1 // Copyright (c) 2017-2024, 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 12 #include <ceed.h> 13 14 CEED_QFUNCTION(Poisson3DBuild)(void *ctx, const CeedInt Q, const CeedScalar *const *in, CeedScalar *const *out) { 15 // At every quadrature point, compute w/det(J).adj(J).adj(J)^T and store the symmetric part of the result. 16 // in[0] is Jacobians with shape [3, nc=3, Q] 17 // in[1] is quadrature weights, size (Q) 18 const CeedScalar(*J)[3][CEED_Q_VLA] = (const CeedScalar(*)[3][CEED_Q_VLA])in[0], *w = in[1]; 19 // out[0] is qdata, size (6*Q) 20 CeedScalar(*q_data)[CEED_Q_VLA] = (CeedScalar(*)[CEED_Q_VLA])out[0]; 21 22 const CeedInt dim = 3; 23 24 // Quadrature point loop 25 CeedPragmaSIMD for (CeedInt i = 0; i < Q; i++) { 26 // Compute the adjoint 27 CeedScalar A[3][3]; 28 for (CeedInt j = 0; j < dim; j++) 29 for (CeedInt k = 0; k < dim; k++) 30 // Equivalent code with no mod operations: 31 // A[k][j] = J[k+1][j+1]*J[k+2][j+2] - J[k+2][j+1]*J[k+1][j+2] 32 A[k][j] = J[(k + 1) % dim][(j + 1) % dim][i] * J[(k + 2) % dim][(j + 2) % dim][i] - 33 J[(k + 2) % dim][(j + 1) % dim][i] * J[(k + 1) % dim][(j + 2) % dim][i]; 34 35 // Compute quadrature weight / det(J) 36 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]); 37 38 // Compute geometric factors 39 // Stored in Voigt convention 40 // 0 5 4 41 // 5 1 3 42 // 4 3 2 43 q_data[0][i] = qw * (A[0][0] * A[0][0] + A[0][1] * A[0][1] + A[0][2] * A[0][2]); 44 q_data[1][i] = qw * (A[1][0] * A[1][0] + A[1][1] * A[1][1] + A[1][2] * A[1][2]); 45 q_data[2][i] = qw * (A[2][0] * A[2][0] + A[2][1] * A[2][1] + A[2][2] * A[2][2]); 46 q_data[3][i] = qw * (A[1][0] * A[2][0] + A[1][1] * A[2][1] + A[1][2] * A[2][2]); 47 q_data[4][i] = qw * (A[0][0] * A[2][0] + A[0][1] * A[2][1] + A[0][2] * A[2][2]); 48 q_data[5][i] = qw * (A[0][0] * A[1][0] + A[0][1] * A[1][1] + A[0][2] * A[1][2]); 49 } // End of Quadrature Point Loop 50 51 return CEED_ERROR_SUCCESS; 52 } 53