xref: /libCEED/include/ceed/jit-source/gallery/ceed-poisson3dbuild.h (revision a0154adecfab8547cdc0febbbf40ac009dbe9d1d)
1*a0154adeSJed Brown // Copyright (c) 2017-2022, Lawrence Livermore National Security, LLC and other CEED contributors.
2*a0154adeSJed Brown // All Rights Reserved. See the top-level LICENSE and NOTICE files for details.
3*a0154adeSJed Brown //
4*a0154adeSJed Brown // SPDX-License-Identifier: BSD-2-Clause
5*a0154adeSJed Brown //
6*a0154adeSJed Brown // This file is part of CEED:  http://github.com/ceed
7*a0154adeSJed Brown 
8*a0154adeSJed Brown /**
9*a0154adeSJed Brown   @brief Ceed QFunction for building the geometric data for the 3D Poisson
10*a0154adeSJed Brown            operator
11*a0154adeSJed Brown **/
12*a0154adeSJed Brown 
13*a0154adeSJed Brown #ifndef poisson3dbuild_h
14*a0154adeSJed Brown #define poisson3dbuild_h
15*a0154adeSJed Brown 
16*a0154adeSJed Brown CEED_QFUNCTION(Poisson3DBuild)(void *ctx, const CeedInt Q,
17*a0154adeSJed Brown                                const CeedScalar *const *in,
18*a0154adeSJed Brown                                CeedScalar *const *out) {
19*a0154adeSJed Brown   // At every quadrature point, compute w/det(J).adj(J).adj(J)^T and store
20*a0154adeSJed Brown   // the symmetric part of the result.
21*a0154adeSJed Brown   // *INDENT-OFF*
22*a0154adeSJed Brown   // in[0] is Jacobians with shape [3, nc=3, Q]
23*a0154adeSJed Brown   // in[1] is quadrature weights, size (Q)
24*a0154adeSJed Brown   const CeedScalar (*J)[3][CEED_Q_VLA] = (const CeedScalar(*)[3][CEED_Q_VLA])in[0],
25*a0154adeSJed Brown                                     *w = in[1];
26*a0154adeSJed Brown   // out[0] is qdata, size (6*Q)
27*a0154adeSJed Brown   CeedScalar     (*q_data)[CEED_Q_VLA] = (CeedScalar(*)[CEED_Q_VLA])out[0];
28*a0154adeSJed Brown   // *INDENT-ON*
29*a0154adeSJed Brown 
30*a0154adeSJed Brown   const CeedInt dim = 3;
31*a0154adeSJed Brown 
32*a0154adeSJed Brown   // Quadrature point loop
33*a0154adeSJed Brown   CeedPragmaSIMD
34*a0154adeSJed Brown   for (CeedInt i=0; i<Q; i++) {
35*a0154adeSJed Brown     // Compute the adjoint
36*a0154adeSJed Brown     CeedScalar A[3][3];
37*a0154adeSJed Brown     for (CeedInt j=0; j<dim; j++)
38*a0154adeSJed Brown       for (CeedInt k=0; k<dim; k++)
39*a0154adeSJed Brown         // Equivalent code with no mod operations:
40*a0154adeSJed Brown         // A[k][j] = J[k+1][j+1]*J[k+2][j+2] - J[k+2][j+1]*J[k+1][j+2]
41*a0154adeSJed Brown         A[k][j] = J[(k+1)%dim][(j+1)%dim][i]*J[(k+2)%dim][(j+2)%dim][i] -
42*a0154adeSJed Brown                   J[(k+2)%dim][(j+1)%dim][i]*J[(k+1)%dim][(j+2)%dim][i];
43*a0154adeSJed Brown 
44*a0154adeSJed Brown     // Compute quadrature weight / det(J)
45*a0154adeSJed Brown     const CeedScalar qw = w[i] / (J[0][0][i]*A[0][0] + J[0][1][i]*A[1][1] +
46*a0154adeSJed Brown                                   J[0][2][i]*A[2][2]);
47*a0154adeSJed Brown 
48*a0154adeSJed Brown     // Compute geometric factors
49*a0154adeSJed Brown     // Stored in Voigt convention
50*a0154adeSJed Brown     // 0 5 4
51*a0154adeSJed Brown     // 5 1 3
52*a0154adeSJed Brown     // 4 3 2
53*a0154adeSJed Brown     q_data[0][i] = qw * (A[0][0]*A[0][0] + A[0][1]*A[0][1] + A[0][2]*A[0][2]);
54*a0154adeSJed Brown     q_data[1][i] = qw * (A[1][0]*A[1][0] + A[1][1]*A[1][1] + A[1][2]*A[1][2]);
55*a0154adeSJed Brown     q_data[2][i] = qw * (A[2][0]*A[2][0] + A[2][1]*A[2][1] + A[2][2]*A[2][2]);
56*a0154adeSJed Brown     q_data[3][i] = qw * (A[1][0]*A[2][0] + A[1][1]*A[2][1] + A[1][2]*A[2][2]);
57*a0154adeSJed Brown     q_data[4][i] = qw * (A[0][0]*A[2][0] + A[0][1]*A[2][1] + A[0][2]*A[2][2]);
58*a0154adeSJed Brown     q_data[5][i] = qw * (A[0][0]*A[1][0] + A[0][1]*A[1][1] + A[0][2]*A[1][2]);
59*a0154adeSJed Brown   } // End of Quadrature Point Loop
60*a0154adeSJed Brown 
61*a0154adeSJed Brown   return CEED_ERROR_SUCCESS;
62*a0154adeSJed Brown }
63*a0154adeSJed Brown 
64*a0154adeSJed Brown #endif // poisson3dbuild_h
65