xref: /libCEED/include/ceed/jit-source/gallery/ceed-poisson3dbuild.h (revision c0b5abf0f23b15c4f0ada76f8abe9f8d2b6fa247)
15aed82e4SJeremy 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 
12*c0b5abf0SJeremy L Thompson #include <ceed/types.h>
13c9c2c079SJeremy L Thompson 
142b730f8bSJeremy L Thompson CEED_QFUNCTION(Poisson3DBuild)(void *ctx, const CeedInt Q, const CeedScalar *const *in, CeedScalar *const *out) {
15ea61e9acSJeremy L Thompson   // At every quadrature point, compute w/det(J).adj(J).adj(J)^T and store the symmetric part of the result.
16a0154adeSJed Brown   // in[0] is Jacobians with shape [3, nc=3, Q]
17a0154adeSJed Brown   // in[1] is quadrature weights, size (Q)
182b730f8bSJeremy L Thompson   const CeedScalar(*J)[3][CEED_Q_VLA] = (const CeedScalar(*)[3][CEED_Q_VLA])in[0], *w = in[1];
19a0154adeSJed Brown   // out[0] is qdata, size (6*Q)
20a0154adeSJed Brown   CeedScalar(*q_data)[CEED_Q_VLA] = (CeedScalar(*)[CEED_Q_VLA])out[0];
21a0154adeSJed Brown 
22a0154adeSJed Brown   const CeedInt dim = 3;
23a0154adeSJed Brown 
24a0154adeSJed Brown   // Quadrature point loop
252b730f8bSJeremy L Thompson   CeedPragmaSIMD for (CeedInt i = 0; i < Q; i++) {
26a0154adeSJed Brown     // Compute the adjoint
27a0154adeSJed Brown     CeedScalar A[3][3];
28a0154adeSJed Brown     for (CeedInt j = 0; j < dim; j++)
29a0154adeSJed Brown       for (CeedInt k = 0; k < dim; k++)
30a0154adeSJed Brown         // Equivalent code with no mod operations:
31a0154adeSJed Brown         // A[k][j] = J[k+1][j+1]*J[k+2][j+2] - J[k+2][j+1]*J[k+1][j+2]
32a0154adeSJed Brown         A[k][j] = J[(k + 1) % dim][(j + 1) % dim][i] * J[(k + 2) % dim][(j + 2) % dim][i] -
33a0154adeSJed Brown                   J[(k + 2) % dim][(j + 1) % dim][i] * J[(k + 1) % dim][(j + 2) % dim][i];
34a0154adeSJed Brown 
35a0154adeSJed Brown     // Compute quadrature weight / det(J)
362b730f8bSJeremy 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]);
37a0154adeSJed Brown 
38a0154adeSJed Brown     // Compute geometric factors
39a0154adeSJed Brown     // Stored in Voigt convention
40a0154adeSJed Brown     // 0 5 4
41a0154adeSJed Brown     // 5 1 3
42a0154adeSJed Brown     // 4 3 2
43a0154adeSJed Brown     q_data[0][i] = qw * (A[0][0] * A[0][0] + A[0][1] * A[0][1] + A[0][2] * A[0][2]);
44a0154adeSJed Brown     q_data[1][i] = qw * (A[1][0] * A[1][0] + A[1][1] * A[1][1] + A[1][2] * A[1][2]);
45a0154adeSJed Brown     q_data[2][i] = qw * (A[2][0] * A[2][0] + A[2][1] * A[2][1] + A[2][2] * A[2][2]);
46a0154adeSJed Brown     q_data[3][i] = qw * (A[1][0] * A[2][0] + A[1][1] * A[2][1] + A[1][2] * A[2][2]);
47a0154adeSJed Brown     q_data[4][i] = qw * (A[0][0] * A[2][0] + A[0][1] * A[2][1] + A[0][2] * A[2][2]);
48a0154adeSJed Brown     q_data[5][i] = qw * (A[0][0] * A[1][0] + A[0][1] * A[1][1] + A[0][2] * A[1][2]);
49a0154adeSJed Brown   }  // End of Quadrature Point Loop
50a0154adeSJed Brown 
51a0154adeSJed Brown   return CEED_ERROR_SUCCESS;
52a0154adeSJed Brown }
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