rexec_threads.c

FFTW, a collection of fast C routines to compute the Discrete Fourier Transform in one or more dime

/*
 * Copyright (c) 1997-1999, 2003 Massachusetts Institute of Technology
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

/*
 * rexec_threads.c -- execute the fft in parallel
 */

#include <stdio.h>
#include <stdlib.h>

#include "fftw_threads-int.h"
#include "rfftw_threads.h"

extern void rfftw_strided_copy(int n, fftw_real *in, int ostride,
			       fftw_real *out);

static void rexec_simple_threads(int n, fftw_real *in,
				 fftw_real *out,
				 fftw_plan_node *p,
				 int istride,
				 int ostride,
				 int nthreads);

typedef struct {
     int m,r;
     fftw_real *in;
     fftw_real *out;
     fftw_plan_node *p;
     int istride, ostride;
     int nthreads;
} rexec_simple_data;

static void *rexec_simple_thread_r2c(fftw_loop_data *ldata)
{
     int min = ldata->min, max = ldata->max;
     rexec_simple_data *d = (rexec_simple_data *) ldata->data;
     int m = d->m, r = d->r;
     fftw_real *in = d->in;
     fftw_real *out = d->out;
     fftw_plan_node *p = d->p;
     int istride = d->istride, ostride = d->ostride;
     int nthreads = d->nthreads;
     
     for (; min < max; ++min)
	  rexec_simple_threads(m, in + min * istride,
			       out + min * (m * ostride),
			       p,
			       istride * r, ostride,
			       nthreads);

     return 0;
}

static void *rexec_simple_thread_c2r(fftw_loop_data *ldata)
{
     int min = ldata->min, max = ldata->max;
     rexec_simple_data *d = (rexec_simple_data *) ldata->data;
     int m = d->m, r = d->r;
     fftw_real *in = d->in;
     fftw_real *out = d->out;
     fftw_plan_node *p = d->p;
     int istride = d->istride, ostride = d->ostride;
     int nthreads = d->nthreads;
     
     for (; min < max; ++min)
	  rexec_simple_threads(m, in + min * (m * istride),
			       out + min * ostride,
			       p,
			       istride, ostride * r,
			       nthreads);

     return 0;
}

static void spawn_h2hc_recurse_threads(int m, int r,
				       fftw_real *in,
				       fftw_real *out,
				       fftw_plan_node *p,
				       int istride,
				       int ostride,
				       int nthreads)
{
     rexec_simple_data d;
     
     d.m = m; d.r = r;
     d.in = in; d.out = out;
     d.p = p->nodeu.hc2hc.recurse;
     d.istride = istride;
     d.ostride = ostride;
     d.nthreads = nthreads / r;
     
     switch (p->nodeu.hc2hc.dir) {
	 case FFTW_REAL_TO_COMPLEX:
	      fftw_thread_spawn_loop(r, nthreads,
				     rexec_simple_thread_r2c, &d);
	      break;
	 case FFTW_COMPLEX_TO_REAL:
	      fftw_thread_spawn_loop(r, nthreads,
				     rexec_simple_thread_c2r, &d);
	      break;
     }
}

static void rexec_simple_threads(int n, fftw_real *in, fftw_real *out,
				 fftw_plan_node *p,
				 int istride,
				 int ostride,
				 int nthreads)
{
     switch (p->type) {
	 case FFTW_REAL2HC:
	      HACK_ALIGN_STACK_ODD;
	      (p->nodeu.real2hc.codelet) (in, out, out + n * ostride,
					  istride, ostride, -ostride);
	      break;

	 case FFTW_HC2REAL:
	      HACK_ALIGN_STACK_ODD;
	      (p->nodeu.hc2real.codelet) (in, in + n * istride, out,
					  istride, -istride, ostride);
	      break;

	 case FFTW_HC2HC:
	      {
		   int r = p->nodeu.hc2hc.size;
		   int m = n / r;
		   int i;
		   fftw_hc2hc_codelet *codelet;
		   fftw_complex *W;

		   if (nthreads <= 1) { 
			switch (p->nodeu.hc2hc.dir) {
			    case FFTW_REAL_TO_COMPLEX:
				 for (i = 0; i < r; ++i)
				      rfftw_executor_simple(m,
						    in + i * istride,
						    out + i * (m * ostride),
						    p->nodeu.hc2hc.recurse,
						    istride * r, ostride,
       						    FFTW_NORMAL_RECURSE);

				 W = p->nodeu.hc2hc.tw->twarray;
				 codelet = p->nodeu.hc2hc.codelet;
				 HACK_ALIGN_STACK_EVEN;
				 codelet(out, W, m * ostride, m, ostride);
				 break;
			    case FFTW_COMPLEX_TO_REAL:
				 W = p->nodeu.hc2hc.tw->twarray;
				 codelet = p->nodeu.hc2hc.codelet;
				 HACK_ALIGN_STACK_EVEN;
				 codelet(in, W, m * istride, m, istride);
				 
				 for (i = 0; i < r; ++i)
				      rfftw_executor_simple(m,
						    in + i * (m * istride),
						    out + i * ostride,
						    p->nodeu.hc2hc.recurse,
						    istride, ostride * r,
						    FFTW_NORMAL_RECURSE);
				 break;
			    default:
				 goto bug;
			}
		   }
		   else
			switch (p->nodeu.hc2hc.dir) {
			    case FFTW_REAL_TO_COMPLEX:
				 spawn_h2hc_recurse_threads(m, r, in, out, p,
							    istride, ostride,
							    nthreads);

				 W = p->nodeu.hc2hc.tw->twarray;
				 codelet = p->nodeu.hc2hc.codelet;
				 HACK_ALIGN_STACK_EVEN;
				 codelet(out, W, m * ostride, m, ostride);

				 break;
			    case FFTW_COMPLEX_TO_REAL:
				 W = p->nodeu.hc2hc.tw->twarray;
				 codelet = p->nodeu.hc2hc.codelet;
				 HACK_ALIGN_STACK_EVEN;
				 codelet(in, W, m * istride, m, istride);
				 
				 spawn_h2hc_recurse_threads(m, r, in, out, p,
							    istride, ostride,
							    nthreads);
				 break;
			}
		   
		   break;
	      }

	 case FFTW_RGENERIC:
	      {
		   int r = p->nodeu.rgeneric.size;
		   int m = n / r;
		   int i;
		   fftw_rgeneric_codelet *codelet = p->nodeu.rgeneric.codelet;
		   fftw_complex *W = p->nodeu.rgeneric.tw->twarray;

		   if (nthreads <= 1)
			switch (p->nodeu.rgeneric.dir) {
			    case FFTW_REAL_TO_COMPLEX:
				 for (i = 0; i < r; ++i)
				      rfftw_executor_simple(m,
						    in + i * istride,
						    out + i * (m * ostride),
						    p->nodeu.rgeneric.recurse,
						    istride * r, ostride,
						    FFTW_NORMAL_RECURSE);
				 
				 codelet(out, W, m, r, n, ostride);
				 break;
			    case FFTW_COMPLEX_TO_REAL:
				 codelet(in, W, m, r, n, istride);
				 
				 for (i = 0; i < r; ++i)
				      rfftw_executor_simple(m,
						    in + i * m * istride,
						    out + i * ostride,
						    p->nodeu.rgeneric.recurse,
						    istride, ostride * r,
						    FFTW_NORMAL_RECURSE);
				 break;
			    default:
				 goto bug;
			}
		   else
			switch (p->nodeu.hc2hc.dir) {
			    case FFTW_REAL_TO_COMPLEX:
				 spawn_h2hc_recurse_threads(m, r, in, out, p,
							    istride, ostride,
							    nthreads);
				 codelet(out, W, m, r, n, ostride);
				 break;
			    case FFTW_COMPLEX_TO_REAL:
				 codelet(in, W, m, r, n, istride);
				 spawn_h2hc_recurse_threads(m, r, in, out, p,
							    istride, ostride,
							    nthreads);
				 break;
			}

		   break;
	      }

	 default:
	    bug:
	      fftw_die("BUG in rexecutor: invalid plan\n");
	      break;
     }
}

static void rexecutor_simple_inplace_threads(int n, fftw_real *in,
					     fftw_real *out,
					     fftw_plan_node *p,
					     int istride,
					     int nthreads)
{
     switch (p->type) {
	 case FFTW_REAL2HC:
	      HACK_ALIGN_STACK_ODD;
	      (p->nodeu.real2hc.codelet) (in, in, in + n * istride,
					  istride, istride, -istride);
	      break;

	 case FFTW_HC2REAL:
	      HACK_ALIGN_STACK_ODD;
	      (p->nodeu.hc2real.codelet) (in, in + n * istride, in,
					  istride, -istride, istride);
	      break;

	 default:
	      {
		   fftw_real *tmp;

		   if (out)
			tmp = out;
		   else
			tmp = (fftw_real *) fftw_malloc(n * sizeof(fftw_real));

		   rexec_simple_threads(n, in, tmp, p, istride, 1, nthreads);
		   rfftw_strided_copy(n, tmp, istride, in);

		   if (!out)
			fftw_free(tmp);
	      }
     }
}

typedef struct {
     union {
          fftw_real2hc_codelet *r2c_codelet;
          fftw_hc2real_codelet *c2r_codelet;
	  fftw_plan_node *p;
     } u;
     int n;
     fftw_real *in;
     fftw_real *out;
     int idist, odist, istride, ostride;
} rexec_many_data;

static void *rexec_many_r2c_codelet_thread(fftw_loop_data *ldata)
{
     int min = ldata->min, max = ldata->max;
     rexec_many_data *d = (rexec_many_data *) ldata->data;
     fftw_real2hc_codelet *r2c_codelet = d->u.r2c_codelet;
     int n = d->n;
     fftw_real *in = d->in;
     fftw_real *out = d->out;
     int idist = d->idist, odist = d->odist;
     int istride = d->istride, ostride = d->ostride;