void VU_vfreqswapIP_d(vsip_vview_d* b)
{ vsip_length N = vsip_vgetlength_d(b);
if(N%2){/* odd */
vsip_vview_d *a1 = vsip_vsubview_d(b,
(vsip_index)(N/2)+1,
(vsip_length)(N/2));
vsip_vview_d *a2 = vsip_vsubview_d(b,
(vsip_index)0,
(vsip_length)(N/2)+1);
vsip_vview_d *a3 = vsip_vcreate_d((vsip_length)(N/2)+1,
VSIP_MEM_NONE);
vsip_vcopy_d_d(a2,a3);
vsip_vputlength_d(a2,(vsip_length)(N/2));
vsip_vcopy_d_d(a1,a2);
vsip_vputlength_d(a2,(vsip_length)(N/2) + 1);
vsip_vputoffset_d(a2,(vsip_offset)(N/2));
vsip_vcopy_d_d(a3,a2);
vsip_vdestroy_d(a1); vsip_vdestroy_d(a2);
vsip_valldestroy_d(a3);
}else{ /* even */
vsip_vview_d *a1 = vsip_vsubview_d(b,
(vsip_index)(N/2),
(vsip_length)(N/2));
vsip_vputlength_d(b,(vsip_length)(N/2));
vsip_vswap_d(b,a1);
vsip_vdestroy_d(a1);
vsip_vputlength_d(b,N);
}
return;
}
void
ref_corr_d(vsip_bias bias, vsip_support_region sup,
vsip_vview_d const *ref,
vsip_vview_d const *in,
vsip_vview_d const *out)
{
vsip_length M = vsip_vgetlength_d(ref);
vsip_length N = vsip_vgetlength_d(in);
vsip_length P = vsip_vgetlength_d(out);
vsip_length expected_P = ref_corr_output_size(sup, M, N);
vsip_stride shift = ref_expected_shift(sup, M);
assert(expected_P == P);
vsip_vview_d *sub = vsip_vcreate_d(M, VSIP_MEM_NONE);
// compute correlation
vsip_index i;
for (i=0; i<P; ++i)
{
vsip_vfill_d(0, sub);
vsip_stride pos = (vsip_stride)i + shift;
double scale;
if (pos < 0)
{
vsip_vview_d *subsub = vsip_vsubview_d(sub, -pos, M + pos);
vsip_vview_d *insub = vsip_vsubview_d(in, 0, M + pos);
vsip_vcopy_d_d(insub, subsub);
vsip_vdestroy_d(subsub);
vsip_vdestroy_d(insub);
scale = M + pos;
}
else if (pos + M > N)
{
vsip_vview_d *subsub = vsip_vsubview_d(sub, 0, N - pos);
vsip_vview_d *insub = vsip_vsubview_d(in, pos, N - pos);
vsip_vcopy_d_d(insub, subsub);
vsip_vdestroy_d(subsub);
vsip_vdestroy_d(insub);
scale = N - pos;
}
else
{
vsip_vview_d *insub = vsip_vsubview_d(in, pos, M);
vsip_vcopy_d_d(insub, sub);
vsip_vdestroy_d(insub);
scale = M;
}
#if VSIP_IMPL_CORR_CORRECT_SAME_SUPPORT_SCALING
#else
if (sup == VSIP_SUPPORT_SAME)
{
if (i < (M/2)) scale = i + (M+1)/2; // i + ceil(M/2)
else if (i < N - (M/2)) scale = M; // M
else scale = N - 1 + (M+1)/2 - i; // N-1+ceil(M/2)-i
}
#endif
double val = vsip_vdot_d(ref, sub);
if (bias == VSIP_UNBIASED) val /= scale;
vsip_vput_d(out, i, val);
}
}
