xref: /libCEED/include/ceed/jit-source/gallery/ceed-poisson2dbuild.h (revision 2b730f8b5a9c809740a0b3b302db43a719c636b1)
1a0154adeSJed Brown // Copyright (c) 2017-2022, Lawrence Livermore National Security, LLC and other CEED contributors.
2a0154adeSJed Brown // All Rights Reserved. See the top-level LICENSE and NOTICE files for details.
3a0154adeSJed Brown //
4a0154adeSJed Brown // SPDX-License-Identifier: BSD-2-Clause
5a0154adeSJed Brown //
6a0154adeSJed Brown // This file is part of CEED:  http://github.com/ceed
7a0154adeSJed Brown 
8a0154adeSJed Brown /**
9a0154adeSJed Brown   @brief Ceed QFunction for building the geometric data for the 2D Poisson operator
10a0154adeSJed Brown **/
11a0154adeSJed Brown 
12a0154adeSJed Brown #ifndef poisson2dbuild_h
13a0154adeSJed Brown #define poisson2dbuild_h
14a0154adeSJed Brown 
15c9c2c079SJeremy L Thompson #include <ceed.h>
16c9c2c079SJeremy L Thompson 
17*2b730f8bSJeremy L Thompson CEED_QFUNCTION(Poisson2DBuild)(void *ctx, const CeedInt Q, const CeedScalar *const *in, CeedScalar *const *out) {
18a0154adeSJed Brown   // At every quadrature point, compute w/det(J).adj(J).adj(J)^T and store
19a0154adeSJed Brown   // the symmetric part of the result.
20a0154adeSJed Brown   // *INDENT-OFF*
21a0154adeSJed Brown   // in[0] is Jacobians with shape [2, nc=2, Q]
22a0154adeSJed Brown   // in[1] is quadrature weights, size (Q)
23*2b730f8bSJeremy L Thompson   const CeedScalar(*J)[2][CEED_Q_VLA] = (const CeedScalar(*)[2][CEED_Q_VLA])in[0], *w = in[1];
24a0154adeSJed Brown   // out[0] is qdata, size (3*Q)
25a0154adeSJed Brown   CeedScalar(*q_data)[CEED_Q_VLA] = (CeedScalar(*)[CEED_Q_VLA])out[0];
26a0154adeSJed Brown   // *INDENT-ON*
27a0154adeSJed Brown 
28a0154adeSJed Brown   // Quadrature point loop
29*2b730f8bSJeremy L Thompson   CeedPragmaSIMD for (CeedInt i = 0; i < Q; i++) {
30a0154adeSJed Brown     // Qdata stored in Voigt convention
31a0154adeSJed Brown     // J: 0 2   q_data: 0 2   adj(J):  J11 -J01
32a0154adeSJed Brown     //    1 3           2 1           -J10  J00
33a0154adeSJed Brown     const CeedScalar J00 = J[0][0][i];
34a0154adeSJed Brown     const CeedScalar J10 = J[0][1][i];
35a0154adeSJed Brown     const CeedScalar J01 = J[1][0][i];
36a0154adeSJed Brown     const CeedScalar J11 = J[1][1][i];
37a0154adeSJed Brown     const CeedScalar qw  = w[i] / (J00 * J11 - J10 * J01);
38a0154adeSJed Brown     q_data[0][i]         = qw * (J01 * J01 + J11 * J11);
39a0154adeSJed Brown     q_data[1][i]         = qw * (J00 * J00 + J10 * J10);
40a0154adeSJed Brown     q_data[2][i]         = -qw * (J00 * J01 + J10 * J11);
41a0154adeSJed Brown   }  // End of Quadrature Point Loop
42a0154adeSJed Brown 
43a0154adeSJed Brown   return CEED_ERROR_SUCCESS;
44a0154adeSJed Brown }
45a0154adeSJed Brown 
46a0154adeSJed Brown #endif  // poisson2dbuild_h
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