116 lines
4.2 KiB
C
116 lines
4.2 KiB
C
#include "xh_tool.h"
|
||
|
||
/*
|
||
* C 版 kodis
|
||
*
|
||
* Fortran signature:
|
||
* subroutine kodis(ex,X,Y,Z,f,f_rhs,SoA,Symmetry,eps)
|
||
*
|
||
* 约定：
|
||
* X: ex1, Y: ex2, Z: ex3
|
||
* f, f_rhs: ex1*ex2*ex3 按 idx_ex 布局
|
||
* SoA[3]
|
||
* eps: double
|
||
*/
|
||
void kodis(const int ex[3],
|
||
const double *X, const double *Y, const double *Z,
|
||
const double *f, double *f_rhs,
|
||
const double SoA[3],
|
||
int Symmetry, double eps)
|
||
{
|
||
const double ONE = 1.0, SIX = 6.0, FIT = 15.0, TWT = 20.0;
|
||
const double cof = 64.0; // 2^6
|
||
const int NO_SYMM = 0, OCTANT = 2;
|
||
|
||
const int ex1 = ex[0], ex2 = ex[1], ex3 = ex[2];
|
||
|
||
// Fortran: dX = X(2)-X(1) -> C: X[1]-X[0]
|
||
const double dX = X[1] - X[0];
|
||
const double dY = Y[1] - Y[0];
|
||
const double dZ = Z[1] - Z[0];
|
||
(void)ONE; // ONE 在原 Fortran 里只是参数，这里不一定用得上
|
||
|
||
// Fortran: imax=ex(1) 等是 1-based 上界
|
||
const int imaxF = ex1;
|
||
const int jmaxF = ex2;
|
||
const int kmaxF = ex3;
|
||
|
||
// Fortran: imin=jmin=kmin=1，某些对称情况变 -2
|
||
int iminF = 1, jminF = 1, kminF = 1;
|
||
|
||
if (Symmetry > NO_SYMM && fabs(Z[0]) < dZ) kminF = -2;
|
||
if (Symmetry == OCTANT && fabs(X[0]) < dX) iminF = -2;
|
||
if (Symmetry == OCTANT && fabs(Y[0]) < dY) jminF = -2;
|
||
|
||
// 分配 fh：大小 (ex1+3)*(ex2+3)*(ex3+3)，对应 ord=3
|
||
const size_t nx = (size_t)ex1 + 3;
|
||
const size_t ny = (size_t)ex2 + 3;
|
||
const size_t nz = (size_t)ex3 + 3;
|
||
const size_t fh_size = nx * ny * nz;
|
||
|
||
static thread_local double *fh = NULL;
|
||
static thread_local size_t cap = 0;
|
||
|
||
if (fh_size > cap) {
|
||
free(fh);
|
||
fh = (double*)aligned_alloc(64, fh_size * sizeof(double));
|
||
cap = fh_size;
|
||
}
|
||
if (!fh) return;
|
||
|
||
// Fortran: call symmetry_bd(3,ex,f,fh,SoA)
|
||
symmetry_bd(3, ex, f, fh, SoA);
|
||
|
||
/*
|
||
* Fortran loops:
|
||
* do k=1,ex3
|
||
* do j=1,ex2
|
||
* do i=1,ex1
|
||
*
|
||
* C: k0=0..ex3-1, j0=0..ex2-1, i0=0..ex1-1
|
||
* 并定义 Fortran index: iF=i0+1, ...
|
||
*/
|
||
for (int k0 = 0; k0 < ex3; ++k0) {
|
||
const int kF = k0 + 1;
|
||
for (int j0 = 0; j0 < ex2; ++j0) {
|
||
const int jF = j0 + 1;
|
||
for (int i0 = 0; i0 < ex1; ++i0) {
|
||
const int iF = i0 + 1;
|
||
|
||
// Fortran if 条件：
|
||
// i-3 >= imin .and. i+3 <= imax 等（都是 Fortran 索引）
|
||
if ((iF - 3) >= iminF && (iF + 3) <= imaxF &&
|
||
(jF - 3) >= jminF && (jF + 3) <= jmaxF &&
|
||
(kF - 3) >= kminF && (kF + 3) <= kmaxF)
|
||
{
|
||
const size_t p = idx_ex(i0, j0, k0, ex);
|
||
|
||
// 三个方向各一份同型的 7 点组合（实际上是对称的 6th-order dissipation/filter 核）
|
||
const double Dx_term =
|
||
( (fh[idx_fh_F(iF - 3, jF, kF, ex)] + fh[idx_fh_F(iF + 3, jF, kF, ex)]) -
|
||
SIX * (fh[idx_fh_F(iF - 2, jF, kF, ex)] + fh[idx_fh_F(iF + 2, jF, kF, ex)]) +
|
||
FIT * (fh[idx_fh_F(iF - 1, jF, kF, ex)] + fh[idx_fh_F(iF + 1, jF, kF, ex)]) -
|
||
TWT * fh[idx_fh_F(iF , jF, kF, ex)] ) / dX;
|
||
|
||
const double Dy_term =
|
||
( (fh[idx_fh_F(iF, jF - 3, kF, ex)] + fh[idx_fh_F(iF, jF + 3, kF, ex)]) -
|
||
SIX * (fh[idx_fh_F(iF, jF - 2, kF, ex)] + fh[idx_fh_F(iF, jF + 2, kF, ex)]) +
|
||
FIT * (fh[idx_fh_F(iF, jF - 1, kF, ex)] + fh[idx_fh_F(iF, jF + 1, kF, ex)]) -
|
||
TWT * fh[idx_fh_F(iF, jF , kF, ex)] ) / dY;
|
||
|
||
const double Dz_term =
|
||
( (fh[idx_fh_F(iF, jF, kF - 3, ex)] + fh[idx_fh_F(iF, jF, kF + 3, ex)]) -
|
||
SIX * (fh[idx_fh_F(iF, jF, kF - 2, ex)] + fh[idx_fh_F(iF, jF, kF + 2, ex)]) +
|
||
FIT * (fh[idx_fh_F(iF, jF, kF - 1, ex)] + fh[idx_fh_F(iF, jF, kF + 1, ex)]) -
|
||
TWT * fh[idx_fh_F(iF, jF, kF , ex)] ) / dZ;
|
||
|
||
// Fortran:
|
||
// f_rhs(i,j,k) = f_rhs(i,j,k) + eps/cof*(Dx_term + Dy_term + Dz_term)
|
||
f_rhs[p] += (eps / cof) * (Dx_term + Dy_term + Dz_term);
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
// free(fh);
|
||
} |