xref: /libCEED/include/ceed/jit-source/gallery/ceed-poisson2dapply.h (revision ea6b58218a3c4883c2efd66165b4d6b684f89f5a)
1 // Copyright (c) 2017-2022, 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 /**
9   @brief Ceed QFunction for applying the 2D Poisson operator
10 **/
11 
12 #ifndef poisson2dapply_h
13 #define poisson2dapply_h
14 
15 CEED_QFUNCTION(Poisson2DApply)(void *ctx, const CeedInt Q,
16                                const CeedScalar *const *in,
17                                CeedScalar *const *out) {
18   // *INDENT-OFF*
19   // in[0] is gradient u, shape [2, nc=1, Q]
20   // in[1] is quadrature data, size (3*Q)
21   const CeedScalar (*ug)[CEED_Q_VLA] = (const CeedScalar(*)[CEED_Q_VLA])in[0],
22                (*q_data)[CEED_Q_VLA] = (const CeedScalar(*)[CEED_Q_VLA])in[1];
23   // out[0] is output to multiply against gradient v, shape [2, nc=1, Q]
24   CeedScalar       (*vg)[CEED_Q_VLA] = (CeedScalar(*)[CEED_Q_VLA])out[0];
25   // *INDENT-ON*
26 
27   const CeedInt dim = 2;
28 
29   // Quadrature point loop
30   CeedPragmaSIMD
31   for (CeedInt i=0; i<Q; i++) {
32     // Read qdata (dXdxdXdxT symmetric matrix)
33     // Stored in Voigt convention
34     // 0 2
35     // 2 1
36     // *INDENT-OFF*
37     const CeedScalar dXdxdXdxT[2][2] = {{q_data[0][i],
38                                          q_data[2][i]},
39                                         {q_data[2][i],
40                                          q_data[1][i]}
41                                        };
42     // *INDENT-ON*
43 
44     // Apply Poisson operator
45     // j = direction of vg
46     for (CeedInt j=0; j<dim; j++)
47       vg[j][i] = (ug[0][i] * dXdxdXdxT[0][j] +
48                   ug[1][i] * dXdxdXdxT[1][j]);
49   } // End of Quadrature Point Loop
50 
51   return CEED_ERROR_SUCCESS;
52 }
53 
54 #endif // poisson2dapply_h
55