1 // Copyright (c) 2017-2025, 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 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 50 return CEED_ERROR_SUCCESS; 51 } 52