend(CeedOperatorFieldGetBasis(op_input_fields[i], &basis));
1742           CeedCallBackend(CeedBasisApplyAtPoints(basis, num_elem, num_points, CEED_NOTRANSPOSE, eval_mode, impl->point_coords_elem, impl->e_vecs[i],
1743                                                  impl->q_vecs_in[i]));
1744           break;
1745         case CEED_EVAL_WEIGHT:
1746           break;  // No action
1747       }
1748 
1749       // Q function
1750       CeedCallBackend(CeedQFunctionApply(qf, num_elem * max_num_points, impl->q_vecs_in, impl->q_vecs_out));
1751 
1752       // Output basis apply if needed
1753       for (CeedInt j = 0; j < num_output_fields; j++) {
1754         bool                is_active_output = false;
1755         CeedInt             elem_size        = 0;
1756         CeedRestrictionType rstr_type;
1757         CeedEvalMode        eval_mode;
1758         CeedVector          vec;
1759         CeedElemRestriction elem_rstr;
1760         CeedBasis           basis;
1761 
1762         CeedCallBackend(CeedOperatorFieldGetVector(op_output_fields[j], &vec));
1763         // ---- Skip non-active output
1764         is_active_output = vec == CEED_VECTOR_ACTIVE;
1765         if (!is_active_output) continue;
1766 
1767         // ---- Check if elem size matches
1768         CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_output_fields[j], &elem_rstr));
1769         CeedCallBackend(CeedElemRestrictionGetType(elem_rstr, &rstr_type));
1770         if (is_active_at_points && rstr_type != CEED_RESTRICTION_POINTS) continue;
1771         if (rstr_type == CEED_RESTRICTION_POINTS) {
1772           CeedCallBackend(CeedElemRestrictionGetMaxPointsInElement(elem_rstr, &elem_size));
1773         } else {
1774           CeedCallBackend(CeedElemRestrictionGetElementSize(elem_rstr, &elem_size));
1775         }
1776         {
1777           CeedInt num_comp = 0;
1778 
1779           CeedCallBackend(CeedElemRestrictionGetNumComponents(elem_rstr, &num_comp));
1780           if (e_vec_size != num_comp * elem_size) continue;
1781         }
1782 
1783         // Basis action
1784         CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_output_fields[j], &eval_mode));
1785         switch (eval_mode) {
1786           case CEED_EVAL_NONE:
1787             CeedCallBackend(CeedVectorRestoreArray(impl->e_vecs[j + impl->num_inputs], &e_data[j + num_input_fields]));
1788             break;
1789           case CEED_EVAL_INTERP:
1790           case CEED_EVAL_GRAD:
1791           case CEED_EVAL_DIV:
1792           case CEED_EVAL_CURL:
1793             CeedCallBackend(CeedOperatorFieldGetBasis(op_output_fields[j], &basis));
1794             CeedCallBackend(CeedBasisApplyAtPoints(basis, num_elem, num_points, CEED_TRANSPOSE, eval_mode, impl->point_coords_elem,
1795                                                    impl->q_vecs_out[j], impl->e_vecs[j + impl->num_inputs]));
1796             break;
1797           // LCOV_EXCL_START
1798           case CEED_EVAL_WEIGHT: {
1799             return CeedError(CeedOperatorReturnCeed(op), CEED_ERROR_BACKEND, "CEED_EVAL_WEIGHT cannot be an output evaluation mode");
1800             // LCOV_EXCL_STOP
1801           }
1802         }
1803 
1804         // Mask output e-vec
1805         CeedCallBackend(CeedVectorPointwiseMult(impl->e_vecs[j + impl->num_inputs], impl->e_vecs[i], impl->e_vecs[j + impl->num_inputs]));
1806 
1807         // Restrict
1808         CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_output_fields[j], &elem_rstr));
1809         CeedCallBackend(CeedElemRestrictionApply(elem_rstr, CEED_TRANSPOSE, impl->e_vecs[j + impl->num_inputs], assembled, request));
1810 
1811         // Reset q_vec for
1812         if (eval_mode == CEED_EVAL_NONE) {
1813           CeedCallBackend(CeedVectorGetArrayWrite(impl->e_vecs[j + impl->num_inputs], CEED_MEM_DEVICE, &e_data[j + num_input_fields]));
1814           CeedCallBackend(CeedVectorSetArray(impl->q_vecs_out[j], CEED_MEM_DEVICE, CEED_USE_POINTER, e_data[j + num_input_fields]));
1815         }
1816       }
1817 
1818       // Reset vec
1819       if (s == e_vec_size - 1 && i != num_input_fields - 1) CeedCallBackend(CeedVectorSetValue(impl->q_vecs_in[i], 0.0));
1820     }
1821   }
1822 
1823   // Restore CEED_EVAL_NONE
1824   for (CeedInt i = 0; i < num_output_fields; i++) {
1825     CeedEvalMode eval_mode;
1826 
1827     // Get eval_mode
1828     CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_output_fields[i], &eval_mode));
1829 
1830     // Restore evec
1831     CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_output_fields[i], &eval_mode));
1832     if (eval_mode == CEED_EVAL_NONE) {
1833       CeedCallBackend(CeedVectorRestoreArray(impl->e_vecs[i + impl->num_inputs], &e_data[i + num_input_fields]));
1834     }
1835   }
1836 
1837   // Restore input arrays
1838   for (CeedInt i = 0; i < num_input_fields; i++) {
1839     CeedCallBackend(CeedOperatorInputRestore_Cuda(op_input_fields[i], qf_input_fields[i], i, true, &e_data[i], impl));
1840   }
1841   return CEED_ERROR_SUCCESS;
1842 }
1843 
1844 //------------------------------------------------------------------------------
1845 // Create operator
1846 //------------------------------------------------------------------------------
1847 int CeedOperatorCreate_Cuda(CeedOperator op) {
1848   Ceed               ceed;
1849   CeedOperator_Cuda *impl;
1850 
1851   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
1852   CeedCallBackend(CeedCalloc(1, &impl));
1853   CeedCallBackend(CeedOperatorSetData(op, impl));
1854 
1855   CeedCallBackend(CeedSetBackendFunction(ceed, "Operator", op, "LinearAssembleQFunction", CeedOperatorLinearAssembleQFunction_Cuda));
1856   CeedCallBackend(CeedSetBackendFunction(ceed, "Operator", op, "LinearAssembleQFunctionUpdate", CeedOperatorLinearAssembleQFunctionUpdate_Cuda));
1857   CeedCallBackend(CeedSetBackendFunction(ceed, "Operator", op, "LinearAssembleAddDiagonal", CeedOperatorLinearAssembleAddDiagonal_Cuda));
1858   CeedCallBackend(
1859       CeedSetBackendFunction(ceed, "Operator", op, "LinearAssembleAddPointBlockDiagonal", CeedOperatorLinearAssembleAddPointBlockDiagonal_Cuda));
1860   CeedCallBackend(CeedSetBackendFunction(ceed, "Operator", op, "LinearAssembleSingle", CeedSingleOperatorAssemble_Cuda));
1861   CeedCallBackend(CeedSetBackendFunction(ceed, "Operator", op, "ApplyAdd", CeedOperatorApplyAdd_Cuda));
1862   CeedCallBackend(CeedSetBackendFunction(ceed, "Operator", op, "Destroy", CeedOperatorDestroy_Cuda));
1863   return CEED_ERROR_SUCCESS;
1864 }
1865 
1866 //------------------------------------------------------------------------------
1867 // Create operator AtPoints
1868 //------------------------------------------------------------------------------
1869 int CeedOperatorCreateAtPoints_Cuda(CeedOperator op) {
1870   Ceed               ceed;
1871   CeedOperator_Cuda *impl;
1872 
1873   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
1874   CeedCallBackend(CeedCalloc(1, &impl));
1875   CeedCallBackend(CeedOperatorSetData(op, impl));
1876 
1877   CeedCallBackend(CeedSetBackendFunction(ceed, "Operator", op, "LinearAssembleQFunction", CeedOperatorLinearAssembleQFunctionAtPoints_Cuda));
1878   CeedCallBackend(CeedSetBackendFunction(ceed, "Operator", op, "LinearAssembleAddDiagonal", CeedOperatorLinearAssembleAddDiagonalAtPoints_Cuda));
1879   CeedCallBackend(CeedSetBackendFunction(ceed, "Operator", op, "ApplyAdd", CeedOperatorApplyAddAtPoints_Cuda));
1880   CeedCallBackend(CeedSetBackendFunction(ceed, "Operator", op, "Destroy", CeedOperatorDestroy_Cuda));
1881   return CEED_ERROR_SUCCESS;
1882 }
1883 
1884 //------------------------------------------------------------------------------
1885