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 #include <ceed/types.h> 9 10 /// A structure used to pass additional data to f_build_diff 11 struct BuildContext { 12 CeedInt dim, space_dim; 13 }; 14 15 /// libCEED Q-function for building quadrature data for a diffusion operator 16 CEED_QFUNCTION(build_diff)(void *ctx, const CeedInt Q, const CeedScalar *const *in, CeedScalar *const *out) { 17 struct BuildContext *build_data = (struct BuildContext *)ctx; 18 19 // in[0] is Jacobians with shape [dim, dim, Q] 20 // in[1] is quadrature weights, size (Q) 21 const CeedScalar *w = in[1]; 22 CeedScalar(*q_data)[CEED_Q_VLA] = (CeedScalar(*)[CEED_Q_VLA])out[0]; 23 24 // At every quadrature point, compute w/det(J).adj(J).adj(J)^T and store 25 // the symmetric part of the result. 26 switch (build_data->dim + 10 * build_data->space_dim) { 27 case 11: { 28 const CeedScalar(*J)[1][CEED_Q_VLA] = (const CeedScalar(*)[1][CEED_Q_VLA])in[0]; 29 30 CeedPragmaSIMD for (CeedInt i = 0; i < Q; i++) { q_data[0][i] = w[i] / J[0][0][i]; } // End of Quadrature Point Loop 31 } break; 32 case 22: { 33 const CeedScalar(*J)[2][CEED_Q_VLA] = (const CeedScalar(*)[2][CEED_Q_VLA])in[0]; 34 35 CeedPragmaSIMD for (CeedInt i = 0; i < Q; i++) { 36 // J: 0 2 q_data: 0 2 adj(J): J11 -J01 37 // 1 3 2 1 -J10 J00 38 const CeedScalar J00 = J[0][0][i]; 39 const CeedScalar J10 = J[0][1][i]; 40 const CeedScalar J01 = J[1][0][i]; 41 const CeedScalar J11 = J[1][1][i]; 42 const CeedScalar qw = w[i] / (J00 * J11 - J10 * J01); 43 44 q_data[0][i] = qw * (J01 * J01 + J11 * J11); 45 q_data[1][i] = qw * (J00 * J00 + J10 * J10); 46 q_data[2][i] = -qw * (J00 * J01 + J10 * J11); 47 } // End of Quadrature Point Loop 48 } break; 49 case 33: { 50 const CeedScalar(*J)[3][CEED_Q_VLA] = (const CeedScalar(*)[3][CEED_Q_VLA])in[0]; 51 52 CeedPragmaSIMD for (CeedInt i = 0; i < Q; i++) { 53 // Compute the adjoint 54 CeedScalar A[3][3]; 55 56 for (CeedInt j = 0; j < 3; j++) { 57 for (CeedInt k = 0; k < 3; k++) { 58 // Equivalent code with J as a VLA and no mod operations: 59 // A[k][j] = J[j+1][k+1]*J[j+2][k+2] - J[j+1][k+2]*J[j+2][k+1] 60 A[k][j] = 61 J[(k + 1) % 3][(j + 1) % 3][i] * J[(k + 2) % 3][(j + 2) % 3][i] - J[(k + 2) % 3][(j + 1) % 3][i] * J[(k + 1) % 3][(j + 2) % 3][i]; 62 } 63 } 64 65 // Compute quadrature weight / det(J) 66 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]); 67 68 // Compute geometric factors 69 // Stored in Voigt convention 70 // 0 5 4 71 // 5 1 3 72 // 4 3 2 73 q_data[0][i] = qw * (A[0][0] * A[0][0] + A[0][1] * A[0][1] + A[0][2] * A[0][2]); 74 q_data[1][i] = qw * (A[1][0] * A[1][0] + A[1][1] * A[1][1] + A[1][2] * A[1][2]); 75 q_data[2][i] = qw * (A[2][0] * A[2][0] + A[2][1] * A[2][1] + A[2][2] * A[2][2]); 76 q_data[3][i] = qw * (A[1][0] * A[2][0] + A[1][1] * A[2][1] + A[1][2] * A[2][2]); 77 q_data[4][i] = qw * (A[0][0] * A[2][0] + A[0][1] * A[2][1] + A[0][2] * A[2][2]); 78 q_data[5][i] = qw * (A[0][0] * A[1][0] + A[0][1] * A[1][1] + A[0][2] * A[1][2]); 79 } // End of Quadrature Point Loop 80 } break; 81 } 82 return CEED_ERROR_SUCCESS; 83 } 84 85 /// libCEED Q-function for applying a diff operator 86 CEED_QFUNCTION(apply_diff)(void *ctx, const CeedInt Q, const CeedScalar *const *in, CeedScalar *const *out) { 87 struct BuildContext *build_data = (struct BuildContext *)ctx; 88 89 // in[0], out[0] solution gradients with shape [dim, 1, Q] 90 // in[1] is quadrature data with shape [num_components, Q] 91 const CeedScalar(*q_data)[CEED_Q_VLA] = (const CeedScalar(*)[CEED_Q_VLA])in[1]; 92 93 switch (build_data->dim) { 94 case 1: { 95 const CeedScalar *ug = in[0]; 96 CeedScalar *vg = out[0]; 97 98 CeedPragmaSIMD for (CeedInt i = 0; i < Q; i++) { vg[i] = ug[i] * q_data[0][i]; } // End of Quadrature Point Loop 99 } break; 100 case 2: { 101 const CeedScalar(*ug)[CEED_Q_VLA] = (const CeedScalar(*)[CEED_Q_VLA])in[0]; 102 CeedScalar(*vg)[CEED_Q_VLA] = (CeedScalar(*)[CEED_Q_VLA])out[0]; 103 104 CeedPragmaSIMD for (CeedInt i = 0; i < Q; i++) { 105 // Read q_data (dXdxdXdx_T symmetric matrix) 106 // Stored in Voigt convention 107 // 0 2 108 // 2 1 109 const CeedScalar dXdxdXdx_T[2][2] = { 110 {q_data[0][i], q_data[2][i]}, 111 {q_data[2][i], q_data[1][i]} 112 }; 113 114 // j = direction of vg 115 for (int j = 0; j < 2; j++) vg[j][i] = (ug[0][i] * dXdxdXdx_T[0][j] + ug[1][i] * dXdxdXdx_T[1][j]); 116 } // End of Quadrature Point Loop 117 } break; 118 case 3: { 119 const CeedScalar(*ug)[CEED_Q_VLA] = (const CeedScalar(*)[CEED_Q_VLA])in[0]; 120 CeedScalar(*vg)[CEED_Q_VLA] = (CeedScalar(*)[CEED_Q_VLA])out[0]; 121 122 CeedPragmaSIMD for (CeedInt i = 0; i < Q; i++) { 123 // Read q_data (dXdxdXdx_T symmetric matrix) 124 // Stored in Voigt convention 125 // 0 5 4 126 // 5 1 3 127 // 4 3 2 128 const CeedScalar dXdxdXdx_T[3][3] = { 129 {q_data[0][i], q_data[5][i], q_data[4][i]}, 130 {q_data[5][i], q_data[1][i], q_data[3][i]}, 131 {q_data[4][i], q_data[3][i], q_data[2][i]} 132 }; 133 134 // j = direction of vg 135 for (int j = 0; j < 3; j++) vg[j][i] = (ug[0][i] * dXdxdXdx_T[0][j] + ug[1][i] * dXdxdXdx_T[1][j] + ug[2][i] * dXdxdXdx_T[2][j]); 136 } // End of Quadrature Point Loop 137 } break; 138 } 139 return CEED_ERROR_SUCCESS; 140 } 141