xref: /libCEED/backends/cuda-ref/ceed-cuda-ref-operator.c (revision 41655a2310ae869cbaf66471563d33865f525ec1)
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->skip_rstr_in));
31   CeedCallBackend(CeedFree(&impl->skip_rstr_out));
32   CeedCallBackend(CeedFree(&impl->apply_add_basis_out));
33   for (CeedInt i = 0; i < impl->num_inputs + impl->num_outputs; i++) {
34     CeedCallBackend(CeedVectorDestroy(&impl->e_vecs[i]));
35   }
36   CeedCallBackend(CeedFree(&impl->e_vecs));
37   CeedCallBackend(CeedFree(&impl->input_states));
38 
39   for (CeedInt i = 0; i < impl->num_inputs; i++) {
40     CeedCallBackend(CeedVectorDestroy(&impl->q_vecs_in[i]));
41   }
42   CeedCallBackend(CeedFree(&impl->q_vecs_in));
43 
44   for (CeedInt i = 0; i < impl->num_outputs; i++) {
45     CeedCallBackend(CeedVectorDestroy(&impl->q_vecs_out[i]));
46   }
47   CeedCallBackend(CeedFree(&impl->q_vecs_out));
48   CeedCallBackend(CeedVectorDestroy(&impl->point_coords_elem));
49 
50   // QFunction assembly data
51   for (CeedInt i = 0; i < impl->num_active_in; i++) {
52     CeedCallBackend(CeedVectorDestroy(&impl->qf_active_in[i]));
53   }
54   CeedCallBackend(CeedFree(&impl->qf_active_in));
55 
56   // Diag data
57   if (impl->diag) {
58     Ceed ceed;
59 
60     CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
61     if (impl->diag->module) {
62       CeedCallCuda(ceed, cuModuleUnload(impl->diag->module));
63     }
64     if (impl->diag->module_point_block) {
65       CeedCallCuda(ceed, cuModuleUnload(impl->diag->module_point_block));
66     }
67     CeedCallCuda(ceed, cudaFree(impl->diag->d_eval_modes_in));
68     CeedCallCuda(ceed, cudaFree(impl->diag->d_eval_modes_out));
69     CeedCallCuda(ceed, cudaFree(impl->diag->d_identity));
70     CeedCallCuda(ceed, cudaFree(impl->diag->d_interp_in));
71     CeedCallCuda(ceed, cudaFree(impl->diag->d_interp_out));
72     CeedCallCuda(ceed, cudaFree(impl->diag->d_grad_in));
73     CeedCallCuda(ceed, cudaFree(impl->diag->d_grad_out));
74     CeedCallCuda(ceed, cudaFree(impl->diag->d_div_in));
75     CeedCallCuda(ceed, cudaFree(impl->diag->d_div_out));
76     CeedCallCuda(ceed, cudaFree(impl->diag->d_curl_in));
77     CeedCallCuda(ceed, cudaFree(impl->diag->d_curl_out));
78     CeedCallBackend(CeedElemRestrictionDestroy(&impl->diag->diag_rstr));
79     CeedCallBackend(CeedElemRestrictionDestroy(&impl->diag->point_block_diag_rstr));
80     CeedCallBackend(CeedVectorDestroy(&impl->diag->elem_diag));
81     CeedCallBackend(CeedVectorDestroy(&impl->diag->point_block_elem_diag));
82   }
83   CeedCallBackend(CeedFree(&impl->diag));
84 
85   if (impl->asmb) {
86     Ceed ceed;
87 
88     CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
89     CeedCallCuda(ceed, cuModuleUnload(impl->asmb->module));
90     CeedCallCuda(ceed, cudaFree(impl->asmb->d_B_in));
91     CeedCallCuda(ceed, cudaFree(impl->asmb->d_B_out));
92   }
93   CeedCallBackend(CeedFree(&impl->asmb));
94 
95   CeedCallBackend(CeedFree(&impl));
96   return CEED_ERROR_SUCCESS;
97 }
98 
99 //------------------------------------------------------------------------------
100 // Setup infields or outfields
101 //------------------------------------------------------------------------------
102 static int CeedOperatorSetupFields_Cuda(CeedQFunction qf, CeedOperator op, bool is_input, bool is_at_points, bool *skip_rstr, bool *apply_add_basis,
103                                         CeedVector *e_vecs, CeedVector *q_vecs, CeedInt start_e, CeedInt num_fields, CeedInt Q, CeedInt num_elem) {
104   Ceed                ceed;
105   CeedQFunctionField *qf_fields;
106   CeedOperatorField  *op_fields;
107 
108   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
109   if (is_input) {
110     CeedCallBackend(CeedOperatorGetFields(op, NULL, &op_fields, NULL, NULL));
111     CeedCallBackend(CeedQFunctionGetFields(qf, NULL, &qf_fields, NULL, NULL));
112   } else {
113     CeedCallBackend(CeedOperatorGetFields(op, NULL, NULL, NULL, &op_fields));
114     CeedCallBackend(CeedQFunctionGetFields(qf, NULL, NULL, NULL, &qf_fields));
115   }
116 
117   // Loop over fields
118   for (CeedInt i = 0; i < num_fields; i++) {
119     bool         is_strided = false, skip_restriction = false;
120     CeedSize     q_size;
121     CeedInt      size;
122     CeedEvalMode eval_mode;
123     CeedBasis    basis;
124 
125     CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_fields[i], &eval_mode));
126     if (eval_mode != CEED_EVAL_WEIGHT) {
127       CeedElemRestriction elem_rstr;
128 
129       // Check whether this field can skip the element restriction:
130       // Must be passive input, with eval_mode NONE, and have a strided restriction with CEED_STRIDES_BACKEND.
131       CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_fields[i], &elem_rstr));
132 
133       // First, check whether the field is input or output:
134       if (is_input) {
135         CeedVector vec;
136 
137         // Check for passive input
138         CeedCallBackend(CeedOperatorFieldGetVector(op_fields[i], &vec));
139         if (vec != CEED_VECTOR_ACTIVE) {
140           // Check eval_mode
141           if (eval_mode == CEED_EVAL_NONE) {
142             // Check for strided restriction
143             CeedCallBackend(CeedElemRestrictionIsStrided(elem_rstr, &is_strided));
144             if (is_strided) {
145               // Check if vector is already in preferred backend ordering
146               CeedCallBackend(CeedElemRestrictionHasBackendStrides(elem_rstr, &skip_restriction));
147             }
148           }
149         }
150       }
151       if (skip_restriction) {
152         // We do not need an E-Vector, but will use the input field vector's data directly in the operator application.
153         e_vecs[i + start_e] = NULL;
154       } else {
155         CeedCallBackend(CeedElemRestrictionCreateVector(elem_rstr, NULL, &e_vecs[i + start_e]));
156       }
157     }
158 
159     switch (eval_mode) {
160       case CEED_EVAL_NONE:
161         CeedCallBackend(CeedQFunctionFieldGetSize(qf_fields[i], &size));
162         q_size = (CeedSize)num_elem * Q * size;
163         CeedCallBackend(CeedVectorCreate(ceed, q_size, &q_vecs[i]));
164         break;
165       case CEED_EVAL_INTERP:
166       case CEED_EVAL_GRAD:
167       case CEED_EVAL_DIV:
168       case CEED_EVAL_CURL:
169         CeedCallBackend(CeedQFunctionFieldGetSize(qf_fields[i], &size));
170         q_size = (CeedSize)num_elem * Q * size;
171         CeedCallBackend(CeedVectorCreate(ceed, q_size, &q_vecs[i]));
172         break;
173       case CEED_EVAL_WEIGHT:  // Only on input fields
174         CeedCallBackend(CeedOperatorFieldGetBasis(op_fields[i], &basis));
175         q_size = (CeedSize)num_elem * Q;
176         CeedCallBackend(CeedVectorCreate(ceed, q_size, &q_vecs[i]));
177         if (is_at_points) {
178           CeedInt num_points[num_elem];
179 
180           for (CeedInt i = 0; i < num_elem; i++) num_points[i] = Q;
181           CeedCallBackend(
182               CeedBasisApplyAtPoints(basis, num_elem, num_points, CEED_NOTRANSPOSE, CEED_EVAL_WEIGHT, CEED_VECTOR_NONE, CEED_VECTOR_NONE, q_vecs[i]));
183         } else {
184           CeedCallBackend(CeedBasisApply(basis, num_elem, CEED_NOTRANSPOSE, CEED_EVAL_WEIGHT, CEED_VECTOR_NONE, q_vecs[i]));
185         }
186         break;
187     }
188   }
189   // Drop duplicate restrictions
190   if (is_input) {
191     for (CeedInt i = 0; i < num_fields; i++) {
192       CeedVector          vec_i;
193       CeedElemRestriction rstr_i;
194 
195       CeedCallBackend(CeedOperatorFieldGetVector(op_fields[i], &vec_i));
196       CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_fields[i], &rstr_i));
197       for (CeedInt j = i + 1; j < num_fields; j++) {
198         CeedVector          vec_j;
199         CeedElemRestriction rstr_j;
200 
201         CeedCallBackend(CeedOperatorFieldGetVector(op_fields[j], &vec_j));
202         CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_fields[j], &rstr_j));
203         if (vec_i == vec_j && rstr_i == rstr_j) {
204           CeedCallBackend(CeedVectorReferenceCopy(e_vecs[i + start_e], &e_vecs[j + start_e]));
205           skip_rstr[j] = true;
206         }
207       }
208     }
209   } else {
210     for (CeedInt i = num_fields - 1; i >= 0; i--) {
211       CeedVector          vec_i;
212       CeedElemRestriction rstr_i;
213 
214       CeedCallBackend(CeedOperatorFieldGetVector(op_fields[i], &vec_i));
215       CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_fields[i], &rstr_i));
216       for (CeedInt j = i - 1; j >= 0; j--) {
217         CeedVector          vec_j;
218         CeedElemRestriction rstr_j;
219 
220         CeedCallBackend(CeedOperatorFieldGetVector(op_fields[j], &vec_j));
221         CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_fields[j], &rstr_j));
222         if (vec_i == vec_j && rstr_i == rstr_j) {
223           CeedCallBackend(CeedVectorReferenceCopy(e_vecs[i + start_e], &e_vecs[j + start_e]));
224           skip_rstr[j]       = true;
225           apply_add_basis[i] = true;
226         }
227       }
228     }
229   }
230   return CEED_ERROR_SUCCESS;
231 }
232 
233 //------------------------------------------------------------------------------
234 // CeedOperator needs to connect all the named fields (be they active or passive) to the named inputs and outputs of its CeedQFunction.
235 //------------------------------------------------------------------------------
236 static int CeedOperatorSetup_Cuda(CeedOperator op) {
237   Ceed                ceed;
238   bool                is_setup_done;
239   CeedInt             Q, num_elem, num_input_fields, num_output_fields;
240   CeedQFunctionField *qf_input_fields, *qf_output_fields;
241   CeedQFunction       qf;
242   CeedOperatorField  *op_input_fields, *op_output_fields;
243   CeedOperator_Cuda  *impl;
244 
245   CeedCallBackend(CeedOperatorIsSetupDone(op, &is_setup_done));
246   if (is_setup_done) return CEED_ERROR_SUCCESS;
247 
248   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
249   CeedCallBackend(CeedOperatorGetData(op, &impl));
250   CeedCallBackend(CeedOperatorGetQFunction(op, &qf));
251   CeedCallBackend(CeedOperatorGetNumQuadraturePoints(op, &Q));
252   CeedCallBackend(CeedOperatorGetNumElements(op, &num_elem));
253   CeedCallBackend(CeedOperatorGetFields(op, &num_input_fields, &op_input_fields, &num_output_fields, &op_output_fields));
254   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, &qf_input_fields, NULL, &qf_output_fields));
255 
256   // Allocate
257   CeedCallBackend(CeedCalloc(num_input_fields + num_output_fields, &impl->e_vecs));
258   CeedCallBackend(CeedCalloc(CEED_FIELD_MAX, &impl->skip_rstr_in));
259   CeedCallBackend(CeedCalloc(CEED_FIELD_MAX, &impl->skip_rstr_out));
260   CeedCallBackend(CeedCalloc(CEED_FIELD_MAX, &impl->apply_add_basis_out));
261   CeedCallBackend(CeedCalloc(CEED_FIELD_MAX, &impl->input_states));
262   CeedCallBackend(CeedCalloc(CEED_FIELD_MAX, &impl->q_vecs_in));
263   CeedCallBackend(CeedCalloc(CEED_FIELD_MAX, &impl->q_vecs_out));
264   impl->num_inputs  = num_input_fields;
265   impl->num_outputs = num_output_fields;
266 
267   // Set up infield and outfield e-vecs and q-vecs
268   // Infields
269   CeedCallBackend(
270       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));
271   // Outfields
272   CeedCallBackend(CeedOperatorSetupFields_Cuda(qf, op, false, false, impl->skip_rstr_out, impl->apply_add_basis_out, impl->e_vecs, impl->q_vecs_out,
273                                                num_input_fields, num_output_fields, Q, num_elem));
274 
275   // Reuse active e-vecs where able
276   {
277     CeedInt              num_used  = 0;
278     CeedElemRestriction *rstr_used = NULL;
279 
280     for (CeedInt i = 0; i < num_input_fields; i++) {
281       bool                is_used = false;
282       CeedVector          vec_i;
283       CeedElemRestriction rstr_i;
284 
285       CeedCallBackend(CeedOperatorFieldGetVector(op_input_fields[i], &vec_i));
286       if (vec_i != CEED_VECTOR_ACTIVE) continue;
287       CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_input_fields[i], &rstr_i));
288       for (CeedInt j = 0; j < num_used; j++) {
289         if (rstr_i == rstr_used[i]) is_used = true;
290       }
291       if (is_used) continue;
292       num_used++;
293       if (num_used == 1) CeedCallBackend(CeedCalloc(num_used, &rstr_used));
294       else CeedCallBackend(CeedRealloc(num_used, &rstr_used));
295       rstr_used[num_used - 1] = rstr_i;
296       for (CeedInt j = num_output_fields - 1; j >= 0; j--) {
297         CeedEvalMode        eval_mode;
298         CeedVector          vec_j;
299         CeedElemRestriction rstr_j;
300 
301         CeedCallBackend(CeedOperatorFieldGetVector(op_output_fields[j], &vec_j));
302         if (vec_j != CEED_VECTOR_ACTIVE) continue;
303         CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_output_fields[j], &eval_mode));
304         if (eval_mode == CEED_EVAL_NONE) continue;
305         CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_output_fields[j], &rstr_j));
306         if (rstr_i == rstr_j) {
307           CeedCallBackend(CeedVectorReferenceCopy(impl->e_vecs[i], &impl->e_vecs[j + impl->num_inputs]));
308         }
309       }
310     }
311     CeedCallBackend(CeedFree(&rstr_used));
312   }
313   CeedCallBackend(CeedOperatorSetSetupDone(op));
314   return CEED_ERROR_SUCCESS;
315 }
316 
317 //------------------------------------------------------------------------------
318 // Setup Operator Inputs
319 //------------------------------------------------------------------------------
320 static inline int CeedOperatorSetupInputs_Cuda(CeedInt num_input_fields, CeedQFunctionField *qf_input_fields, CeedOperatorField *op_input_fields,
321                                                CeedVector in_vec, const bool skip_active, CeedScalar *e_data[2 * CEED_FIELD_MAX],
322                                                CeedOperator_Cuda *impl, CeedRequest *request) {
323   for (CeedInt i = 0; i < num_input_fields; i++) {
324     CeedEvalMode        eval_mode;
325     CeedVector          vec;
326     CeedElemRestriction elem_rstr;
327 
328     // Get input vector
329     CeedCallBackend(CeedOperatorFieldGetVector(op_input_fields[i], &vec));
330     if (vec == CEED_VECTOR_ACTIVE) {
331       if (skip_active) continue;
332       else vec = in_vec;
333     }
334 
335     CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_input_fields[i], &eval_mode));
336     if (eval_mode == CEED_EVAL_WEIGHT) {  // Skip
337     } else {
338       // Get input vector
339       CeedCallBackend(CeedOperatorFieldGetVector(op_input_fields[i], &vec));
340       // Get input element restriction
341       CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_input_fields[i], &elem_rstr));
342       if (vec == CEED_VECTOR_ACTIVE) vec = in_vec;
343       // Restrict, if necessary
344       if (!impl->e_vecs[i]) {
345         // No restriction for this field; read data directly from vec.
346         CeedCallBackend(CeedVectorGetArrayRead(vec, CEED_MEM_DEVICE, (const CeedScalar **)&e_data[i]));
347       } else {
348         uint64_t state;
349 
350         CeedCallBackend(CeedVectorGetState(vec, &state));
351         if ((state != impl->input_states[i] || vec == in_vec) && !impl->skip_rstr_in[i]) {
352           CeedCallBackend(CeedElemRestrictionApply(elem_rstr, CEED_NOTRANSPOSE, vec, impl->e_vecs[i], request));
353         }
354         impl->input_states[i] = state;
355         // Get evec
356         CeedCallBackend(CeedVectorGetArrayRead(impl->e_vecs[i], CEED_MEM_DEVICE, (const CeedScalar **)&e_data[i]));
357       }
358     }
359   }
360   return CEED_ERROR_SUCCESS;
361 }
362 
363 //------------------------------------------------------------------------------
364 // Input Basis Action
365 //------------------------------------------------------------------------------
366 static inline int CeedOperatorInputBasis_Cuda(CeedInt num_elem, CeedQFunctionField *qf_input_fields, CeedOperatorField *op_input_fields,
367                                               CeedInt num_input_fields, const bool skip_active, CeedScalar *e_data[2 * CEED_FIELD_MAX],
368                                               CeedOperator_Cuda *impl) {
369   for (CeedInt i = 0; i < num_input_fields; i++) {
370     CeedInt             elem_size, size;
371     CeedEvalMode        eval_mode;
372     CeedElemRestriction elem_rstr;
373     CeedBasis           basis;
374 
375     // Skip active input
376     if (skip_active) {
377       CeedVector vec;
378 
379       CeedCallBackend(CeedOperatorFieldGetVector(op_input_fields[i], &vec));
380       if (vec == CEED_VECTOR_ACTIVE) continue;
381     }
382     // Get elem_size, eval_mode, size
383     CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_input_fields[i], &elem_rstr));
384     CeedCallBackend(CeedElemRestrictionGetElementSize(elem_rstr, &elem_size));
385     CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_input_fields[i], &eval_mode));
386     CeedCallBackend(CeedQFunctionFieldGetSize(qf_input_fields[i], &size));
387     // Basis action
388     switch (eval_mode) {
389       case CEED_EVAL_NONE:
390         CeedCallBackend(CeedVectorSetArray(impl->q_vecs_in[i], CEED_MEM_DEVICE, CEED_USE_POINTER, e_data[i]));
391         break;
392       case CEED_EVAL_INTERP:
393       case CEED_EVAL_GRAD:
394       case CEED_EVAL_DIV:
395       case CEED_EVAL_CURL:
396         CeedCallBackend(CeedOperatorFieldGetBasis(op_input_fields[i], &basis));
397         CeedCallBackend(CeedBasisApply(basis, num_elem, CEED_NOTRANSPOSE, eval_mode, impl->e_vecs[i], impl->q_vecs_in[i]));
398         break;
399       case CEED_EVAL_WEIGHT:
400         break;  // No action
401     }
402   }
403   return CEED_ERROR_SUCCESS;
404 }
405 
406 //------------------------------------------------------------------------------
407 // Restore Input Vectors
408 //------------------------------------------------------------------------------
409 static inline int CeedOperatorRestoreInputs_Cuda(CeedInt num_input_fields, CeedQFunctionField *qf_input_fields, CeedOperatorField *op_input_fields,
410                                                  const bool skip_active, CeedScalar *e_data[2 * CEED_FIELD_MAX], CeedOperator_Cuda *impl) {
411   for (CeedInt i = 0; i < num_input_fields; i++) {
412     CeedEvalMode eval_mode;
413     CeedVector   vec;
414 
415     // Skip active input
416     if (skip_active) {
417       CeedCallBackend(CeedOperatorFieldGetVector(op_input_fields[i], &vec));
418       if (vec == CEED_VECTOR_ACTIVE) continue;
419     }
420     CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_input_fields[i], &eval_mode));
421     if (eval_mode == CEED_EVAL_WEIGHT) {  // Skip
422     } else {
423       if (!impl->e_vecs[i]) {  // This was a skip_restriction case
424         CeedCallBackend(CeedOperatorFieldGetVector(op_input_fields[i], &vec));
425         CeedCallBackend(CeedVectorRestoreArrayRead(vec, (const CeedScalar **)&e_data[i]));
426       } else {
427         CeedCallBackend(CeedVectorRestoreArrayRead(impl->e_vecs[i], (const CeedScalar **)&e_data[i]));
428       }
429     }
430   }
431   return CEED_ERROR_SUCCESS;
432 }
433 
434 //------------------------------------------------------------------------------
435 // Apply and add to output
436 //------------------------------------------------------------------------------
437 static int CeedOperatorApplyAdd_Cuda(CeedOperator op, CeedVector in_vec, CeedVector out_vec, CeedRequest *request) {
438   CeedInt             Q, num_elem, elem_size, num_input_fields, num_output_fields, size;
439   CeedScalar         *e_data[2 * CEED_FIELD_MAX] = {NULL};
440   CeedQFunctionField *qf_input_fields, *qf_output_fields;
441   CeedQFunction       qf;
442   CeedOperatorField  *op_input_fields, *op_output_fields;
443   CeedOperator_Cuda  *impl;
444 
445   CeedCallBackend(CeedOperatorGetData(op, &impl));
446   CeedCallBackend(CeedOperatorGetQFunction(op, &qf));
447   CeedCallBackend(CeedOperatorGetNumQuadraturePoints(op, &Q));
448   CeedCallBackend(CeedOperatorGetNumElements(op, &num_elem));
449   CeedCallBackend(CeedOperatorGetFields(op, &num_input_fields, &op_input_fields, &num_output_fields, &op_output_fields));
450   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, &qf_input_fields, NULL, &qf_output_fields));
451 
452   // Setup
453   CeedCallBackend(CeedOperatorSetup_Cuda(op));
454 
455   // Input Evecs and Restriction
456   CeedCallBackend(CeedOperatorSetupInputs_Cuda(num_input_fields, qf_input_fields, op_input_fields, in_vec, false, e_data, impl, request));
457 
458   // Input basis apply if needed
459   CeedCallBackend(CeedOperatorInputBasis_Cuda(num_elem, qf_input_fields, op_input_fields, num_input_fields, false, e_data, impl));
460 
461   // Output pointers, as necessary
462   for (CeedInt i = 0; i < num_output_fields; i++) {
463     CeedEvalMode eval_mode;
464 
465     CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_output_fields[i], &eval_mode));
466     if (eval_mode == CEED_EVAL_NONE) {
467       // Set the output Q-Vector to use the E-Vector data directly.
468       CeedCallBackend(CeedVectorGetArrayWrite(impl->e_vecs[i + impl->num_inputs], CEED_MEM_DEVICE, &e_data[i + num_input_fields]));
469       CeedCallBackend(CeedVectorSetArray(impl->q_vecs_out[i], CEED_MEM_DEVICE, CEED_USE_POINTER, e_data[i + num_input_fields]));
470     }
471   }
472 
473   // Q function
474   CeedCallBackend(CeedQFunctionApply(qf, num_elem * Q, impl->q_vecs_in, impl->q_vecs_out));
475 
476   // Restore input arrays
477   CeedCallBackend(CeedOperatorRestoreInputs_Cuda(num_input_fields, qf_input_fields, op_input_fields, false, e_data, impl));
478 
479   // Output basis apply if needed
480   for (CeedInt i = 0; i < num_output_fields; i++) {
481     CeedEvalMode        eval_mode;
482     CeedElemRestriction elem_rstr;
483     CeedBasis           basis;
484 
485     // Get elem_size, eval_mode, size
486     CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_output_fields[i], &elem_rstr));
487     CeedCallBackend(CeedElemRestrictionGetElementSize(elem_rstr, &elem_size));
488     CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_output_fields[i], &eval_mode));
489     CeedCallBackend(CeedQFunctionFieldGetSize(qf_output_fields[i], &size));
490     // Basis action
491     switch (eval_mode) {
492       case CEED_EVAL_NONE:
493         break;  // No action
494       case CEED_EVAL_INTERP:
495       case CEED_EVAL_GRAD:
496       case CEED_EVAL_DIV:
497       case CEED_EVAL_CURL:
498         CeedCallBackend(CeedOperatorFieldGetBasis(op_output_fields[i], &basis));
499         if (impl->apply_add_basis_out[i]) {
500           CeedCallBackend(CeedBasisApplyAdd(basis, num_elem, CEED_TRANSPOSE, eval_mode, impl->q_vecs_out[i], impl->e_vecs[i + impl->num_inputs]));
501         } else {
502           CeedCallBackend(CeedBasisApply(basis, num_elem, CEED_TRANSPOSE, eval_mode, impl->q_vecs_out[i], impl->e_vecs[i + impl->num_inputs]));
503         }
504         break;
505       // LCOV_EXCL_START
506       case CEED_EVAL_WEIGHT: {
507         return CeedError(CeedOperatorReturnCeed(op), CEED_ERROR_BACKEND, "CEED_EVAL_WEIGHT cannot be an output evaluation mode");
508         // LCOV_EXCL_STOP
509       }
510     }
511   }
512 
513   // Output restriction
514   for (CeedInt i = 0; i < num_output_fields; i++) {
515     CeedEvalMode        eval_mode;
516     CeedVector          vec;
517     CeedElemRestriction elem_rstr;
518 
519     // Restore evec
520     CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_output_fields[i], &eval_mode));
521     if (eval_mode == CEED_EVAL_NONE) {
522       CeedCallBackend(CeedVectorRestoreArray(impl->e_vecs[i + impl->num_inputs], &e_data[i + num_input_fields]));
523     }
524     if (impl->skip_rstr_out[i]) continue;
525     // Get output vector
526     CeedCallBackend(CeedOperatorFieldGetVector(op_output_fields[i], &vec));
527     // Restrict
528     CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_output_fields[i], &elem_rstr));
529     // Active
530     if (vec == CEED_VECTOR_ACTIVE) vec = out_vec;
531 
532     CeedCallBackend(CeedElemRestrictionApply(elem_rstr, CEED_TRANSPOSE, impl->e_vecs[i + impl->num_inputs], vec, request));
533   }
534   return CEED_ERROR_SUCCESS;
535 }
536 
537 //------------------------------------------------------------------------------
538 // CeedOperator needs to connect all the named fields (be they active or passive) to the named inputs and outputs of its CeedQFunction.
539 //------------------------------------------------------------------------------
540 static int CeedOperatorSetupAtPoints_Cuda(CeedOperator op) {
541   Ceed                ceed;
542   bool                is_setup_done;
543   CeedInt             max_num_points = -1, num_elem, num_input_fields, num_output_fields;
544   CeedQFunctionField *qf_input_fields, *qf_output_fields;
545   CeedQFunction       qf;
546   CeedOperatorField  *op_input_fields, *op_output_fields;
547   CeedOperator_Cuda  *impl;
548 
549   CeedCallBackend(CeedOperatorIsSetupDone(op, &is_setup_done));
550   if (is_setup_done) return CEED_ERROR_SUCCESS;
551 
552   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
553   CeedCallBackend(CeedOperatorGetData(op, &impl));
554   CeedCallBackend(CeedOperatorGetQFunction(op, &qf));
555   CeedCallBackend(CeedOperatorGetNumElements(op, &num_elem));
556   CeedCallBackend(CeedOperatorGetFields(op, &num_input_fields, &op_input_fields, &num_output_fields, &op_output_fields));
557   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, &qf_input_fields, NULL, &qf_output_fields));
558   {
559     CeedElemRestriction elem_rstr = NULL;
560 
561     CeedCallBackend(CeedOperatorAtPointsGetPoints(op, &elem_rstr, NULL));
562     CeedCallBackend(CeedElemRestrictionGetMaxPointsInElement(elem_rstr, &max_num_points));
563   }
564   impl->max_num_points = max_num_points;
565 
566   // Allocate
567   CeedCallBackend(CeedCalloc(num_input_fields + num_output_fields, &impl->e_vecs));
568   CeedCallBackend(CeedCalloc(CEED_FIELD_MAX, &impl->skip_rstr_in));
569   CeedCallBackend(CeedCalloc(CEED_FIELD_MAX, &impl->skip_rstr_out));
570   CeedCallBackend(CeedCalloc(CEED_FIELD_MAX, &impl->apply_add_basis_out));
571   CeedCallBackend(CeedCalloc(CEED_FIELD_MAX, &impl->input_states));
572   CeedCallBackend(CeedCalloc(CEED_FIELD_MAX, &impl->q_vecs_in));
573   CeedCallBackend(CeedCalloc(CEED_FIELD_MAX, &impl->q_vecs_out));
574   impl->num_inputs  = num_input_fields;
575   impl->num_outputs = num_output_fields;
576 
577   // Set up infield and outfield e_vecs and q_vecs
578   // Infields
579   CeedCallBackend(CeedOperatorSetupFields_Cuda(qf, op, true, true, impl->skip_rstr_in, NULL, impl->e_vecs, impl->q_vecs_in, 0, num_input_fields,
580                                                max_num_points, num_elem));
581   // Outfields
582   CeedCallBackend(CeedOperatorSetupFields_Cuda(qf, op, false, true, impl->skip_rstr_out, impl->apply_add_basis_out, impl->e_vecs, impl->q_vecs_out,
583                                                num_input_fields, num_output_fields, max_num_points, num_elem));
584 
585   CeedCallBackend(CeedOperatorSetSetupDone(op));
586   return CEED_ERROR_SUCCESS;
587 }
588 
589 //------------------------------------------------------------------------------
590 // Input Basis Action AtPoints
591 //------------------------------------------------------------------------------
592 static inline int CeedOperatorInputBasisAtPoints_Cuda(CeedInt num_elem, const CeedInt *num_points, CeedQFunctionField *qf_input_fields,
593                                                       CeedOperatorField *op_input_fields, CeedInt num_input_fields, const bool skip_active,
594                                                       CeedScalar *e_data[2 * CEED_FIELD_MAX], CeedOperator_Cuda *impl) {
595   for (CeedInt i = 0; i < num_input_fields; i++) {
596     CeedInt             elem_size, size;
597     CeedEvalMode        eval_mode;
598     CeedElemRestriction elem_rstr;
599     CeedBasis           basis;
600 
601     // Skip active input
602     if (skip_active) {
603       CeedVector vec;
604 
605       CeedCallBackend(CeedOperatorFieldGetVector(op_input_fields[i], &vec));
606       if (vec == CEED_VECTOR_ACTIVE) continue;
607     }
608     // Get elem_size, eval_mode, size
609     CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_input_fields[i], &elem_rstr));
610     CeedCallBackend(CeedElemRestrictionGetElementSize(elem_rstr, &elem_size));
611     CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_input_fields[i], &eval_mode));
612     CeedCallBackend(CeedQFunctionFieldGetSize(qf_input_fields[i], &size));
613     // Basis action
614     switch (eval_mode) {
615       case CEED_EVAL_NONE:
616         CeedCallBackend(CeedVectorSetArray(impl->q_vecs_in[i], CEED_MEM_DEVICE, CEED_USE_POINTER, e_data[i]));
617         break;
618       case CEED_EVAL_INTERP:
619       case CEED_EVAL_GRAD:
620       case CEED_EVAL_DIV:
621       case CEED_EVAL_CURL:
622         CeedCallBackend(CeedOperatorFieldGetBasis(op_input_fields[i], &basis));
623         CeedCallBackend(CeedBasisApplyAtPoints(basis, num_elem, num_points, CEED_NOTRANSPOSE, eval_mode, impl->point_coords_elem, impl->e_vecs[i],
624                                                impl->q_vecs_in[i]));
625         break;
626       case CEED_EVAL_WEIGHT:
627         break;  // No action
628     }
629   }
630   return CEED_ERROR_SUCCESS;
631 }
632 
633 //------------------------------------------------------------------------------
634 // Apply and add to output AtPoints
635 //------------------------------------------------------------------------------
636 static int CeedOperatorApplyAddAtPoints_Cuda(CeedOperator op, CeedVector in_vec, CeedVector out_vec, CeedRequest *request) {
637   CeedInt             max_num_points, num_elem, elem_size, num_input_fields, num_output_fields, size;
638   CeedScalar         *e_data[2 * CEED_FIELD_MAX] = {NULL};
639   CeedQFunctionField *qf_input_fields, *qf_output_fields;
640   CeedQFunction       qf;
641   CeedOperatorField  *op_input_fields, *op_output_fields;
642   CeedOperator_Cuda  *impl;
643 
644   CeedCallBackend(CeedOperatorGetData(op, &impl));
645   CeedCallBackend(CeedOperatorGetQFunction(op, &qf));
646   CeedCallBackend(CeedOperatorGetNumElements(op, &num_elem));
647   CeedCallBackend(CeedOperatorGetFields(op, &num_input_fields, &op_input_fields, &num_output_fields, &op_output_fields));
648   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, &qf_input_fields, NULL, &qf_output_fields));
649   CeedInt num_points[num_elem];
650 
651   // Setup
652   CeedCallBackend(CeedOperatorSetupAtPoints_Cuda(op));
653   max_num_points = impl->max_num_points;
654   for (CeedInt i = 0; i < num_elem; i++) num_points[i] = max_num_points;
655 
656   // Input Evecs and Restriction
657   CeedCallBackend(CeedOperatorSetupInputs_Cuda(num_input_fields, qf_input_fields, op_input_fields, in_vec, false, e_data, impl, request));
658 
659   // Get point coordinates
660   if (!impl->point_coords_elem) {
661     CeedVector          point_coords = NULL;
662     CeedElemRestriction rstr_points  = NULL;
663 
664     CeedCallBackend(CeedOperatorAtPointsGetPoints(op, &rstr_points, &point_coords));
665     CeedCallBackend(CeedElemRestrictionCreateVector(rstr_points, NULL, &impl->point_coords_elem));
666     CeedCallBackend(CeedElemRestrictionApply(rstr_points, CEED_NOTRANSPOSE, point_coords, impl->point_coords_elem, request));
667   }
668 
669   // Input basis apply if needed
670   CeedCallBackend(CeedOperatorInputBasisAtPoints_Cuda(num_elem, num_points, qf_input_fields, op_input_fields, num_input_fields, false, e_data, impl));
671 
672   // Output pointers, as necessary
673   for (CeedInt i = 0; i < num_output_fields; i++) {
674     CeedEvalMode eval_mode;
675 
676     CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_output_fields[i], &eval_mode));
677     if (eval_mode == CEED_EVAL_NONE) {
678       // Set the output Q-Vector to use the E-Vector data directly.
679       CeedCallBackend(CeedVectorGetArrayWrite(impl->e_vecs[i + impl->num_inputs], CEED_MEM_DEVICE, &e_data[i + num_input_fields]));
680       CeedCallBackend(CeedVectorSetArray(impl->q_vecs_out[i], CEED_MEM_DEVICE, CEED_USE_POINTER, e_data[i + num_input_fields]));
681     }
682   }
683 
684   // Q function
685   CeedCallBackend(CeedQFunctionApply(qf, num_elem * max_num_points, impl->q_vecs_in, impl->q_vecs_out));
686 
687   // Output basis apply if needed
688   for (CeedInt i = 0; i < num_output_fields; i++) {
689     CeedEvalMode        eval_mode;
690     CeedElemRestriction elem_rstr;
691     CeedBasis           basis;
692 
693     // Get elem_size, eval_mode, size
694     CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_output_fields[i], &elem_rstr));
695     CeedCallBackend(CeedElemRestrictionGetElementSize(elem_rstr, &elem_size));
696     CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_output_fields[i], &eval_mode));
697     CeedCallBackend(CeedQFunctionFieldGetSize(qf_output_fields[i], &size));
698     // Basis action
699     switch (eval_mode) {
700       case CEED_EVAL_NONE:
701         break;  // No action
702       case CEED_EVAL_INTERP:
703       case CEED_EVAL_GRAD:
704       case CEED_EVAL_DIV:
705       case CEED_EVAL_CURL:
706         CeedCallBackend(CeedOperatorFieldGetBasis(op_output_fields[i], &basis));
707         if (impl->apply_add_basis_out[i]) {
708           CeedCallBackend(CeedBasisApplyAddAtPoints(basis, num_elem, num_points, CEED_TRANSPOSE, eval_mode, impl->point_coords_elem,
709                                                     impl->q_vecs_out[i], impl->e_vecs[i + impl->num_inputs]));
710         } else {
711           CeedCallBackend(CeedBasisApplyAtPoints(basis, num_elem, num_points, CEED_TRANSPOSE, eval_mode, impl->point_coords_elem, impl->q_vecs_out[i],
712                                                  impl->e_vecs[i + impl->num_inputs]));
713         }
714         break;
715       // LCOV_EXCL_START
716       case CEED_EVAL_WEIGHT: {
717         return CeedError(CeedOperatorReturnCeed(op), CEED_ERROR_BACKEND, "CEED_EVAL_WEIGHT cannot be an output evaluation mode");
718         // LCOV_EXCL_STOP
719       }
720     }
721   }
722 
723   // Output restriction
724   for (CeedInt i = 0; i < num_output_fields; i++) {
725     CeedEvalMode        eval_mode;
726     CeedVector          vec;
727     CeedElemRestriction elem_rstr;
728 
729     // Restore evec
730     CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_output_fields[i], &eval_mode));
731     if (eval_mode == CEED_EVAL_NONE) {
732       CeedCallBackend(CeedVectorRestoreArray(impl->e_vecs[i + impl->num_inputs], &e_data[i + num_input_fields]));
733     }
734     if (impl->skip_rstr_out[i]) continue;
735     // Get output vector
736     CeedCallBackend(CeedOperatorFieldGetVector(op_output_fields[i], &vec));
737     // Restrict
738     CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_output_fields[i], &elem_rstr));
739     // Active
740     if (vec == CEED_VECTOR_ACTIVE) vec = out_vec;
741 
742     CeedCallBackend(CeedElemRestrictionApply(elem_rstr, CEED_TRANSPOSE, impl->e_vecs[i + impl->num_inputs], vec, request));
743   }
744 
745   // Restore input arrays
746   CeedCallBackend(CeedOperatorRestoreInputs_Cuda(num_input_fields, qf_input_fields, op_input_fields, false, e_data, impl));
747   return CEED_ERROR_SUCCESS;
748 }
749 
750 //------------------------------------------------------------------------------
751 // Linear QFunction Assembly Core
752 //------------------------------------------------------------------------------
753 static inline int CeedOperatorLinearAssembleQFunctionCore_Cuda(CeedOperator op, bool build_objects, CeedVector *assembled, CeedElemRestriction *rstr,
754                                                                CeedRequest *request) {
755   Ceed                ceed, ceed_parent;
756   CeedInt             num_active_in, num_active_out, Q, num_elem, num_input_fields, num_output_fields, size;
757   CeedScalar         *assembled_array, *e_data[2 * CEED_FIELD_MAX] = {NULL};
758   CeedVector         *active_inputs;
759   CeedQFunctionField *qf_input_fields, *qf_output_fields;
760   CeedQFunction       qf;
761   CeedOperatorField  *op_input_fields, *op_output_fields;
762   CeedOperator_Cuda  *impl;
763 
764   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
765   CeedCallBackend(CeedOperatorGetFallbackParentCeed(op, &ceed_parent));
766   CeedCallBackend(CeedOperatorGetData(op, &impl));
767   CeedCallBackend(CeedOperatorGetNumQuadraturePoints(op, &Q));
768   CeedCallBackend(CeedOperatorGetNumElements(op, &num_elem));
769   CeedCallBackend(CeedOperatorGetQFunction(op, &qf));
770   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, &qf_input_fields, NULL, &qf_output_fields));
771   CeedCallBackend(CeedOperatorGetFields(op, &num_input_fields, &op_input_fields, &num_output_fields, &op_output_fields));
772   active_inputs = impl->qf_active_in;
773   num_active_in = impl->num_active_in, num_active_out = impl->num_active_out;
774 
775   // Setup
776   CeedCallBackend(CeedOperatorSetup_Cuda(op));
777 
778   // Input Evecs and Restriction
779   CeedCallBackend(CeedOperatorSetupInputs_Cuda(num_input_fields, qf_input_fields, op_input_fields, NULL, true, e_data, impl, request));
780 
781   // Count number of active input fields
782   if (!num_active_in) {
783     for (CeedInt i = 0; i < num_input_fields; i++) {
784       CeedScalar *q_vec_array;
785       CeedVector  vec;
786 
787       // Get input vector
788       CeedCallBackend(CeedOperatorFieldGetVector(op_input_fields[i], &vec));
789       // Check if active input
790       if (vec == CEED_VECTOR_ACTIVE) {
791         CeedCallBackend(CeedQFunctionFieldGetSize(qf_input_fields[i], &size));
792         CeedCallBackend(CeedVectorSetValue(impl->q_vecs_in[i], 0.0));
793         CeedCallBackend(CeedVectorGetArray(impl->q_vecs_in[i], CEED_MEM_DEVICE, &q_vec_array));
794         CeedCallBackend(CeedRealloc(num_active_in + size, &active_inputs));
795         for (CeedInt field = 0; field < size; field++) {
796           CeedSize q_size = (CeedSize)Q * num_elem;
797 
798           CeedCallBackend(CeedVectorCreate(ceed, q_size, &active_inputs[num_active_in + field]));
799           CeedCallBackend(
800               CeedVectorSetArray(active_inputs[num_active_in + field], CEED_MEM_DEVICE, CEED_USE_POINTER, &q_vec_array[field * Q * num_elem]));
801         }
802         num_active_in += size;
803         CeedCallBackend(CeedVectorRestoreArray(impl->q_vecs_in[i], &q_vec_array));
804       }
805     }
806     impl->num_active_in = num_active_in;
807     impl->qf_active_in  = active_inputs;
808   }
809 
810   // Count number of active output fields
811   if (!num_active_out) {
812     for (CeedInt i = 0; i < num_output_fields; i++) {
813       CeedVector vec;
814 
815       // Get output vector
816       CeedCallBackend(CeedOperatorFieldGetVector(op_output_fields[i], &vec));
817       // Check if active output
818       if (vec == CEED_VECTOR_ACTIVE) {
819         CeedCallBackend(CeedQFunctionFieldGetSize(qf_output_fields[i], &size));
820         num_active_out += size;
821       }
822     }
823     impl->num_active_out = num_active_out;
824   }
825 
826   // Check sizes
827   CeedCheck(num_active_in > 0 && num_active_out > 0, ceed, CEED_ERROR_BACKEND, "Cannot assemble QFunction without active inputs and outputs");
828 
829   // Build objects if needed
830   if (build_objects) {
831     CeedSize l_size     = (CeedSize)num_elem * Q * num_active_in * num_active_out;
832     CeedInt  strides[3] = {1, num_elem * Q, Q}; /* *NOPAD* */
833 
834     // Create output restriction
835     CeedCallBackend(CeedElemRestrictionCreateStrided(ceed_parent, num_elem, Q, num_active_in * num_active_out,
836                                                      (CeedSize)num_active_in * (CeedSize)num_active_out * (CeedSize)num_elem * (CeedSize)Q, strides,
837                                                      rstr));
838     // Create assembled vector
839     CeedCallBackend(CeedVectorCreate(ceed_parent, l_size, assembled));
840   }
841   CeedCallBackend(CeedVectorSetValue(*assembled, 0.0));
842   CeedCallBackend(CeedVectorGetArray(*assembled, CEED_MEM_DEVICE, &assembled_array));
843 
844   // Input basis apply
845   CeedCallBackend(CeedOperatorInputBasis_Cuda(num_elem, qf_input_fields, op_input_fields, num_input_fields, true, e_data, impl));
846 
847   // Assemble QFunction
848   for (CeedInt in = 0; in < num_active_in; in++) {
849     // Set Inputs
850     CeedCallBackend(CeedVectorSetValue(active_inputs[in], 1.0));
851     if (num_active_in > 1) {
852       CeedCallBackend(CeedVectorSetValue(active_inputs[(in + num_active_in - 1) % num_active_in], 0.0));
853     }
854     // Set Outputs
855     for (CeedInt out = 0; out < num_output_fields; out++) {
856       CeedVector vec;
857 
858       // Get output vector
859       CeedCallBackend(CeedOperatorFieldGetVector(op_output_fields[out], &vec));
860       // Check if active output
861       if (vec == CEED_VECTOR_ACTIVE) {
862         CeedCallBackend(CeedVectorSetArray(impl->q_vecs_out[out], CEED_MEM_DEVICE, CEED_USE_POINTER, assembled_array));
863         CeedCallBackend(CeedQFunctionFieldGetSize(qf_output_fields[out], &size));
864         assembled_array += size * Q * num_elem;  // Advance the pointer by the size of the output
865       }
866     }
867     // Apply QFunction
868     CeedCallBackend(CeedQFunctionApply(qf, Q * num_elem, impl->q_vecs_in, impl->q_vecs_out));
869   }
870 
871   // Un-set output q_vecs to prevent accidental overwrite of Assembled
872   for (CeedInt out = 0; out < num_output_fields; out++) {
873     CeedVector vec;
874 
875     // Get output vector
876     CeedCallBackend(CeedOperatorFieldGetVector(op_output_fields[out], &vec));
877     // Check if active output
878     if (vec == CEED_VECTOR_ACTIVE) {
879       CeedCallBackend(CeedVectorTakeArray(impl->q_vecs_out[out], CEED_MEM_DEVICE, NULL));
880     }
881   }
882 
883   // Restore input arrays
884   CeedCallBackend(CeedOperatorRestoreInputs_Cuda(num_input_fields, qf_input_fields, op_input_fields, true, e_data, impl));
885 
886   // Restore output
887   CeedCallBackend(CeedVectorRestoreArray(*assembled, &assembled_array));
888   return CEED_ERROR_SUCCESS;
889 }
890 
891 //------------------------------------------------------------------------------
892 // Assemble Linear QFunction
893 //------------------------------------------------------------------------------
894 static int CeedOperatorLinearAssembleQFunction_Cuda(CeedOperator op, CeedVector *assembled, CeedElemRestriction *rstr, CeedRequest *request) {
895   return CeedOperatorLinearAssembleQFunctionCore_Cuda(op, true, assembled, rstr, request);
896 }
897 
898 //------------------------------------------------------------------------------
899 // Update Assembled Linear QFunction
900 //------------------------------------------------------------------------------
901 static int CeedOperatorLinearAssembleQFunctionUpdate_Cuda(CeedOperator op, CeedVector assembled, CeedElemRestriction rstr, CeedRequest *request) {
902   return CeedOperatorLinearAssembleQFunctionCore_Cuda(op, false, &assembled, &rstr, request);
903 }
904 
905 //------------------------------------------------------------------------------
906 // Assemble Diagonal Setup
907 //------------------------------------------------------------------------------
908 static inline int CeedOperatorAssembleDiagonalSetup_Cuda(CeedOperator op) {
909   Ceed                ceed;
910   CeedInt             num_input_fields, num_output_fields, num_eval_modes_in = 0, num_eval_modes_out = 0;
911   CeedInt             q_comp, num_nodes, num_qpts;
912   CeedEvalMode       *eval_modes_in = NULL, *eval_modes_out = NULL;
913   CeedBasis           basis_in = NULL, basis_out = NULL;
914   CeedQFunctionField *qf_fields;
915   CeedQFunction       qf;
916   CeedOperatorField  *op_fields;
917   CeedOperator_Cuda  *impl;
918 
919   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
920   CeedCallBackend(CeedOperatorGetQFunction(op, &qf));
921   CeedCallBackend(CeedQFunctionGetNumArgs(qf, &num_input_fields, &num_output_fields));
922 
923   // Determine active input basis
924   CeedCallBackend(CeedOperatorGetFields(op, NULL, &op_fields, NULL, NULL));
925   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, &qf_fields, NULL, NULL));
926   for (CeedInt i = 0; i < num_input_fields; i++) {
927     CeedVector vec;
928 
929     CeedCallBackend(CeedOperatorFieldGetVector(op_fields[i], &vec));
930     if (vec == CEED_VECTOR_ACTIVE) {
931       CeedBasis    basis;
932       CeedEvalMode eval_mode;
933 
934       CeedCallBackend(CeedOperatorFieldGetBasis(op_fields[i], &basis));
935       CeedCheck(!basis_in || basis_in == basis, ceed, CEED_ERROR_BACKEND,
936                 "Backend does not implement operator diagonal assembly with multiple active bases");
937       basis_in = basis;
938       CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_fields[i], &eval_mode));
939       CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis_in, eval_mode, &q_comp));
940       if (eval_mode != CEED_EVAL_WEIGHT) {
941         // q_comp = 1 if CEED_EVAL_NONE, CEED_EVAL_WEIGHT caught by QF assembly
942         CeedCallBackend(CeedRealloc(num_eval_modes_in + q_comp, &eval_modes_in));
943         for (CeedInt d = 0; d < q_comp; d++) eval_modes_in[num_eval_modes_in + d] = eval_mode;
944         num_eval_modes_in += q_comp;
945       }
946     }
947   }
948 
949   // Determine active output basis
950   CeedCallBackend(CeedOperatorGetFields(op, NULL, NULL, NULL, &op_fields));
951   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, NULL, NULL, &qf_fields));
952   for (CeedInt i = 0; i < num_output_fields; i++) {
953     CeedVector vec;
954 
955     CeedCallBackend(CeedOperatorFieldGetVector(op_fields[i], &vec));
956     if (vec == CEED_VECTOR_ACTIVE) {
957       CeedBasis    basis;
958       CeedEvalMode eval_mode;
959 
960       CeedCallBackend(CeedOperatorFieldGetBasis(op_fields[i], &basis));
961       CeedCheck(!basis_out || basis_out == basis, ceed, CEED_ERROR_BACKEND,
962                 "Backend does not implement operator diagonal assembly with multiple active bases");
963       basis_out = basis;
964       CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_fields[i], &eval_mode));
965       CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis_out, eval_mode, &q_comp));
966       if (eval_mode != CEED_EVAL_WEIGHT) {
967         // q_comp = 1 if CEED_EVAL_NONE, CEED_EVAL_WEIGHT caught by QF assembly
968         CeedCallBackend(CeedRealloc(num_eval_modes_out + q_comp, &eval_modes_out));
969         for (CeedInt d = 0; d < q_comp; d++) eval_modes_out[num_eval_modes_out + d] = eval_mode;
970         num_eval_modes_out += q_comp;
971       }
972     }
973   }
974 
975   // Operator data struct
976   CeedCallBackend(CeedOperatorGetData(op, &impl));
977   CeedCallBackend(CeedCalloc(1, &impl->diag));
978   CeedOperatorDiag_Cuda *diag = impl->diag;
979 
980   // Basis matrices
981   CeedCallBackend(CeedBasisGetNumNodes(basis_in, &num_nodes));
982   if (basis_in == CEED_BASIS_NONE) num_qpts = num_nodes;
983   else CeedCallBackend(CeedBasisGetNumQuadraturePoints(basis_in, &num_qpts));
984   const CeedInt interp_bytes     = num_nodes * num_qpts * sizeof(CeedScalar);
985   const CeedInt eval_modes_bytes = sizeof(CeedEvalMode);
986   bool          has_eval_none    = false;
987 
988   // CEED_EVAL_NONE
989   for (CeedInt i = 0; i < num_eval_modes_in; i++) has_eval_none = has_eval_none || (eval_modes_in[i] == CEED_EVAL_NONE);
990   for (CeedInt i = 0; i < num_eval_modes_out; i++) has_eval_none = has_eval_none || (eval_modes_out[i] == CEED_EVAL_NONE);
991   if (has_eval_none) {
992     CeedScalar *identity = NULL;
993 
994     CeedCallBackend(CeedCalloc(num_nodes * num_qpts, &identity));
995     for (CeedInt i = 0; i < (num_nodes < num_qpts ? num_nodes : num_qpts); i++) identity[i * num_nodes + i] = 1.0;
996     CeedCallCuda(ceed, cudaMalloc((void **)&diag->d_identity, interp_bytes));
997     CeedCallCuda(ceed, cudaMemcpy(diag->d_identity, identity, interp_bytes, cudaMemcpyHostToDevice));
998     CeedCallBackend(CeedFree(&identity));
999   }
1000 
1001   // CEED_EVAL_INTERP, CEED_EVAL_GRAD, CEED_EVAL_DIV, and CEED_EVAL_CURL
1002   for (CeedInt in = 0; in < 2; in++) {
1003     CeedFESpace fespace;
1004     CeedBasis   basis = in ? basis_in : basis_out;
1005 
1006     CeedCallBackend(CeedBasisGetFESpace(basis, &fespace));
1007     switch (fespace) {
1008       case CEED_FE_SPACE_H1: {
1009         CeedInt           q_comp_interp, q_comp_grad;
1010         const CeedScalar *interp, *grad;
1011         CeedScalar       *d_interp, *d_grad;
1012 
1013         CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis, CEED_EVAL_INTERP, &q_comp_interp));
1014         CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis, CEED_EVAL_GRAD, &q_comp_grad));
1015 
1016         CeedCallBackend(CeedBasisGetInterp(basis, &interp));
1017         CeedCallCuda(ceed, cudaMalloc((void **)&d_interp, interp_bytes * q_comp_interp));
1018         CeedCallCuda(ceed, cudaMemcpy(d_interp, interp, interp_bytes * q_comp_interp, cudaMemcpyHostToDevice));
1019         CeedCallBackend(CeedBasisGetGrad(basis, &grad));
1020         CeedCallCuda(ceed, cudaMalloc((void **)&d_grad, interp_bytes * q_comp_grad));
1021         CeedCallCuda(ceed, cudaMemcpy(d_grad, grad, interp_bytes * q_comp_grad, cudaMemcpyHostToDevice));
1022         if (in) {
1023           diag->d_interp_in = d_interp;
1024           diag->d_grad_in   = d_grad;
1025         } else {
1026           diag->d_interp_out = d_interp;
1027           diag->d_grad_out   = d_grad;
1028         }
1029       } break;
1030       case CEED_FE_SPACE_HDIV: {
1031         CeedInt           q_comp_interp, q_comp_div;
1032         const CeedScalar *interp, *div;
1033         CeedScalar       *d_interp, *d_div;
1034 
1035         CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis, CEED_EVAL_INTERP, &q_comp_interp));
1036         CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis, CEED_EVAL_DIV, &q_comp_div));
1037 
1038         CeedCallBackend(CeedBasisGetInterp(basis, &interp));
1039         CeedCallCuda(ceed, cudaMalloc((void **)&d_interp, interp_bytes * q_comp_interp));
1040         CeedCallCuda(ceed, cudaMemcpy(d_interp, interp, interp_bytes * q_comp_interp, cudaMemcpyHostToDevice));
1041         CeedCallBackend(CeedBasisGetDiv(basis, &div));
1042         CeedCallCuda(ceed, cudaMalloc((void **)&d_div, interp_bytes * q_comp_div));
1043         CeedCallCuda(ceed, cudaMemcpy(d_div, div, interp_bytes * q_comp_div, cudaMemcpyHostToDevice));
1044         if (in) {
1045           diag->d_interp_in = d_interp;
1046           diag->d_div_in    = d_div;
1047         } else {
1048           diag->d_interp_out = d_interp;
1049           diag->d_div_out    = d_div;
1050         }
1051       } break;
1052       case CEED_FE_SPACE_HCURL: {
1053         CeedInt           q_comp_interp, q_comp_curl;
1054         const CeedScalar *interp, *curl;
1055         CeedScalar       *d_interp, *d_curl;
1056 
1057         CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis, CEED_EVAL_INTERP, &q_comp_interp));
1058         CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis, CEED_EVAL_CURL, &q_comp_curl));
1059 
1060         CeedCallBackend(CeedBasisGetInterp(basis, &interp));
1061         CeedCallCuda(ceed, cudaMalloc((void **)&d_interp, interp_bytes * q_comp_interp));
1062         CeedCallCuda(ceed, cudaMemcpy(d_interp, interp, interp_bytes * q_comp_interp, cudaMemcpyHostToDevice));
1063         CeedCallBackend(CeedBasisGetCurl(basis, &curl));
1064         CeedCallCuda(ceed, cudaMalloc((void **)&d_curl, interp_bytes * q_comp_curl));
1065         CeedCallCuda(ceed, cudaMemcpy(d_curl, curl, interp_bytes * q_comp_curl, cudaMemcpyHostToDevice));
1066         if (in) {
1067           diag->d_interp_in = d_interp;
1068           diag->d_curl_in   = d_curl;
1069         } else {
1070           diag->d_interp_out = d_interp;
1071           diag->d_curl_out   = d_curl;
1072         }
1073       } break;
1074     }
1075   }
1076 
1077   // Arrays of eval_modes
1078   CeedCallCuda(ceed, cudaMalloc((void **)&diag->d_eval_modes_in, num_eval_modes_in * eval_modes_bytes));
1079   CeedCallCuda(ceed, cudaMemcpy(diag->d_eval_modes_in, eval_modes_in, num_eval_modes_in * eval_modes_bytes, cudaMemcpyHostToDevice));
1080   CeedCallCuda(ceed, cudaMalloc((void **)&diag->d_eval_modes_out, num_eval_modes_out * eval_modes_bytes));
1081   CeedCallCuda(ceed, cudaMemcpy(diag->d_eval_modes_out, eval_modes_out, num_eval_modes_out * eval_modes_bytes, cudaMemcpyHostToDevice));
1082   CeedCallBackend(CeedFree(&eval_modes_in));
1083   CeedCallBackend(CeedFree(&eval_modes_out));
1084   return CEED_ERROR_SUCCESS;
1085 }
1086 
1087 //------------------------------------------------------------------------------
1088 // Assemble Diagonal Setup (Compilation)
1089 //------------------------------------------------------------------------------
1090 static inline int CeedOperatorAssembleDiagonalSetupCompile_Cuda(CeedOperator op, CeedInt use_ceedsize_idx, const bool is_point_block) {
1091   Ceed                ceed;
1092   char               *diagonal_kernel_source;
1093   const char         *diagonal_kernel_path;
1094   CeedInt             num_input_fields, num_output_fields, num_eval_modes_in = 0, num_eval_modes_out = 0;
1095   CeedInt             num_comp, q_comp, num_nodes, num_qpts;
1096   CeedBasis           basis_in = NULL, basis_out = NULL;
1097   CeedQFunctionField *qf_fields;
1098   CeedQFunction       qf;
1099   CeedOperatorField  *op_fields;
1100   CeedOperator_Cuda  *impl;
1101 
1102   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
1103   CeedCallBackend(CeedOperatorGetQFunction(op, &qf));
1104   CeedCallBackend(CeedQFunctionGetNumArgs(qf, &num_input_fields, &num_output_fields));
1105 
1106   // Determine active input basis
1107   CeedCallBackend(CeedOperatorGetFields(op, NULL, &op_fields, NULL, NULL));
1108   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, &qf_fields, NULL, NULL));
1109   for (CeedInt i = 0; i < num_input_fields; i++) {
1110     CeedVector vec;
1111 
1112     CeedCallBackend(CeedOperatorFieldGetVector(op_fields[i], &vec));
1113     if (vec == CEED_VECTOR_ACTIVE) {
1114       CeedEvalMode eval_mode;
1115 
1116       CeedCallBackend(CeedOperatorFieldGetBasis(op_fields[i], &basis_in));
1117       CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_fields[i], &eval_mode));
1118       CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis_in, eval_mode, &q_comp));
1119       if (eval_mode != CEED_EVAL_WEIGHT) {
1120         num_eval_modes_in += q_comp;
1121       }
1122     }
1123   }
1124 
1125   // Determine active output basis
1126   CeedCallBackend(CeedOperatorGetFields(op, NULL, NULL, NULL, &op_fields));
1127   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, NULL, NULL, &qf_fields));
1128   for (CeedInt i = 0; i < num_output_fields; i++) {
1129     CeedVector vec;
1130 
1131     CeedCallBackend(CeedOperatorFieldGetVector(op_fields[i], &vec));
1132     if (vec == CEED_VECTOR_ACTIVE) {
1133       CeedEvalMode eval_mode;
1134 
1135       CeedCallBackend(CeedOperatorFieldGetBasis(op_fields[i], &basis_out));
1136       CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_fields[i], &eval_mode));
1137       CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis_out, eval_mode, &q_comp));
1138       if (eval_mode != CEED_EVAL_WEIGHT) {
1139         num_eval_modes_out += q_comp;
1140       }
1141     }
1142   }
1143 
1144   // Operator data struct
1145   CeedCallBackend(CeedOperatorGetData(op, &impl));
1146   CeedOperatorDiag_Cuda *diag = impl->diag;
1147 
1148   // Assemble kernel
1149   CUmodule *module          = is_point_block ? &diag->module_point_block : &diag->module;
1150   CeedInt   elems_per_block = 1;
1151   CeedCallBackend(CeedBasisGetNumNodes(basis_in, &num_nodes));
1152   CeedCallBackend(CeedBasisGetNumComponents(basis_in, &num_comp));
1153   if (basis_in == CEED_BASIS_NONE) num_qpts = num_nodes;
1154   else CeedCallBackend(CeedBasisGetNumQuadraturePoints(basis_in, &num_qpts));
1155   CeedCallBackend(CeedGetJitAbsolutePath(ceed, "ceed/jit-source/cuda/cuda-ref-operator-assemble-diagonal.h", &diagonal_kernel_path));
1156   CeedDebug256(ceed, CEED_DEBUG_COLOR_SUCCESS, "----- Loading Diagonal Assembly Kernel Source -----\n");
1157   CeedCallBackend(CeedLoadSourceToBuffer(ceed, diagonal_kernel_path, &diagonal_kernel_source));
1158   CeedDebug256(ceed, CEED_DEBUG_COLOR_SUCCESS, "----- Loading Diagonal Assembly Source Complete! -----\n");
1159   CeedCallCuda(ceed, CeedCompile_Cuda(ceed, diagonal_kernel_source, module, 8, "NUM_EVAL_MODES_IN", num_eval_modes_in, "NUM_EVAL_MODES_OUT",
1160                                       num_eval_modes_out, "NUM_COMP", num_comp, "NUM_NODES", num_nodes, "NUM_QPTS", num_qpts, "USE_CEEDSIZE",
1161                                       use_ceedsize_idx, "USE_POINT_BLOCK", is_point_block ? 1 : 0, "BLOCK_SIZE", num_nodes * elems_per_block));
1162   CeedCallCuda(ceed, CeedGetKernel_Cuda(ceed, *module, "LinearDiagonal", is_point_block ? &diag->LinearPointBlock : &diag->LinearDiagonal));
1163   CeedCallBackend(CeedFree(&diagonal_kernel_path));
1164   CeedCallBackend(CeedFree(&diagonal_kernel_source));
1165   return CEED_ERROR_SUCCESS;
1166 }
1167 
1168 //------------------------------------------------------------------------------
1169 // Assemble Diagonal Core
1170 //------------------------------------------------------------------------------
1171 static inline int CeedOperatorAssembleDiagonalCore_Cuda(CeedOperator op, CeedVector assembled, CeedRequest *request, const bool is_point_block) {
1172   Ceed                ceed;
1173   CeedInt             num_elem, num_nodes;
1174   CeedScalar         *elem_diag_array;
1175   const CeedScalar   *assembled_qf_array;
1176   CeedVector          assembled_qf   = NULL, elem_diag;
1177   CeedElemRestriction assembled_rstr = NULL, rstr_in, rstr_out, diag_rstr;
1178   CeedOperator_Cuda  *impl;
1179 
1180   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
1181   CeedCallBackend(CeedOperatorGetData(op, &impl));
1182 
1183   // Assemble QFunction
1184   CeedCallBackend(CeedOperatorLinearAssembleQFunctionBuildOrUpdate(op, &assembled_qf, &assembled_rstr, request));
1185   CeedCallBackend(CeedElemRestrictionDestroy(&assembled_rstr));
1186   CeedCallBackend(CeedVectorGetArrayRead(assembled_qf, CEED_MEM_DEVICE, &assembled_qf_array));
1187 
1188   // Setup
1189   if (!impl->diag) CeedCallBackend(CeedOperatorAssembleDiagonalSetup_Cuda(op));
1190   CeedOperatorDiag_Cuda *diag = impl->diag;
1191 
1192   assert(diag != NULL);
1193 
1194   // Assemble kernel if needed
1195   if ((!is_point_block && !diag->LinearDiagonal) || (is_point_block && !diag->LinearPointBlock)) {
1196     CeedSize assembled_length, assembled_qf_length;
1197     CeedInt  use_ceedsize_idx = 0;
1198     CeedCallBackend(CeedVectorGetLength(assembled, &assembled_length));
1199     CeedCallBackend(CeedVectorGetLength(assembled_qf, &assembled_qf_length));
1200     if ((assembled_length > INT_MAX) || (assembled_qf_length > INT_MAX)) use_ceedsize_idx = 1;
1201 
1202     CeedCallBackend(CeedOperatorAssembleDiagonalSetupCompile_Cuda(op, use_ceedsize_idx, is_point_block));
1203   }
1204 
1205   // Restriction and diagonal vector
1206   CeedCallBackend(CeedOperatorGetActiveElemRestrictions(op, &rstr_in, &rstr_out));
1207   CeedCheck(rstr_in == rstr_out, ceed, CEED_ERROR_BACKEND,
1208             "Cannot assemble operator diagonal with different input and output active element restrictions");
1209   if (!is_point_block && !diag->diag_rstr) {
1210     CeedCallBackend(CeedElemRestrictionCreateUnsignedCopy(rstr_out, &diag->diag_rstr));
1211     CeedCallBackend(CeedElemRestrictionCreateVector(diag->diag_rstr, NULL, &diag->elem_diag));
1212   } else if (is_point_block && !diag->point_block_diag_rstr) {
1213     CeedCallBackend(CeedOperatorCreateActivePointBlockRestriction(rstr_out, &diag->point_block_diag_rstr));
1214     CeedCallBackend(CeedElemRestrictionCreateVector(diag->point_block_diag_rstr, NULL, &diag->point_block_elem_diag));
1215   }
1216   diag_rstr = is_point_block ? diag->point_block_diag_rstr : diag->diag_rstr;
1217   elem_diag = is_point_block ? diag->point_block_elem_diag : diag->elem_diag;
1218   CeedCallBackend(CeedVectorSetValue(elem_diag, 0.0));
1219 
1220   // Only assemble diagonal if the basis has nodes, otherwise inputs are null pointers
1221   CeedCallBackend(CeedElemRestrictionGetElementSize(diag_rstr, &num_nodes));
1222   if (num_nodes > 0) {
1223     // Assemble element operator diagonals
1224     CeedCallBackend(CeedElemRestrictionGetNumElements(diag_rstr, &num_elem));
1225     CeedCallBackend(CeedVectorGetArray(elem_diag, CEED_MEM_DEVICE, &elem_diag_array));
1226 
1227     // Compute the diagonal of B^T D B
1228     CeedInt elems_per_block = 1;
1229     CeedInt grid            = CeedDivUpInt(num_elem, elems_per_block);
1230     void   *args[]          = {(void *)&num_elem,      &diag->d_identity,       &diag->d_interp_in,  &diag->d_grad_in, &diag->d_div_in,
1231                                &diag->d_curl_in,       &diag->d_interp_out,     &diag->d_grad_out,   &diag->d_div_out, &diag->d_curl_out,
1232                                &diag->d_eval_modes_in, &diag->d_eval_modes_out, &assembled_qf_array, &elem_diag_array};
1233 
1234     if (is_point_block) {
1235       CeedCallBackend(CeedRunKernelDim_Cuda(ceed, diag->LinearPointBlock, grid, num_nodes, 1, elems_per_block, args));
1236     } else {
1237       CeedCallBackend(CeedRunKernelDim_Cuda(ceed, diag->LinearDiagonal, grid, num_nodes, 1, elems_per_block, args));
1238     }
1239 
1240     // Restore arrays
1241     CeedCallBackend(CeedVectorRestoreArray(elem_diag, &elem_diag_array));
1242     CeedCallBackend(CeedVectorRestoreArrayRead(assembled_qf, &assembled_qf_array));
1243   }
1244 
1245   // Assemble local operator diagonal
1246   CeedCallBackend(CeedElemRestrictionApply(diag_rstr, CEED_TRANSPOSE, elem_diag, assembled, request));
1247 
1248   // Cleanup
1249   CeedCallBackend(CeedVectorDestroy(&assembled_qf));
1250   return CEED_ERROR_SUCCESS;
1251 }
1252 
1253 //------------------------------------------------------------------------------
1254 // Assemble Linear Diagonal
1255 //------------------------------------------------------------------------------
1256 static int CeedOperatorLinearAssembleAddDiagonal_Cuda(CeedOperator op, CeedVector assembled, CeedRequest *request) {
1257   CeedCallBackend(CeedOperatorAssembleDiagonalCore_Cuda(op, assembled, request, false));
1258   return CEED_ERROR_SUCCESS;
1259 }
1260 
1261 //------------------------------------------------------------------------------
1262 // Assemble Linear Point Block Diagonal
1263 //------------------------------------------------------------------------------
1264 static int CeedOperatorLinearAssembleAddPointBlockDiagonal_Cuda(CeedOperator op, CeedVector assembled, CeedRequest *request) {
1265   CeedCallBackend(CeedOperatorAssembleDiagonalCore_Cuda(op, assembled, request, true));
1266   return CEED_ERROR_SUCCESS;
1267 }
1268 
1269 //------------------------------------------------------------------------------
1270 // Single Operator Assembly Setup
1271 //------------------------------------------------------------------------------
1272 static int CeedSingleOperatorAssembleSetup_Cuda(CeedOperator op, CeedInt use_ceedsize_idx) {
1273   Ceed                ceed;
1274   Ceed_Cuda          *cuda_data;
1275   char               *assembly_kernel_source;
1276   const char         *assembly_kernel_path;
1277   CeedInt             num_input_fields, num_output_fields, num_eval_modes_in = 0, num_eval_modes_out = 0;
1278   CeedInt             elem_size_in, num_qpts_in = 0, num_comp_in, elem_size_out, num_qpts_out, num_comp_out, q_comp;
1279   CeedEvalMode       *eval_modes_in = NULL, *eval_modes_out = NULL;
1280   CeedElemRestriction rstr_in = NULL, rstr_out = NULL;
1281   CeedBasis           basis_in = NULL, basis_out = NULL;
1282   CeedQFunctionField *qf_fields;
1283   CeedQFunction       qf;
1284   CeedOperatorField  *input_fields, *output_fields;
1285   CeedOperator_Cuda  *impl;
1286 
1287   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
1288   CeedCallBackend(CeedOperatorGetData(op, &impl));
1289 
1290   // Get intput and output fields
1291   CeedCallBackend(CeedOperatorGetFields(op, &num_input_fields, &input_fields, &num_output_fields, &output_fields));
1292 
1293   // Determine active input basis eval mode
1294   CeedCallBackend(CeedOperatorGetQFunction(op, &qf));
1295   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, &qf_fields, NULL, NULL));
1296   for (CeedInt i = 0; i < num_input_fields; i++) {
1297     CeedVector vec;
1298 
1299     CeedCallBackend(CeedOperatorFieldGetVector(input_fields[i], &vec));
1300     if (vec == CEED_VECTOR_ACTIVE) {
1301       CeedBasis    basis;
1302       CeedEvalMode eval_mode;
1303 
1304       CeedCallBackend(CeedOperatorFieldGetBasis(input_fields[i], &basis));
1305       CeedCheck(!basis_in || basis_in == basis, ceed, CEED_ERROR_BACKEND, "Backend does not implement operator assembly with multiple active bases");
1306       basis_in = basis;
1307       CeedCallBackend(CeedOperatorFieldGetElemRestriction(input_fields[i], &rstr_in));
1308       CeedCallBackend(CeedElemRestrictionGetElementSize(rstr_in, &elem_size_in));
1309       if (basis_in == CEED_BASIS_NONE) num_qpts_in = elem_size_in;
1310       else CeedCallBackend(CeedBasisGetNumQuadraturePoints(basis_in, &num_qpts_in));
1311       CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_fields[i], &eval_mode));
1312       CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis_in, eval_mode, &q_comp));
1313       if (eval_mode != CEED_EVAL_WEIGHT) {
1314         // q_comp = 1 if CEED_EVAL_NONE, CEED_EVAL_WEIGHT caught by QF Assembly
1315         CeedCallBackend(CeedRealloc(num_eval_modes_in + q_comp, &eval_modes_in));
1316         for (CeedInt d = 0; d < q_comp; d++) {
1317           eval_modes_in[num_eval_modes_in + d] = eval_mode;
1318         }
1319         num_eval_modes_in += q_comp;
1320       }
1321     }
1322   }
1323 
1324   // Determine active output basis; basis_out and rstr_out only used if same as input, TODO
1325   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, NULL, NULL, &qf_fields));
1326   for (CeedInt i = 0; i < num_output_fields; i++) {
1327     CeedVector vec;
1328 
1329     CeedCallBackend(CeedOperatorFieldGetVector(output_fields[i], &vec));
1330     if (vec == CEED_VECTOR_ACTIVE) {
1331       CeedBasis    basis;
1332       CeedEvalMode eval_mode;
1333 
1334       CeedCallBackend(CeedOperatorFieldGetBasis(output_fields[i], &basis));
1335       CeedCheck(!basis_out || basis_out == basis, ceed, CEED_ERROR_BACKEND,
1336                 "Backend does not implement operator assembly with multiple active bases");
1337       basis_out = basis;
1338       CeedCallBackend(CeedOperatorFieldGetElemRestriction(output_fields[i], &rstr_out));
1339       CeedCallBackend(CeedElemRestrictionGetElementSize(rstr_out, &elem_size_out));
1340       if (basis_out == CEED_BASIS_NONE) num_qpts_out = elem_size_out;
1341       else CeedCallBackend(CeedBasisGetNumQuadraturePoints(basis_out, &num_qpts_out));
1342       CeedCheck(num_qpts_in == num_qpts_out, ceed, CEED_ERROR_UNSUPPORTED,
1343                 "Active input and output bases must have the same number of quadrature points");
1344       CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_fields[i], &eval_mode));
1345       CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis_out, eval_mode, &q_comp));
1346       if (eval_mode != CEED_EVAL_WEIGHT) {
1347         // q_comp = 1 if CEED_EVAL_NONE, CEED_EVAL_WEIGHT caught by QF Assembly
1348         CeedCallBackend(CeedRealloc(num_eval_modes_out + q_comp, &eval_modes_out));
1349         for (CeedInt d = 0; d < q_comp; d++) {
1350           eval_modes_out[num_eval_modes_out + d] = eval_mode;
1351         }
1352         num_eval_modes_out += q_comp;
1353       }
1354     }
1355   }
1356   CeedCheck(num_eval_modes_in > 0 && num_eval_modes_out > 0, ceed, CEED_ERROR_UNSUPPORTED, "Cannot assemble operator without inputs/outputs");
1357 
1358   CeedCallBackend(CeedCalloc(1, &impl->asmb));
1359   CeedOperatorAssemble_Cuda *asmb = impl->asmb;
1360   asmb->elems_per_block           = 1;
1361   asmb->block_size_x              = elem_size_in;
1362   asmb->block_size_y              = elem_size_out;
1363 
1364   CeedCallBackend(CeedGetData(ceed, &cuda_data));
1365   bool fallback = asmb->block_size_x * asmb->block_size_y * asmb->elems_per_block > cuda_data->device_prop.maxThreadsPerBlock;
1366 
1367   if (fallback) {
1368     // Use fallback kernel with 1D threadblock
1369     asmb->block_size_y = 1;
1370   }
1371 
1372   // Compile kernels
1373   CeedCallBackend(CeedElemRestrictionGetNumComponents(rstr_in, &num_comp_in));
1374   CeedCallBackend(CeedElemRestrictionGetNumComponents(rstr_out, &num_comp_out));
1375   CeedCallBackend(CeedGetJitAbsolutePath(ceed, "ceed/jit-source/cuda/cuda-ref-operator-assemble.h", &assembly_kernel_path));
1376   CeedDebug256(ceed, CEED_DEBUG_COLOR_SUCCESS, "----- Loading Assembly Kernel Source -----\n");
1377   CeedCallBackend(CeedLoadSourceToBuffer(ceed, assembly_kernel_path, &assembly_kernel_source));
1378   CeedDebug256(ceed, CEED_DEBUG_COLOR_SUCCESS, "----- Loading Assembly Source Complete! -----\n");
1379   CeedCallBackend(CeedCompile_Cuda(ceed, assembly_kernel_source, &asmb->module, 10, "NUM_EVAL_MODES_IN", num_eval_modes_in, "NUM_EVAL_MODES_OUT",
1380                                    num_eval_modes_out, "NUM_COMP_IN", num_comp_in, "NUM_COMP_OUT", num_comp_out, "NUM_NODES_IN", elem_size_in,
1381                                    "NUM_NODES_OUT", elem_size_out, "NUM_QPTS", num_qpts_in, "BLOCK_SIZE",
1382                                    asmb->block_size_x * asmb->block_size_y * asmb->elems_per_block, "BLOCK_SIZE_Y", asmb->block_size_y,
1383                                    "USE_CEEDSIZE", use_ceedsize_idx));
1384   CeedCallBackend(CeedGetKernel_Cuda(ceed, asmb->module, "LinearAssemble", &asmb->LinearAssemble));
1385   CeedCallBackend(CeedFree(&assembly_kernel_path));
1386   CeedCallBackend(CeedFree(&assembly_kernel_source));
1387 
1388   // Load into B_in, in order that they will be used in eval_modes_in
1389   {
1390     const CeedInt in_bytes           = elem_size_in * num_qpts_in * num_eval_modes_in * sizeof(CeedScalar);
1391     CeedInt       d_in               = 0;
1392     CeedEvalMode  eval_modes_in_prev = CEED_EVAL_NONE;
1393     bool          has_eval_none      = false;
1394     CeedScalar   *identity           = NULL;
1395 
1396     for (CeedInt i = 0; i < num_eval_modes_in; i++) {
1397       has_eval_none = has_eval_none || (eval_modes_in[i] == CEED_EVAL_NONE);
1398     }
1399     if (has_eval_none) {
1400       CeedCallBackend(CeedCalloc(elem_size_in * num_qpts_in, &identity));
1401       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;
1402     }
1403 
1404     CeedCallCuda(ceed, cudaMalloc((void **)&asmb->d_B_in, in_bytes));
1405     for (CeedInt i = 0; i < num_eval_modes_in; i++) {
1406       const CeedScalar *h_B_in;
1407 
1408       CeedCallBackend(CeedOperatorGetBasisPointer(basis_in, eval_modes_in[i], identity, &h_B_in));
1409       CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis_in, eval_modes_in[i], &q_comp));
1410       if (q_comp > 1) {
1411         if (i == 0 || eval_modes_in[i] != eval_modes_in_prev) d_in = 0;
1412         else h_B_in = &h_B_in[(++d_in) * elem_size_in * num_qpts_in];
1413       }
1414       eval_modes_in_prev = eval_modes_in[i];
1415 
1416       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),
1417                                     cudaMemcpyHostToDevice));
1418     }
1419 
1420     if (identity) {
1421       CeedCallBackend(CeedFree(&identity));
1422     }
1423   }
1424 
1425   // Load into B_out, in order that they will be used in eval_modes_out
1426   {
1427     const CeedInt out_bytes           = elem_size_out * num_qpts_out * num_eval_modes_out * sizeof(CeedScalar);
1428     CeedInt       d_out               = 0;
1429     CeedEvalMode  eval_modes_out_prev = CEED_EVAL_NONE;
1430     bool          has_eval_none       = false;
1431     CeedScalar   *identity            = NULL;
1432 
1433     for (CeedInt i = 0; i < num_eval_modes_out; i++) {
1434       has_eval_none = has_eval_none || (eval_modes_out[i] == CEED_EVAL_NONE);
1435     }
1436     if (has_eval_none) {
1437       CeedCallBackend(CeedCalloc(elem_size_out * num_qpts_out, &identity));
1438       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;
1439     }
1440 
1441     CeedCallCuda(ceed, cudaMalloc((void **)&asmb->d_B_out, out_bytes));
1442     for (CeedInt i = 0; i < num_eval_modes_out; i++) {
1443       const CeedScalar *h_B_out;
1444 
1445       CeedCallBackend(CeedOperatorGetBasisPointer(basis_out, eval_modes_out[i], identity, &h_B_out));
1446       CeedCallBackend(CeedBasisGetNumQuadratureComponents(basis_out, eval_modes_out[i], &q_comp));
1447       if (q_comp > 1) {
1448         if (i == 0 || eval_modes_out[i] != eval_modes_out_prev) d_out = 0;
1449         else h_B_out = &h_B_out[(++d_out) * elem_size_out * num_qpts_out];
1450       }
1451       eval_modes_out_prev = eval_modes_out[i];
1452 
1453       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),
1454                                     cudaMemcpyHostToDevice));
1455     }
1456 
1457     if (identity) {
1458       CeedCallBackend(CeedFree(&identity));
1459     }
1460   }
1461   return CEED_ERROR_SUCCESS;
1462 }
1463 
1464 //------------------------------------------------------------------------------
1465 // Assemble matrix data for COO matrix of assembled operator.
1466 // The sparsity pattern is set by CeedOperatorLinearAssembleSymbolic.
1467 //
1468 // Note that this (and other assembly routines) currently assume only one active input restriction/basis per operator (could have multiple basis eval
1469 // modes).
1470 // TODO: allow multiple active input restrictions/basis objects
1471 //------------------------------------------------------------------------------
1472 static int CeedSingleOperatorAssemble_Cuda(CeedOperator op, CeedInt offset, CeedVector values) {
1473   Ceed                ceed;
1474   CeedSize            values_length = 0, assembled_qf_length = 0;
1475   CeedInt             use_ceedsize_idx = 0, num_elem_in, num_elem_out, elem_size_in, elem_size_out;
1476   CeedScalar         *values_array;
1477   const CeedScalar   *assembled_qf_array;
1478   CeedVector          assembled_qf   = NULL;
1479   CeedElemRestriction assembled_rstr = NULL, rstr_in, rstr_out;
1480   CeedRestrictionType rstr_type_in, rstr_type_out;
1481   const bool         *orients_in = NULL, *orients_out = NULL;
1482   const CeedInt8     *curl_orients_in = NULL, *curl_orients_out = NULL;
1483   CeedOperator_Cuda  *impl;
1484 
1485   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
1486   CeedCallBackend(CeedOperatorGetData(op, &impl));
1487 
1488   // Assemble QFunction
1489   CeedCallBackend(CeedOperatorLinearAssembleQFunctionBuildOrUpdate(op, &assembled_qf, &assembled_rstr, CEED_REQUEST_IMMEDIATE));
1490   CeedCallBackend(CeedElemRestrictionDestroy(&assembled_rstr));
1491   CeedCallBackend(CeedVectorGetArrayRead(assembled_qf, CEED_MEM_DEVICE, &assembled_qf_array));
1492 
1493   CeedCallBackend(CeedVectorGetLength(values, &values_length));
1494   CeedCallBackend(CeedVectorGetLength(assembled_qf, &assembled_qf_length));
1495   if ((values_length > INT_MAX) || (assembled_qf_length > INT_MAX)) use_ceedsize_idx = 1;
1496 
1497   // Setup
1498   if (!impl->asmb) CeedCallBackend(CeedSingleOperatorAssembleSetup_Cuda(op, use_ceedsize_idx));
1499   CeedOperatorAssemble_Cuda *asmb = impl->asmb;
1500 
1501   assert(asmb != NULL);
1502 
1503   // Assemble element operator
1504   CeedCallBackend(CeedVectorGetArray(values, CEED_MEM_DEVICE, &values_array));
1505   values_array += offset;
1506 
1507   CeedCallBackend(CeedOperatorGetActiveElemRestrictions(op, &rstr_in, &rstr_out));
1508   CeedCallBackend(CeedElemRestrictionGetNumElements(rstr_in, &num_elem_in));
1509   CeedCallBackend(CeedElemRestrictionGetElementSize(rstr_in, &elem_size_in));
1510 
1511   CeedCallBackend(CeedElemRestrictionGetType(rstr_in, &rstr_type_in));
1512   if (rstr_type_in == CEED_RESTRICTION_ORIENTED) {
1513     CeedCallBackend(CeedElemRestrictionGetOrientations(rstr_in, CEED_MEM_DEVICE, &orients_in));
1514   } else if (rstr_type_in == CEED_RESTRICTION_CURL_ORIENTED) {
1515     CeedCallBackend(CeedElemRestrictionGetCurlOrientations(rstr_in, CEED_MEM_DEVICE, &curl_orients_in));
1516   }
1517 
1518   if (rstr_in != rstr_out) {
1519     CeedCallBackend(CeedElemRestrictionGetNumElements(rstr_out, &num_elem_out));
1520     CeedCheck(num_elem_in == num_elem_out, ceed, CEED_ERROR_UNSUPPORTED,
1521               "Active input and output operator restrictions must have the same number of elements");
1522     CeedCallBackend(CeedElemRestrictionGetElementSize(rstr_out, &elem_size_out));
1523 
1524     CeedCallBackend(CeedElemRestrictionGetType(rstr_out, &rstr_type_out));
1525     if (rstr_type_out == CEED_RESTRICTION_ORIENTED) {
1526       CeedCallBackend(CeedElemRestrictionGetOrientations(rstr_out, CEED_MEM_DEVICE, &orients_out));
1527     } else if (rstr_type_out == CEED_RESTRICTION_CURL_ORIENTED) {
1528       CeedCallBackend(CeedElemRestrictionGetCurlOrientations(rstr_out, CEED_MEM_DEVICE, &curl_orients_out));
1529     }
1530   } else {
1531     elem_size_out    = elem_size_in;
1532     orients_out      = orients_in;
1533     curl_orients_out = curl_orients_in;
1534   }
1535 
1536   // Compute B^T D B
1537   CeedInt shared_mem =
1538       ((curl_orients_in || curl_orients_out ? elem_size_in * elem_size_out : 0) + (curl_orients_in ? elem_size_in * asmb->block_size_y : 0)) *
1539       sizeof(CeedScalar);
1540   CeedInt grid   = CeedDivUpInt(num_elem_in, asmb->elems_per_block);
1541   void   *args[] = {(void *)&num_elem_in, &asmb->d_B_in,     &asmb->d_B_out,      &orients_in,  &curl_orients_in,
1542                     &orients_out,         &curl_orients_out, &assembled_qf_array, &values_array};
1543 
1544   CeedCallBackend(
1545       CeedRunKernelDimShared_Cuda(ceed, asmb->LinearAssemble, grid, asmb->block_size_x, asmb->block_size_y, asmb->elems_per_block, shared_mem, args));
1546 
1547   // Restore arrays
1548   CeedCallBackend(CeedVectorRestoreArray(values, &values_array));
1549   CeedCallBackend(CeedVectorRestoreArrayRead(assembled_qf, &assembled_qf_array));
1550 
1551   // Cleanup
1552   CeedCallBackend(CeedVectorDestroy(&assembled_qf));
1553   if (rstr_type_in == CEED_RESTRICTION_ORIENTED) {
1554     CeedCallBackend(CeedElemRestrictionRestoreOrientations(rstr_in, &orients_in));
1555   } else if (rstr_type_in == CEED_RESTRICTION_CURL_ORIENTED) {
1556     CeedCallBackend(CeedElemRestrictionRestoreCurlOrientations(rstr_in, &curl_orients_in));
1557   }
1558   if (rstr_in != rstr_out) {
1559     if (rstr_type_out == CEED_RESTRICTION_ORIENTED) {
1560       CeedCallBackend(CeedElemRestrictionRestoreOrientations(rstr_out, &orients_out));
1561     } else if (rstr_type_out == CEED_RESTRICTION_CURL_ORIENTED) {
1562       CeedCallBackend(CeedElemRestrictionRestoreCurlOrientations(rstr_out, &curl_orients_out));
1563     }
1564   }
1565   return CEED_ERROR_SUCCESS;
1566 }
1567 
1568 //------------------------------------------------------------------------------
1569 // Assemble Linear QFunction AtPoints
1570 //------------------------------------------------------------------------------
1571 static int CeedOperatorLinearAssembleQFunctionAtPoints_Cuda(CeedOperator op, CeedVector *assembled, CeedElemRestriction *rstr, CeedRequest *request) {
1572   return CeedError(CeedOperatorReturnCeed(op), CEED_ERROR_BACKEND, "Backend does not implement CeedOperatorLinearAssembleQFunction");
1573 }
1574 
1575 //------------------------------------------------------------------------------
1576 // Assemble Linear Diagonal AtPoints
1577 //------------------------------------------------------------------------------
1578 static int CeedOperatorLinearAssembleAddDiagonalAtPoints_Cuda(CeedOperator op, CeedVector assembled, CeedRequest *request) {
1579   CeedInt             max_num_points, num_elem, num_input_fields, num_output_fields;
1580   CeedScalar         *e_data[2 * CEED_FIELD_MAX] = {NULL};
1581   CeedQFunctionField *qf_input_fields, *qf_output_fields;
1582   CeedQFunction       qf;
1583   CeedOperatorField  *op_input_fields, *op_output_fields;
1584   CeedOperator_Cuda  *impl;
1585 
1586   CeedCallBackend(CeedOperatorGetData(op, &impl));
1587   CeedCallBackend(CeedOperatorGetQFunction(op, &qf));
1588   CeedCallBackend(CeedOperatorGetNumElements(op, &num_elem));
1589   CeedCallBackend(CeedOperatorGetFields(op, &num_input_fields, &op_input_fields, &num_output_fields, &op_output_fields));
1590   CeedCallBackend(CeedQFunctionGetFields(qf, NULL, &qf_input_fields, NULL, &qf_output_fields));
1591   CeedInt num_points[num_elem];
1592 
1593   // Setup
1594   CeedCallBackend(CeedOperatorSetupAtPoints_Cuda(op));
1595   max_num_points = impl->max_num_points;
1596   for (CeedInt i = 0; i < num_elem; i++) num_points[i] = max_num_points;
1597 
1598   // Input Evecs and Restriction
1599   CeedCallBackend(CeedOperatorSetupInputs_Cuda(num_input_fields, qf_input_fields, op_input_fields, NULL, true, e_data, impl, request));
1600 
1601   // Get point coordinates
1602   if (!impl->point_coords_elem) {
1603     CeedVector          point_coords = NULL;
1604     CeedElemRestriction rstr_points  = NULL;
1605 
1606     CeedCallBackend(CeedOperatorAtPointsGetPoints(op, &rstr_points, &point_coords));
1607     CeedCallBackend(CeedElemRestrictionCreateVector(rstr_points, NULL, &impl->point_coords_elem));
1608     CeedCallBackend(CeedElemRestrictionApply(rstr_points, CEED_NOTRANSPOSE, point_coords, impl->point_coords_elem, request));
1609   }
1610 
1611   // Clear active input Qvecs
1612   for (CeedInt i = 0; i < num_input_fields; i++) {
1613     CeedVector vec;
1614 
1615     CeedCallBackend(CeedOperatorFieldGetVector(op_input_fields[i], &vec));
1616     if (vec != CEED_VECTOR_ACTIVE) continue;
1617     CeedCallBackend(CeedVectorSetValue(impl->q_vecs_in[i], 0.0));
1618   }
1619 
1620   // Input basis apply if needed
1621   CeedCallBackend(CeedOperatorInputBasisAtPoints_Cuda(num_elem, num_points, qf_input_fields, op_input_fields, num_input_fields, true, e_data, impl));
1622 
1623   // Output pointers, as necessary
1624   for (CeedInt i = 0; i < num_output_fields; i++) {
1625     CeedEvalMode eval_mode;
1626 
1627     CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_output_fields[i], &eval_mode));
1628     if (eval_mode == CEED_EVAL_NONE) {
1629       // Set the output Q-Vector to use the E-Vector data directly.
1630       CeedCallBackend(CeedVectorGetArrayWrite(impl->e_vecs[i + impl->num_inputs], CEED_MEM_DEVICE, &e_data[i + num_input_fields]));
1631       CeedCallBackend(CeedVectorSetArray(impl->q_vecs_out[i], CEED_MEM_DEVICE, CEED_USE_POINTER, e_data[i + num_input_fields]));
1632     }
1633   }
1634 
1635   // Loop over active fields
1636   for (CeedInt i = 0; i < num_input_fields; i++) {
1637     bool                is_active_at_points = true;
1638     CeedInt             elem_size = 1, num_comp_active = 1, e_vec_size = 0;
1639     CeedRestrictionType rstr_type;
1640     CeedVector          vec;
1641     CeedElemRestriction elem_rstr;
1642 
1643     CeedCallBackend(CeedOperatorFieldGetVector(op_input_fields[i], &vec));
1644     // -- Skip non-active input
1645     if (vec != CEED_VECTOR_ACTIVE) continue;
1646 
1647     // -- Get active restriction type
1648     CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_input_fields[i], &elem_rstr));
1649     CeedCallBackend(CeedElemRestrictionGetType(elem_rstr, &rstr_type));
1650     is_active_at_points = rstr_type == CEED_RESTRICTION_POINTS;
1651     if (!is_active_at_points) CeedCallBackend(CeedElemRestrictionGetElementSize(elem_rstr, &elem_size));
1652     else elem_size = max_num_points;
1653     CeedCallBackend(CeedElemRestrictionGetNumComponents(elem_rstr, &num_comp_active));
1654 
1655     e_vec_size = elem_size * num_comp_active;
1656     for (CeedInt s = 0; s < e_vec_size; s++) {
1657       bool         is_active_input = false;
1658       CeedEvalMode eval_mode;
1659       CeedVector   vec;
1660       CeedBasis    basis;
1661 
1662       CeedCallBackend(CeedOperatorFieldGetVector(op_input_fields[i], &vec));
1663       // Skip non-active input
1664       is_active_input = vec == CEED_VECTOR_ACTIVE;
1665       if (!is_active_input) continue;
1666 
1667       // Update unit vector
1668       if (s == 0) CeedCallBackend(CeedVectorSetValue(impl->e_vecs[i], 0.0));
1669       else CeedCallBackend(CeedVectorSetValueStrided(impl->e_vecs[i], s - 1, e_vec_size, 0.0));
1670       CeedCallBackend(CeedVectorSetValueStrided(impl->e_vecs[i], s, e_vec_size, 1.0));
1671 
1672       // Basis action
1673       CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_input_fields[i], &eval_mode));
1674       switch (eval_mode) {
1675         case CEED_EVAL_NONE:
1676           CeedCallBackend(CeedVectorSetArray(impl->q_vecs_in[i], CEED_MEM_DEVICE, CEED_USE_POINTER, e_data[i]));
1677           break;
1678         case CEED_EVAL_INTERP:
1679         case CEED_EVAL_GRAD:
1680         case CEED_EVAL_DIV:
1681         case CEED_EVAL_CURL:
1682           CeedCallBackend(CeedOperatorFieldGetBasis(op_input_fields[i], &basis));
1683           CeedCallBackend(CeedBasisApplyAtPoints(basis, num_elem, num_points, CEED_NOTRANSPOSE, eval_mode, impl->point_coords_elem, impl->e_vecs[i],
1684                                                  impl->q_vecs_in[i]));
1685           break;
1686         case CEED_EVAL_WEIGHT:
1687           break;  // No action
1688       }
1689 
1690       // Q function
1691       CeedCallBackend(CeedQFunctionApply(qf, num_elem * max_num_points, impl->q_vecs_in, impl->q_vecs_out));
1692 
1693       // Output basis apply if needed
1694       for (CeedInt j = 0; j < num_output_fields; j++) {
1695         bool                is_active_output = false;
1696         CeedInt             elem_size        = 0;
1697         CeedRestrictionType rstr_type;
1698         CeedEvalMode        eval_mode;
1699         CeedVector          vec;
1700         CeedElemRestriction elem_rstr;
1701         CeedBasis           basis;
1702 
1703         CeedCallBackend(CeedOperatorFieldGetVector(op_output_fields[j], &vec));
1704         // ---- Skip non-active output
1705         is_active_output = vec == CEED_VECTOR_ACTIVE;
1706         if (!is_active_output) continue;
1707 
1708         // ---- Check if elem size matches
1709         CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_output_fields[j], &elem_rstr));
1710         CeedCallBackend(CeedElemRestrictionGetType(elem_rstr, &rstr_type));
1711         if (is_active_at_points && rstr_type != CEED_RESTRICTION_POINTS) continue;
1712         if (rstr_type == CEED_RESTRICTION_POINTS) {
1713           CeedCallBackend(CeedElemRestrictionGetMaxPointsInElement(elem_rstr, &elem_size));
1714         } else {
1715           CeedCallBackend(CeedElemRestrictionGetElementSize(elem_rstr, &elem_size));
1716         }
1717         {
1718           CeedInt num_comp = 0;
1719 
1720           CeedCallBackend(CeedElemRestrictionGetNumComponents(elem_rstr, &num_comp));
1721           if (e_vec_size != num_comp * elem_size) continue;
1722         }
1723 
1724         // Basis action
1725         CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_output_fields[j], &eval_mode));
1726         switch (eval_mode) {
1727           case CEED_EVAL_NONE:
1728             CeedCallBackend(CeedVectorRestoreArray(impl->e_vecs[j + impl->num_inputs], &e_data[j + num_input_fields]));
1729             break;
1730           case CEED_EVAL_INTERP:
1731           case CEED_EVAL_GRAD:
1732           case CEED_EVAL_DIV:
1733           case CEED_EVAL_CURL:
1734             CeedCallBackend(CeedOperatorFieldGetBasis(op_output_fields[j], &basis));
1735             CeedCallBackend(CeedBasisApplyAtPoints(basis, num_elem, num_points, CEED_TRANSPOSE, eval_mode, impl->point_coords_elem,
1736                                                    impl->q_vecs_out[j], impl->e_vecs[j + impl->num_inputs]));
1737             break;
1738           // LCOV_EXCL_START
1739           case CEED_EVAL_WEIGHT: {
1740             return CeedError(CeedOperatorReturnCeed(op), CEED_ERROR_BACKEND, "CEED_EVAL_WEIGHT cannot be an output evaluation mode");
1741             // LCOV_EXCL_STOP
1742           }
1743         }
1744 
1745         // Mask output e-vec
1746         CeedCallBackend(CeedVectorPointwiseMult(impl->e_vecs[j + impl->num_inputs], impl->e_vecs[i], impl->e_vecs[j + impl->num_inputs]));
1747 
1748         // Restrict
1749         CeedCallBackend(CeedOperatorFieldGetElemRestriction(op_output_fields[j], &elem_rstr));
1750         CeedCallBackend(CeedElemRestrictionApply(elem_rstr, CEED_TRANSPOSE, impl->e_vecs[j + impl->num_inputs], assembled, request));
1751 
1752         // Reset q_vec for
1753         if (eval_mode == CEED_EVAL_NONE) {
1754           CeedCallBackend(CeedVectorGetArrayWrite(impl->e_vecs[j + impl->num_inputs], CEED_MEM_DEVICE, &e_data[j + num_input_fields]));
1755           CeedCallBackend(CeedVectorSetArray(impl->q_vecs_out[j], CEED_MEM_DEVICE, CEED_USE_POINTER, e_data[j + num_input_fields]));
1756         }
1757       }
1758 
1759       // Reset vec
1760       if (s == e_vec_size - 1 && i != num_input_fields - 1) CeedCallBackend(CeedVectorSetValue(impl->q_vecs_in[i], 0.0));
1761     }
1762   }
1763 
1764   // Restore CEED_EVAL_NONE
1765   for (CeedInt i = 0; i < num_output_fields; i++) {
1766     CeedEvalMode eval_mode;
1767 
1768     // Get eval_mode
1769     CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_output_fields[i], &eval_mode));
1770 
1771     // Restore evec
1772     CeedCallBackend(CeedQFunctionFieldGetEvalMode(qf_output_fields[i], &eval_mode));
1773     if (eval_mode == CEED_EVAL_NONE) {
1774       CeedCallBackend(CeedVectorRestoreArray(impl->e_vecs[i + impl->num_inputs], &e_data[i + num_input_fields]));
1775     }
1776   }
1777 
1778   // Restore input arrays
1779   CeedCallBackend(CeedOperatorRestoreInputs_Cuda(num_input_fields, qf_input_fields, op_input_fields, true, e_data, impl));
1780   return CEED_ERROR_SUCCESS;
1781 }
1782 
1783 //------------------------------------------------------------------------------
1784 // Create operator
1785 //------------------------------------------------------------------------------
1786 int CeedOperatorCreate_Cuda(CeedOperator op) {
1787   Ceed               ceed;
1788   CeedOperator_Cuda *impl;
1789 
1790   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
1791   CeedCallBackend(CeedCalloc(1, &impl));
1792   CeedCallBackend(CeedOperatorSetData(op, impl));
1793 
1794   CeedCallBackend(CeedSetBackendFunction(ceed, "Operator", op, "LinearAssembleQFunction", CeedOperatorLinearAssembleQFunction_Cuda));
1795   CeedCallBackend(CeedSetBackendFunction(ceed, "Operator", op, "LinearAssembleQFunctionUpdate", CeedOperatorLinearAssembleQFunctionUpdate_Cuda));
1796   CeedCallBackend(CeedSetBackendFunction(ceed, "Operator", op, "LinearAssembleAddDiagonal", CeedOperatorLinearAssembleAddDiagonal_Cuda));
1797   CeedCallBackend(
1798       CeedSetBackendFunction(ceed, "Operator", op, "LinearAssembleAddPointBlockDiagonal", CeedOperatorLinearAssembleAddPointBlockDiagonal_Cuda));
1799   CeedCallBackend(CeedSetBackendFunction(ceed, "Operator", op, "LinearAssembleSingle", CeedSingleOperatorAssemble_Cuda));
1800   CeedCallBackend(CeedSetBackendFunction(ceed, "Operator", op, "ApplyAdd", CeedOperatorApplyAdd_Cuda));
1801   CeedCallBackend(CeedSetBackendFunction(ceed, "Operator", op, "Destroy", CeedOperatorDestroy_Cuda));
1802   return CEED_ERROR_SUCCESS;
1803 }
1804 
1805 //------------------------------------------------------------------------------
1806 // Create operator AtPoints
1807 //------------------------------------------------------------------------------
1808 int CeedOperatorCreateAtPoints_Cuda(CeedOperator op) {
1809   Ceed               ceed;
1810   CeedOperator_Cuda *impl;
1811 
1812   CeedCallBackend(CeedOperatorGetCeed(op, &ceed));
1813   CeedCallBackend(CeedCalloc(1, &impl));
1814   CeedCallBackend(CeedOperatorSetData(op, impl));
1815 
1816   CeedCallBackend(CeedSetBackendFunction(ceed, "Operator", op, "LinearAssembleQFunction", CeedOperatorLinearAssembleQFunctionAtPoints_Cuda));
1817   CeedCallBackend(CeedSetBackendFunction(ceed, "Operator", op, "LinearAssembleAddDiagonal", CeedOperatorLinearAssembleAddDiagonalAtPoints_Cuda));
1818   CeedCallBackend(CeedSetBackendFunction(ceed, "Operator", op, "ApplyAdd", CeedOperatorApplyAddAtPoints_Cuda));
1819   CeedCallBackend(CeedSetBackendFunction(ceed, "Operator", op, "Destroy", CeedOperatorDestroy_Cuda));
1820   return CEED_ERROR_SUCCESS;
1821 }
1822 
1823 //------------------------------------------------------------------------------
1824