rexec_threads.c

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

     HACK_ALIGN_STACK_ODD;
     for (; min < max; ++min)
          r2c_codelet(in + min * idist,
		      out + min * odist,
		      out + n * ostride + min * odist,
		      istride, ostride, -ostride);
     return 0;
}

static void *rexec_many_c2r_codelet_thread(fftw_loop_data *ldata)
{
     int min = ldata->min, max = ldata->max;
     rexec_many_data *d = (rexec_many_data *) ldata->data;
     fftw_hc2real_codelet *c2r_codelet = d->u.c2r_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;

     HACK_ALIGN_STACK_ODD;
     for (; min < max; ++min)
          c2r_codelet(in + min * idist,
		      in + n * istride + min * idist,
		      out + min * odist,
		      istride, -istride, ostride);
     return 0;
}

static void *rexec_many_simple_thread(fftw_loop_data *ldata)
{
     int min = ldata->min, max = ldata->max;
     rexec_many_data *d = (rexec_many_data *) ldata->data;
     fftw_plan_node *p = d->u.p;
     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;

     for (; min < max; ++min)
          rfftw_executor_simple(n, in + min * idist,
				out + min * odist,
				p, istride, ostride,
				FFTW_NORMAL_RECURSE);

     return 0;
}

static void rexecutor_many_threads(int n, fftw_real *in,
				   fftw_real *out,
				   fftw_plan_node *p,
				   int istride,
				   int ostride,
				   int howmany, int idist, int odist,
				   int nthreads)
{
     if (nthreads > howmany)
	  nthreads = howmany;

     switch (p->type) {
	 case FFTW_REAL2HC:
	 {
	      int s;
	      fftw_real2hc_codelet *codelet = p->nodeu.real2hc.codelet;
	      
	      if (nthreads <= 1) {
		   HACK_ALIGN_STACK_ODD;
		   for (s = 0; s < howmany; ++s)
			codelet(in + s * idist, out + s * odist,
				out + n * ostride + s * odist,
				istride, ostride, -ostride);
	      }
	      else {
		   rexec_many_data d;
		   
		   d.n = n;
		   d.in = in;
		   d.out = out;
		   d.u.r2c_codelet = codelet;
		   d.istride = istride;
		   d.ostride = ostride;
		   d.idist = idist;
		   d.odist = odist;
		   fftw_thread_spawn_loop(howmany, nthreads,
					  rexec_many_r2c_codelet_thread, &d);
	      }
	      
	      break;
	 }
	 
	 case FFTW_HC2REAL:
	 {
	      int s;
	      fftw_hc2real_codelet *codelet = p->nodeu.hc2real.codelet;
	      
	      if (nthreads <= 1) {
		   HACK_ALIGN_STACK_ODD;
		   for (s = 0; s < howmany; ++s)
			codelet(in + s * idist,
				in + n * istride + s * idist,
				out + s * odist,
				istride, -istride, ostride);
	      }
	      else {
		   rexec_many_data d;

		   d.n = n;
		   d.in = in;
		   d.out = out;
		   d.u.c2r_codelet = codelet;
		   d.istride = istride;
		   d.ostride = ostride;
		   d.idist = idist;
		   d.odist = odist;
		   fftw_thread_spawn_loop(howmany, nthreads,
					  rexec_many_c2r_codelet_thread, &d);
	      }
	      
	      break;
	 }
	 
	 default:
	 {
	      int s;		   
	      
	      if (nthreads <= 1)
		   for (s = 0; s < howmany; ++s) {
			rfftw_executor_simple(n, in + s * idist,
					      out + s * odist,
					      p, istride, ostride,
					      FFTW_NORMAL_RECURSE);
		   }
	      else {
		   rexec_many_data d;

		   d.in = in; d.out = out;
		   d.n = n;
		   d.u.p = p;
		   d.istride = istride;
		   d.ostride = ostride;
		   d.idist = idist;
		   d.odist = odist;
		   fftw_thread_spawn_loop(howmany, nthreads,
					  rexec_many_simple_thread, &d);
	      }
	 }
     }
}

static void *rexec_many_simple_inplace_thread(fftw_loop_data *ldata)
{
     int min = ldata->min, max = ldata->max;
     rexec_many_data *d = (rexec_many_data *) ldata->data;
     fftw_plan_node *p = d->u.p;
     int n = d->n;
     fftw_real *in = d->in;
     fftw_real *out = d->out + n * ldata->thread_num;
     int idist = d->idist;
     int istride = d->istride;

     for (; min < max; ++min) {
          rfftw_executor_simple(n, in + min * idist, out, p, istride, 1,
				FFTW_NORMAL_RECURSE);
	  rfftw_strided_copy(n, out, istride, in + min * idist);
     }

     return 0;
}

static void rexecutor_many_inplace_threads(int n, fftw_real *in,
					   fftw_real *out,
					   fftw_plan_node *p,
					   int istride,
					   int howmany, int idist,
					   int nthreads)
{
     switch (p->type) {
	 case FFTW_REAL2HC:
	 {
	      int s;
	      fftw_real2hc_codelet *codelet = p->nodeu.real2hc.codelet;
	      
	      if (nthreads <= 1) {
		   HACK_ALIGN_STACK_ODD;
		   for (s = 0; s < howmany; ++s)
			codelet(in + s * idist, in + s * idist,
				in + n * istride + s * idist,
				istride, istride, -istride);
	      }
	      else {
		   rexec_many_data d;
		   
		   d.n = n;
		   d.in = in;
		   d.out = in;
		   d.u.r2c_codelet = codelet;
		   d.istride = istride;
		   d.ostride = istride;
		   d.idist = idist;
		   d.odist = idist;
		   fftw_thread_spawn_loop(howmany, nthreads,
					  rexec_many_r2c_codelet_thread, &d);
	      }
	      
	      break;
	 }
	 
	 case FFTW_HC2REAL:
	 {
	      int s;
	      fftw_hc2real_codelet *codelet = p->nodeu.hc2real.codelet;
	      
	      if (nthreads <= 1) {
		   HACK_ALIGN_STACK_ODD;
		   for (s = 0; s < howmany; ++s)
			codelet(in + s * idist,
				in + n * istride + s * idist,
				in + s * idist,
				istride, -istride, istride);
	      }
	      else {
		   rexec_many_data d;
		   
		   d.n = n;
		   d.in = in;
		   d.out = in;
		   d.u.c2r_codelet = codelet;
		   d.istride = istride;
		   d.ostride = istride;
		   d.idist = idist;
		   d.odist = idist;
		   fftw_thread_spawn_loop(howmany, nthreads,
					  rexec_many_c2r_codelet_thread, &d);
	      }
	      
	      break;
	 }
	 
	 default:
	 {
	      int s;
	      fftw_real *tmp;
	      
	      if (nthreads > howmany)
		   nthreads = howmany;
	      
	      if (nthreads <= 1) {
		   if (out)
			tmp = out;
		   else
			tmp =(fftw_real *) fftw_malloc(n * 
						       sizeof(fftw_real));
		   
		   for (s = 0; s < howmany; ++s) {
			rfftw_executor_simple(n,
					      in + s * idist,
					      tmp,
					      p, istride, 1,
					      FFTW_NORMAL_RECURSE);
			rfftw_strided_copy(n, tmp, istride,
					   in + s * idist);
		   }
		   
		   if (!out)
			fftw_free(tmp);
	      }
	      else {
		   rexec_many_data d;
		   
		   tmp = (fftw_real *)
			fftw_malloc(nthreads * n * sizeof(fftw_real));

		   d.in = in; 
		   d.out = tmp;
		   d.n = n;
		   d.u.p = p;
		   d.istride = istride;
		   d.ostride = 1;
		   d.idist = idist;
		   d.odist = 0;
		   fftw_thread_spawn_loop(howmany, nthreads,
					  rexec_many_simple_inplace_thread,&d);
		   
		   fftw_free(tmp);
	      }
	 }
     }
}

/* user interface */
void rfftw_threads(int nthreads,
		   fftw_plan plan, int howmany, fftw_real *in, int istride,
		   int idist, fftw_real *out, int ostride, int odist)
{
     int n = plan->n;

     if (plan->flags & FFTW_IN_PLACE) {
	  if (howmany == 1) {
	       rexecutor_simple_inplace_threads(n, in, out, plan->root, 
						istride, nthreads);
	  } else {
	       rexecutor_many_inplace_threads(n, in, out, plan->root,
					      istride, howmany, idist,
					      nthreads);
	  }
     } else {
	  if (howmany == 1) {
	       rexec_simple_threads(n, in, out, plan->root, istride, ostride,
				    nthreads);
	  } else {
	       rexecutor_many_threads(n, in, out, plan->root, istride, ostride,
				      howmany, idist, odist, nthreads);
	  }
     }
}

void rfftw_threads_one(int nthreads,
		       fftw_plan plan, fftw_real *in, fftw_real *out)
{
     int n = plan->n;

     if (plan->flags & FFTW_IN_PLACE)
	  rexecutor_simple_inplace_threads(n, in, out, plan->root, 1,
					   nthreads);
     else
	  rexec_simple_threads(n, in, out, plan->root, 1, 1, nthreads);
}