iverilog/net_event.cc

/*
 * Copyright (c) 2000 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
 */
#ifdef HAVE_CVS_IDENT
#ident "$Id: net_event.cc,v 1.24 2004/02/18 17:11:56 steve Exp $"
#endif

# include  "config.h"
# include  "compiler.h"
# include  "netlist.h"

/*
 * NOTE: The name_ is perm-allocated by the caller.
 */
NetEvent::NetEvent(const char*n)
: name_(n)
{
      scope_ = 0;
      snext_ = 0;
      probes_ = 0;
      trig_ = 0;
      waitref_ = 0;
      exprref_ = 0;
      wlist_ = 0;
}

NetEvent::~NetEvent()
{
      assert(waitref_ == 0);
      if (scope_) scope_->rem_event(this);
      while (probes_) {
	    NetEvProbe*tmp = probes_->enext_;
	    delete probes_;
	    probes_ = tmp;
      }
	/* name_ is lex_strings. */
}

const char* NetEvent::name() const
{
      return name_;
}

string NetEvent::full_name() const
{
      assert(scope_);
      return scope_->name() + "." + name_;
}

const NetScope* NetEvent::scope() const
{
      assert(scope_);
      return scope_;
}

unsigned NetEvent::nprobe() const
{
      unsigned cnt = 0;
      NetEvProbe*cur = probes_;
      while (cur) {
	    cnt += 1;
	    cur = cur->enext_;
      }

      return cnt;
}

NetEvProbe* NetEvent::probe(unsigned idx)
{
      NetEvProbe*cur = probes_;
      while (cur && idx) {
	    cur = cur->enext_;
	    idx -= 1;
      }
      return cur;
}

const NetEvProbe* NetEvent::probe(unsigned idx) const
{
      NetEvProbe*cur = probes_;
      while (cur && idx) {
	    cur = cur->enext_;
	    idx -= 1;
      }
      return cur;
}

unsigned NetEvent::ntrig() const
{
      unsigned cnt = 0;
      NetEvTrig*cur = trig_;
      while (cur) {
	    cnt += 1;
	    cur = cur->enext_;
      }

      return cnt;
}

unsigned NetEvent::nwait() const
{
      return waitref_;
}

unsigned NetEvent::nexpr() const
{
      return exprref_;
}

/*
 * A "similar" event is one that has an identical non-nil set of
 * probes.
 */
void NetEvent::find_similar_event(list<NetEvent*>&event_list)
{
      if (probes_ == 0)
	    return;

      map<NetEvent*,unsigned> event_matches;

	/* First, get a list of all the NetEvProbes that are connected
	   to my first probe. Then use that to create a set of
	   candidate events. These candidate events are a superset of
	   the similar events, so I will be culling this list later. */
      list<NetEvProbe*>first_probes;
      probes_->find_similar_probes(first_probes);

      for (list<NetEvProbe*>::iterator idx = first_probes.begin()
		 ; idx != first_probes.end() ;  idx ++) {
	    event_matches[ (*idx)->event() ] = 1;
      }

	/* Now scan the remaining probes, in each case ticking the
	   candidate event. The events that really are similar to this
	   one will turn up in every probe list. */
      unsigned probe_count = 1;
      for (NetEvProbe*cur = probes_->enext_ ; cur ;  cur = cur->enext_) {
	    list<NetEvProbe*>similar_probes;
	    cur->find_similar_probes(similar_probes);

	    for (list<NetEvProbe*>::iterator idx = similar_probes.begin()
		       ; idx != similar_probes.end() ;  idx ++) {
		  event_matches[ (*idx)->event() ] += 1;
	    }

	    probe_count += 1;
      }

	/* Now scan the candidate events. Those events that are
	   connected to all my probes (match_count[x] == probe_count)
	   are possible. If those events have the same number of
	   events, then jackpot. */
      for (map<NetEvent*,unsigned>::iterator idx = event_matches.begin()
		 ; idx != event_matches.end() ;  idx ++) {

	    NetEvent*tmp = (*idx).first;

	    if (tmp == this)
		  continue;

	    if ((*idx).second != probe_count)
		  continue;

	    unsigned tcnt = 0;
	    for (NetEvProbe*cur = tmp->probes_ ; cur ; cur = cur->enext_)
		  tcnt += 1;

	    if (tcnt == probe_count)
		  event_list .push_back(tmp);
      }

}


void NetEvent::replace_event(NetEvent*that)
{
      while (wlist_) {
	    wlist_->obj->replace_event(this, that);
      }
}

NexusSet* NetEvent::nex_async_()
{
	/* If there are behavioral trigger statements attached to me,
	   then this is not an asynchronous event. */
      if (trig_ != 0)
	    return 0;

      
      NexusSet*tmp = new NexusSet;
      for (NetEvProbe*cur = probes_ ;  cur != 0 ;  cur = cur->enext_) {
	    if (cur->edge() != NetEvProbe::ANYEDGE) {
		  delete tmp;
		  return 0;
	    }

	    for (unsigned idx = 0 ;  idx < cur->pin_count() ;  idx += 1)
		  tmp->add(cur->pin(idx).nexus());

      }

      return tmp;
}

NetEvTrig::NetEvTrig(NetEvent*ev)
: event_(ev)
{
      enext_ = event_->trig_;
      event_->trig_ = this;
}

NetEvTrig::~NetEvTrig()
{
      if (event_->trig_ == this) {
	    event_->trig_ = enext_;

      } else {
	    NetEvTrig*cur = event_->trig_;
	    while (cur->enext_ != this) {
		  assert(cur->enext_);
		  cur = cur->enext_;
	    }

	    cur->enext_ = this->enext_;
      }
}

const NetEvent* NetEvTrig::event() const
{
      return event_;
}

NetEvProbe::NetEvProbe(NetScope*s, perm_string n, NetEvent*tgt,
		       edge_t t, unsigned p)
: NetNode(s, n, p), event_(tgt), edge_(t)
{
      for (unsigned idx = 0 ;  idx < p ;  idx += 1) {
	    pin(idx).set_dir(Link::INPUT);
	    pin(idx).set_name(perm_string::literal("P"), idx);
      }

      enext_ = event_->probes_;
      event_->probes_ = this;
}

NetEvProbe::~NetEvProbe()
{
      if (event_->probes_ == this) {
	    event_->probes_ = enext_;

      } else {
	    NetEvProbe*cur = event_->probes_;
	    while (cur->enext_ != this) {
		  assert(cur->enext_);
		  cur = cur->enext_;
	    }

	    cur->enext_ = this->enext_;
      }
}

NetEvProbe::edge_t NetEvProbe::edge() const
{
      return edge_;
}

NetEvent* NetEvProbe::event()
{
      return event_;
}

const NetEvent* NetEvProbe::event() const
{
      return event_;
}

/*
 * A similar NetEvProbe is one that is connected to all the same nexa
 * that this probe is connected to, and also is the same edge
 * type. Don't count myself as a similar probe.
 */
void NetEvProbe::find_similar_probes(list<NetEvProbe*>&plist)
{
      Nexus*nex = pin(0).nexus();

      for (Link*lcur = nex->first_nlink(); lcur; lcur = lcur->next_nlink()) {
	    NetObj*obj = lcur->get_obj();
	    if (obj->pin_count() != pin_count())
		  continue;

	    NetEvProbe*tmp = dynamic_cast<NetEvProbe*>(obj);
	    if (tmp == 0)
		  continue;

	    if (tmp == this)
		  continue;

	    if (edge() != tmp->edge())
		  continue;

	    bool ok_flag = true;
	    for (unsigned idx = 1 ;  idx < pin_count() ;  idx += 1)
		  if (pin(idx).nexus() != tmp->pin(idx).nexus()) {
			ok_flag = false;
			break;
		  }

	    if (ok_flag == true)
		  plist .push_back(tmp);
      }
}

NetEvWait::NetEvWait(NetProc*pr)
: statement_(pr), nevents_(0), events_(0)
{
}

NetEvWait::~NetEvWait()
{
      if (events_) {
	    for (unsigned idx = 0 ;  idx < nevents_ ;  idx += 1) {
		  NetEvent*tgt = events_[idx];
		  tgt->waitref_ -= 1;

		  struct NetEvent::wcell_*tmp = tgt->wlist_;
		  if (tmp->obj == this) {
			tgt->wlist_ = tmp->next;
			delete tmp;
		  } else {
			assert(tmp->next);
			while (tmp->next->obj != this) {
			      tmp = tmp->next;
			      assert(tmp->next);
			}
			tmp->next = tmp->next->next;
			delete tmp;
		  }
	    }
	    delete[]events_;
      }
      delete statement_;
}

void NetEvWait::add_event(NetEvent*tgt)
{
      assert(tgt);
      if (nevents_ == 0) {
	    events_ = new NetEvent*[1];

      } else {
	    NetEvent**tmp = new NetEvent*[nevents_+1];
	    for (unsigned idx = 0 ;  idx < nevents_ ;  idx += 1) {
		  tmp[idx] = events_[idx];
		  assert(tmp[idx] != tgt);
	    }
	    delete[]events_;
	    events_ = tmp;
      }

      events_[nevents_] = tgt;
      nevents_ += 1;

	// Remember to tell the NetEvent that there is someone
	// pointing to it.
      tgt->waitref_ += 1;

      struct NetEvent::wcell_*tmp = new NetEvent::wcell_;
      tmp->obj = this;
      tmp->next = tgt->wlist_;
      tgt->wlist_ = tmp;
}

void NetEvWait::replace_event(NetEvent*src, NetEvent*repl)
{
      unsigned idx;
      for (idx = 0 ;  idx < nevents_ ;  idx += 1) {
	    if (events_[idx] == src)
		  break;
      }

      assert(idx < nevents_);

	/* First, remove me from the list held by the src NetEvent. */
      assert(src->waitref_ > 0);
      src->waitref_ -= 1;
      struct NetEvent::wcell_*tmp = src->wlist_;
      if (tmp->obj == this) {
	    src->wlist_ = tmp->next;
	    delete tmp;
      } else {
	    assert(tmp->next);
	    while (tmp->next->obj != this) {
		  tmp = tmp->next;
		  assert(tmp->next);
	    }
	    tmp->next = tmp->next->next;
	    delete tmp;
      }

      events_[idx] = repl;

	// Remember to tell the replacement NetEvent that there is
	// someone pointing to it.
      repl->waitref_ += 1;

      tmp = new NetEvent::wcell_;
      tmp->obj = this;
      tmp->next = repl->wlist_;
      repl->wlist_ = tmp;

}

unsigned NetEvWait::nevents() const
{
      return nevents_;
}

const NetEvent* NetEvWait::event(unsigned idx) const
{
      assert(idx < nevents_);
      return events_[idx];
}

NetEvent* NetEvWait::event(unsigned idx)
{
      assert(idx < nevents_);
      return events_[idx];
}

NetProc* NetEvWait::statement()
{
      return statement_;
}

/*
 * $Log: net_event.cc,v $
 * Revision 1.24  2004/02/18 17:11:56  steve
 *  Use perm_strings for named langiage items.
 *
 * Revision 1.23  2003/04/22 04:48:29  steve
 *  Support event names as expressions elements.
 *
 * Revision 1.22  2003/03/06 00:28:41  steve
 *  All NetObj objects have lex_string base names.
 *
 * Revision 1.21  2003/03/01 06:25:30  steve
 *  Add the lex_strings string handler, and put
 *  scope names and system task/function names
 *  into this table. Also, permallocate event
 *  names from the beginning.
 *
 * Revision 1.20  2002/08/12 01:34:59  steve
 *  conditional ident string using autoconfig.
 *
 * Revision 1.19  2002/07/24 16:24:45  steve
 *  Rewrite find_similar_event to support doing
 *  all event matching and replacement in one
 *  shot, saving time in the scans.
 *
 * Revision 1.18  2002/06/30 02:21:31  steve
 *  Add structure for asynchronous logic synthesis.
 *
 * Revision 1.17  2002/02/02 06:13:38  steve
 *  event find_similar should not find self.
 *
 * Revision 1.16  2001/10/28 01:14:53  steve
 *  NetObj constructor finally requires a scope.
 *
 * Revision 1.15  2001/07/25 03:10:49  steve
 *  Create a config.h.in file to hold all the config
 *  junk, and support gcc 3.0. (Stephan Boettcher)
 *
 * Revision 1.14  2001/03/29 02:52:19  steve
 *  Add const probe method to NetEvent.
 *
 * Revision 1.13  2001/03/28 06:07:39  steve
 *  Add the ivl_event_t to ivl_target, and use that to generate
 *  .event statements in vvp way ahead of the thread that uses it.
 *
 * Revision 1.12  2000/12/15 17:45:07  steve
 *  Remove limits from the similar events search.
 *
 * Revision 1.11  2000/10/04 16:30:39  steve
 *  Use char8 instead of string to store name.
 *
 * Revision 1.10  2000/09/19 03:00:36  steve
 *  Typo stepping ot next probe in delete.
 *
 * Revision 1.9  2000/07/29 03:55:38  steve
 *  fix problem coalescing events w/ probes.
 *
 * Revision 1.8  2000/05/31 02:26:49  steve
 *  Globally merge redundant event objects.
 *
 * Revision 1.7  2000/05/27 19:33:23  steve
 *  Merge similar probes within a module.
 *
 * Revision 1.6  2000/04/18 04:50:20  steve
 *  Clean up unneeded NetEvent objects.
 *
 * Revision 1.5  2000/04/16 23:32:18  steve
 *  Synthesis of comparator in expressions.
 *
 *  Connect the NetEvent and related classes
 *  together better.
 *
 * Revision 1.4  2000/04/12 20:02:53  steve
 *  Finally remove the NetNEvent and NetPEvent classes,
 *  Get synthesis working with the NetEvWait class,
 *  and get started supporting multiple events in a
 *  wait in vvm.
 *
 * Revision 1.3  2000/04/12 04:23:58  steve
 *  Named events really should be expressed with PEIdent
 *  objects in the pform,
 *
 *  Handle named events within the mix of net events
 *  and edges. As a unified lot they get caught together.
 *  wait statements are broken into more complex statements
 *  that include a conditional.
 *
 *  Do not generate NetPEvent or NetNEvent objects in
 *  elaboration. NetEvent, NetEvWait and NetEvProbe
 *  take over those functions in the netlist.
 *
 * Revision 1.2  2000/04/10 05:26:06  steve
 *  All events now use the NetEvent class.
 *
 * Revision 1.1  2000/04/04 03:20:15  steve
 *  Simulate named event trigger and waits.
 *
 */