static void *c2real_aux_thread(fftw_loop_data *ldata) { int min = ldata->min, max = ldata->max; aux_data *d = (aux_data *) ldata->data; fftwnd_plan p = d->p; int cur_dim = d->cur_dim; fftw_complex *in = (fftw_complex *) d->in; int istride = d->istride, idist = d->idist; fftw_real *out = (fftw_real *) d->out; int ostride = d->ostride, odist = d->odist; fftw_real *work = (fftw_real*) (d->work + p->nwork * ldata->thread_num); for (; min < max; ++min) rfftwnd_c2real_aux(p, cur_dim, in + idist * min, istride, out + odist * min, ostride, work); return 0; }
void rfftwnd_c2real_aux(fftwnd_plan p, int cur_dim, fftw_complex *in, int istride, fftw_real *out, int ostride, fftw_real *work) { int n_after = p->n_after[cur_dim], n = p->n[cur_dim]; /* do the current dimension (in-place): */ fftw(p->plans[cur_dim], n_after, in, n_after * istride, istride, (fftw_complex *) work, 1, 0); if (cur_dim == p->rank - 2) { /* just do the last dimension directly: */ if (p->is_in_place) rfftw_c2real_aux(p->plans[p->rank - 1], n, in, istride, n_after * istride, out, istride, (n_after * istride) * 2, work); else rfftw_c2real_aux(p->plans[p->rank - 1], n, in, istride, n_after * istride, out, ostride, p->plans[p->rank - 1]->n * ostride, work); } else { /* we have at least two dimensions to go */ int nr = p->plans[p->rank - 1]->n; int n_after_r = p->is_in_place ? n_after * 2 : nr * (n_after / (nr/2 + 1)); int i; /* * process the subsequent dimensions recursively, in hyperslabs, * to get maximum locality: */ for (i = 0; i < n; ++i) rfftwnd_c2real_aux(p, cur_dim + 1, in + i * n_after * istride, istride, out + i * n_after_r * ostride, ostride, work); } }
void rfftwnd_complex_to_real(fftwnd_plan p, int howmany, fftw_complex *in, int istride, int idist, fftw_real *out, int ostride, int odist) { fftw_complex *work = p->work; int rank = p->rank; int free_work = 0; if (p->dir != FFTW_COMPLEX_TO_REAL) fftw_die("rfftwnd_complex_to_real with real-to-complex plan"); #ifdef FFTW_DEBUG if (p->rank > 0 && (p->plans[0]->flags & FFTW_THREADSAFE) && p->nwork && p->work) fftw_die("bug with FFTW_THREADSAFE flag"); #endif if (p->is_in_place) { ostride = istride; odist = idist; odist = (idist == 1 && idist < istride) ? 1 : (idist * 2); /* ugh */ out = (fftw_real *) in; if (howmany > 1 && istride > idist && rank > 0) { int new_nwork = p->n[rank - 1] * howmany; if (new_nwork > p->nwork) { work = (fftw_complex *) fftw_malloc(sizeof(fftw_complex) * new_nwork); if (!work) fftw_die("error allocating work array"); free_work = 1; } } } if (p->nwork && !work) { work = (fftw_complex *) fftw_malloc(sizeof(fftw_complex) * p->nwork); free_work = 1; } switch (rank) { case 0: break; case 1: if (p->is_in_place && howmany > 1 && istride > idist) rfftw_c2real_overlap_aux(p->plans[0], howmany, in, istride, idist, out, ostride, odist, (fftw_real *) work); else rfftw_c2real_aux(p->plans[0], howmany, in, istride, idist, out, ostride, odist, (fftw_real *) work); break; default: /* rank >= 2 */ { if (howmany > 1 && ostride > odist) rfftwnd_c2real_aux_howmany(p, 0, howmany, in, istride, idist, out, ostride, odist, work); else { int i; for (i = 0; i < howmany; ++i) rfftwnd_c2real_aux(p, 0, in + i * idist, istride, out + i * odist, ostride, (fftw_real *) work); } } } if (free_work) fftw_free(work); }