xref: /libCEED/include/ceed/jit-source/gallery/ceed-poisson3dbuild.h (revision 5aed82e4fa97acf4ba24a7f10a35f5303a6798e0)
1*5aed82e4SJeremy L Thompson // Copyright (c) 2017-2024, 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 /**
9ea61e9acSJeremy L Thompson   @brief Ceed QFunction for building the geometric data for the 3D Poisson operator
10a0154adeSJed Brown **/
11a0154adeSJed Brown 
1294b7b29bSJeremy L Thompson #ifndef CEED_POISSON3DBUILD_H
1394b7b29bSJeremy L Thompson #define CEED_POISSON3DBUILD_H
14a0154adeSJed Brown 
15c9c2c079SJeremy L Thompson #include <ceed.h>
16c9c2c079SJeremy L Thompson 
172b730f8bSJeremy L Thompson CEED_QFUNCTION(Poisson3DBuild)(void *ctx, const CeedInt Q, const CeedScalar *const *in, CeedScalar *const *out) {
18ea61e9acSJeremy L Thompson   // At every quadrature point, compute w/det(J).adj(J).adj(J)^T and store the symmetric part of the result.
19a0154adeSJed Brown   // in[0] is Jacobians with shape [3, nc=3, Q]
20a0154adeSJed Brown   // in[1] is quadrature weights, size (Q)
212b730f8bSJeremy L Thompson   const CeedScalar(*J)[3][CEED_Q_VLA] = (const CeedScalar(*)[3][CEED_Q_VLA])in[0], *w = in[1];
22a0154adeSJed Brown   // out[0] is qdata, size (6*Q)
23a0154adeSJed Brown   CeedScalar(*q_data)[CEED_Q_VLA] = (CeedScalar(*)[CEED_Q_VLA])out[0];
24a0154adeSJed Brown 
25a0154adeSJed Brown   const CeedInt dim = 3;
26a0154adeSJed Brown 
27a0154adeSJed Brown   // Quadrature point loop
282b730f8bSJeremy L Thompson   CeedPragmaSIMD for (CeedInt i = 0; i < Q; i++) {
29a0154adeSJed Brown     // Compute the adjoint
30a0154adeSJed Brown     CeedScalar A[3][3];
31a0154adeSJed Brown     for (CeedInt j = 0; j < dim; j++)
32a0154adeSJed Brown       for (CeedInt k = 0; k < dim; k++)
33a0154adeSJed Brown         // Equivalent code with no mod operations:
34a0154adeSJed Brown         // A[k][j] = J[k+1][j+1]*J[k+2][j+2] - J[k+2][j+1]*J[k+1][j+2]
35a0154adeSJed Brown         A[k][j] = J[(k + 1) % dim][(j + 1) % dim][i] * J[(k + 2) % dim][(j + 2) % dim][i] -
36a0154adeSJed Brown                   J[(k + 2) % dim][(j + 1) % dim][i] * J[(k + 1) % dim][(j + 2) % dim][i];
37a0154adeSJed Brown 
38a0154adeSJed Brown     // Compute quadrature weight / det(J)
392b730f8bSJeremy L Thompson     const CeedScalar qw = w[i] / (J[0][0][i] * A[0][0] + J[0][1][i] * A[0][1] + J[0][2][i] * A[0][2]);
40a0154adeSJed Brown 
41a0154adeSJed Brown     // Compute geometric factors
42a0154adeSJed Brown     // Stored in Voigt convention
43a0154adeSJed Brown     // 0 5 4
44a0154adeSJed Brown     // 5 1 3
45a0154adeSJed Brown     // 4 3 2
46a0154adeSJed Brown     q_data[0][i] = qw * (A[0][0] * A[0][0] + A[0][1] * A[0][1] + A[0][2] * A[0][2]);
47a0154adeSJed Brown     q_data[1][i] = qw * (A[1][0] * A[1][0] + A[1][1] * A[1][1] + A[1][2] * A[1][2]);
48a0154adeSJed Brown     q_data[2][i] = qw * (A[2][0] * A[2][0] + A[2][1] * A[2][1] + A[2][2] * A[2][2]);
49a0154adeSJed Brown     q_data[3][i] = qw * (A[1][0] * A[2][0] + A[1][1] * A[2][1] + A[1][2] * A[2][2]);
50a0154adeSJed Brown     q_data[4][i] = qw * (A[0][0] * A[2][0] + A[0][1] * A[2][1] + A[0][2] * A[2][2]);
51a0154adeSJed Brown     q_data[5][i] = qw * (A[0][0] * A[1][0] + A[0][1] * A[1][1] + A[0][2] * A[1][2]);
52a0154adeSJed Brown   }  // End of Quadrature Point Loop
53a0154adeSJed Brown 
54a0154adeSJed Brown   return CEED_ERROR_SUCCESS;
55a0154adeSJed Brown }
56a0154adeSJed Brown 
5794b7b29bSJeremy L Thompson #endif  // CEED_POISSON3DBUILD_H
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