core.cc

/*************************************************************************
 *
 *  Copyright (c) 2024 Rajit Manohar
 *
 *  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., 51 Franklin Street, Fifth Floor,
 *  Boston, MA  02110-1301, USA.
 *
 **************************************************************************
 */
#include "actsim.h"
#include "chpsim.h"
#include "prssim.h"
#include "xycesim.h"
#include <time.h>
#include <math.h>
#include <ctype.h>


/*
 * Construct core simulation data structures
 */

struct process_info {
  process_info() { chp = NULL; hse = NULL; prs = NULL; ci = NULL; }
  chpsimgraph_info *chp, *hse;
  PrsSimGraph *prs;
  sdf_celltype *ci;
};


/*
 * Record multi-driver information
 */
class multi_driver_info {
 public:
  multi_driver_info() {
    local = NULL;
  }
  ~multi_driver_info() {
    if (local) {
      ihash_free (local);
      local = NULL;
    }
  }

  void addmd (int idx, int count) {
    if (!local) {
      local = ihash_new (2);
    }
    ihash_bucket_t *b;
    b = ihash_lookup (local, idx);
    if (!b) {
      b = ihash_add (local, idx);
      b->i = 0;
    }
    b->i += count;
  }

  int getcount (int idx) {
    if (!local) {
      return 0;
    }
    ihash_bucket_t *b;
    b = ihash_lookup (local, idx);
    if (!b) {
      return 0;
    }
    return b->i;
  }

  void iter_init () {
    if (!local) return;
    ihash_iter_init (local, &it);
  }
  ihash_bucket_t *iter_next () {
    return ihash_iter_next (local, &it);
  }

  void dump (FILE *fp, ActStatePass *sp, stateinfo_t *si) {
    if (!local) return;
    ihash_bucket_t *b;
    ihash_iter_t it;
    ihash_iter_init (local, &it);
    while ((b = ihash_iter_next (local, &it))) {
      act_connection *c;
      int dy = 0;
      fprintf (fp, "[");
      c = sp->getConnFromOffset (si, b->key, 0, &dy);
      c->Print (fp);
      fprintf (fp, "] ");
      fprintf (fp, "%ld -> count %d\n", (long)b->key, b->i);
    }
  }

  private:
  ihash_iter_t it;
  struct iHashtable *local;	/* local table */
};


char *ActSimCore::_trname[TRACE_NUM_FORMATS] =
  { NULL, NULL, NULL };


ActSimCore::ActSimCore (Process *p, SDF *sdf)
{
  _have_filter = 0;
  for (int i=0; i < TRACE_NUM_FORMATS; i++) {
    _trfn[i] = NULL;
    _tr[i] = NULL;
  }
  
  _black_box_mode = config_get_int ("net.black_box_mode");

  if (config_exists ("sim.device.timescale")) {
    _int_to_float_timescale = config_get_real ("sim.device.timescale");
  }
  else {
    /* 10ps default */
    _int_to_float_timescale = 10e-12;
  }

  A_INIT (_rand_init);
  
  if (!p) {
    root_is_ns = 1;
    root_lang = ActNamespace::Global()->getlang();
    root_scope = ActNamespace::Global()->CurScope();
    simroot = NULL;
  }
  else {
    simroot = p;
    root_lang = p->getlang();
    root_scope = p->CurScope();
  }
  state = NULL;
  a = ActNamespace::Act();
  map = ihash_new (8);
  ewidths = phash_new (4);
  chan = NULL;
  I.H = NULL;
  I.obj = NULL;

  _is_internal_parallel = 0;

  _sdf = sdf;
  _sdf_errs = NULL;

  if (!root_scope->isExpanded()) {
    fatal_error ("Need to expand ACT prior to starting a simulation");
  }

  ActPass *tmp;
  tmp = a->pass_find ("collect_state");
  if (!tmp) {
    fatal_error ("Please run the state pass prior to using the simulator");
  }
  sp = dynamic_cast<ActStatePass *> (tmp);
  Assert (sp, "what?");

  tmp = a->pass_find ("booleanize");
  if (!tmp) {
    fatal_error ("Please run the Booleanize pass!");
  }
  bp = dynamic_cast<ActBooleanizePass *> (tmp);
  Assert (bp, "What?");
  
  stateinfo_t *si = sp->getStateInfo (p);
  
  if (!si) {
    fatal_error ("No state information recorded for process `%s'",
		 p ? p->getName() : "-global-");
  }

  /* 
     Allocate state.
     We need:
     - all ports (all port bools, and chp ports)
     - all local vars including sub-instance local vars
  */
  state_counts globals = sp->getGlobals();

  state = new ActSimState (si->ports.numAllBools() + si->all.numAllBools()
			   + globals.numAllBools(),
			   si->ports.numInts() + si->all.numInts() +
			   globals.numInts(),
			   si->ports.numChans() +  si->all.numChans() +
			   globals.numChans());

  nfo_len = si->ports.numAllBools() + si->all.numAllBools()
    + globals.numAllBools() + si->ports.numInts() + si->all.numInts()
    + globals.numInts();

  nint_start = si->ports.numAllBools() + si->all.numAllBools()
    + globals.numAllBools();

  if (nfo_len > 0) {
    MALLOC (nfo, int, nfo_len);
    MALLOC (fo, SimDES **, nfo_len);
    for (int i=0; i < nfo_len; i++) {
      nfo[i] = 0;
      fo[i] = NULL;
    }
  }
  else {
    nfo = NULL;
    fo = NULL;
  }
  hfo = NULL;

  _seed = 0;
  _rand_min = 1;
  _rand_max = 100;
  _sim_rand_excl = 0;
  _sim_rand = 0;
  _sim_rand_when = 0;
  _prs_sim_mode = 0;
  _on_warning = 0;

  _chp_sim_objects = list_new ();
  
  _rootsi = si;


  _W = ihash_new (4);
  _B = ihash_new (4);

  _multi_driver = phash_new (4);
  _global_multi = NULL;

  _initSim();

  /* add in handlers for the exclhi/excllo directives in prs bodies */
  _register_prssim_with_excl (&I);

  _inf_loop_opt = 0;
  if (config_exists ("sim.chp.inf_loop_opt") &&
      (config_get_int ("sim.chp.inf_loop_opt") == 1)) {
    _inf_loop_opt = 1;
  }
}


static void _delete_sim_objs (ActInstTable *I, int del)
{
  hash_bucket_t *b;
  hash_iter_t hi;
  if (!I) return;

  if (I->obj) {
    delete I->obj;
  }
  I->obj = NULL;

  if (I->H) {
    hash_iter_init (I->H, &hi);
    while ((b = hash_iter_next (I->H, &hi))) {
      ActInstTable *x = (ActInstTable *)b->v;
      _delete_sim_objs (x, 1);
    }
    hash_free (I->H);
  }
  I->H = NULL;
  if (del) {
    FREE (I);
  }
}

ActSimCore::~ActSimCore()
{
  Assert (_rootsi, "What");

  A_FREE (_rand_init);
  
  for (int i=0; i < A_LEN (_rootsi->bnl->used_globals); i++) {
    act_booleanized_var_t *v;
    ihash_bucket_t *b;
    b = ihash_lookup (_rootsi->bnl->cH, (long)_rootsi->bnl->used_globals[i].c);
    Assert (b, "WHat?");
    v = (act_booleanized_var_t *) b->v;
    Assert (v, "What?");
    Assert (v->isglobal, "What?");
  }

  /* free chp */
  if (map) {
    for (int i=0; i < map->size; i++) {
      for (ihash_bucket_t *b = map->head[i]; b; b = b->next) {
	process_info *pgi = (process_info *)b->v;
	if (pgi->chp) {
	  delete pgi->chp->g;
	  FREE (pgi->chp);
	}
	if (pgi->hse) {
	  delete pgi->hse->g;
	  FREE (pgi->hse);
	}
	if (pgi->prs) {
	  delete pgi->prs;
	}
	delete pgi;
      }
    }
    ihash_free (map);
  }

  if (chan) {
    phash_iter_t iter;
    phash_bucket_t *b;
    phash_iter_init (chan, &iter);
    while ((b = phash_iter_next (chan, &iter))) {
      ChanMethods *ch = (ChanMethods *)b->v;
      delete ch;
    }
    phash_free (chan);
  }

  if (ewidths) {
    phash_free (ewidths);
  }

  if (state) {
    delete state;
  }

  /*-- fanout tables --*/
  if (nfo) {
    Assert (fo, "What?");
    for (int i=0; i < nfo_len; i++) {
      if (nfo[i] > 0) {
	Assert (fo[i], "What?");
	FREE (fo[i]);
      }
      else {
	Assert (!fo[i], "Hmm");
      }
    }
    FREE (fo);
    FREE (nfo);
  }
  if (hfo) {
    ihash_free (hfo);
  }

  /*-- chp objects --*/
  list_free (_chp_sim_objects);

  ihash_bucket_t *b;
  ihash_iter_t it;
  ihash_iter_init (_W, &it);
  while ((b = ihash_iter_next (_W, &it))) {
    FREE (b->v);
  }
  ihash_free (_W);
  ihash_iter_init (_B, &it);
  while ((b = ihash_iter_next (_B, &it))) {
    FREE (b->v);
  }
  ihash_free (_B);

  /*-- instance tables --*/
  _delete_sim_objs (&I, 0);

  /*-- close any pending trace files --*/
  for (int i=0; i < TRACE_NUM_FORMATS; i++) {
    if (_tr[i]) {
      act_trace_close (_tr[i]);
    }
  }

  /*-- delete SDF, if it exists --*/
  if (_sdf) {
    delete _sdf;
  }

  /*-- delete multi-driver info --*/
  phash_bucket_t *pb;
  phash_iter_t pit;
  phash_iter_init (_multi_driver, &pit);
  while ((pb = phash_iter_next (_multi_driver, &pit))) {
    multi_driver_info *x = (multi_driver_info *) pb->v;
    if (x) {
      delete x;
    }
  }
  phash_free (_multi_driver);
  _multi_driver = NULL;

  /*-- delete global multi --*/
  if (_global_multi) {
    ihash_iter_init (_global_multi, &it);
    while ((b = ihash_iter_next (_global_multi, &it))) {
      MultiPrsSim *mp = (MultiPrsSim *) b->v;
      if (mp) {
	delete mp;
      }
    }
    ihash_free (_global_multi);
  }
}


/*------------------------------------------------------------------------
 *
 *  _add_<language> methods
 *
 *    Each of these creates an ACT simulation object corresponding to
 *    the current instance at the appropriate level of abstraction
 *    (chp, hse, prs, spice).
 *
 *------------------------------------------------------------------------
 */

/*
 * Create a CHP simulation object
 */
ChpSim *ActSimCore::_add_chp (act_chp *c)
{
  ihash_bucket_t *b;

#if 0  
  printf ("add-chp-inst: ");
  if (_curinst) {
    _curinst->Print (stdout);
  }
  else {
    printf ("-none-");
  }
  printf ("\n");
#endif

  ChpSim *x;
  process_info *pgi = NULL;
  
  if (c) {
    b = ihash_lookup (map, (long)_curproc);
    if (b) {
      pgi = (process_info *) b->v;
    }
    else {
      pgi = new process_info();
      b = ihash_add (map, (long)_curproc);
      b->v = pgi;

      if (_sdf) {
	char buf[1024];
	a->msnprintfproc (buf, 1024, _curproc);
	pgi->ci = _sdf->getCell (buf);
	if (pgi->ci) {
	  pgi->ci->used = true;
	}
	else {
	  _add_sdf_type_error (_curproc);
	}
      }
    }
    if (!pgi->chp) {
      if (c->c && c->c->type == ACT_CHP_COMMA) {
	setInternalParallel (1);
      }
      else {
	setInternalParallel (0);
      }
      pgi->chp = ChpSimGraph::buildChpSimGraph (this, c->c);
    }
    x = new ChpSim (pgi->chp, c->c, this, _curproc);
  }
  else {
    x = new ChpSim (NULL, NULL, this, _curproc);
  }
  x->setName (_curinst);
  x->setOffsets (&_curoffset);
  x->setPorts (_cur_abs_port_bool, _cur_abs_port_int, _cur_abs_port_chan);
  x->zeroInit ();

  list_append (_chp_sim_objects, x);

  return x;
}


/*
 * No dataflow simulation objects!
 */
ActSimObj *ActSimCore::_add_dflow (act_dataflow *d)
{
  printf ("add-dflow-inst (not currently supported): ");
  if (_curinst) {
    _curinst->Print (stdout);
  }
  else {
    printf ("-none-");
  }
  printf ("\n");
  return NULL;
}


/*
 * Add HSE simulation object
 */
ChpSim *ActSimCore::_add_hse (act_chp *c)
{
  ihash_bucket_t *b;
#if 0 
  printf ("add-hse-inst: ");
  if (_curinst) {
    _curinst->Print (stdout);
  }
  else {
    printf ("-none-");
  }
  printf ("\n");
#endif  

  process_info *pgi;
  b = ihash_lookup (map, (long)_curproc);
  if (b) {
    pgi = (process_info *)b->v;
  }
  else {
    pgi = new process_info();
    b = ihash_add (map, (long)_curproc);
    b->v = pgi;

    if (_sdf) {
      char buf[1024];
      a->msnprintfproc (buf, 1024, _curproc);
      pgi->ci = _sdf->getCell (buf);
      if (pgi->ci) {
	pgi->ci->used = true;
      }
      else {
	_add_sdf_type_error (_curproc);
      }
    }
  }

  if (!pgi->hse) {
    if (c->c && c->c->type == ACT_CHP_COMMA) {
      setInternalParallel (1);
    }
    else {
      setInternalParallel (0);
    }
    pgi->hse = ChpSimGraph::buildChpSimGraph (this, c->c);
  }
  ChpSim *x = new ChpSim (pgi->hse, c->c, this, _curproc);
  x->setHseMode ();
  x->setName (_curinst);
  x->setOffsets (&_curoffset);
  x->setPorts (_cur_abs_port_bool, _cur_abs_port_int, _cur_abs_port_chan);
  
  return x;
}

/*
 * Add prs simulation object
 */
PrsSim *ActSimCore::_add_prs (act_prs *p)
{
#if 0  
  printf ("add-prs-inst: ");
  if (_curinst) {
    _curinst->Print (stdout);
  }
  else {
    printf ("-none-");
  }
  printf ("\n");
#endif
  process_info *pgi;
  ihash_bucket_t *b;
  b = ihash_lookup (map, (long)_curproc);
  if (b) {
    pgi = (process_info *)b->v;
  }
  else {
    b = ihash_add (map, (long)_curproc);
    pgi = new process_info ();
    b->v = pgi;

    if (_sdf) {
      char buf[1024];
      a->msnprintfproc (buf, 1024, _curproc);
      pgi->ci = _sdf->getCell (buf);
      if (pgi->ci) {
	pgi->ci->used = true;
      }
      else {
	_add_sdf_type_error (_curproc);
      }
    }
  }
  
  if (!pgi->prs) {
    sdf_cell *di;
    if (pgi->ci && pgi->ci->all) {
      di = pgi->ci->all;
    }
    else {
      di = NULL;
    }
    /* di is the generic cell delay, non-instance specific */
    pgi->prs = PrsSimGraph::buildPrsSimGraph (this, p, di);
  }
  
  /* need prs simulation graph */
  PrsSim *x = new PrsSim (pgi->prs, this, _curproc);
  x->setName (_curinst);
  x->setOffsets (&_curoffset);
  x->setPorts (_cur_abs_port_bool, _cur_abs_port_int, _cur_abs_port_chan);
  x->updateDelays (p, pgi->ci);

  return x;
}

/*
 * Add a Xyce simulation object
 */
XyceSim *ActSimCore::_add_xyce ()
{
  XyceSim *x = new XyceSim (this, _curproc);
  x->setName (_curinst);
  x->setOffsets (&_curoffset);
  x->setPorts (_cur_abs_port_bool, _cur_abs_port_int, _cur_abs_port_chan);

  return x;
}


/*------------------------------------------------------------------------
 *
 * SPEC bodies add checks and mutex elements
 *
 *------------------------------------------------------------------------
 */

/*
 *      sc = Scope of parent 
 *  parent = root of identifier
 *      tl = tail pointer of parent id
 *    rest = additional bit of ID to be appended
 *
 *  Returns canonical pointer in "sc" scope of "parent . rest",
 *  assuming "tl" is the parent tail pointer
 *
 */
static act_connection *_parent_canonical (Scope *sc,
					  ActId *parent, ActId *tl, ActId *rest)
{
  act_connection *ret;
  
  if (tl) {
    tl->Append (rest);
    ret = parent->Canonical (sc);
    tl->prune ();
  }
  else {
    ret = rest->Canonical (sc);
  }
  return ret;
}


/** code to process a spec body associated with a simulation object **/
void ActSimCore::_add_spec (ActSimObj *obj, act_spec *s)
{
  stateinfo_t *si;
  ActId *p_tl;
  int type;
  A_DECL (int, idx);
  
  if (!s) return;

  si = sp->getStateInfo (obj->getProc());
  /* XXX: this can happen for wiring processes? */
  Assert (si, "No stateinfo found?");

  if (_cursuffix) {
    p_tl = _cursuffix->Tail();
  }
  else {
    p_tl = NULL;
  }

  Scope *sc = si->bnl->cur;
  A_INIT (idx);
  
  while (s) {
    if (ACT_SPEC_ISTIMINGFORK (s)) {
      /* create runtime checks for timing forks */
      
      InstType *it[3];
      Array *aref[3];
      act_connection *r, *a, *b;
      ActId *tl[2];
      Arraystep *as[2];
      int roff, aoff, boff;
      int valid_constr = 1;

      for (int i=0; i < 3; i++) {
	if (p_tl) {
	  p_tl->Append (s->ids[i]);
	  it[i] = sc->FullLookup (_cursuffix, &aref[i]);
	  p_tl->prune();
	}
	else {
	  it[i] = sc->FullLookup (s->ids[i], &aref[i]);
	}
	if (!it[i]) {
	  valid_constr = 0;
	}
      }
      
      if (!valid_constr) {
	/* constraint with unknown signals */
	s = s->next;
	continue;
      }

      if (it[0]->arrayInfo() && (!aref[0] || !aref[0]->isDeref())) {
	fprintf (stderr, "Timing constraint error for `%s'\n",
		 obj->getProc()->getName());
	fprintf (stderr, "  LHS `");
	s->ids[0]->Print (stderr);
	fprintf (stderr, "' is an array.\n");
	s = s->next;
	continue;
      }
      
      r = _parent_canonical (sc, _cursuffix, p_tl, s->ids[0]);
      if (!hasLocalOffset (r, si)) {
	/* just skip it! */
	s = s->next;
	continue;
      }
      roff = getLocalOffset (r, si, &type, NULL);
      Assert (type == 0, "Non-boolean in timing spec");
      //roff = obj->getGlobalOffset (roff, 0);

      for (int i=1; i < 3; i++) {
	if (it[i]->arrayInfo() && (!aref[i] || !aref[i]->isDeref())) {
	  if (aref[i]) {
	    as[i-1] = it[i]->arrayInfo()->stepper (aref[i]);
	  }
	  else {
	    as[i-1] = it[i]->arrayInfo()->stepper ();
	  }
	  tl[i-1] = s->ids[i]->Tail();
	}
	else {
	  as[i-1] = NULL;
	  tl[i-1] = NULL;
	}
      }

      if (!as[0] && !as[1]) {
	a = _parent_canonical (sc, _cursuffix, p_tl, s->ids[1]);
	b = _parent_canonical (sc, _cursuffix, p_tl, s->ids[2]);

	if (hasLocalOffset (a, si) && hasLocalOffset (b, si)) {
	  aoff = getLocalOffset (a, si, &type, NULL);
	  Assert (type == 0, "Non-boolean in timing spec");
	  //aoff = obj->getGlobalOffset (aoff, 0);
	  boff = getLocalOffset (b, si, &type, NULL);
	  Assert (type == 0, "Non-boolean in timing spec");
	  //boff = obj->getGlobalOffset (boff, 0);

	  _add_timing_fork (obj, si, roff, aoff, boff, (Expr *)s->ids[3], s->extra);
	}
      }
      else {
	for (int i=1; i < 3; i++) {
	  if (aref[i]) {
	    tl[i-1]->setArray (NULL);
	  }
	}

	while ((as[0] && !as[0]->isend()) ||
	       (as[1] && !as[1]->isend())) {
	  Array *ta[2];

	  for (int i=1; i < 3; i++) {
	    if (as[i-1]) {
	      ta[i-1] = as[i-1]->toArray();
	      tl[i-1]->setArray (ta[i-1]);
	    }
	    else {
	      ta[i-1] = NULL;
	    }
	  }

	  a = _parent_canonical (sc, _cursuffix, p_tl, s->ids[1]);
	  b = _parent_canonical (sc, _cursuffix, p_tl, s->ids[2]);

	  if (hasLocalOffset (a, si) && hasLocalOffset (b, si)) {
	    aoff = getLocalOffset (a, si, &type, NULL);
	    Assert (type == 0, "Non-boolean in timing spec");
	    //aoff = obj->getGlobalOffset (aoff, 0);
	    boff = getLocalOffset (b, si, &type, NULL);
	    Assert (type == 0, "Non-boolean in timing spec");
	    //boff = obj->getGlobalOffset (boff, 0);

	    _add_timing_fork (obj, si, roff, aoff, boff, (Expr *)s->ids[3], s->extra);
	  }

	  for (int i=1; i < 3; i++) {
	    if (ta[i-1]) {
	      delete ta[i-1];
	    }
	  }
	  
	  if (as[1]) {
	    as[1]->step();
	    if (as[1]->isend()) {
	      if (as[0]) {
		as[0]->step();
		if (!as[0]->isend()) {
		  delete as[1];
		  if (aref[2]) {
		    as[1] = it[2]->arrayInfo()->stepper (aref[2]);
		  }
		  else {
		    as[1] = it[2]->arrayInfo()->stepper ();
		  }
		}
	      }
	    }
	  }
	  else {
	    if (as[0]) {
	      as[0]->step();
	    }
	  }
	}

	if (as[0]) {
	  delete as[0];
	}
	if (as[1]) {
	  delete as[1];
	}

	for (int i=1; i < 3; i++) {
	  if (tl[i-1]) {
	    tl[i-1]->setArray (aref[i]);
	  }
	}
      }
    }
    else if (ACT_SPEC_ISTIMING(s)) {
      /* ignore timing graph specifiers */
    }
    else {
      /* check for other directives that impact simulation */
      const char *tmp = act_spec_string (s->type);
      if (strcmp (tmp, "mk_exclhi") == 0 || strcmp (tmp, "mk_excllo") == 0 ||
	  strcmp (tmp, "rand_init") == 0 || strcmp (tmp, "hazard") == 0) {

	/* helper function to add the ID to the list */
	auto add_id_to_idx = [&] (ActId *id_val, ValueIdx *myvx)
        {
	  Array *aref;
	  InstType *it;
	  Arraystep *astep;
	  int off;
	  act_connection *cx;
	    
	  if (p_tl) {
	    p_tl->Append (id_val);
	    it = sc->FullLookup (_cursuffix, &aref);
	    p_tl->prune();
	  }
	  else {
	    it = sc->FullLookup (id_val, &aref);
	  }

	  astep = NULL;
	  if (it->arrayInfo() && (!aref || !aref->isDeref())) {
	    if (aref) {
	      astep = it->arrayInfo()->stepper (aref);
	    }
	    else {
	      astep = it->arrayInfo()->stepper ();
	    }
	  }
	  if (!astep) {
	    cx = _parent_canonical (sc, _cursuffix, p_tl, id_val);
	    if (hasLocalOffset (cx, si)) {
	      off = getLocalOffset (cx, si, &type, NULL);
	      Assert (type == 0, "Non-boolean in signal list");
	      off = obj->getGlobalOffset (off, 0);
	      A_NEW (idx, int);
	      A_NEXT (idx) = off;
	      A_INC (idx);
	    }
	  }
	  else {
	    ActId *tl = id_val->Tail();
	    int cnt = 0;
	    while (!astep->isend()) {
	      if (!myvx || myvx->isPrimary (cnt)) {
		Array *a = astep->toArray();
		tl->setArray (a);
		cx = _parent_canonical (sc, _cursuffix, p_tl, id_val);
		if (hasLocalOffset (cx, si)) {
		  off = getLocalOffset (cx, si, &type, NULL);
		  Assert (type == 0, "Non-boolean in signal list");
		  off = obj->getGlobalOffset (off, 0);
		  A_NEW (idx, int);
		  A_NEXT (idx) = off;
		  A_INC (idx);
		}
		tl->setArray (NULL);
		delete a;
	      }
	      cnt++;
	      astep->step();
	    }
	  }
	};
	
	/*-- signal list --*/
	for (int i=0; i < s->count; i++) {
	  add_id_to_idx (s->ids[i], NULL);
	}
	if (s->count < 0) {
	  ActInstiter it(sc);
	  for (it = it.begin(); it != it.end(); it++) {
	    ValueIdx *vx = *it;
	    if (!vx->isPrimary()) {
	      continue;
	    }
	    if (TypeFactory::isBoolType (vx->t) &&
		(vx->t->getDir() != Type::IN)) {
	      ActId *tmp = new ActId (vx->getName());
	      add_id_to_idx (tmp, vx);
	      delete tmp;
	    }
	  }
	}
	if (strcmp (tmp, "mk_exclhi") == 0) {
	  _add_excl (1, idx, A_LEN (idx));
	}
	else if (strcmp (tmp, "mk_excllo") == 0) {
	  _add_excl (0, idx, A_LEN (idx));
	}
	else if (strcmp (tmp, "rand_init") == 0) {
	  _add_rand_init (idx, A_LEN (idx));
	}
	else {
	  _add_hazard (idx, A_LEN (idx));
	}
	A_LEN_RAW (idx) = 0;
      }
    }
    s = s->next;
  }
  A_FREE (idx);
}


/*
 * This returns the level of abstraction that a particular
 * instance/process must be modeled. This uses the ACT API getLevel()
 * methods, which in turn look at configuration file options to
 * determine the simulator level that is appropriate for an
 * instance/process combination.
 */
int ActSimCore::_getlevel ()
{
  int lev;

  lev = -1;
  
  if (_curinst) {
    lev = ActNamespace::Act()->getLevel (_curinst);
  }
  if (lev == -1 && _curproc) {
    lev = ActNamespace::Act()->getLevel (_curproc);
  }
  if (lev == -1) {
    lev = ActNamespace::Act()->getLevel ();
  }
  
  return lev;
}



/*
 * Given a set of languages, add the appropriate one given the
 * selected simulation level.
 */
void ActSimCore::_add_language (int lev, act_languages *l)
{
  if (!l) {
    _curI->obj = _add_chp (NULL);
    return;
  }

  /*- we have the full path here -*/
  if ((l->getchp() || l->getdflow()) && lev == ACT_MODEL_CHP) {
    /* chp or dataflow */
    if (l->getchp()) {
      _curI->obj = _add_chp (l->getchp());
    }
    else {
      _curI->obj = _add_dflow (l->getdflow());
    }
  }
  else if (l->gethse() && lev == ACT_MODEL_HSE) {
    ChpSim *x;
    /* hse */
    _check_fragmentation ((x = _add_hse (l->gethse())));
    _curI->obj = x;
  }
  else if (l->getprs() && lev == ACT_MODEL_PRS) {
    /* prs */
    PrsSim *x;
    _check_fragmentation ((x = _add_prs (l->getprs())));
    _curI->obj = x;
  }
  else if (lev == ACT_MODEL_DEVICE) {
    XyceSim *x;
    _check_fragmentation ((x = _add_xyce ()));
    _curI->obj = x;
  }
  else {
    /* substitute a less detailed model, if possible */
    if (l->gethse() && lev == ACT_MODEL_PRS) {
      ChpSim *x;
      if (Act::lang_subst) {
	warning ("%s: substituting hse model (requested %s, not found)", _curproc ? _curproc->getName() : "-top-", act_model_names[lev]);
      }
      _check_fragmentation ((x = _add_hse (l->gethse())));
      _curI->obj = x;
    }
    else if ((l->getdflow() || l->getchp()) &&
	     (lev == ACT_MODEL_PRS || lev == ACT_MODEL_HSE)) {
      if (l->getdflow() && !l->getchp() /* XXX: currently we don't
					   directly simulate dataflow */) {
	if (Act::lang_subst) {
	  warning ("%s: substituting dataflow model (requested %s, not found)", _curproc ? _curproc->getName() : "-top-", act_model_names[lev]);
	}
	_curI->obj = _add_dflow (l->getdflow());
      }
      else {
	Assert (l->getchp(), "What?");
	if (Act::lang_subst) {
	  warning ("%s: substituting chp model (requested %s, not found)", _curproc ? _curproc->getName() : "-top-", act_model_names[lev]);
	}
	_curI->obj = _add_chp (l->getchp());
      }
    }
    else {
      if (l->getchp() || l->getdflow() || l->gethse() || l->getprs()) {
	fprintf (stderr, "%s: circuit found, but not at the modeling level requested [level=%s]\n", _curproc ? _curproc->getName() : "-top-", act_model_names[lev]);
	fprintf (stderr, "  found:");
	if (l->getchp()) {
	  fprintf (stderr, " %s", act_model_names[ACT_MODEL_CHP]);
	}
	if (l->getdflow()) {
	  fprintf (stderr, " %s[d-flow]", act_model_names[ACT_MODEL_CHP]);
	}
	if (l->gethse()) {
	  fprintf (stderr, " %s", act_model_names[ACT_MODEL_HSE]);
	}
	if (l->getprs()) {
	  fprintf (stderr, " %s", act_model_names[ACT_MODEL_PRS]);
	}
	fprintf (stderr, "\n");
	fatal_error ("Model level requirement inconsistent with ACT");
      }
      else {
	_curI->obj = _add_chp (NULL);
      }
    }
  }
  if (_curI->obj) {
    _cursuffix = NULL;
    _add_spec (_curI->obj, l->getspec());
  }
}



/*
 * Add spec bodies for all user-defined types, walking through the
 * port lists recursively. This is called for non-process user-defined
 * types, so Data/Channel only.
 */
void ActSimCore::_check_add_spec (const char *name, InstType *it,
				  ActSimObj *obj) 
{
  UserDef *u;
  if (!TypeFactory::isUserType (it)) {
    return;
  }
  u = dynamic_cast<UserDef *> (it->BaseType());
  Arraystep *as;
  if (it->arrayInfo()) {
    as = new Arraystep (it->arrayInfo());
  }
  else {
    as = NULL;
  }
  
  ActId *tmpid, *previd;

  if (!_cursuffix) {
    _cursuffix = new ActId (name);
    tmpid = _cursuffix;
    previd = NULL;
  }
  else {
    tmpid = _cursuffix->Tail();
    tmpid->Append (new ActId (name));
    previd = tmpid;
    tmpid = tmpid->Rest();
  }
  
  do {
    if (as) {
      tmpid->setArray (as->toArray ());
    }

    /* _cursuffix has the name */
    if (u->getlang() && u->getlang()->getspec()) {
      _add_spec (obj, u->getlang()->getspec());
    }
    for (int i=0; i < u->getNumPorts(); i++) {
      InstType *it = u->getPortType (i);
      if (TypeFactory::isUserType (it)) {
	_check_add_spec (u->getPortName (i), it, obj);
      }
    }

    if (as) {
      Array *atmp = tmpid->arrayInfo();
      delete atmp;
      tmpid->setArray (NULL);
    }
    if (as) {
      as->step();
    }
  } while (as && !as->isend());

  if (previd) {
    previd->prune();
    delete tmpid;
  }
  else {
    delete _cursuffix;
    _cursuffix = NULL;
  }
  if (as) {
    delete as;
  }
}

/*
 * Mark the connection as used and propagate the used flag through
 * the ports list
 */
static void _prop_used_flags (act_boolean_netlist_t *bnl, act_connection *c)
{
  for (int i=0; i < A_LEN (bnl->ports); i++) {
    if (bnl->ports[i].c == c) {
      bnl->ports[i].used = 1;
      break;
    }
  }
  for (int i=0; i < A_LEN (bnl->chpports); i++) {
    if (bnl->chpports[i].c == c) {
      bnl->chpports[i].used = 1;
      break;
    }
  }
}


/*
 * Add simulation objects required for this scope. All instances
 * within the scope are added to the simulation.
 */
void ActSimCore::_add_all_inst (Scope *sc)
{
  int lev;
  int iportbool, iportchp;
  act_boolean_netlist_t *mynl;
  int *_my_port_int, *_my_port_chan, *_my_port_bool;
  stateinfo_t *mysi;
  state_counts myoffset;
  ActInstTable *myI;

  Assert (sc->isExpanded(), "What?");

  iportbool = 0;
  iportchp = 0;
  mynl = bp->getBNL (_curproc);
  _my_port_int = _cur_abs_port_int;
  _my_port_bool = _cur_abs_port_bool;
  _my_port_chan = _cur_abs_port_chan;
  mysi = _cursi;
  myoffset = _curoffset;
  myI = _curI;

  /* -- increment cur offset after allocating all the items -- */
  if (!_cursi) {
    return;
  }

  stack_push (_si_stack, mysi);
  stack_push (_obj_stack, myI->obj);
  
  _curoffset.addVar (_cursi->local);

  ActUniqProcInstiter ipt(sc);

  if (ipt.begin() != ipt.end()) {
    myI->H = hash_new (4);
  }

  for (ipt = ipt.begin(); ipt != ipt.end(); ipt++) {
    ValueIdx *vx = (*ipt);
    stateinfo_t *si;
    Process *x = dynamic_cast<Process *> (vx->t->BaseType());
    Arraystep *as = NULL;
    Assert (x->isExpanded(), "What?");

    if (vx->t->arrayInfo()) {
      as = new Arraystep (vx->t->arrayInfo());
    }
    else {
      as = NULL;
    }

    ActId *tmpid, *previd;

    if (!_curinst) {
      _curinst = new ActId (vx->getName());
      tmpid = _curinst;
      previd = NULL;
    }
    else {
      tmpid = _curinst->Tail();
      tmpid->Append (new ActId (vx->getName()));
      previd = tmpid;
      tmpid = tmpid->Rest();
    }

    si = sp->getStateInfo (x);
    _cursi = si;

    do {
      _curproc = x;
      _cursi = si;

      if (!as || vx->isPrimary (as->index())) {
	if (as) {
	  tmpid->setArray (as->toArray());
	}

	/*-- tmpid = name of the id --*/

	char buf[1024];
	hash_bucket_t *ib;
	ActInstTable *iT;
	tmpid->sPrint (buf, 1024);
	ib = hash_add (myI->H, buf);
	NEW (iT, ActInstTable);
	iT->obj = NULL;
	iT->H = NULL;
	ib->v = iT;
	_curI = iT;

	/*-- compute ports for this process --*/
	lev = _getlevel();
	act_boolean_netlist_t *bnl = bp->getBNL (_curproc);

	int ports_exist = 0;
	int chpports_exist_int = 0;
	int chpports_exist_bool = 0;
	int chpports_exist_chan = 0;

	for (int i=0; i < A_LEN (bnl->ports); i++) {
	  if (bnl->ports[i].omit == 0) {
	    ports_exist++;
	  }
	}
	for (int i=0; i < A_LEN (bnl->chpports); i++) {
	  if (bnl->chpports[i].omit == 0) {
	    ValueIdx *lvx = bnl->chpports[i].c->getvx();
	    Assert (lvx, "What?");
	    if (TypeFactory::isChanType (lvx->t)) {
	      chpports_exist_chan++;
	    }
	    else if (TypeFactory::isBoolType (lvx->t)) {
	      chpports_exist_bool++;
	    }
	    else {
	      chpports_exist_int++;
	    }
	  }
	}

	/* compute port bool, int and chan ports */
	_cur_abs_port_bool = NULL;
	_cur_abs_port_int = NULL;
	_cur_abs_port_chan = NULL;

	if (chpports_exist_bool || chpports_exist_int || chpports_exist_chan ||
	    ports_exist) {
	  if (chpports_exist_chan) {
	    MALLOC (_cur_abs_port_chan, int, chpports_exist_chan);
	  }
	  if (chpports_exist_int) {
	    MALLOC (_cur_abs_port_int, int, chpports_exist_int);
	  }
	  if (chpports_exist_bool || ports_exist) {
	    MALLOC (_cur_abs_port_bool, int, chpports_exist_bool + ports_exist);
	  }
	}

	int ibool = 0;
	int iportbool_orig = iportbool;
	if (ports_exist) {
	  for (int i=0; i < A_LEN (bnl->ports); i++) {
	    if (bnl->ports[i].omit) continue;
	    Assert (iportbool < A_LEN (mynl->instports), "What?");

	    act_connection *c = mynl->instports[iportbool];

	    if (bnl->ports[i].used) {
	      checkFragmentation (c, NULL, myI->obj, mysi, bnl->ports[i].input);
	    }

	    int off = getLocalOffset (c, mysi, NULL);

	    if (sp->isGlobalOffset (off)) {
	      off = sp->globalIdx (off);
	    }
	    else if (sp->isPortOffset (off)) {
	      off = sp->portIdx (off);
	      off = _my_port_bool[off];
	    }
	    else {
	      /* local state */
	      off += myoffset.numAllBools();
	    }
	    _cur_abs_port_bool[ibool++] = off;
	    iportbool++;
	  }
	}
	
	int ichan = 0;
	int iint = 0;
	int iportchp_orig = iportchp;
	if (chpports_exist_int|| chpports_exist_bool || chpports_exist_chan) {
	  /* then we use the chp instports */
	  for (int i=0; i < A_LEN (bnl->chpports); i++) {
	    if (bnl->chpports[i].omit) continue;
	    Assert (iportchp < A_LEN (mynl->instchpports), "What?");
	    ValueIdx *lvx = bnl->chpports[i].c->getvx();
	    Assert (lvx, "Hmm");

	    act_connection *c = mynl->instchpports[iportchp];

	    if (bnl->chpports[i].used) {
	      checkFragmentation (c, NULL, myI->obj, mysi, bnl->chpports[i].input);
	    }

	    iportchp++;

	    ihash_bucket_t *xb = ihash_lookup (bnl->cH, (long)bnl->chpports[i].c);
	    if (xb) {
	      act_booleanized_var_t *v;
	      v = (act_booleanized_var_t *)xb->v;
	      if (v->used) continue; /* already covered */
	    }

	    int type;
	    int off = getLocalOffset (c, mysi, &type);

	    if (sp->isGlobalOffset (off)) {
	      off = sp->globalIdx (off);
	    }
	    else if (sp->isPortOffset (off)) {
	      off = sp->portIdx (off);
	      if (type == 2 || type == 3) {
		off = _my_port_chan[off];
	      }
	      else if (type == 1) {
		off = _my_port_int[off];
	      }
	      else {
		off = _my_port_bool[off];
	      }
	    }
	    else {
	      /* local state */
	      if (type == 2 || type == 3) {
		off += myoffset.numChans();
	      }
	      else if (type == 1) {
		off += myoffset.numInts();
	      }
	      else {
		off += myoffset.numAllBools();
	      }
	    }
	    if (TypeFactory::isChanType (lvx->t)) {
	      _cur_abs_port_chan[ichan++] = off;
	    }
	    else if (TypeFactory::isBoolType (lvx->t)) {
	      _cur_abs_port_bool[ibool++] = off;
	    }
	    else {
	      _cur_abs_port_int[iint++] = off;
	    }
	  }
	}

	for (int i=0; i < ibool/2; i++) {
	  int x = _cur_abs_port_bool[i];
	  _cur_abs_port_bool[i] = _cur_abs_port_bool[ibool-1-i];
	  _cur_abs_port_bool[ibool-1-i] = x;
	}
	for (int i=0; i < iint/2; i++) {
	  int x = _cur_abs_port_int[i];
	  _cur_abs_port_int[i] = _cur_abs_port_int[iint-1-i];
	  _cur_abs_port_int[iint-1-i] = x;
	}
	for (int i=0; i < ichan/2; i++) {
	  int x = _cur_abs_port_chan[i];
	  _cur_abs_port_chan[i] = _cur_abs_port_chan[ichan-1-i];
	  _cur_abs_port_chan[ichan-1-i] = x;
	}

#if 0
	printf ("inst: "); _curinst->Print (stdout); printf ("\n");
	printf ("  [bool %d] ", ibool);
	for (int i=0; i < ibool; i++) {
	  printf (" %d", _cur_abs_port_bool[i]);
	}
	printf ("\n");
	printf ("  [int %d] ", iint);
	for (int i=0; i < iint; i++) {
	  printf (" %d", _cur_abs_port_int[i]);
	}
	printf ("\n");
	printf ("  [chan %d] ", ichan);
	for (int i=0; i < ichan; i++) {
	  printf(" %d", _cur_abs_port_chan[i]);
	}
	printf ("\n");
#endif

	// XXX: add multi-driver instances needed for the current process!
	_add_multidrivers (x, _curoffset.numBools(), _cur_abs_port_bool);
	_add_language (lev, x->getlang());

	if (lev != ACT_MODEL_DEVICE) {
	  /* a device level model applies to the *entire* sub-tree */
	  _add_all_inst (x->CurScope());
	}


	iportbool = iportbool_orig;
	if (ports_exist) {
	  for (int i=0; i < A_LEN (bnl->ports); i++) {
	    if (bnl->ports[i].omit) continue;
	    Assert (iportbool < A_LEN (mynl->instports), "What?");
	    act_connection *c = mynl->instports[iportbool];

	    if (bnl->ports[i].used) {
	      //_prop_used_flags (mysi->bnl, c);
	      checkFragmentation (c, NULL, myI->obj, mysi, bnl->ports[i].input);
	    }
	    iportbool++;
	  }
	}
	iportchp = iportchp_orig;
	if (chpports_exist_int|| chpports_exist_bool || chpports_exist_chan) {
	  /* then we use the chp instports */
	  for (int i=0; i < A_LEN (bnl->chpports); i++) {
	    if (bnl->chpports[i].omit) continue;
	    Assert (iportchp < A_LEN (mynl->instchpports), "What?");
	    act_connection *c = mynl->instchpports[iportchp];

	    if (bnl->chpports[i].used) {
	      //_prop_used_flags (mysi->bnl, c);
	      checkFragmentation (c, NULL, myI->obj, mysi, bnl->chpports[i].input);
	    }

	    iportchp++;
	  }
	}

	if (as) {
	  Array *atmp = tmpid->arrayInfo();
	  delete atmp;
	  tmpid->setArray (NULL);
	}

      }
      
      if (as) {
	as->step();
      }
    } while (as && !as->isend());

    if (previd) {
      previd->prune();
      delete tmpid;
    }
    else {
      delete _curinst;
      _curinst = NULL;
    }
    if (as) {
      delete as;
    }
  }
  Assert (iportbool == A_LEN (mynl->instports), "What?");
  Assert (iportchp == A_LEN (mynl->instchpports), "What?");

  _cursuffix = NULL;
  ActInstiter it(sc);
  for (it = it.begin(); it != it.end(); it++) {
    ValueIdx *vx = (*it);
    if (!TypeFactory::isProcessType (vx->t)) {
      _check_add_spec (vx->getName(), vx->t, myI->obj);
    }
  }

  _cursi = (stateinfo_t *) stack_pop (_si_stack);
  stack_pop (_obj_stack);
}

/*
 * Compute the fanout of every instance in the simulation. Traversal
 * is done through the instance table created after the simulation is
 * initialized.
 */
void ActSimCore::computeFanout (ActInstTable *I)
{
  stateinfo_t *si = _cursi;
  if (I->obj) {
    _cursi = sp->getStateInfo (I->obj->getProc());
    I->obj->computeFanout();
  }
  if (I->H) {
    hash_bucket_t *b;
    hash_iter_t it;
    hash_iter_init (I->H, &it);
    while ((b = hash_iter_next (I->H, &it))) {
      computeFanout ((ActInstTable *)b->v);
    }
  }
  _cursi = si;
}


/*
 * Initialize simulation data structures by creating simulation
 * objects for all instances, and then computing the fanout tables for
 * event propagation across simulation objects.
 */
void ActSimCore::_initSim ()
{
  /* 
     We need to add:
      - top level languages, if any
      - all instances (recursively)
  */
  _curproc = simroot;
  _curinst = NULL;
  _cursuffix = NULL;
  _cursi = sp->getStateInfo (_curproc);
  _curoffset = sp->getGlobals();
  _curI = &I;

  /*
    Allocate top-level ports
  */
  act_boolean_netlist_t *bnl = bp->getBNL (_curproc);

  int ports_exist = 0;
  int chpports_exist_int = 0;
  int chpports_exist_bool = 0;
  int chpports_exist_chan = 0;

  for (int i=0; i < A_LEN (bnl->ports); i++) {
    if (bnl->ports[i].omit == 0) {
      ports_exist++;
    }
  }
  for (int i=0; i < A_LEN (bnl->chpports); i++) {
    if (bnl->chpports[i].omit == 0) {
      ihash_bucket_t *xb = ihash_lookup (bnl->cH, (long)bnl->chpports[i].c);
      act_booleanized_var_t *v;
      Assert (xb, "What?");
      v = (act_booleanized_var_t *)xb->v;
      if (v->ischan) {
	chpports_exist_chan++;
      }
      else if (v->isint) {
	chpports_exist_int++;
      }
      else {
	chpports_exist_bool++;
      }
    }
  }

#if 0
  Assert (chpports_exist_bool >= ports_exist, "What?");
  chpports_exist_bool -= ports_exist;
  printf ("ports_exist = %d\n", ports_exist);
  printf ("chpports_exist_chan = %d\n", chpports_exist_chan);
  printf ("chpports_exist_int = %d\n", chpports_exist_int);
  printf ("chpports_exist_bool = %d\n", chpports_exist_bool);
#endif

  /* compute port bool, int and chan ports */
  _cur_abs_port_bool = NULL;
  _cur_abs_port_int = NULL;
  _cur_abs_port_chan = NULL;

  if (chpports_exist_bool || chpports_exist_int || chpports_exist_chan ||
      ports_exist) {
    if (chpports_exist_chan) {
      MALLOC (_cur_abs_port_chan, int, chpports_exist_chan);
    }
    if (chpports_exist_int) {
      MALLOC (_cur_abs_port_int, int, chpports_exist_int);
    }
    if (chpports_exist_bool || ports_exist) {
      MALLOC (_cur_abs_port_bool, int, chpports_exist_bool + ports_exist);
    }
  }

  int i;
  for (i=0; i < ports_exist + chpports_exist_bool; i++) {
    _cur_abs_port_bool[i] = i + _curoffset.numAllBools();
  }
  _curoffset.addBool (i);
  for (i=0; i < chpports_exist_int; i++) {
    _cur_abs_port_int[i] = i + _curoffset.numInts();
  }
  _curoffset.addInt (i);
  for (i=0; i < chpports_exist_chan; i++) {
    _cur_abs_port_chan[i] = i + _curoffset.numChans();
  }
  _curoffset.addChan (i);

  if (_getlevel() == ACT_MODEL_DEVICE) {
    warning ("Modeling the entire design at device level is unsupported; use a circuit simulator instead!");
  }

  /*-- compute multi-drivers --*/
  _computeMultiDrivers (_curproc);

  /*-- create simulation data structures --*/
  _si_stack = list_new ();
  _obj_stack = list_new ();


  // create multi-driver objects for the current scope!
  _add_multidrivers (_curproc, _curoffset.numBools(), _cur_abs_port_bool);
  _add_language (_getlevel(), root_lang);
  _add_all_inst (root_scope);

  if (simroot && _sdf) {
    char buf[1024];
    a->msnprintfproc (buf, 1024, simroot);
    sdf_celltype *ci = _sdf->getCell (buf);
    if (ci) {
      ci->used = 1;
      if (ci->all) {
	// we always use the generic instance for the top-level
	ci->all->used = true;
      }
    }
    else {
      _add_sdf_type_error (simroot);
    }
    // XXX: SDF do something here! After fanout is computed, 
    //      we need to assign interconnect delays
  }

  list_free (_si_stack);
  list_free (_obj_stack);

  /*
    Now compute all the fanout dependencies
  */
  computeFanout(&I);

  /* 
     Add the initialization environment, if needed:

     1. For any top-level dangling channels, add the channel environment
     process.

     2. Add any top-level initialize block from the global namespace
  */

  /* at this point, all the fanout tables have been updated */
#if 0
  {
    int i;
    printf ("*-- bools --\n");
    for (i=0; i < nint_start; i++) {
      printf ("b[%d] : fo=%d", i, nfo[i]);
      if (nfo[i] > 0) {
	for (int j=0; j < nfo[i]; j++) {
	  printf (" ");
	  dynamic_cast<ActSimObj *>(fo[i][j])->getName()->Print (stdout);
	}
      }
      printf ("\n");
    }
    printf ("*-- ints --\n");
    for (; i < nfo_len; i++) {
      printf ("i[%d] : fo=%d", i-nint_start, nfo[i]);
      if (nfo[i] > 0) {
	for (int j=0; j < nfo[i]; j++) {
	  printf (" ");
	  dynamic_cast<ActSimObj *>(fo[i][j])->getName()->Print (stdout);
	}
      }
      printf ("\n");
    }
  }
#endif
}




/*
 *  Walk through instance table and register exclusive requirements
 *  from prs bodies with the exclusive high/low handler.
 */
void ActSimCore::_register_prssim_with_excl (ActInstTable *t)
{
  if (t->obj && dynamic_cast <PrsSim *> (t->obj)) {
    ((PrsSim *)t->obj)->registerExcl ();
  }
  if (t->H) {
    hash_bucket_t *b;
    hash_iter_t it;
    hash_iter_init (t->H, &it);
    while ((b = hash_iter_next (t->H, &it))) {
      _register_prssim_with_excl ((ActInstTable *)b->v);
    }
  }
}


/*------------------------------------------------------------------------
 *
 * Misc. helper functions needed all over the place!
 *
 *------------------------------------------------------------------------
 */


int ActSimCore::getLocalOffset (act_connection *c, stateinfo_t *si, int *type,
				int *width)
{
  int res;
  int offset;

  res = sp->getTypeOffset (si, c, &offset, type, width);
  if (res) {
    return offset;
  }
  else {
    ActId *t = c->toid();
    fprintf (stderr, "Identifier `");
    t->Print (stderr);
    fprintf (stderr, "' used, but not used in the design hierarchy selected.\n");
    fatal_error ("Error in initializer block?");
  }
  return 0;
}


int ActSimCore::hasLocalOffset (ActId *id, stateinfo_t *si)
{
  act_connection *c = id->Canonical (si->bnl->cur);
  return hasLocalOffset (c, si);
}


int ActSimCore::hasLocalOffset (act_connection *c, stateinfo_t *si)
{
  int res;
  int offset, type;

  res = sp->getTypeOffset (si, c, &offset, &type, NULL);

  if (res) {
    return 1;
  }
  else {
    return 0;
  }
}

int ActSimCore::getLocalDynamicStructOffset (act_connection *c,
					     stateinfo_t *si,
					     int *offset_i, int *offset_b)
{
  int res;

  if (!sp->connExists (si, c)) {
    ActId *t = c->toid();
    fprintf (stderr, "Identifier `");
    t->Print (stderr);
    fprintf (stderr, "' used, but not used in the design hierarchy selected.\n");
    fatal_error ("Error in initializer block?");
  }

  res = sp->getTypeDynamicStructOffset (si, c, offset_i, offset_b);
  if (res) {
    return 1;
  }
  else {
    fatal_error ("getLocalOffset() failed!");
  }
  return 0;
}


act_connection *ActSimCore::getConnFromOffset (Process *p, int off, int type,
					       int *dy)
{
  return sp->getConnFromOffset (p, off, type, dy);
}


int ActSimCore::getLocalOffset (ActId *id, stateinfo_t *si, int *type, int *width)
{
  act_connection *c;
  Scope *sc = si->bnl->cur;

  c = id->Canonical (sc);
  return getLocalOffset (c, si, type, width);
}


/*
 * Add fanout object
 */
void ActSimCore::incFanout (int off, int type, SimDES *who)
{
  if (type == 0) {
    /* bool */
    Assert (off >=0 && off < nint_start, "What?");
  }
  else {
    Assert (type == 1, "What?");
    Assert (off >= 0 && off < nfo_len - nint_start, "What?");
    off = off + nint_start;
  }
  
  if (nfo[off] == 0) {
    /* first entry! */
    NEW (fo[off], SimDES *);
  }
  else if (nfo[off] >= 8) {
    for (int i=nfo[off]-1; i >= 0 && i >= nfo[off]-10; i--) {
      if (fo[off][i] == who) {
	return;
      }
    }
    
    /* this is a tentative high fanout net */
    ihash_bucket_t *b;
    if (!hfo) {
      hfo = ihash_new (4);
    }
    b = ihash_lookup (hfo, off);
    if (!b) {
      b = ihash_add (hfo, off);
      b->i = nfo[off]; // the allocated slots
    }
    if (nfo[off] == b->i) {
      b->i = b->i*2;
      REALLOC (fo[off], SimDES *, b->i);
    }
  }
  else {
    for (int i=nfo[off]-1; i >= 0 ; i--) {
      if (fo[off][i] == who) {
	return;
      }
    }
    REALLOC (fo[off], SimDES *, nfo[off]+1);
  }
  fo[off][nfo[off]] = who;
  nfo[off]++;
}



/*------------------------------------------------------------------------
 *
 *  Log message filter regular expression management across the entire
 *  simulation.
 *
 *------------------------------------------------------------------------
 */
void ActSimCore::logFilter (const char *s)
{
  if (s[0] == '\0') {
    _have_filter = 0;
  }
  else {
    _have_filter = 1;
    if (regcomp (&match, s, REG_EXTENDED) != 0) {
      _have_filter = 0;
      warning ("Regular expression `%s' didn't compile; skipped.", s);
    }
  }
}

int ActSimCore::isFiltered (const char *s)
{
  if (!_have_filter) {
    return 1;
  }
  else {
    if (regexec (&match, s, 0, NULL, 0) == 0) {
      return 1;
    }
    else {
      return 0;
    }
  }
}



/*------------------------------------------------------------------------
 *
 *  Handling of fragmented channels
 *
 *------------------------------------------------------------------------
 */
void ActSimCore::registerFragmented (Channel *c)
{
  phash_bucket_t *b;
  Assert (c, "Hmm");
  if (!chan) {
    chan = phash_new (4);
  }
  b = phash_lookup (chan, c);
  if (b) {
    return;
  }
  b = phash_add (chan, c);
  b->v = new ChanMethods (c);
}

ChanMethods *ActSimCore::getFragmented (Channel *c)
{
  phash_bucket_t *b;
  Assert (c, "Hmm");
  if (!chan) {
    chan = phash_new (4);
  }
  b = phash_lookup (chan, c);
  if (b) {
    return (ChanMethods *)b->v;
  }
  return NULL;
}


/*------------------------------------------------------------------------
 *
 * Special boolean signal handling:
 *
 *   - timing forks
 *   - excl constraints
 *   - random initialization
 *   - known hazards
 *
 *------------------------------------------------------------------------
 */


/*
  root, a, b are all global state offsets! 
*/
void ActSimCore::_add_timing_fork (ActSimObj *obj, stateinfo_t *si,
				   int root, int a, int b, Expr *e, int *extra)
{
  ActTimingConstraint *tc;
  int rg, ag, bg;
  Assert (!e || e->type == E_INT, "Internal error on timing forks");

  rg = obj->getGlobalOffset (root, 0);
  ag = obj->getGlobalOffset (a, 0);
  bg = obj->getGlobalOffset (b, 0);
  
  tc = new ActTimingConstraint (obj, rg, ag, bg, e ? e->u.ival.v : 0, extra);

  if (tc->isDup()) {
    delete tc;
    return;
  }

  int dy;
  act_connection *c = sp->getConnFromOffset (si, root, 0, &dy);
  
  tc->setConn (0, c);
  c = sp->getConnFromOffset (si, a, 0, &dy);
  tc->setConn (1, c);
  c = sp->getConnFromOffset (si, b, 0, &dy);
  tc->setConn (2, c);
  
  state->mkSpecialBool (rg);
  state->mkSpecialBool (ag);
  state->mkSpecialBool (bg);
  return;
}

/*
  ids is a list of global state ids 
*/
void ActSimCore::_add_excl (int type, int *ids, int sz)
{
  ActExclConstraint *ec = new ActExclConstraint (ids, sz, type);
  if (ec->illegal()) {
    delete ec;
  }
  for (int i=0; i < sz; i++) {
    state->mkSpecialBool (ids[i]);
  }
  return;
}

/*
  ids for rand init
*/
void ActSimCore::_add_rand_init (int *ids, int sz)
{
  for (int i=0; i < sz; i++) {
    A_NEW (_rand_init, int);
    A_NEXT (_rand_init) = ids[i];
    A_INC (_rand_init);
  }
}

void ActSimCore::_add_hazard (int *ids, int sz)
{
  for (int i=0; i < sz; i++) {
    state->mkHazard (ids[i]);
  }
}



/*------------------------------------------------------------------------
 *
 *  Trace file management and recording
 *
 *------------------------------------------------------------------------
 */

void ActSimCore::recordTrace (const watchpt_bucket *w, int type, 
			      act_chan_state_t state, const BigInt &val)
{
  if (w->ignore_fmt == ~0U) {
    return;
  }
  
  float cur_time = curTimeMetricUnits();

  BigInt tm = SimDES::CurTime();
  int len = tm.getLen();
  unsigned long v;
  unsigned long *ptm;
  if (len == 1) {
    v = tm.getVal (0);
    ptm = &v;
  }
  else {
    MALLOC (ptm, unsigned long, len);
    for (int i=0; i < len; i++) {
      ptm[i] = tm.getVal (i);
    }
  }
  
  if (type == 0) {
    int v = val.getVal (0);
    if (v == 0) {
      v = ACT_SIG_BOOL_FALSE;
    }
    else if (v == 1) {
      v = ACT_SIG_BOOL_TRUE;
    }
    else if (v == 2) {
      v = ACT_SIG_BOOL_X;
    }
    for (int fmt=0; fmt < TRACE_NUM_FORMATS; fmt++) {
      if (!((w->ignore_fmt >> fmt) & 1)) {
	if (act_trace_has_alt (_trfn[fmt])) {
	  act_trace_digital_change_alt (_tr[fmt], w->node[fmt],
					len, ptm, v);
	}
	else {
	  act_trace_digital_change (_tr[fmt], w->node[fmt], cur_time, v);
	}
      }
    }
  }
  else if (type == 1) {
    if (ACT_TRACE_WIDE_NUM (val.getWidth()) <= 1) {
      for (int fmt=0; fmt < TRACE_NUM_FORMATS; fmt++) {
	if (!((w->ignore_fmt >> fmt) & 1)) {
	  if (act_trace_has_alt (_trfn[fmt])) {
	    act_trace_digital_change_alt (_tr[fmt], w->node[fmt], len, ptm,
					  val.getVal (0));
	  }
	  else {
	    act_trace_digital_change (_tr[fmt], w->node[fmt], cur_time,
				      val.getVal (0));
	  }
	}
      }
    }
    else {
      unsigned long *valp;
      MALLOC (valp, unsigned long, val.getLen());
      for (int i=0; i < val.getLen(); i++) {
	valp[i] = val.getVal (i);
      }
      for (int fmt=0; fmt < TRACE_NUM_FORMATS; fmt++) {
	if (!((w->ignore_fmt >> fmt) & 1)) {
	  if (act_trace_has_alt (_trfn[fmt])) {
	    act_trace_wide_digital_change_alt (_tr[fmt], w->node[fmt], len, ptm,
					   val.getLen(), valp);
	  }
	  else {
	    act_trace_wide_digital_change (_tr[fmt], w->node[fmt], cur_time,
					   val.getLen(), valp);
	  }
	}
      }
      FREE (valp);
    }
  }
  else if (type == 2) {
    if (ACT_TRACE_WIDE_NUM (val.getWidth()) > 1) {
      unsigned long *valp;
      MALLOC (valp, unsigned long, ACT_TRACE_WIDE_NUM (val.getWidth()));
      for (int i=0; i < ACT_TRACE_WIDE_NUM(val.getWidth()); i++) {
	if (i < val.getLen()) {
	  valp[i] = val.getVal (i);
	}
	else {
	  valp[i] = 0;
	}
      }
      for (int fmt = 0; fmt < TRACE_NUM_FORMATS; fmt++) {
	if (!((w->ignore_fmt >> fmt) & 1)) {
	  if (act_trace_has_alt (_trfn[fmt])) {
	    act_trace_wide_chan_change_alt (_tr[fmt], w->node[fmt], len, ptm,
					    state,
					    ACT_TRACE_WIDE_NUM (val.getWidth()),
					    valp);
	  }
	  else {
	    act_trace_wide_chan_change (_tr[fmt], w->node[fmt], cur_time,
					state,
					ACT_TRACE_WIDE_NUM (val.getWidth()),
					valp);
	  }
	}
      }
      FREE (valp);
    }
    else {
      for (int fmt = 0; fmt < TRACE_NUM_FORMATS; fmt++) {
	if (!((w->ignore_fmt >> fmt) & 1)) {
	  if (act_trace_has_alt (_trfn[fmt])) {
	    act_trace_chan_change_alt (_tr[fmt], w->node[fmt], len, ptm, state,
				       val.getVal (0));
	  }
	  else {
	    act_trace_chan_change (_tr[fmt], w->node[fmt], cur_time, state,
				   val.getVal (0));
	  }
	}
      }
    }
  }
  if (len > 1) {
    FREE (ptm);
  }
}

int ActSimCore::initTrace (int fmt, const char *file)
{
  double cur_time = curTimeMetricUnits ();
  double tm = cur_time + 1;

  Assert (0 <= fmt && fmt < TRACE_NUM_FORMATS, "Illegal format!");

  if (_tr[fmt]) {
    act_trace_close (_tr[fmt]);
  }
  if (!file) {
    _tr[fmt] = NULL;

    if (_W) {
      ihash_bucket_t *b;
      watchpt_bucket *w;
      ihash_iter_t it;

      ihash_iter_init (_W, &it);
      while ((b = ihash_iter_next (_W, &it))) {
	w = (watchpt_bucket *) b->v;
	w->ignore_fmt |= (1 << fmt);
      }
    }
    return 1;
  }

  if (!_trfn[fmt]) {
    _trfn[fmt] = act_trace_load_format (_trname[fmt], NULL);
  }
  if (!_trfn[fmt]) {
    return 0;
  }
  if (!act_trace_fmt_has_writer (_trfn[fmt])) {
    act_trace_close_format (_trfn[fmt]);
    _trfn[fmt] = NULL;
    return 0;
  }

  _tr[fmt] = act_trace_create (_trfn[fmt], file, tm, _int_to_float_timescale,
			       act_trace_has_alt (_trfn[fmt]) ? 1 : 0);
  
  if (!_tr[fmt]) {
    return 0;
  }
  
  if (_W) {
    ihash_bucket_t *b;
    watchpt_bucket *w;
    ihash_iter_t it;

    ihash_iter_init (_W, &it);
    while ((b = ihash_iter_next (_W, &it))) {
      unsigned long off = b->key;
      int type = off & 0x3;
      off >>= 2;

      w = (watchpt_bucket *) b->v;
      w->ignore_fmt &= ~(1 << fmt);
      if (type == 0) {
	w->node[fmt] = act_trace_add_signal (_tr[fmt], ACT_SIG_BOOL, w->s, 0);
      }
      else if (type == 1) {
	BigInt *tmp = getInt (off);
	w->node[fmt] = act_trace_add_signal (_tr[fmt], ACT_SIG_INT, w->s,
					     tmp->getWidth());
      }
      else if (type == 2) {
	act_channel_state *ch = getChan (off);
	w->node[fmt] = act_trace_add_signal (_tr[fmt], ACT_SIG_CHAN, w->s,
					     ch->width);
      }
    }

    // now dump current  value
    BigInt tm = SimDES::CurTime();
    int tmlen = tm.getLen ();
    unsigned long tmpv;
    unsigned long *ptm;
    if (tmlen == 1) {
      tmpv = tm.getVal (0);
      ptm = &tmpv;
    }
    else {
      MALLOC (ptm, unsigned long, tmlen);
      for (int i=0; i < tmlen; i++) {
	ptm[i] = tm.getVal (i);
      }
    }
    
    act_trace_init_start (_tr[fmt]);
    ihash_iter_init (_W, &it);
    while ((b = ihash_iter_next (_W, &it))) {
      unsigned long off = b->key;
      int type = off & 0x3;
      off >>= 2;

      w = (watchpt_bucket *) b->v;
      if (type == 0) {
	int v = getBool (off);
	if (v == 0) {
	  v = ACT_SIG_BOOL_FALSE;
	}
	else if (v == 1) {
	  v = ACT_SIG_BOOL_TRUE;
	}
	else if (v == 2) {
	  v = ACT_SIG_BOOL_X;
	}
	if (act_trace_has_alt (_trfn[fmt])) {
	  act_trace_digital_change_alt (_tr[fmt], w->node[fmt], tmlen, ptm, v);
	}
	else {
	  act_trace_digital_change (_tr[fmt], w->node[fmt], cur_time, v);
	}
      }
      else if (type == 1) {
	BigInt *tmp = getInt (off);
	if (ACT_TRACE_WIDE_NUM (tmp->getWidth()) <= 1) {
	  if (act_trace_has_alt (_trfn[fmt])) {
	    act_trace_digital_change_alt (_tr[fmt], w->node[fmt], tmlen, ptm,
				      tmp->getVal (0));
	  }
	  else {
	    act_trace_digital_change (_tr[fmt], w->node[fmt], cur_time,
				      tmp->getVal (0));
	  }
	}
	else {
	  unsigned long *v;
	  MALLOC (v, unsigned long, tmp->getLen());
	  for (int i=0; i < tmp->getLen(); i++) {
	    v[i] = tmp->getVal (i);
	  }
	  if (act_trace_has_alt (_trfn[fmt])) {
	    act_trace_wide_digital_change_alt (_tr[fmt], w->node[fmt],
					       tmlen, ptm, 
					       tmp->getLen(), v);
	  }
	  else {
	    act_trace_wide_digital_change (_tr[fmt], w->node[fmt], cur_time,
					   tmp->getLen(), v);
	  }
	  FREE (v);
	}
      }
      else if (type == 2) {
	act_channel_state *ch = getChan (off);
	act_chan_state_t state;
	if (WAITING_SENDER (ch)) {
	  state = ACT_CHAN_SEND_BLOCKED;
	}
	else if (WAITING_RECEIVER(ch)) {
	  state = ACT_CHAN_RECV_BLOCKED;
	}
	else {
	  state = ACT_CHAN_IDLE;
	}
	if (ACT_TRACE_WIDE_NUM (ch->width) > 1) {
	  unsigned long *v;
	  MALLOC (v, unsigned long, ACT_TRACE_WIDE_NUM (ch->width));
	  for (int i=0; i < ACT_TRACE_WIDE_NUM(ch->width); i++) {
	    v[i] = 0;
	  }
	  if (act_trace_has_alt (_trfn[fmt])) {
	    act_trace_wide_chan_change_alt (_tr[fmt], w->node[fmt],
					    tmlen, ptm, state,
					    ACT_TRACE_WIDE_NUM (ch->width), v);
	  }
	  else {
	    act_trace_wide_chan_change (_tr[fmt], w->node[fmt], cur_time,
					state, ACT_TRACE_WIDE_NUM (ch->width),
					v);
	  }
	  FREE (v);
	}
	else {
	  if (act_trace_has_alt (_trfn[fmt])) {
	    act_trace_chan_change_alt (_tr[fmt], w->node[fmt], tmlen, ptm,
				       state, 0);
	  }
	  else {
	    act_trace_chan_change (_tr[fmt], w->node[fmt], cur_time, state, 0);
	  }
	}
      }
    }
    if (tmlen > 1) {
      FREE (ptm);
    }
    act_trace_init_end (_tr[fmt]);
  }
  return 1;
}



/*------------------------------------------------------------------------
 *
 *  API to check for fragmentation. A "fragmented" channel/etc. are
 *  data types that are accessed as "normal" types (e.g. channels in
 *  CHP), as well as in a fragmented form (e.g. pieces of the channel
 *  as bools in production rules). We need to mark these types
 *  explicitly, since they must be simulated at the lower level of
 *  abstraction.
 *
 *------------------------------------------------------------------------
 */
void ActSimCore::_check_fragmentation (ChpSim *c)
{
  ChpSimGraph::checkFragmentation (this, c, _curproc->getlang()->gethse()->c);
}

void ActSimCore::_check_fragmentation (PrsSim *p)
{
  PrsSimGraph::checkFragmentation (this, p, _curproc->getlang()->getprs());
}

void ActSimCore::_check_fragmentation (XyceSim *x)
{
  stateinfo_t *si = x->getSI();
  act_boolean_netlist_t *bnl = x->getBNL();

  Assert (bnl, "Hmm");
  for (int i=0; i < A_LEN (bnl->ports); i++) {
    if (bnl->ports[i].omit) continue;

    ActId *tmp = bnl->ports[i].c->toid();

    if (!tmp->isFragmented (bnl->cur)) continue;

    if (!si) { continue; }

    ActId *un = tmp->unFragment (bnl->cur);
    int type;
    int loff = getLocalOffset (un, si, &type);

    if (type == 2 || type == 3) {
      loff = x->getGlobalOffset (loff, 2);
      act_channel_state *ch = getChan (loff);

      if (type == 2) {
	/* input */
	ch->fragmented |= 1;
      }
      else {
	ch->fragmented |= 2;
	/* output */
      }
      sim_recordChannel (this, x, un);
      registerFragmented (ch->ct);
      ch->cm = getFragmented (ch->ct);
    }
    delete un;
    delete tmp;
  }
}


void ActSimCore::checkFragmentation (ActId *id, ActSimObj *obj, stateinfo_t *si, int read_only)
{
  act_boolean_netlist_t *bn = si->bnl;
  act_connection *tmpc = id->Canonical (bn->cur);
  checkFragmentation (tmpc, id, obj, si, read_only);
}


void ActSimCore::checkFragmentation (act_connection *idc, ActId *rid, ActSimObj *obj, stateinfo_t *si, int read_only)
{
  act_boolean_netlist_t *bn = si->bnl;
  int is_global;

  _prop_used_flags (bn, idc);

  ActConniter it(idc);

#if 0
  printf ("[ %s ] check frag: ", si->bnl->p ? si->bnl->p->getName() : "-none-");
  idc->toid()->Print (stdout);
  printf ("\n");
#endif

  is_global = idc->isglobal();

  /*
     If the connection is a global, then we are actually walking
     through different scopes as we walk through the connection list
  */

  for (it = it.begin(); it != it.end(); it++) {
    act_connection *c = (*it);
    ActId *id;

    /*
       If the canonical name is a global, then only check global
       scopes for this particular degragmentation check. Other
       elements may not be in the current scope.
    */
    
    if (is_global && !c->isglobal()) {
      if (!rid) {
	continue;
      }
      id = c->toid();
      if (!rid->isEqual (id)) {
	delete id;
	continue;
      }
    }
    else {
      id = c->toid();
    }

    if (id->isFragmented (si->bnl->cur)) {
      ActId *tmp = id->unFragment (si->bnl->cur);
      /*--  tmp is the unfragmented identifier --*/

      int type;

      if (hasLocalOffset (tmp, si)) {
	int loff = getLocalOffset (tmp, si, &type);

#if 0
	printf ("[ %s ] Unfragment: ", si->bnl->p ? si->bnl->p->getName() : "-none-");
	tmp->Print (stdout);
	printf ("\n");
	printf ("  -> original: ");
	id->Print (stdout);
	printf (" (type = %d, read_only = %d)\n", type, read_only);
#endif

	if (type == 2 || type == 3) {
	  stateinfo_t *mysi = cursi();
	  setsi (si);
	  loff = obj->getGlobalOffset (loff, 2);

	  act_channel_state *ch = getChan (loff);

	  sim_recordChannel (this, obj, tmp);
	  registerFragmented (ch->ct);
	  ch->cm = getFragmented (ch->ct);
	  setsi (mysi);

	  ActId *xtmp = tmp;
	  ActId *tail = id;
	  while (tmp) {
	    tmp = tmp->Rest();
	    tail = tail->Rest();
	    Assert (tail, "What?");
	  }
	  tmp = xtmp;

	  InstType *chit = ch->ct->CurScope()->FullLookup (tail, NULL);
	  Assert (chit, "Channel didn't have pieces?");
	  if (chit->getDir() == Type::INOUT) {
	    if (read_only) {
	      ch->fragmented |= 1;
	    }
	    else {
	      ch->fragmented |= 2;
	    }
	  }
	  else if (chit->getDir() == Type::OUTIN) {
	    if (read_only) {
	      ch->fragmented |= 2;
	    }
	    else {
	      ch->fragmented |= 1;
	    }
	  }
	  else {
	    /* guessing channel fragmentation */
	    if (type == 2) {
	      /* input */
	      ch->fragmented |= 1;
	    }
	    else {
	      /* output: reading a fragment */
	      ch->fragmented |= 2;
	    }
	  }
	}
      }
      delete tmp;
    }
    delete id;
  }
}

void ActSimCore::_add_sdf_type_error (Process *p)
{
  if (!_sdf_errs) {
    _sdf_errs = phash_new (4);
  }
  phash_bucket_t *b;
  b = phash_lookup (_sdf_errs, p);
  if (!b) {
    b = phash_add (_sdf_errs, p);
  }
}

void ActSimCore::_sdf_report ()
{
  phash_bucket_t *b;
  phash_iter_t it;
  char buf[1024];

  if (!_sdf_errs) return;

  phash_iter_init (_sdf_errs, &it);
  while ((b = phash_iter_next (_sdf_errs, &it))) {
    Process *p = (Process *) b->key;
    fprintf (stderr, ">> Missing SDF entry for ");
    if (p->getns() && p->getns() != ActNamespace::Global()) {
      char *s = p->getns()->Name();
      fprintf (stderr, "%s::", s);
      FREE (s);
    }
    fprintf (stderr, "%s", p->getName());
    a->msnprintfproc (buf, 1024, p);
    fprintf (stderr, " [%s]\n", buf);
  }
}

void ActSimCore::_sdf_clear_errors ()
{
  if (!_sdf_errs) return;
  phash_free (_sdf_errs);
  _sdf_errs = NULL;
}



void ActSimCore::_computeMultiDrivers (Process *p)
{
  int offset, type;
  struct multi_driver_info *my = NULL;
  phash_bucket_t *b;
  // multi-driver scenario:
  //  count drivers in instances
  //  count drivers locally
  // save multi-driver record for this process
  //   record: <bool> is multi-driver, with driver count = k.
  b = phash_lookup (_multi_driver, p);
  if (b) return;

  b = phash_add (_multi_driver, p);
  b->v = NULL;

  // deal with all sub-processes
  ActUniqProcInstiter i(p ? p->CurScope() : ActNamespace::Global()->CurScope());

  for (i = i.begin(); i != i.end(); i++) {
    ValueIdx *vx = *i;
    Process *px = dynamic_cast<Process *>  (vx->t->BaseType());
    Assert (px, "What?");
    if (!px->isExpanded()) continue;
    _computeMultiDrivers (px);
  }

  // now walk through all local drivers and port drivers, constructing
  // any multi-driver record.
  stateinfo_t *si = sp->getStateInfo (p);
  act_boolean_netlist_t *bnl;
  Assert (si, "What?");

  bnl = si->bnl;

  if (si->local.numBools()  + si->ports.numBools() == 0) {
    return;
  }


  // tmpbits is used to record which locally accessible/port variables
  // are multi-drivers.
  bitset_t *tmpbits;
  tmpbits = bitset_new (si->local.numBools() + si->ports.numBools());

  // now walk through the local state table and mark drivers
  phash_iter_t pit;
  phash_bucket_t *pb;
  phash_iter_init (bnl->cH, &pit);
  while ((pb = phash_iter_next (bnl->cH, &pit))) {
    act_booleanized_var_t *v = (act_booleanized_var_t *) pb->v;

    if (ActBooleanizePass::isDynamicRef (bnl, v->id)) continue;
    
    offset = getLocalOffset ((act_connection *)pb->key, si, &type, NULL);
    if (type != 0) {
      continue;
    }

    // -ve offsets: globals and ports
    // >=0 offsets: locals
    if (v->localout) {
      // ok we have a local driver here!
      if (v->isport) {
	Assert (offset < 0, "What?");
	Assert (sp->isPortOffset (offset), "What?");
	offset = sp->portIdx (offset);
      }
      else if (v->isglobal) {
	Assert (offset < 0, "Wat?");
	Assert (sp->isGlobalOffset (offset), "What?");
	offset = sp->globalIdx (offset);
      }
      else {
	offset += si->ports.numBools();
	Assert (offset >= 0, "What?");
      }

      if (v->isglobal) continue;
      // XXX: we can't handle global multi-drivers?

      Assert (!bitset_tst (tmpbits, offset), "What?");
      bitset_set (tmpbits, offset);
    }
  }

  // now check instances!
  int instcnt = 0;
  for (i = i.begin(); i != i.end(); i++) {
    ValueIdx *vx = *i;
    Process *px = dynamic_cast<Process *> (vx->t->BaseType());
    if (!px->isExpanded()) continue;
    stateinfo_t *subsi;
    subsi = sp->getStateInfo (px);
    Assert (subsi, "What?");
    int ports_exist = 0;
    for (int j=0; j < A_LEN (subsi->bnl->ports); j++) {
      if (subsi->bnl->ports[j].omit == 0) {
	ports_exist = 1;
	break;
      }
    }
    if (ports_exist) {
      phash_bucket_t *mb;
      mb = phash_lookup (_multi_driver, px);
      multi_driver_info *submd;
      if (mb) {
	submd = (multi_driver_info *)mb->v;
      }
      else {
	submd = NULL;
      }
      
      // do something here!
      int sz;
      if (vx->t->arrayInfo()) {
	int count = 0;
	sz = vx->t->arrayInfo()->size();
	for (int k=0; k < sz; k++) {
	  if (vx->isPrimary (k)) {
	    count++;
	  }
	}
	sz = count;
      }
      else {
	sz = 1;
      }
      while (sz > 0) {
	sz--;
	for (int j=0; j < A_LEN (subsi->bnl->ports); j++) {
	  if (subsi->bnl->ports[j].omit) continue;
	  act_connection *c, *subc;

	  // c is the connection pointer in the current process
	  c = si->bnl->instports[instcnt];
	  instcnt++;

	  // csub is the connection pointer in the sub-process
	  subc = subsi->bnl->ports[j].c;

	  // check subc driver / multi-driver!
	  int subcoffset, subctype;
	  int mid;
	  int subcount;

	  subcoffset = getLocalOffset (subc, subsi, &subctype, NULL);
	  Assert (subctype == 0, "A bool is not a bool?!");

	  offset = getLocalOffset (c, si, &type, NULL);
	  Assert (type == 0, "A bool is not a bool?!");

	  subcount = 0;
	  if (submd) {
	    subcount = submd->getcount (subcoffset);
	  }
	  if (subcount == 0) {
	    phash_bucket_t *xb;
	    xb = phash_lookup (subsi->bnl->cH, subc);
	    Assert (xb, "What?");
	    act_booleanized_var_t *xv = (act_booleanized_var_t *) xb->v;
	    if (xv->output) {
	      // we have a driver!
	      subcount = 1;
	    }
	  }
	  // now we check the current state of this offset

	  if (subcount > 0) {
	    // we just increment the multi-driver
	    if (subcount > 1) {
	      if (!my) {
		my = new multi_driver_info;
	      }
	      my->addmd (offset, subcount);
	    }
	    else if (my && my->getcount (offset) > 0) {
	      // we've registered the multi-driver already
	      my->addmd (offset, subcount);
	    }
	    else {
	      // we have 1 driver; perhaps we have a local driver
	      // too? if so, create the multi-driver instance;
	      // otherwise this is not yet a multi-driver
	      int noffset;
	      if (sp->isPortOffset (offset)) {
		noffset = sp->portIdx (offset);
	      }
	      else {
		Assert (!sp->isGlobalOffset (offset), "What?");
		noffset = offset + si->ports.numBools();
	      }
	      if (bitset_tst (tmpbits, noffset)) {
		if (!my) {
		  my = new multi_driver_info;
		}
		/* plus a local driver! */
		my->addmd (offset, 2);
	      }
	      else {
		// record the first driver
		bitset_set (tmpbits, noffset);
	      }
	    }
	  }
	}
      }
    }
  }

  if (my) {
    b->v = my;
  }
  
  bitset_free (tmpbits);
}



void ActSimCore::_add_multidrivers (Process *p, int booloffset, int *ports)
{
  phash_bucket_t *pmb = phash_lookup (_multi_driver, p);
  if (pmb) {
    multi_driver_info *mx = (multi_driver_info *)pmb->v;
    if (mx) {
      // create multi-driver instances!
      ihash_bucket_t *ib;
      mx->iter_init ();
      while ((ib = mx->iter_next())) {
	// XXX: get global id!
	int gid;
	int lid = (int)ib->key;
	Assert (ib->i > 1, "What?");
	if (lid >= 0) {
	  gid = lid + booloffset;
	}
	else {
	  lid = -lid;
	  Assert (lid & 1, "What?");
	  lid = (lid + 1)/2-1;
	  gid = ports[lid];
	}
	if (!_global_multi) {
	  _global_multi = ihash_new (4);
	}
	ihash_bucket_t *gb;
	gb = ihash_lookup (_global_multi, gid);
	if (!gb) {
	  gb = ihash_add (_global_multi, gid);
	  gb->v = new MultiPrsSim (ib->i);
	}
      }
    }
  }
}