netlist.cc

/*
 * Copyright (c) 1998-2000 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
 */
#if !defined(WINNT) && !defined(macintosh)
#ident "$Id: netlist.cc,v 1.136 2000/09/22 03:58:30 steve Exp $"
#endif

# include  <cassert>
# include  <typeinfo>
# include  "netlist.h"
# include  "netmisc.h"

ostream& operator<< (ostream&o, NetNet::Type t)
{
      switch (t) {
	  case NetNet::IMPLICIT:
	    o << "wire /*implicit*/";
	    break;
	  case NetNet::IMPLICIT_REG:
	    o << "reg /*implicit*/";
	    break;
	  case NetNet::INTEGER:
	    o << "integer";
	    break;
	  case NetNet::REG:
	    o << "reg";
	    break;
	  case NetNet::SUPPLY0:
	    o << "supply0";
	    break;
	  case NetNet::SUPPLY1:
	    o << "supply1";
	    break;
	  case NetNet::TRI:
	    o << "tri";
	    break;
	  case NetNet::TRI0:
	    o << "tri0";
	    break;
	  case NetNet::TRI1:
	    o << "tri1";
	    break;
	  case NetNet::TRIAND:
	    o << "triand";
	    break;
	  case NetNet::TRIOR:
	    o << "trior";
	    break;
	  case NetNet::WAND:
	    o << "wand";
	    break;
	  case NetNet::WOR:
	    o << "wor";
	    break;
	  case NetNet::WIRE:
	    o << "wire";
	    break;
      }
      return o;
}


unsigned count_inputs(const Link&pin)
{
      unsigned count = 0;

      const Nexus*nex = pin.nexus();
      for (const Link*clnk = nex->first_nlink()
		 ; clnk ; clnk = clnk->next_nlink()) {
	    const NetObj*cur;
	    unsigned cpin;
	    clnk->cur_link(cur, cpin);
	    if (cur->pin(cpin).get_dir() == Link::INPUT)
		  count += 1;
      }

      return count;
}

unsigned count_outputs(const Link&pin)
{
      unsigned count = 0;

      const Nexus*nex = pin.nexus();
      for (const Link*clnk = nex->first_nlink()
		 ; clnk ; clnk = clnk->next_nlink()) {
	    const NetObj*cur;
	    unsigned cpin;
	    clnk->cur_link(cur, cpin);
	    if (cur->pin(cpin).get_dir() == Link::OUTPUT)
		  count += 1;
      }

      return count;
}

unsigned count_signals(const Link&pin)
{
      unsigned count = 0;

      const Nexus*nex = pin.nexus();
      for (const Link*clnk = nex->first_nlink()
		 ; clnk ; clnk = clnk->next_nlink()) {
	    const NetObj*cur;
	    unsigned cpin;
	    clnk->cur_link(cur, cpin);
	    if (dynamic_cast<const NetNet*>(cur))
		  count += 1;
      }

      return count;
}

const NetNet* find_link_signal(const NetObj*net, unsigned pin, unsigned&bidx)
{
      const Nexus*nex = net->pin(pin).nexus();

      for (const Link*clnk = nex->first_nlink()
		 ; clnk ; clnk = clnk->next_nlink()) {

	    const NetObj*cur;
	    unsigned cpin;
	    clnk->cur_link(cur, cpin);

	    const NetNet*sig = dynamic_cast<const NetNet*>(cur);
	    if (sig) {
		  bidx = cpin;
		  return sig;
	    }
      }

      return 0;
}

Link* find_next_output(Link*lnk)
{
      Link*cur = lnk->next_nlink();
      while (cur != lnk) {
	    if (cur->get_dir() == Link::OUTPUT)
		  return cur;

	    cur = cur->next_nlink();
	    if (cur == 0)
		  cur = lnk->nexus()->first_nlink();
      }

      return 0;
}

NetObj::NetObj(const string&n, unsigned np)
: npins_(np), delay1_(0), delay2_(0), delay3_(0)
{
      name_ = new char[n.length()+1];
      strcpy(name_, n.c_str());

      pins_ = new Link[npins_];
      for (unsigned idx = 0 ;  idx < npins_ ;  idx += 1) {
	    pins_[idx].node_ = this;
	    pins_[idx].pin_  = idx;
      }
}

NetObj::~NetObj()
{
      delete[]name_;
      delete[]pins_;
}

void NetObj::set_attributes(const map<string,string>&attr)
{
      assert(attributes_.size() == 0);
      attributes_ = attr;
}

string NetObj::attribute(const string&key) const
{
      map<string,string>::const_iterator idx = attributes_.find(key);
      if (idx == attributes_.end())
	    return "";

      return (*idx).second;
}

void NetObj::attribute(const string&key, const string&value)
{
      attributes_[key] = value;
}

bool NetObj::has_compat_attributes(const NetObj&that) const
{
      map<string,string>::const_iterator idx;
      for (idx = that.attributes_.begin()
		 ; idx != that.attributes_.end() ;  idx ++) {
	   map<string,string>::const_iterator cur;
	   cur = attributes_.find((*idx).first);

	   if (cur == attributes_.end())
		 return false;
	   if ((*cur).second != (*idx).second)
		 return false;
      }

      return true;
}

Link& NetObj::pin(unsigned idx)
{
      assert(idx < npins_);
      return pins_[idx];
}

const Link& NetObj::pin(unsigned idx) const
{
      assert(idx < npins_);
      return pins_[idx];
}

NetNode::NetNode(const string&n, unsigned npins)
: NetObj(n, npins), node_next_(0), node_prev_(0), design_(0)
{
}

NetNode::~NetNode()
{
      if (design_)
	    design_->del_node(this);
}

NetNode* NetNode::next_node()
{
      Link*pin0 = pin(0).next_nlink();
      if (pin0 == 0)
	    pin0 = pin(0).nexus()->first_nlink();

      while (pin0 != &pin(0)) {
	    NetNode*cur = dynamic_cast<NetNode*>(pin0->get_obj());
	    if (cur == 0)
		  goto continue_label;
	    if (cur->pin_count() != pin_count())
		  goto continue_label;

	    { bool flag = true;
	      for (unsigned idx = 0 ;  idx < pin_count() ;  idx += 1)
		    flag = flag && pin(idx).is_linked(cur->pin(idx));

	      if (flag == true)
		    return cur;
	    }

      continue_label:
	    pin0 = pin0->next_nlink();
	    if (pin0 == 0)
		  pin0 = pin(0).nexus()->first_nlink();
      }

      return 0;
}

NetNet::NetNet(NetScope*s, const string&n, Type t, unsigned npins)
: NetObj(n, npins), sig_next_(0), sig_prev_(0), scope_(s),
    type_(t), port_type_(NOT_A_PORT), msb_(npins-1), lsb_(0),
    local_flag_(false), eref_count_(0)
{
      assert(scope_);

      verinum::V init_value = verinum::Vz;
      switch (t) {
	  case REG:
	  case IMPLICIT_REG:
	  case INTEGER:
	    init_value = verinum::Vx;
	    break;
	  default:
	    break;
      }

      for (unsigned idx = 0 ;  idx < npins ;  idx += 1) {
	    pin(idx).set_name("P", idx);
	    pin(idx).set_init(init_value);
      }

      scope_->add_signal(this);
}

NetNet::NetNet(NetScope*s, const string&n, Type t, long ms, long ls)
: NetObj(n, ((ms>ls)?ms-ls:ls-ms) + 1), sig_next_(0),
    sig_prev_(0), scope_(s), type_(t),
    port_type_(NOT_A_PORT), msb_(ms), lsb_(ls), local_flag_(false),
    eref_count_(0)
{
      assert(scope_);

      verinum::V init_value = verinum::Vz;
      switch (t) {
	  case REG:
	  case IMPLICIT_REG:
	  case INTEGER:
	    init_value = verinum::Vx;
	    break;
	  default:
	    break;
      }

      for (unsigned idx = 0 ;  idx < pin_count() ;  idx += 1) {
	    pin(idx).set_name("P", idx);
	    pin(idx).set_init(init_value);
      }

      scope_->add_signal(this);
}

NetNet::~NetNet()
{
      assert(eref_count_ == 0);
      if (scope_)
	    scope_->rem_signal(this);
}

NetScope* NetNet::scope()
{
      return scope_;
}

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

unsigned NetNet::sb_to_idx(long sb) const
{
      if (msb_ >= lsb_)
	    return sb - lsb_;
      else
	    return lsb_ - sb;
}

void NetNet::incr_eref()
{
      eref_count_ += 1;
}

void NetNet::decr_eref()
{
      assert(eref_count_ > 0);
      eref_count_ -= 1;
}

unsigned NetNet::get_eref() const
{
      return eref_count_;
}

NetTmp::NetTmp(NetScope*s, const string&name, unsigned npins)
: NetNet(s, name, IMPLICIT, npins)
{
      local_flag(true);
}

NetProc::NetProc()
: next_(0)
{
}

NetProc::~NetProc()
{
}

NetProcTop::NetProcTop(Type t, NetProc*st)
: type_(t), statement_(st)
{
}

NetProcTop::~NetProcTop()
{
      delete statement_;
}

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

const NetProc* NetProcTop::statement() const
{
      return statement_;
}

/*
 * The NetFF class represents an LPM_FF device. The pinout is assigned
 * like so:
 *    0  -- Clock
 *    1  -- Enable
 *    2  -- Aload
 *    3  -- Aset
 *    4  -- Aclr
 *    5  -- Sload
 *    6  -- Sset
 *    7  -- Sclr
 *
 *    8  -- Data[0]
 *    9  -- Q[0]
 *     ...
 */

NetFF::NetFF(const string&n, unsigned wid)
: NetNode(n, 8 + 2*wid)
{
      pin_Clock().set_dir(Link::INPUT);
      pin_Clock().set_name("Clock", 0);
      pin_Enable().set_dir(Link::INPUT);
      pin_Enable().set_name("Enable", 0);
      pin_Aload().set_dir(Link::INPUT);
      pin_Aload().set_name("Aload", 0);
      pin_Aset().set_dir(Link::INPUT);
      pin_Aset().set_name("Aset", 0);
      pin_Aclr().set_dir(Link::INPUT);
      pin_Aclr().set_name("Aclr", 0);
      pin_Sload().set_dir(Link::INPUT);
      pin_Sload().set_name("Sload", 0);
      pin_Sset().set_dir(Link::INPUT);
      pin_Sset().set_name("Sset", 0);
      pin_Sclr().set_dir(Link::INPUT);
      pin_Sclr().set_name("Sclr", 0);
      for (unsigned idx = 0 ;  idx < wid ;  idx += 1) {
	    pin_Data(idx).set_dir(Link::INPUT);
	    pin_Data(idx).set_name("Data", idx);
	    pin_Q(idx).set_dir(Link::OUTPUT);
	    pin_Q(idx).set_name("Q", idx);
      }
}

NetFF::~NetFF()
{
}

unsigned NetFF::width() const
{
      return (pin_count() - 8) / 2;
}

Link& NetFF::pin_Clock()
{
      return pin(0);
}

const Link& NetFF::pin_Clock() const
{
      return pin(0);
}

Link& NetFF::pin_Enable()
{
      return pin(1);
}

const Link& NetFF::pin_Enable() const
{
      return pin(1);
}

Link& NetFF::pin_Aload()
{
      return pin(2);
}

Link& NetFF::pin_Aset()
{
      return pin(3);
}

Link& NetFF::pin_Aclr()
{
      return pin(4);
}

Link& NetFF::pin_Sload()
{
      return pin(5);
}

Link& NetFF::pin_Sset()
{
      return pin(6);
}

Link& NetFF::pin_Sclr()
{
      return pin(7);
}

Link& NetFF::pin_Data(unsigned w)
{
      unsigned pn = 8 + 2*w;
      assert(pn < pin_count());
      return pin(pn);
}

const Link& NetFF::pin_Data(unsigned w) const
{
      unsigned pn = 8 + 2*w;
      assert(pn < pin_count());
      return pin(pn);
}

Link& NetFF::pin_Q(unsigned w)
{
      unsigned pn = 9 + w*2;
      assert(pn < pin_count());
      return pin(pn);
}

const Link& NetFF::pin_Q(unsigned w) const
{
      unsigned pn = 9 + w*2;
      assert(pn < pin_count());
      return pin(pn);
}


/*
 * The NetAddSub class represents an LPM_ADD_SUB device. The pinout is
 * assigned like so:
 *    0  -- Add_Sub
 *    1  -- Aclr
 *    2  -- Clock
 *    3  -- Cin
 *    4  -- Cout
 *    5  -- Overflow
 *    6  -- DataA[0]
 *    7  -- DataB[0]
 *    8  -- Result[0]
 */
NetAddSub::NetAddSub(const string&n, unsigned w)
: NetNode(n, w*3+6)
{
      pin(0).set_dir(Link::INPUT); pin(0).set_name("Add_Sub", 0);
      pin(1).set_dir(Link::INPUT); pin(1).set_name("Aclr", 0);
      pin(2).set_dir(Link::INPUT); pin(2).set_name("Clock", 0);
      pin(3).set_dir(Link::INPUT); pin(3).set_name("Cin", 0);
      pin(4).set_dir(Link::OUTPUT); pin(4).set_name("Cout", 0);
      pin(5).set_dir(Link::OUTPUT); pin(5).set_name("Overflow", 0);
      for (unsigned idx = 0 ;  idx < w ;  idx += 1) {
	    pin_DataA(idx).set_dir(Link::INPUT);
	    pin_DataB(idx).set_dir(Link::INPUT);
	    pin_Result(idx).set_dir(Link::OUTPUT);
	    pin_DataA(idx).set_name("DataA", idx);
	    pin_DataB(idx).set_name("DataB", idx);
	    pin_Result(idx).set_name("Result", idx);
      }
}

NetAddSub::~NetAddSub()
{
}

unsigned NetAddSub::width()const
{
      return (pin_count() - 6) / 3;
}

Link& NetAddSub::pin_Cout()
{
      return pin(4);
}

const Link& NetAddSub::pin_Cout() const
{
      return pin(4);
}

Link& NetAddSub::pin_DataA(unsigned idx)
{
      idx = 6 + idx*3;
      assert(idx < pin_count());
      return pin(idx);
}

const Link& NetAddSub::pin_DataA(unsigned idx) const
{
      idx = 6 + idx*3;
      assert(idx < pin_count());
      return pin(idx);
}

Link& NetAddSub::pin_DataB(unsigned idx)
{
      idx = 7 + idx*3;
      assert(idx < pin_count());
      return pin(idx);
}

const Link& NetAddSub::pin_DataB(unsigned idx) const
{
      idx = 7 + idx*3;
      assert(idx < pin_count());
      return pin(idx);
}

Link& NetAddSub::pin_Result(unsigned idx)
{
      idx = 8 + idx*3;
      assert(idx < pin_count());
      return pin(idx);
}

const Link& NetAddSub::pin_Result(unsigned idx) const
{
      idx = 8 + idx*3;
      assert(idx < pin_count());
      return pin(idx);
}

/*
 * The pinout for the NetCLShift is:
 *    0   -- Direction
 *    1   -- Underflow
 *    2   -- Overflow
 *    3   -- Data(0)
 *    3+W -- Result(0)
 *    3+2W -- Distance(0)
 */
NetCLShift::NetCLShift(const string&n, unsigned width, unsigned width_dist)
: NetNode(n, 3+2*width+width_dist), width_(width), width_dist_(width_dist)
{
      pin(0).set_dir(Link::INPUT); pin(0).set_name("Direction", 0);
      pin(1).set_dir(Link::OUTPUT); pin(1).set_name("Underflow", 0);
      pin(2).set_dir(Link::OUTPUT); pin(2).set_name("Overflow", 0);

      for (unsigned idx = 0 ;  idx < width_ ;  idx += 1) {
	    pin(3+idx).set_dir(Link::INPUT);
	    pin(3+idx).set_name("Data", idx);

	    pin(3+width_+idx).set_dir(Link::OUTPUT);
	    pin(3+width_+idx).set_name("Result", idx);
      }

      for (unsigned idx = 0 ;  idx < width_dist_ ;  idx += 1) {
	    pin(3+2*width_+idx).set_dir(Link::INPUT);
	    pin(3+2*width_+idx).set_name("Distance", idx);
      }
}

NetCLShift::~NetCLShift()
{
}

unsigned NetCLShift::width() const
{
      return width_;
}

unsigned NetCLShift::width_dist() const
{
      return width_dist_;
}

Link& NetCLShift::pin_Direction()
{
      return pin(0);
}

const Link& NetCLShift::pin_Direction() const
{
      return pin(0);
}

Link& NetCLShift::pin_Underflow()
{
      return pin(1);
}

const Link& NetCLShift::pin_Underflow() const
{
      return pin(1);
}

Link& NetCLShift::pin_Overflow()
{
      return pin(2);
}

const Link& NetCLShift::pin_Overflow() const
{
      return pin(2);
}

Link& NetCLShift::pin_Data(unsigned idx)
{
      assert(idx < width_);
      return pin(3+idx);
}

const Link& NetCLShift::pin_Data(unsigned idx) const
{
      assert(idx < width_);
      return pin(3+idx);
}

Link& NetCLShift::pin_Result(unsigned idx)
{
      assert(idx < width_);
      return pin(3+width_+idx);
}

const Link& NetCLShift::pin_Result(unsigned idx) const
{
      assert(idx < width_);
      return pin(3+width_+idx);
}

Link& NetCLShift::pin_Distance(unsigned idx)
{
      assert(idx < width_dist_);
      return pin(3+2*width_+idx);
}

const Link& NetCLShift::pin_Distance(unsigned idx) const
{
      assert(idx < width_dist_);
      return pin(3+2*width_+idx);
}

NetCompare::NetCompare(const string&n, unsigned wi)
: NetNode(n, 8+2*wi), width_(wi)
{
      pin(0).set_dir(Link::INPUT); pin(0).set_name("Aclr");
      pin(1).set_dir(Link::INPUT); pin(1).set_name("Clock");
      pin(2).set_dir(Link::OUTPUT); pin(2).set_name("AGB");
      pin(3).set_dir(Link::OUTPUT); pin(3).set_name("AGEB");
      pin(4).set_dir(Link::OUTPUT); pin(4).set_name("AEB");
      pin(5).set_dir(Link::OUTPUT); pin(5).set_name("ANEB");
      pin(6).set_dir(Link::OUTPUT); pin(6).set_name("ALB");
      pin(7).set_dir(Link::OUTPUT); pin(7).set_name("ALEB");
      for (unsigned idx = 0 ;  idx < width_ ;  idx += 1) {
	    pin(8+idx).set_dir(Link::INPUT);
	    pin(8+idx).set_name("DataA", idx);
	    pin(8+width_+idx).set_dir(Link::INPUT);
	    pin(8+width_+idx).set_name("DataB", idx);
      }
}

NetCompare::~NetCompare()
{
}

unsigned NetCompare::width() const
{
      return width_;
}

Link& NetCompare::pin_Aclr()
{
      return pin(0);
}

const Link& NetCompare::pin_Aclr() const
{
      return pin(0);
}

Link& NetCompare::pin_Clock()
{
      return pin(1);
}

const Link& NetCompare::pin_Clock() const
{
      return pin(1);
}

Link& NetCompare::pin_AGB()
{
      return pin(2);
}

const Link& NetCompare::pin_AGB() const
{
      return pin(2);
}

Link& NetCompare::pin_AGEB()
{
      return pin(3);
}

const Link& NetCompare::pin_AGEB() const
{
      return pin(3);
}

Link& NetCompare::pin_AEB()
{
      return pin(4);
}

const Link& NetCompare::pin_AEB() const
{
      return pin(4);
}

Link& NetCompare::pin_ANEB()
{
      return pin(5);
}

const Link& NetCompare::pin_ANEB() const
{
      return pin(5);
}

Link& NetCompare::pin_ALB()
{
      return pin(6);
}

const Link& NetCompare::pin_ALB() const
{
      return pin(6);
}

Link& NetCompare::pin_ALEB()
{
      return pin(7);
}

const Link& NetCompare::pin_ALEB() const
{
      return pin(7);
}

Link& NetCompare::pin_DataA(unsigned idx)
{
      return pin(8+idx);
}

const Link& NetCompare::pin_DataA(unsigned idx) const
{
      return pin(8+idx);
}

Link& NetCompare::pin_DataB(unsigned idx)
{
      return pin(8+width_+idx);
}

const Link& NetCompare::pin_DataB(unsigned idx) const
{
      return pin(8+width_+idx);
}

NetDivide::NetDivide(const string&n, unsigned wr,
		     unsigned wa, unsigned wb)
: NetNode(n, wr+wa+wb), width_r_(wr), width_a_(wa), width_b_(wb)
{
      unsigned p = 0;
      for (unsigned idx = 0 ;  idx < width_r_ ;  idx += 1, p += 1) {
	    pin(p).set_dir(Link::OUTPUT);
	    pin(p).set_name("Result", idx);
      }
      for (unsigned idx = 0 ;  idx < width_a_ ;  idx += 1, p += 1) {
	    pin(p).set_dir(Link::INPUT);
	    pin(p).set_name("DataA", idx);
      }
      for (unsigned idx = 0 ;  idx < width_b_ ;  idx += 1, p += 1) {
	    pin(p).set_dir(Link::INPUT);
	    pin(p).set_name("DataB", idx);
      }
}

NetDivide::~NetDivide()
{
}

unsigned NetDivide::width_r() const
{
      return width_r_;
}

unsigned NetDivide::width_a() const
{
      return width_a_;
}

unsigned NetDivide::width_b() const
{
      return width_b_;
}

Link& NetDivide::pin_Result(unsigned idx)
{
      assert(idx < width_r_);
      return pin(idx);
}

const Link& NetDivide::pin_Result(unsigned idx) const
{
      assert(idx < width_r_);
      return pin(idx);
}

Link& NetDivide::pin_DataA(unsigned idx)
{
      assert(idx < width_a_);
      return pin(idx+width_r_);
}

const Link& NetDivide::pin_DataA(unsigned idx) const
{
      assert(idx < width_a_);
      return pin(idx+width_r_);
}

Link& NetDivide::pin_DataB(unsigned idx)
{
      assert(idx < width_b_);
      return pin(idx+width_r_+width_a_);
}

const Link& NetDivide::pin_DataB(unsigned idx) const
{
      assert(idx < width_b_);
      return pin(idx+width_r_+width_a_);
}

NetMult::NetMult(const string&n, unsigned wr, unsigned wa, unsigned wb,
		 unsigned ws)
: NetNode(n, 2+wr+wa+wb+ws), width_r_(wr), width_a_(wa), width_b_(wb),
    width_s_(ws)
{
      pin(0).set_dir(Link::INPUT); pin(0).set_name("Aclr", 0);
      pin(1).set_dir(Link::INPUT); pin(1).set_name("Clock", 0);


      unsigned p = 2;
      for (unsigned idx = 0 ;  idx < width_r_ ;  idx += 1, p += 1) {
	    pin(p).set_dir(Link::OUTPUT);
	    pin(p).set_name("Result", idx);
      }
      for (unsigned idx = 0 ;  idx < width_a_ ;  idx += 1, p += 1) {
	    pin(p).set_dir(Link::INPUT);
	    pin(p).set_name("DataA", idx);
      }
      for (unsigned idx = 0 ;  idx < width_b_ ;  idx += 1, p += 1) {
	    pin(p).set_dir(Link::INPUT);
	    pin(p).set_name("DataB", idx);
      }
      for (unsigned idx = 0 ;  idx < width_s_ ;  idx += 1, p += 1) {
	    pin(p).set_dir(Link::INPUT);
	    pin(p).set_name("Sum", idx);
      }
}

NetMult::~NetMult()
{
}

unsigned NetMult::width_r() const
{
      return width_r_;
}

unsigned NetMult::width_a() const
{
      return width_a_;
}

unsigned NetMult::width_b() const
{
      return width_b_;
}

unsigned NetMult::width_s() const
{
      return width_s_;
}

Link& NetMult::pin_Aclr()
{
      return pin(0);
}

const Link& NetMult::pin_Aclr() const
{
      return pin(0);
}

Link& NetMult::pin_Clock()
{
      return pin(1);
}

const Link& NetMult::pin_Clock() const
{
      return pin(1);
}

Link& NetMult::pin_Result(unsigned idx)
{
      assert(idx < width_r_);
      return pin(idx+2);
}

const Link& NetMult::pin_Result(unsigned idx) const
{
      assert(idx < width_r_);
      return pin(idx+2);
}

Link& NetMult::pin_DataA(unsigned idx)
{
      assert(idx < width_a_);
      return pin(idx+2+width_r_);
}

const Link& NetMult::pin_DataA(unsigned idx) const
{
      assert(idx < width_a_);
      return pin(idx+2+width_r_);
}

Link& NetMult::pin_DataB(unsigned idx)
{
      assert(idx < width_b_);
      return pin(idx+2+width_r_+width_a_);
}

const Link& NetMult::pin_DataB(unsigned idx) const
{
      assert(idx < width_b_);
      return pin(idx+2+width_r_+width_a_);
}

Link& NetMult::pin_Sum(unsigned idx)
{
      assert(idx < width_s_);
      return pin(idx+2+width_r_+width_a_+width_b_);
}

const Link& NetMult::pin_Sum(unsigned idx) const
{
      assert(idx < width_s_);
      return pin(idx+2+width_r_+width_a_+width_b_);
}

/*
 * The NetMux class represents an LPM_MUX device. The pinout is assigned
 * like so:
 *    0   -- Aclr (optional)
 *    1   -- Clock (optional)
 *    2   -- Result[0]
 *    2+N -- Result[N]
 */

NetMux::NetMux(const string&n, unsigned wi, unsigned si, unsigned sw)
: NetNode(n, 2+wi+sw+wi*si), width_(wi), size_(si), swidth_(sw)
{
      pin(0).set_dir(Link::INPUT); pin(0).set_name("Aclr",  0);
      pin(1).set_dir(Link::INPUT); pin(1).set_name("Clock", 0);

      for (unsigned idx = 0 ;  idx < width_ ;  idx += 1) {
	    pin_Result(idx).set_dir(Link::OUTPUT);
	    pin_Result(idx).set_name("Result", idx);

	    for (unsigned jdx = 0 ;  jdx < size_ ;  jdx += 1) {
		  pin_Data(idx,jdx).set_dir(Link::INPUT);
		  pin_Data(idx,jdx).set_name("Data", jdx*width_+idx);
	    }
      }

      for (unsigned idx = 0 ;  idx < swidth_ ;  idx += 1) {
	    pin_Sel(idx).set_dir(Link::INPUT);
	    pin_Sel(idx).set_name("Sel", idx);
      }
}

NetMux::~NetMux()
{
}

unsigned NetMux::width()const
{
      return width_;
}

unsigned NetMux::size() const
{
      return size_;
}

unsigned NetMux::sel_width() const
{
      return swidth_;
}

Link& NetMux::pin_Aclr()
{
      return pin(0);
}

const Link& NetMux::pin_Aclr() const
{
      return pin(0);
}

Link& NetMux::pin_Clock()
{
      return pin(1);
}

const Link& NetMux::pin_Clock() const
{
      return pin(1);
}

Link& NetMux::pin_Result(unsigned w)
{
      assert(w < width_);
      return pin(2+w);
}

const Link& NetMux::pin_Result(unsigned w) const
{
      assert(w < width_);
      return pin(2+w);
}

Link& NetMux::pin_Sel(unsigned w)
{
      assert(w < swidth_);
      return pin(2+width_+w);
}

const Link& NetMux::pin_Sel(unsigned w) const
{
      assert(w < swidth_);
      return pin(2+width_+w);
}

Link& NetMux::pin_Data(unsigned w, unsigned s)
{
      assert(w < width_);
      assert(s < size_);
      return pin(2+width_+swidth_+s*width_+w);
}

const Link& NetMux::pin_Data(unsigned w, unsigned s) const
{
      assert(w < width_);
      assert(s < size_);
      return pin(2+width_+swidth_+s*width_+w);
}


NetRamDq::NetRamDq(const string&n, NetMemory*mem, unsigned awid)
: NetNode(n, 3+2*mem->width()+awid), mem_(mem), awidth_(awid)
{
      pin(0).set_dir(Link::INPUT); pin(0).set_name("InClock", 0);
      pin(1).set_dir(Link::INPUT); pin(1).set_name("OutClock", 0);
      pin(2).set_dir(Link::INPUT); pin(2).set_name("WE", 0);

      for (unsigned idx = 0 ;  idx < awidth_ ;  idx += 1) {
	    pin(3+idx).set_dir(Link::INPUT);
	    pin(3+idx).set_name("Address", idx);
      }

      for (unsigned idx = 0 ;  idx < width() ;  idx += 1) {
	    pin(3+awidth_+idx).set_dir(Link::INPUT);
	    pin(3+awidth_+idx).set_name("Data", idx);
      }

      for (unsigned idx = 0 ;  idx < width() ;  idx += 1) {
	    pin(3+awidth_+width()+idx).set_dir(Link::OUTPUT);
	    pin(3+awidth_+width()+idx).set_name("Q", idx);
      }

      next_ = mem_->ram_list_;
      mem_->ram_list_ = this;
}

NetRamDq::~NetRamDq()
{
      if (mem_->ram_list_ == this) {
	    mem_->ram_list_ = next_;

      } else {
	    NetRamDq*cur = mem_->ram_list_;
	    while (cur->next_ != this) {
		  assert(cur->next_);
		  cur = cur->next_;
	    }
	    assert(cur->next_ == this);
	    cur->next_ = next_;
      }
}

unsigned NetRamDq::width() const
{
      return mem_->width();
}

unsigned NetRamDq::awidth() const
{
      return awidth_;
}

unsigned NetRamDq::size() const
{
      return mem_->count();
}

const NetMemory* NetRamDq::mem() const
{
      return mem_;
}

unsigned NetRamDq::count_partners() const
{
      unsigned count = 0;
      for (NetRamDq*cur = mem_->ram_list_ ;  cur ;  cur = cur->next_)
	    count += 1;

      return count;
}

void NetRamDq::absorb_partners()
{
      NetRamDq*cur, *tmp;
      for (cur = mem_->ram_list_, tmp = 0
		 ;  cur||tmp ;  cur = cur? cur->next_ : tmp) {
	    tmp = 0;
	    if (cur == this) continue;

	    bool ok_flag = true;
	    for (unsigned idx = 0 ;  idx < awidth() ;  idx += 1)
		  ok_flag &= pin_Address(idx).is_linked(cur->pin_Address(idx));

	    if (!ok_flag) continue;

	    if (pin_InClock().is_linked()
		&& cur->pin_InClock().is_linked()
		&& ! pin_InClock().is_linked(cur->pin_InClock()))
		  continue;

	    if (pin_OutClock().is_linked()
		&& cur->pin_OutClock().is_linked()
		&& ! pin_OutClock().is_linked(cur->pin_OutClock()))
		  continue;

	    if (pin_WE().is_linked()
		&& cur->pin_WE().is_linked()
		&& ! pin_WE().is_linked(cur->pin_WE()))
		  continue;

	    for (unsigned idx = 0 ;  idx < width() ;  idx += 1) {
		  if (!pin_Data(idx).is_linked()) continue;
		  if (! cur->pin_Data(idx).is_linked()) continue;

		  ok_flag &= pin_Data(idx).is_linked(cur->pin_Data(idx));
	    }

	    if (! ok_flag) continue;

	    for (unsigned idx = 0 ;  idx < width() ;  idx += 1) {
		  if (!pin_Q(idx).is_linked()) continue;
		  if (! cur->pin_Q(idx).is_linked()) continue;

		  ok_flag &= pin_Q(idx).is_linked(cur->pin_Q(idx));
	    }

	    if (! ok_flag) continue;

	      // I see no other reason to reject cur, so link up all
	      // my pins and delete it.
	    connect(pin_InClock(), cur->pin_InClock());
	    connect(pin_OutClock(), cur->pin_OutClock());
	    connect(pin_WE(), cur->pin_WE());

	    for (unsigned idx = 0 ;  idx < awidth() ;  idx += 1)
		  connect(pin_Address(idx), cur->pin_Address(idx));

	    for (unsigned idx = 0 ;  idx < width() ;  idx += 1) {
		  connect(pin_Data(idx), cur->pin_Data(idx));
		  connect(pin_Q(idx), cur->pin_Q(idx));
	    }

	    tmp = cur->next_;
	    delete cur;
	    cur = 0;
      }
}

Link& NetRamDq::pin_InClock()
{
      return pin(0);
}

const Link& NetRamDq::pin_InClock() const
{
      return pin(0);
}

Link& NetRamDq::pin_OutClock()
{
      return pin(1);
}

const Link& NetRamDq::pin_OutClock() const
{
      return pin(1);
}

Link& NetRamDq::pin_WE()
{
      return pin(2);
}

const Link& NetRamDq::pin_WE() const
{
      return pin(2);
}

Link& NetRamDq::pin_Address(unsigned idx)
{
      assert(idx < awidth_);
      return pin(3+idx);
}

const Link& NetRamDq::pin_Address(unsigned idx) const
{
      assert(idx < awidth_);
      return pin(3+idx);
}

Link& NetRamDq::pin_Data(unsigned idx)
{
      assert(idx < width());
      return pin(3+awidth_+idx);
}

const Link& NetRamDq::pin_Data(unsigned idx) const
{
      assert(idx < width());
      return pin(3+awidth_+idx);
}

Link& NetRamDq::pin_Q(unsigned idx)
{
      assert(idx < width());
      return pin(3+awidth_+width()+idx);
}

const Link& NetRamDq::pin_Q(unsigned idx) const
{
      assert(idx < width());
      return pin(3+awidth_+width()+idx);
}

NetAssignMem_::NetAssignMem_(NetMemory*m, NetExpr*i, NetExpr*r)
: mem_(m), index_(i), rval_(r)
{
}

NetAssignMem_::~NetAssignMem_()
{
}

NetAssignMem::NetAssignMem(NetMemory*m, NetExpr*i, NetExpr*r)
: NetAssignMem_(m, i, r)
{
}

NetAssignMem::~NetAssignMem()
{
}

NetAssignMemNB::NetAssignMemNB(NetMemory*m, NetExpr*i, NetExpr*r)
: NetAssignMem_(m, i, r)
{
}

NetAssignMemNB::~NetAssignMemNB()
{
}


NetBlock::~NetBlock()
{
}

void NetBlock::append(NetProc*cur)
{
      if (last_ == 0) {
	    last_ = cur;
	    cur->next_ = cur;
      } else {
	    cur->next_ = last_->next_;
	    last_->next_ = cur;
	    last_ = cur;
      }
}

const NetProc* NetBlock::proc_first() const
{
      if (last_ == 0)
	    return 0;

      return last_->next_;
}

const NetProc* NetBlock::proc_next(const NetProc*cur) const
{
      if (cur == last_)
	    return 0;

      return cur->next_;
}

NetBUFZ::NetBUFZ(const string&n)
: NetNode(n, 2)
{
      pin(0).set_dir(Link::OUTPUT);
      pin(1).set_dir(Link::INPUT);
      pin(0).set_name("O", 0);
      pin(1).set_name("I", 0);
}

NetBUFZ::~NetBUFZ()
{
}


NetCase::NetCase(NetCase::TYPE c, NetExpr*ex, unsigned cnt)
: type_(c), expr_(ex), nitems_(cnt)
{
      assert(expr_);
      items_ = new Item[nitems_];
      for (unsigned idx = 0 ;  idx < nitems_ ;  idx += 1) {
	    items_[idx].statement = 0;
      }
}

NetCase::~NetCase()
{
      delete expr_;
      for (unsigned idx = 0 ;  idx < nitems_ ;  idx += 1) {
	    delete items_[idx].guard;
	    if (items_[idx].statement) delete items_[idx].statement;
      }
      delete[]items_;
}

NetCase::TYPE NetCase::type() const
{
      return type_;
}

void NetCase::set_case(unsigned idx, NetExpr*e, NetProc*p)
{
      assert(idx < nitems_);
      items_[idx].guard = e;
      items_[idx].statement = p;
      if (items_[idx].guard)
	    items_[idx].guard->set_width(expr_->expr_width());
}

NetCaseCmp::NetCaseCmp(const string&n)
: NetNode(n, 3)
{
      pin(0).set_dir(Link::OUTPUT); pin(0).set_name("O",0);
      pin(1).set_dir(Link::INPUT); pin(1).set_name("I",0);
      pin(2).set_dir(Link::INPUT); pin(2).set_name("I",1);
}

NetCaseCmp::~NetCaseCmp()
{
}

NetCondit::NetCondit(NetExpr*ex, NetProc*i, NetProc*e)
: expr_(ex), if_(i), else_(e)
{
}

NetCondit::~NetCondit()
{
      delete expr_;
      if (if_) delete if_;
      if (else_) delete else_;
}

const NetExpr* NetCondit::expr() const
{
      return expr_;
}

NetExpr* NetCondit::expr()
{
      return expr_;
}

void NetCondit::set_expr(NetExpr*ex)
{
      delete expr_;
      expr_ = ex;
}

NetProc* NetCondit::if_clause()
{
      return if_;
}

NetProc* NetCondit::else_clause()
{
      return else_;
}

NetConst::NetConst(const string&n, verinum::V v)
: NetNode(n, 1)
{
      pin(0).set_dir(Link::OUTPUT);
      pin(0).set_name("O", 0);
      value_ = new verinum::V[1];
      value_[0] = v;
}

NetConst::NetConst(const string&n, const verinum&val)
: NetNode(n, val.len())
{
      value_ = new verinum::V[pin_count()];
      for (unsigned idx = 0 ;  idx < pin_count() ;  idx += 1) {
	    pin(idx).set_dir(Link::OUTPUT);
	    pin(idx).set_name("O", idx);
	    value_[idx] = val.get(idx);
      }
}

NetConst::~NetConst()
{
      delete[]value_;
}

verinum::V NetConst::value(unsigned idx) const
{
      assert(idx < pin_count());
      return value_[idx];
}

NetFuncDef::NetFuncDef(NetScope*s, const svector<NetNet*>&po)
: scope_(s), statement_(0), ports_(po)
{
}

NetFuncDef::~NetFuncDef()
{
}

const string NetFuncDef::name() const
{
      return scope_->name();
}

void NetFuncDef::set_proc(NetProc*st)
{
      assert(statement_ == 0);
      assert(st != 0);
      statement_ = st;
}

const NetProc* NetFuncDef::proc() const
{
      return statement_;
}

NetScope*NetFuncDef::scope()
{
      return scope_;
}

unsigned NetFuncDef::port_count() const
{
      return ports_.count();
}

const NetNet* NetFuncDef::port(unsigned idx) const
{
      assert(idx < ports_.count());
      return ports_[idx];
}

NetSTask::NetSTask(const string&na, const svector<NetExpr*>&pa)
: name_(0), parms_(pa)
{
      name_ = new char[na.length() + 1];
      strcpy(name_, na.c_str());
      assert(name_[0] == '$');
}

NetSTask::~NetSTask()
{
      for (unsigned idx = 0 ;  idx < parms_.count() ;  idx += 1)
	    delete parms_[idx];

      delete[]name_;
}

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

unsigned NetSTask::nparms() const
{
      return parms_.count();
}

const NetExpr* NetSTask::parm(unsigned idx) const
{
      return parms_[idx];
}

NetEUFunc::NetEUFunc(NetFuncDef*def, NetESignal*res, svector<NetExpr*>&p)
: func_(def), result_(res), parms_(p)
{
      expr_width(result_->expr_width());
}

NetEUFunc::~NetEUFunc()
{
      for (unsigned idx = 0 ;  idx < parms_.count() ;  idx += 1)
	    delete parms_[idx];
}

const string NetEUFunc::name() const
{
      return func_->name();
}

const NetESignal*NetEUFunc::result() const
{
      return result_;
}

unsigned NetEUFunc::parm_count() const
{
      return parms_.count();
}

const NetExpr* NetEUFunc::parm(unsigned idx) const
{
      assert(idx < parms_.count());
      return parms_[idx];
}

const NetFuncDef* NetEUFunc::definition() const
{
      return func_;
}

NetEUFunc* NetEUFunc::dup_expr() const
{
      assert(0);
      return 0;
}

NetUTask::NetUTask(NetTaskDef*def)
: task_(def)
{
}

NetUTask::~NetUTask()
{
}

NetExpr::NetExpr(unsigned w)
: width_(w)
{
}

NetExpr::~NetExpr()
{
}

NetEBAdd::NetEBAdd(char op, NetExpr*l, NetExpr*r)
: NetEBinary(op, l, r)
{
      if (l->expr_width() > r->expr_width())
	    r->set_width(l->expr_width());

      if (r->expr_width() > l->expr_width())
	    l->set_width(r->expr_width());

      if (l->expr_width() < r->expr_width())
	    r->set_width(l->expr_width());

      if (r->expr_width() < l->expr_width())
	    l->set_width(r->expr_width());

      if (r->expr_width() > l->expr_width())
	    expr_width(r->expr_width());
      else
	    expr_width(l->expr_width());
}

NetEBAdd::~NetEBAdd()
{
}

NetEBAdd* NetEBAdd::dup_expr() const
{
      NetEBAdd*result = new NetEBAdd(op_, left_->dup_expr(),
				     right_->dup_expr());
      return result;
}

NetEBBits::NetEBBits(char op, NetExpr*l, NetExpr*r)
: NetEBinary(op, l, r)
{
	/* First try to naturally adjust the size of the
	   expressions to match. */
      if (l->expr_width() > r->expr_width())
	    r->set_width(l->expr_width());

      if (r->expr_width() > l->expr_width())
	    l->set_width(r->expr_width());

      if (l->expr_width() < r->expr_width())
	    r->set_width(l->expr_width());

      if (r->expr_width() < l->expr_width())
	    l->set_width(r->expr_width());

	/* If the expressions cannot be matched, pad them to fit. */
      if (l->expr_width() > r->expr_width())
	    right_ = pad_to_width(r, l->expr_width());

      if (r->expr_width() > l->expr_width())
	    left_ = pad_to_width(l, r->expr_width());

      assert(left_->expr_width() == right_->expr_width());
      expr_width(left_->expr_width());
}

NetEBBits::~NetEBBits()
{
}

NetEBBits* NetEBBits::dup_expr() const
{
      NetEBBits*result = new NetEBBits(op_, left_->dup_expr(),
				       right_->dup_expr());
      return result;
}

NetEBComp::NetEBComp(char op, NetExpr*l, NetExpr*r)
: NetEBinary(op, l, r)
{
      expr_width(1);
}

NetEBComp::~NetEBComp()
{
}

NetEBComp* NetEBComp::dup_expr() const
{
      NetEBComp*result = new NetEBComp(op_, left_->dup_expr(),
				       right_->dup_expr());
      return result;
}

NetEBDiv::NetEBDiv(char op, NetExpr*l, NetExpr*r)
: NetEBinary(op, l, r)
{
      unsigned w = l->expr_width();
      if (r->expr_width() > w)
	    w = r->expr_width();

      expr_width(w);
}

NetEBDiv::~NetEBDiv()
{
}

NetEBDiv* NetEBDiv::dup_expr() const
{
      NetEBDiv*result = new NetEBDiv(op_, left_->dup_expr(),
				       right_->dup_expr());
      return result;
}

NetEBinary::NetEBinary(char op, NetExpr*l, NetExpr*r)
: op_(op), left_(l), right_(r)
{
}

NetEBinary::~NetEBinary()
{
      delete left_;
      delete right_;
}

NetEBinary* NetEBinary::dup_expr() const
{
      assert(0);
}

NetEBLogic::NetEBLogic(char op, NetExpr*l, NetExpr*r)
: NetEBinary(op, l, r)
{
      expr_width(1);
}

NetEBLogic::~NetEBLogic()
{
}

NetEBLogic* NetEBLogic::dup_expr() const
{
      NetEBLogic*result = new NetEBLogic(op_, left_->dup_expr(),
					 right_->dup_expr());
      return result;
}

NetEBMult::NetEBMult(char op, NetExpr*l, NetExpr*r)
: NetEBinary(op, l, r)
{
      expr_width(l->expr_width() + r->expr_width());
}

NetEBMult::~NetEBMult()
{
}

NetEBMult* NetEBMult::dup_expr() const
{
      NetEBMult*result = new NetEBMult(op_, left_->dup_expr(),
				       right_->dup_expr());
      return result;
}

NetEBShift::NetEBShift(char op, NetExpr*l, NetExpr*r)
: NetEBinary(op, l, r)
{
      expr_width(l->expr_width());
}

NetEBShift::~NetEBShift()
{
}

NetEBShift* NetEBShift::dup_expr() const
{
      NetEBShift*result = new NetEBShift(op_, left_->dup_expr(),
					 right_->dup_expr());
      return result;
}

NetEConcat::NetEConcat(unsigned cnt, unsigned r)
: parms_(cnt), repeat_(r)
{
      expr_width(0);
}

NetEConcat::~NetEConcat()
{
      for (unsigned idx = 0 ;  idx < parms_.count() ;  idx += 1)
	    delete parms_[idx];
}

void NetEConcat::set(unsigned idx, NetExpr*e)
{
      assert(idx < parms_.count());
      assert(parms_[idx] == 0);
      parms_[idx] = e;
      expr_width( expr_width() + repeat_*e->expr_width() );
}

NetEConcat* NetEConcat::dup_expr() const
{
      NetEConcat*dup = new NetEConcat(parms_.count(), repeat_);
      for (unsigned idx = 0 ;  idx < parms_.count() ;  idx += 1)
	    if (parms_[idx]) {
		  assert(parms_[idx]->dup_expr());
		  dup->parms_[idx] = parms_[idx]->dup_expr();
	    }


      dup->expr_width(expr_width());
      return dup;
}

NetEConst::NetEConst(const verinum&val)
: NetExpr(val.len()), value_(val)
{
}

NetEConst::~NetEConst()
{
}

NetEConst* NetEConst::dup_expr() const
{
      NetEConst*tmp = new NetEConst(value_);
      tmp->set_line(*this);
      return tmp;
}

NetEIdent* NetEIdent::dup_expr() const
{
      assert(0);
}

NetEMemory::NetEMemory(NetMemory*m, NetExpr*i)
: NetExpr(m->width()), mem_(m), idx_(i)
{
}

NetEMemory::~NetEMemory()
{
}

NetMemory::NetMemory(NetScope*sc, const string&n, long w, long s, long e)
: name_(n), width_(w), idxh_(s), idxl_(e), ram_list_(0), scope_(sc)
{
      scope_->add_memory(this);
}

NetMemory::~NetMemory()
{
      assert(scope_);
      scope_->rem_memory(this);
}

unsigned NetMemory::count() const
{
      if (idxh_ < idxl_)
	    return idxl_ - idxh_ + 1;
      else
	    return idxh_ - idxl_ + 1;
}

unsigned NetMemory::index_to_address(long idx) const
{
      if (idxh_ < idxl_)
	    return idx - idxh_;
      else
	    return idx - idxl_;
}


void NetMemory::set_attributes(const map<string,string>&attr)
{
      assert(attributes_.size() == 0);
      attributes_ = attr;
}

NetEMemory* NetEMemory::dup_expr() const
{
      assert(0);
}

NetEParam::NetEParam()
: des_(0)
{
}

NetEParam::NetEParam(Design*d, NetScope*s, const string&n)
: des_(d), scope_(s), name_(n)
{
}

NetEParam::~NetEParam()
{
}

NetEParam* NetEParam::dup_expr() const
{
      return new NetEParam(des_, scope_, name_);
}

NetEScope::NetEScope(NetScope*s)
: scope_(s)
{
}

NetEScope::~NetEScope()
{
}

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

NetESFunc::NetESFunc(const string&n, unsigned width, unsigned np)
: name_(n)
{
      expr_width(width);
      nparms_ = np;
      parms_ = new NetExpr*[np];
      for (unsigned idx = 0 ;  idx < nparms_ ;  idx += 1)
	    parms_[idx] = 0;
}

NetESFunc::~NetESFunc()
{
      for (unsigned idx = 0 ;  idx < nparms_ ;  idx += 1)
	    if (parms_[idx]) delete parms_[idx];

      delete[]parms_;
}

const string& NetESFunc::name() const
{
      return name_;
}

unsigned NetESFunc::nparms() const
{
      return nparms_;
}

void NetESFunc::parm(unsigned idx, NetExpr*v)
{
      assert(idx < nparms_);
      if (parms_[idx])
	    delete parms_[idx];
      parms_[idx] = v;
}

const NetExpr* NetESFunc::parm(unsigned idx) const
{
      assert(idx < nparms_);
      return parms_[idx];
}

NetExpr* NetESFunc::parm(unsigned idx)
{
      assert(idx < nparms_);
      return parms_[idx];
}

NetESignal::NetESignal(NetNet*n)
: NetExpr(n->pin_count()), net_(n)
{
      net_->incr_eref();
      set_line(*n);
}

NetESignal::~NetESignal()
{
      net_->decr_eref();
}

string NetESignal::name() const
{
      return net_->name();
}

unsigned NetESignal::pin_count() const
{
      return net_->pin_count();
}

Link& NetESignal::pin(unsigned idx)
{
      return net_->pin(idx);
}

NetESignal* NetESignal::dup_expr() const
{
      assert(0);
}

NetESubSignal::NetESubSignal(NetESignal*sig, NetExpr*ex)
: sig_(sig), idx_(ex)
{
	// This supports mux type indexing of an expression, so the
	// with is by definition 1 bit.
      expr_width(1);
}

NetESubSignal::~NetESubSignal()
{
      delete idx_;
}

string NetESubSignal::name() const
{
      return sig_->name();
}

NetESubSignal* NetESubSignal::dup_expr() const
{
      assert(0);
}

NetETernary::NetETernary(NetExpr*c, NetExpr*t, NetExpr*f)
: cond_(c), true_val_(t), false_val_(f)
{
      expr_width(true_val_->expr_width());
}

NetETernary::~NetETernary()
{
      delete cond_;
      delete true_val_;
      delete false_val_;
}

const NetExpr* NetETernary::cond_expr() const
{
      return cond_;
}

const NetExpr* NetETernary::true_expr() const
{
      return true_val_;
}

const NetExpr* NetETernary::false_expr() const
{
      return false_val_;
}

NetETernary* NetETernary::dup_expr() const
{
      assert(0);
}

NetEUnary::NetEUnary(char op, NetExpr*ex)
: NetExpr(ex->expr_width()), op_(op), expr_(ex)
{
      switch (op_) {
	  case '!': // Logical not
	  case '&': // Reduction and
	  case '|': // Reduction or
	  case '^': // Reduction XOR
	  case 'A': // Reduction NAND (~&)
	  case 'N': // Reduction NOR (~|)
	  case 'X': // Reduction NXOR (~^)
	    expr_width(1);
	    break;
      }
}

NetEUnary::~NetEUnary()
{
      delete expr_;
}

NetEUnary* NetEUnary::dup_expr() const
{
      assert(0);
}

NetEUBits::NetEUBits(char op, NetExpr*ex)
: NetEUnary(op, ex)
{
}

NetEUBits::~NetEUBits()
{
}

NetLogic::NetLogic(const string&n, unsigned pins, TYPE t)
: NetNode(n, pins), type_(t)
{
      pin(0).set_dir(Link::OUTPUT);
      pin(0).set_name("O", 0);
      for (unsigned idx = 1 ;  idx < pins ;  idx += 1) {
	    pin(idx).set_dir(Link::INPUT);
	    pin(idx).set_name("I", idx-1);
      }
}

NetTaskDef::NetTaskDef(const string&n, const svector<NetNet*>&po)
: name_(n), proc_(0), ports_(po)
{
}

NetTaskDef::~NetTaskDef()
{
      delete proc_;
}

void NetTaskDef::set_proc(NetProc*p)
{
      assert(proc_ == 0);
      proc_ = p;
}

unsigned NetTaskDef::port_count() const
{
      return ports_.count();
}

NetNet* NetTaskDef::port(unsigned idx)
{
      assert(idx < ports_.count());
      return ports_[idx];
}

const string& NetTaskDef::name() const
{
      return name_;
}

const NetProc*NetTaskDef::proc() const
{
      return proc_;
}

/*
 * This method takes the input string, which contains exactly one
 * edge, and connects it to the correct output state. The output state
 * will be generated if needed, and the value compared.
 */
bool NetUDP::set_sequ_(const string&input, char output)
{
      if (output == '-')
	    output = input[0];

      string frm = input;
      string to  = input;
      to[0] = output;

      unsigned edge = frm.find_first_not_of("01x");
      assert(frm.find_last_not_of("01x") == edge);

      switch (input[edge]) {
	  case 'r':
	    frm[edge] = '0';
	    to[edge] = '1';
	    break;
	  case 'R':
	    frm[edge] = 'x';
	    to[edge] = '1';
	    break;
	  case 'f':
	    frm[edge] = '1';
	    to[edge] = '0';
	    break;
	  case 'F':
	    frm[edge] = 'x';
	    to[edge] = '0';
	    break;
	  case 'P':
	    frm[edge] = '0';
	    to[edge] = 'x';
	    break;
	  case 'N':
	    frm[edge] = '1';
	    to[edge] = 'x';
	    break;
	  default:
	    assert(0);
      }

      state_t_*sfrm = find_state_(frm);
      state_t_*sto  = find_state_(to);

      switch (to[edge]) {
	  case '0':
	      // Notice that I might have caught this edge already
	    if (sfrm->pins[edge].zer != sto) {
		  assert(sfrm->pins[edge].zer == 0);
		  sfrm->pins[edge].zer = sto;
	    }
	    break;
	  case '1':
	      // Notice that I might have caught this edge already
	    if (sfrm->pins[edge].one != sto) {
		    assert(sfrm->pins[edge].one == 0);
		    sfrm->pins[edge].one = sto;
	    }
	    break;
	  case 'x':
	      // Notice that I might have caught this edge already
	    if (sfrm->pins[edge].xxx != sto) {
		    assert(sfrm->pins[edge].xxx == 0);
		    sfrm->pins[edge].xxx = sto;
	    }
	    break;
      }

      return true;
}

bool NetUDP::sequ_glob_(string input, char output)
{
      for (unsigned idx = 0 ;  idx < input.length() ;  idx += 1)
	    switch (input[idx]) {
		case '0':
		case '1':
		case 'x':
		case 'r':
		case 'R':
		case 'f':
		case 'F':
		case 'P':
		case 'N':
		  break;

		case '?': // Iterate over all the levels
		  input[idx] = '0';
		  sequ_glob_(input, output);
		  input[idx] = '1';
		  sequ_glob_(input, output);
		  input[idx] = 'x';
		  sequ_glob_(input, output);
		  return true;

		case 'n': // Iterate over (n) edges
		  input[idx] = 'f';
		  sequ_glob_(input, output);
		  input[idx] = 'F';
		  sequ_glob_(input, output);
		  input[idx] = 'N';
		  sequ_glob_(input, output);
		  return true;

		case 'p': // Iterate over (p) edges
		  input[idx] = 'r';
		  sequ_glob_(input, output);
		  input[idx] = 'R';
		  sequ_glob_(input, output);
		  input[idx] = 'P';
		  sequ_glob_(input, output);
		  return true;

		case '_': // Iterate over (?0) edges
		  input[idx] = 'f';
		  sequ_glob_(input, output);
		  input[idx] = 'F';
		  sequ_glob_(input, output);
		  return true;

		case '*': // Iterate over all the edges
		  input[idx] = 'r';
		  sequ_glob_(input, output);
		  input[idx] = 'R';
		  sequ_glob_(input, output);
		  input[idx] = 'f';
		  sequ_glob_(input, output);
		  input[idx] = 'F';
		  sequ_glob_(input, output);
		  input[idx] = 'P';
		  sequ_glob_(input, output);
		  input[idx] = 'N';
		  sequ_glob_(input, output);
		  return true;

		default:
		  assert(0);
	    }

      return set_sequ_(input, output);
}

/*
 * $Log: netlist.cc,v $
 * Revision 1.136  2000/09/22 03:58:30  steve
 *  Access to the name of a system task call.
 *
 * Revision 1.135  2000/09/02 20:54:20  steve
 *  Rearrange NetAssign to make NetAssign_ separate.
 *
 * Revision 1.134  2000/08/27 15:51:50  steve
 *  t-dll iterates signals, and passes them to the
 *  target module.
 *
 *  Some of NetObj should return char*, not string.
 *
 * Revision 1.133  2000/07/14 06:12:57  steve
 *  Move inital value handling from NetNet to Nexus
 *  objects. This allows better propogation of inital
 *  values.
 *
 *  Clean up constant propagation  a bit to account
 *  for regs that are not really values.
 *
 * Revision 1.132  2000/07/07 04:53:54  steve
 *  Add support for non-constant delays in delay statements,
 *  Support evaluating ! in constant expressions, and
 *  move some code from netlist.cc to net_proc.cc.
 *
 * Revision 1.131  2000/06/25 19:59:42  steve
 *  Redesign Links to include the Nexus class that
 *  carries properties of the connected set of links.
 *
 * Revision 1.130  2000/06/24 22:55:19  steve
 *  Get rid of useless next_link method.
 *
 * Revision 1.129  2000/06/13 03:24:48  steve
 *  Index in memory assign should be a NetExpr.
 *
 * Revision 1.128  2000/06/12 03:57:10  steve
 *  NetEParam supports dup_expr.
 *
 * Revision 1.127  2000/05/27 19:33:23  steve
 *  Merge similar probes within a module.
 *
 * Revision 1.126  2000/05/19 01:43:16  steve
 *  Accept different widths for add operands.
 *
 * Revision 1.125  2000/05/11 23:37:27  steve
 *  Add support for procedural continuous assignment.
 *
 * Revision 1.124  2000/05/07 18:20:07  steve
 *  Import MCD support from Stephen Tell, and add
 *  system function parameter support to the IVL core.
 *
 * Revision 1.123  2000/05/07 04:37:56  steve
 *  Carry strength values from Verilog source to the
 *  pform and netlist for gates.
 *
 *  Change vvm constants to use the driver_t to drive
 *  a constant value. This works better if there are
 *  multiple drivers on a signal.
 *
 * Revision 1.122  2000/05/04 03:37:58  steve
 *  Add infrastructure for system functions, move
 *  $time to that structure and add $random.
 *
 * Revision 1.121  2000/05/02 03:13:31  steve
 *  Move memories to the NetScope object.
 *
 * Revision 1.120  2000/05/02 00:58:12  steve
 *  Move signal tables to the NetScope class.
 *
 * Revision 1.119  2000/04/28 18:43:23  steve
 *  integer division in expressions properly get width.
 *
 * Revision 1.118  2000/04/23 03:45:24  steve
 *  Add support for the procedural release statement.
 *
 * Revision 1.117  2000/04/22 04:20:19  steve
 *  Add support for force assignment.
 *
 * Revision 1.116  2000/04/18 01:02:54  steve
 *  Minor cleanup of NetTaskDef.
 *
 * Revision 1.115  2000/04/16 23:32:19  steve
 *  Synthesis of comparator in expressions.
 *
 *  Connect the NetEvent and related classes
 *  together better.
 *
 * Revision 1.114  2000/04/15 19:51:30  steve
 *  fork-join support in vvm.
 *
 * Revision 1.113  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 1.112  2000/04/04 03:20:15  steve
 *  Simulate named event trigger and waits.
 *
 * Revision 1.111  2000/04/02 04:26:06  steve
 *  Remove the useless sref template.
 *
 * Revision 1.110  2000/04/01 21:40:22  steve
 *  Add support for integer division.
 *
 * Revision 1.109  2000/03/29 04:37:11  steve
 *  New and improved combinational primitives.
 *
 * Revision 1.108  2000/03/12 17:09:41  steve
 *  Support localparam.
 *
 * Revision 1.107  2000/03/10 06:20:48  steve
 *  Handle defparam to partial hierarchical names.
 *
 * Revision 1.106  2000/03/08 04:36:53  steve
 *  Redesign the implementation of scopes and parameters.
 *  I now generate the scopes and notice the parameters
 *  in a separate pass over the pform. Once the scopes
 *  are generated, I can process overrides and evalutate
 *  paremeters before elaboration begins.
 *
 * Revision 1.105  2000/02/23 02:56:54  steve
 *  Macintosh compilers do not support ident.
 *
 * Revision 1.104  2000/01/13 03:35:35  steve
 *  Multiplication all the way to simulation.
 *
 * Revision 1.103  2000/01/10 01:35:24  steve
 *  Elaborate parameters afer binding of overrides.
 *
 * Revision 1.102  1999/12/30 04:19:12  steve
 *  Propogate constant 0 in low bits of adders.
 */