iverilog/vvp/event.cc

/*
 * Copyright (c) 2001 Stephen Williams (steve@icarus.com)
 *
 *    This source code is free software; you can redistribute it
 *    and/or modify it in source code form 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
 */
#if !defined(WINNT)
#ident "$Id: event.cc,v 1.2 2001/11/16 04:22:27 steve Exp $"
#endif

# include  "event.h"
# include  "compile.h"
# include  "vthread.h"
# include  "schedule.h"

# include  <string.h>
# include  <assert.h>
# include  <stdlib.h>
#ifdef HAVE_MALLOC_H
# include  <malloc.h>
#endif

event_functor_s::event_functor_s(edge_t e) 
      : edge(e), threads(0) 
{}

event_functor_s::~event_functor_s() 
{}

void event_functor_s::set(vvp_ipoint_t ptr, bool, unsigned val, unsigned)
{
      old_ival = ival;
      put(ptr, val);
	/* Only go through the effort if there is someone interested
	   in the results... */
      if (threads || out) {

	    bool edge_p = true;

	    if (edge) {
		  
		  unsigned pp = ipoint_port(ptr);
		  
		  unsigned oval = (old_ival >> 2*pp) & 3;
		  unsigned nval = (ival     >> 2*pp) & 3;
		  
		  unsigned val = (oval << 2) | nval;
		  edge_p = ((edge>>val) & 1) != 0;
	    }

	    if (edge_p) {
		  vthread_t tmp = threads;
		  threads = 0;
		  vthread_schedule_list(tmp);
		  
		  if (out)
			// only one output?  Why not propagate?
			schedule_assign(out, 0, 0);
	    }
      }
}

/*
**  Create an event functor
**  edge:  compile_event(label, type, argc, argv)
**  or:    compile_event(label, NULL, argc, argv)
**  name:  compile_event(label, name, NULL, NULL)
*/

void compile_event(char*label, char*type,
		   unsigned argc, struct symb_s*argv)
{
      event_functor_s::edge_t edge = vvp_edge_none;

      if (argc && type) {
	    if (strcmp(type,"posedge") == 0)
		  edge = vvp_edge_posedge;
	    else if (strcmp(type,"negedge") == 0)
		  edge = vvp_edge_negedge;
	    else if (strcmp(type,"edge") == 0)
		  edge = vvp_edge_anyedge;

	    assert(argc <= 4 || edge == vvp_edge_none);
      }
      
      if (!argc && type) {
	    // "type" is the name of the named event
      }

      free(type);

      functor_t obj = new event_functor_s(edge);

      vvp_ipoint_t fdx = functor_allocate(1);
      functor_define(fdx, obj);
      define_functor_symbol(label, fdx);
      free(label);

	/* Run through the arguments looking for the functors that are
	   connected to my input ports. For each source functor that I
	   find, connect the output of that functor to the indexed
	   input by inserting myself (complete with the port number in
	   the vvp_ipoint_t) into the list that the source heads.

	   If the source functor is not declared yet, then don't do
	   the link yet. Save the reference to be resolved later. */
      
      if (edge != vvp_edge_none)
	    inputs_connect(fdx, argc, argv);
      else
	    // Are we sure that we have those .event/or 
	    // drivers exclusively?
	    for (unsigned i=0; i<argc; i++) {
		  inputs_connect(fdx, 1, argv+i);
	    }

      free(argv);
}

/*
 * $Log: event.cc,v $
 * Revision 1.2  2001/11/16 04:22:27  steve
 *  include stdlib.h for portability.
 *
 * Revision 1.1  2001/11/06 03:07:22  steve
 *  Code rearrange. (Stephan Boettcher)
 *
 */