Commit c929113c authored by James Willis's avatar James Willis
Browse files

Added function to caclculate the kernel with one set of vectors.

parent 1b0030c6
......@@ -372,6 +372,82 @@ static const vector wendland_const_c4 = FILL_VEC(0.f);
static const vector wendland_const_c5 = FILL_VEC(1.f);
#endif
/**
* @brief Computes the kernel function and its derivative for two particles
* using interleaved vectors.
*
* Return 0 if $u > \\gamma = H/h$
*
* @param u The ratio of the distance to the smoothing length $u = x/h$.
* @param w (return) The value of the kernel function $W(x,h)$.
* @param dw_dx (return) The norm of the gradient of $|\\nabla W(x,h)|$.
* @param u2 The ratio of the distance to the smoothing length $u = x/h$ for
* second particle.
* @param w2 (return) The value of the kernel function $W(x,h)$ for second
* particle.
* @param dw_dx2 (return) The norm of the gradient of $|\\nabla W(x,h)|$ for
* second particle.
*/
__attribute__((always_inline)) INLINE static void kernel_deval_1_vec(
vector *u, vector *w, vector *dw_dx) {
/* Go to the range [0,1[ from [0,H[ */
vector x;
x.v = vec_mul(u->v, kernel_gamma_inv_vec.v);
#ifdef WENDLAND_C2_KERNEL
/* Init the iteration for Horner's scheme. */
w->v = vec_fma(wendland_const_c0.v, x.v, wendland_const_c1.v);
dw_dx->v = wendland_const_c0.v;
/* Calculate the polynomial interleaving vector operations */
dw_dx->v = vec_fma(dw_dx->v, x.v, w->v);
w->v = vec_fma(x.v, w->v, wendland_const_c2.v);
dw_dx->v = vec_fma(dw_dx->v, x.v, w->v);
w->v = vec_fma(x.v, w->v, wendland_const_c3.v);
dw_dx->v = vec_fma(dw_dx->v, x.v, w->v);
w->v = vec_fma(x.v, w->v, wendland_const_c4.v);
dw_dx->v = vec_fma(dw_dx->v, x.v, w->v);
w->v = vec_fma(x.v, w->v, wendland_const_c5.v);
/* Return everything */
w->v =
vec_mul(w->v, vec_mul(kernel_constant_vec.v, kernel_gamma_inv_dim_vec.v));
dw_dx->v = vec_mul(dw_dx->v, vec_mul(kernel_constant_vec.v,
kernel_gamma_inv_dim_plus_one_vec.v));
#else
/* Load x and get the interval id. */
vector ind;
ind.m = vec_ftoi(vec_fmin(x.v * kernel_ivals_vec.v, kernel_ivals_vec.v));
/* load the coefficients. */
vector c[kernel_degree + 1];
for (int k = 0; k < VEC_SIZE; k++)
for (int j = 0; j < kernel_degree + 1; j++) {
c[j].f[k] = kernel_coeffs[ind.i[k] * (kernel_degree + 1) + j];
}
/* Init the iteration for Horner's scheme. */
w->v = (c[0].v * x.v) + c[1].v;
dw_dx->v = c[0].v;
/* And we're off! */
for (int k = 2; k <= kernel_degree; k++) {
dw_dx->v = (dw_dx->v * x.v) + w->v;
w->v = (x.v * w->v) + c[k].v;
}
/* Return everything */
w->v = w->v * kernel_constant_vec.v * kernel_gamma_inv_dim_vec.v;
dw_dx->v =
dw_dx->v * kernel_constant_vec.v * kernel_gamma_inv_dim_plus_one_vec.v;
#endif
}
/**
* @brief Computes the kernel function and its derivative for two particles
* using interleaved vectors.
......
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