1 // Copyright (c) 2017-2026, 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 building the geometric data for the 3D Poisson operator
10 **/
11 #include <ceed/types.h>
12
Poisson3DBuild(void * ctx,const CeedInt Q,const CeedScalar * const * in,CeedScalar * const * out)13 CEED_QFUNCTION(Poisson3DBuild)(void *ctx, const CeedInt Q, const CeedScalar *const *in, CeedScalar *const *out) {
14 // At every quadrature point, compute w/det(J).adj(J).adj(J)^T and store the symmetric part of the result.
15 // in[0] is Jacobians with shape [3, nc=3, Q]
16 // in[1] is quadrature weights, size (Q)
17 const CeedScalar(*J)[3][CEED_Q_VLA] = (const CeedScalar(*)[3][CEED_Q_VLA])in[0], *w = in[1];
18 // out[0] is qdata, size (6*Q)
19 CeedScalar(*q_data)[CEED_Q_VLA] = (CeedScalar(*)[CEED_Q_VLA])out[0];
20
21 const CeedInt dim = 3;
22
23 // Quadrature point loop
24 CeedPragmaSIMD for (CeedInt i = 0; i < Q; i++) {
25 // Compute the adjoint
26 CeedScalar A[3][3];
27 for (CeedInt j = 0; j < dim; j++)
28 for (CeedInt k = 0; k < dim; k++)
29 // Equivalent code with no mod operations:
30 // A[k][j] = J[k+1][j+1]*J[k+2][j+2] - J[k+2][j+1]*J[k+1][j+2]
31 A[k][j] = J[(k + 1) % dim][(j + 1) % dim][i] * J[(k + 2) % dim][(j + 2) % dim][i] -
32 J[(k + 2) % dim][(j + 1) % dim][i] * J[(k + 1) % dim][(j + 2) % dim][i];
33
34 // Compute quadrature weight / det(J)
35 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]);
36
37 // Compute geometric factors
38 // Stored in Voigt convention
39 // 0 5 4
40 // 5 1 3
41 // 4 3 2
42 q_data[0][i] = qw * (A[0][0] * A[0][0] + A[0][1] * A[0][1] + A[0][2] * A[0][2]);
43 q_data[1][i] = qw * (A[1][0] * A[1][0] + A[1][1] * A[1][1] + A[1][2] * A[1][2]);
44 q_data[2][i] = qw * (A[2][0] * A[2][0] + A[2][1] * A[2][1] + A[2][2] * A[2][2]);
45 q_data[3][i] = qw * (A[1][0] * A[2][0] + A[1][1] * A[2][1] + A[1][2] * A[2][2]);
46 q_data[4][i] = qw * (A[0][0] * A[2][0] + A[0][1] * A[2][1] + A[0][2] * A[2][2]);
47 q_data[5][i] = qw * (A[0][0] * A[1][0] + A[0][1] * A[1][1] + A[0][2] * A[1][2]);
48 } // End of Quadrature Point Loop
49 return CEED_ERROR_SUCCESS;
50 }
51