xref: /libCEED/include/ceed/jit-source/gallery/ceed-poisson2dbuild.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 2D Poisson operator
10*a0154adeSJed Brown **/
11*a0154adeSJed Brown 
12*a0154adeSJed Brown #ifndef poisson2dbuild_h
13*a0154adeSJed Brown #define poisson2dbuild_h
14*a0154adeSJed Brown 
15*a0154adeSJed Brown CEED_QFUNCTION(Poisson2DBuild)(void *ctx, const CeedInt Q,
16*a0154adeSJed Brown                                const CeedScalar *const *in,
17*a0154adeSJed Brown                                CeedScalar *const *out) {
18*a0154adeSJed Brown   // At every quadrature point, compute w/det(J).adj(J).adj(J)^T and store
19*a0154adeSJed Brown   // the symmetric part of the result.
20*a0154adeSJed Brown   // *INDENT-OFF*
21*a0154adeSJed Brown   // in[0] is Jacobians with shape [2, nc=2, Q]
22*a0154adeSJed Brown   // in[1] is quadrature weights, size (Q)
23*a0154adeSJed Brown   const CeedScalar (*J)[2][CEED_Q_VLA] = (const CeedScalar(*)[2][CEED_Q_VLA])in[0],
24*a0154adeSJed Brown                                     *w = in[1];
25*a0154adeSJed Brown   // out[0] is qdata, size (3*Q)
26*a0154adeSJed Brown   CeedScalar     (*q_data)[CEED_Q_VLA] = (CeedScalar(*)[CEED_Q_VLA])out[0];
27*a0154adeSJed Brown   // *INDENT-ON*
28*a0154adeSJed Brown 
29*a0154adeSJed Brown   // Quadrature point loop
30*a0154adeSJed Brown   CeedPragmaSIMD
31*a0154adeSJed Brown   for (CeedInt i=0; i<Q; i++) {
32*a0154adeSJed Brown     // Qdata stored in Voigt convention
33*a0154adeSJed Brown     // J: 0 2   q_data: 0 2   adj(J):  J11 -J01
34*a0154adeSJed Brown     //    1 3           2 1           -J10  J00
35*a0154adeSJed Brown     const CeedScalar J00 = J[0][0][i];
36*a0154adeSJed Brown     const CeedScalar J10 = J[0][1][i];
37*a0154adeSJed Brown     const CeedScalar J01 = J[1][0][i];
38*a0154adeSJed Brown     const CeedScalar J11 = J[1][1][i];
39*a0154adeSJed Brown     const CeedScalar qw = w[i] / (J00*J11 - J10*J01);
40*a0154adeSJed Brown     q_data[0][i] =   qw * (J01*J01 + J11*J11);
41*a0154adeSJed Brown     q_data[1][i] =   qw * (J00*J00 + J10*J10);
42*a0154adeSJed Brown     q_data[2][i] = - qw * (J00*J01 + J10*J11);
43*a0154adeSJed Brown   } // End of Quadrature Point Loop
44*a0154adeSJed Brown 
45*a0154adeSJed Brown   return CEED_ERROR_SUCCESS;
46*a0154adeSJed Brown }
47*a0154adeSJed Brown 
48*a0154adeSJed Brown #endif // poisson2dbuild_h
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