Implement $ftell, $fseek and $rewind system functions.

[iverilog.git] / t-dll-proc.cc

/*
 * Copyright (c) 2000 Stephen Williams (steve@icarus.com)
 *
 *    This source code is free software; you can redistribute it
 *    and/or modify it in source code form under the terms of the GNU
 *    General Public License as published by the Free Software
 *    Foundation; either version 2 of the License, or (at your option)
 *    any later version.will need a Picture Elements Binary Software
 *    License.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
 */
#ifdef HAVE_CVS_IDENT
#ident "$Id: $"
#endif

# include "config.h"

# include  <iostream>

# include  "target.h"
# include  "ivl_target.h"
# include  "compiler.h"
# include  "t-dll.h"
#ifdef HAVE_MALLOC_H
# include  <malloc.h>
#endif
# include  <stdlib.h>


bool dll_target::process(const NetProcTop*net)
{
      ivl_process_t obj = (struct ivl_process_s*)
            calloc(1, sizeof(struct ivl_process_s));

      switch (net->type()) {
          case NetProcTop::KINITIAL:
            obj->type_ = IVL_PR_INITIAL;
            break;
          case NetProcTop::KALWAYS:
            obj->type_ = IVL_PR_ALWAYS;
            break;
          default:
            assert(0);
      }

        /* Save the scope of the process. */
      obj->scope_ = lookup_scope_(net->scope());

      obj->nattr = net->attr_cnt();
      obj->attr = fill_in_attributes(net);

        /* This little bit causes the process to be completely
           generated so that it can be passed to the DLL. The
           stmt_cur_ member us used to hold a pointer to the current
           statement in progress, and the emit_proc() method fills in
           that object.

           We know a few things about the current statement: we are
           not in the middle of one, and when we are done, we have our
           statement back. The asserts check these conditions. */

      assert(stmt_cur_ == 0);
      stmt_cur_ = (struct ivl_statement_s*)calloc(1, sizeof*stmt_cur_);
      assert(stmt_cur_);
      net->statement()->emit_proc(this);

      assert(stmt_cur_);
      obj->stmt_ = stmt_cur_;
      stmt_cur_ = 0;

        /* Save the process in the design. */
      obj->next_ = des_.threads_;
      des_.threads_ = obj;

      return true;
}

void dll_target::task_def(const NetScope*net)
{
      ivl_scope_t scope = lookup_scope_(net);
      const NetTaskDef*def = net->task_def();

      assert(stmt_cur_ == 0);
      stmt_cur_ = (struct ivl_statement_s*)calloc(1, sizeof*stmt_cur_);
      assert(stmt_cur_);
      def->proc()->emit_proc(this);

      assert(stmt_cur_);
      scope->def = stmt_cur_;
      stmt_cur_ = 0;

}

bool dll_target::func_def(const NetScope*net)
{
      ivl_scope_t scope = lookup_scope_(net);
      const NetFuncDef*def = net->func_def();

      assert(stmt_cur_ == 0);
      stmt_cur_ = (struct ivl_statement_s*)calloc(1, sizeof*stmt_cur_);
      assert(stmt_cur_);
      def->proc()->emit_proc(this);

      assert(stmt_cur_);
      scope->def = stmt_cur_;
      stmt_cur_ = 0;

      scope->ports = def->port_count() + 1;
      if (scope->ports > 0) {
            scope->port = new ivl_signal_t[scope->ports];
            for (unsigned idx = 1 ;  idx < scope->ports ;  idx += 1)
                  scope->port[idx] = find_signal(des_, def->port(idx-1));
      }

        /* FIXME: the ivl_target API expects port-0 to be the output
           port. This assumes that the return value is a signal, which
           is *not* correct. Someday, I'm going to have to change
           this, but that will break code generators that use this
           result. */
      if (const NetNet*ret_sig = def->return_sig()) {
            scope->port[0] = find_signal(des_, ret_sig);
            return true;
      }

      cerr << "?:0" << ": internal error: "
           << "Function " << net->basename() << " has a return type"
           << " that I do not understand." << endl;

      return false;
}

/*
 * This private function makes the assignment lvals for the various
 * kinds of assignment statements.
 */
void dll_target::make_assign_lvals_(const NetAssignBase*net)
{
      assert(stmt_cur_);

      unsigned cnt = net->l_val_count();

      stmt_cur_->u_.assign_.lvals_ = cnt;
      stmt_cur_->u_.assign_.lval_  = new struct ivl_lval_s[cnt];
      stmt_cur_->u_.assign_.delay  = 0;

      for (unsigned idx = 0 ;  idx < cnt ;  idx += 1) {
            struct ivl_lval_s*cur = stmt_cur_->u_.assign_.lval_ + idx;
            const NetAssign_*asn = net->l_val(idx);
            const NetExpr*loff = asn->get_base();

            if (loff == 0) {
                  cur->loff = 0;
            } else {
                  loff->expr_scan(this);
                  cur->loff = expr_;
                  expr_ = 0;
            }

            cur->width_ = asn->lwidth();

            if (asn->sig()) {
                  cur->type_ = IVL_LVAL_REG;
                  cur->n.sig = find_signal(des_, asn->sig());

                  cur->idx = 0;
                    // If there is a word select expression, it is
                    // really an array index. Note that the word index
                    // expression is already converted to canonical
                    // form by elaboration.
                  if (asn->word()) {
                        assert(expr_ == 0);
                        asn->word()->expr_scan(this);
                        cur->type_ = IVL_LVAL_ARR;
                        cur->idx = expr_;
                        expr_ = 0;
                  }
            } else {
                  assert(0);
            }
      }
}

/*
 */
void dll_target::proc_assign(const NetAssign*net)
{
      assert(stmt_cur_);
      assert(stmt_cur_->type_ == IVL_ST_NONE);

      stmt_cur_->type_ = IVL_ST_ASSIGN;

      stmt_cur_->u_.assign_.delay = 0;

        /* Make the lval fields. */
      make_assign_lvals_(net);

      assert(expr_ == 0);
      net->rval()->expr_scan(this);
      stmt_cur_->u_.assign_.rval_ = expr_;
      expr_ = 0;

      const NetExpr*del = net->get_delay();
      if (del) {
            del->expr_scan(this);
            stmt_cur_->u_.assign_.delay = expr_;
            expr_ = 0;
      }
}


void dll_target::proc_assign_nb(const NetAssignNB*net)
{
      const NetExpr* delay_exp = net->get_delay();
      assert(stmt_cur_);
      assert(stmt_cur_->type_ == IVL_ST_NONE);

      stmt_cur_->type_ = IVL_ST_ASSIGN_NB;
      stmt_cur_->u_.assign_.delay  = 0;

        /* Make the lval fields. */
      make_assign_lvals_(net);

        /* Make the rval field. */
      assert(expr_ == 0);
      net->rval()->expr_scan(this);
      stmt_cur_->u_.assign_.rval_ = expr_;
      expr_ = 0;

      if (const NetEConst*delay_num = dynamic_cast<const NetEConst*>(delay_exp)) {
            verinum val = delay_num->value();
            ivl_expr_t de = new struct ivl_expr_s;
            de->type_ = IVL_EX_ULONG;
            de->width_  = 8 * sizeof(unsigned long);
            de->signed_ = 0;
            de->u_.ulong_.value = val.as_ulong();
            stmt_cur_->u_.assign_.delay = de;

      } else if (delay_exp != 0) {
            delay_exp->expr_scan(this);
            stmt_cur_->u_.assign_.delay = expr_;
            expr_ = 0;
      }
}

bool dll_target::proc_block(const NetBlock*net)
{
      assert(stmt_cur_);
      assert(stmt_cur_->type_ == IVL_ST_NONE);

        /* First, count the statements in the block. */
      unsigned count = 0;
      for (const NetProc*cur = net->proc_first()
                 ;  cur ;  cur = net->proc_next(cur))
            count += 1;

        /* If the block has no statements, then turn it into a no-op */
      if (count == 0) {
            stmt_cur_->type_ = IVL_ST_NOOP;
            return true;
      }

        /* If there is exactly one statement, there is no need for the
           block wrapper, generate the contained statement instead. */
      if ((count == 1) && (net->subscope() == 0)) {
            return net->proc_first()->emit_proc(this);
      }


        /* Handle the general case. The block has some statements in
           it, so fill in the block fields of the existing statement,
           and generate the contents for the statement array. */

      stmt_cur_->type_ = (net->type() == NetBlock::SEQU)
            ? IVL_ST_BLOCK
            : IVL_ST_FORK;
      stmt_cur_->u_.block_.nstmt_ = count;
      stmt_cur_->u_.block_.stmt_ = (struct ivl_statement_s*)
            calloc(count, sizeof(struct ivl_statement_s));

      if (net->subscope())
            stmt_cur_->u_.block_.scope = lookup_scope_(net->subscope());
      else
            stmt_cur_->u_.block_.scope = 0;

      struct ivl_statement_s*save_cur_ = stmt_cur_;
      unsigned idx = 0;
      bool flag = true;

      for (const NetProc*cur = net->proc_first()
                 ;  cur ;  cur = net->proc_next(cur), idx += 1) {
            assert(idx < count);
            stmt_cur_ = save_cur_->u_.block_.stmt_ + idx;
            bool rc = cur->emit_proc(this);
            flag = flag && rc;
      }
      assert(idx == count);

      stmt_cur_ = save_cur_;

      return flag;
}

/*
 * A case statement is in turn an array of statements with gate
 * expressions. This builds arrays of the right size and builds the
 * ivl_expr_t and ivl_statement_s arrays for the substatements.
 */
void dll_target::proc_case(const NetCase*net)
{
      assert(stmt_cur_);
      assert(stmt_cur_->type_ == IVL_ST_NONE);

      switch (net->type()) {
          case NetCase::EQ:
            stmt_cur_->type_ = IVL_ST_CASE;
            break;
          case NetCase::EQX:
            stmt_cur_->type_ = IVL_ST_CASEX;
            break;
          case NetCase::EQZ:
            stmt_cur_->type_ = IVL_ST_CASEZ;
            break;
      }
      assert(stmt_cur_->type_ != IVL_ST_NONE);

      assert(expr_ == 0);
      assert(net->expr());
      net->expr()->expr_scan(this);
      stmt_cur_->u_.case_.cond = expr_;
      expr_ = 0;

        /* If the condition expression is a real valued expression,
           then change the case statement to a CASER statement. */
      if (stmt_cur_->u_.case_.cond->value_ == IVL_VT_REAL)
            stmt_cur_->type_ = IVL_ST_CASER;

      unsigned ncase = net->nitems();
      stmt_cur_->u_.case_.ncase = ncase;

      stmt_cur_->u_.case_.case_ex = new ivl_expr_t[ncase];
      stmt_cur_->u_.case_.case_st = new struct ivl_statement_s[ncase];

      ivl_statement_t save_cur = stmt_cur_;

      for (unsigned idx = 0 ;  idx < ncase ;  idx += 1) {
            const NetExpr*ex = net->expr(idx);
            if (ex) {
                  ex->expr_scan(this);
                  save_cur->u_.case_.case_ex[idx] = expr_;
                  expr_ = 0;
            } else {
                  save_cur->u_.case_.case_ex[idx] = 0;
            }

            stmt_cur_ = save_cur->u_.case_.case_st + idx;
            stmt_cur_->type_ = IVL_ST_NONE;
            if (net->stat(idx) == 0) {
                  stmt_cur_->type_ = IVL_ST_NOOP;
            } else {
                  net->stat(idx)->emit_proc(this);
            }
      }

      stmt_cur_ = save_cur;
}

bool dll_target::proc_cassign(const NetCAssign*net)
{

      assert(stmt_cur_);
      assert(stmt_cur_->type_ == IVL_ST_NONE);

      stmt_cur_->type_ = IVL_ST_CASSIGN;

        /* Make the l-value fields. */
      make_assign_lvals_(net);

      assert(expr_ == 0);
      net->rval()->expr_scan(this);
      stmt_cur_->u_.assign_.rval_ = expr_;
      expr_ = 0;

      return true;
}

bool dll_target::proc_condit(const NetCondit*net)
{
      assert(stmt_cur_);
      assert(stmt_cur_->type_ == IVL_ST_NONE);

      stmt_cur_->type_ = IVL_ST_CONDIT;
      stmt_cur_->u_.condit_.stmt_ = (struct ivl_statement_s*)
            calloc(2, sizeof(struct ivl_statement_s));

      assert(expr_ == 0);
      net->expr()->expr_scan(this);
      stmt_cur_->u_.condit_.cond_ = expr_;
      expr_ = 0;

      ivl_statement_t save_cur_ = stmt_cur_;

      stmt_cur_ = save_cur_->u_.condit_.stmt_+0;
      bool flag = net->emit_recurse_if(this);

      stmt_cur_ = save_cur_->u_.condit_.stmt_+1;
      flag = flag && net->emit_recurse_else(this);

      stmt_cur_ = save_cur_;
      return flag;
}

bool dll_target::proc_deassign(const NetDeassign*net)
{
      assert(stmt_cur_);
      assert(stmt_cur_->type_ == IVL_ST_NONE);

      stmt_cur_->type_ = IVL_ST_DEASSIGN;

        /* Make the l-value fields. */
      make_assign_lvals_(net);

      return true;
}

bool dll_target::proc_delay(const NetPDelay*net)
{
      assert(stmt_cur_);
      assert(stmt_cur_->type_ == IVL_ST_NONE);

      ivl_statement_t tmp = (struct ivl_statement_s*)
            calloc(1, sizeof(struct ivl_statement_s));

      if (const NetExpr*expr = net->expr()) {

            stmt_cur_->type_ = IVL_ST_DELAYX;
            assert(expr_ == 0);
            expr->expr_scan(this);
            stmt_cur_->u_.delayx_.expr = expr_;
            expr_ = 0;

            stmt_cur_->u_.delayx_.stmt_ = tmp;

      } else {
            stmt_cur_->type_ = IVL_ST_DELAY;
            stmt_cur_->u_.delay_.stmt_  = tmp;
            stmt_cur_->u_.delay_.delay_ = net->delay();
      }

      ivl_statement_t save_cur_ = stmt_cur_;
      stmt_cur_ = tmp;
      bool flag = net->emit_proc_recurse(this);

        /* If the recurse doesn't turn this new item into something,
           then either it failed or there is no statement
           there. Either way, draw a no-op into the statement. */
      if (stmt_cur_->type_ == IVL_ST_NONE) {
            stmt_cur_->type_ = IVL_ST_NOOP;
      }

      stmt_cur_ = save_cur_;

      return flag;
}

bool dll_target::proc_disable(const NetDisable*net)
{
      assert(stmt_cur_);
      assert(stmt_cur_->type_ == IVL_ST_NONE);

      stmt_cur_->type_ = IVL_ST_DISABLE;
      stmt_cur_->u_.disable_.scope = lookup_scope_(net->target());
      return true;
}

bool dll_target::proc_force(const NetForce*net)
{

      assert(stmt_cur_);
      assert(stmt_cur_->type_ == IVL_ST_NONE);

      stmt_cur_->type_ = IVL_ST_FORCE;

        /* Make the l-value fields. */
      make_assign_lvals_(net);

      assert(expr_ == 0);
      net->rval()->expr_scan(this);
      stmt_cur_->u_.assign_.rval_ = expr_;
      expr_ = 0;

      return true;
}

void dll_target::proc_forever(const NetForever*net)
{
      assert(stmt_cur_);
      assert(stmt_cur_->type_ == IVL_ST_NONE);

      stmt_cur_->type_ = IVL_ST_FOREVER;

      ivl_statement_t tmp = (struct ivl_statement_s*)
            calloc(1, sizeof(struct ivl_statement_s));

      ivl_statement_t save_cur_ = stmt_cur_;
      stmt_cur_ = tmp;

      net->emit_recurse(this);

      save_cur_->u_.forever_.stmt_ = stmt_cur_;
      stmt_cur_ = save_cur_;
}

bool dll_target::proc_release(const NetRelease*net)
{
      assert(stmt_cur_);
      assert(stmt_cur_->type_ == IVL_ST_NONE);

      stmt_cur_->type_ = IVL_ST_RELEASE;

        /* Make the l-value fields. */
      make_assign_lvals_(net);

      return true;
}

void dll_target::proc_repeat(const NetRepeat*net)
{
      assert(stmt_cur_);
      assert(stmt_cur_->type_ == IVL_ST_NONE);

      stmt_cur_->type_ = IVL_ST_REPEAT;

      assert(expr_ == 0);
      net->expr()->expr_scan(this);
      stmt_cur_->u_.while_.cond_ = expr_;
      expr_ = 0;

      ivl_statement_t tmp = (struct ivl_statement_s*)
            calloc(1, sizeof(struct ivl_statement_s));

      ivl_statement_t save_cur_ = stmt_cur_;
      stmt_cur_ = tmp;

      net->emit_recurse(this);

      save_cur_->u_.while_.stmt_ = stmt_cur_;
      stmt_cur_ = save_cur_;
}

void dll_target::proc_stask(const NetSTask*net)
{
      unsigned nparms = net->nparms();
      assert(stmt_cur_);
      assert(stmt_cur_->type_ == IVL_ST_NONE);

      stmt_cur_->type_ = IVL_ST_STASK;
        /* System task names are lex_strings strings. */
      stmt_cur_->u_.stask_.name_ = net->name();
      stmt_cur_->u_.stask_.nparm_= nparms;
      stmt_cur_->u_.stask_.parms_= (ivl_expr_t*)
            calloc(nparms, sizeof(ivl_expr_t));

      for (unsigned idx = 0 ;  idx < nparms ;  idx += 1) {
            if (net->parm(idx))
                  net->parm(idx)->expr_scan(this);
            stmt_cur_->u_.stask_.parms_[idx] = expr_;
            expr_ = 0;
      }

}

bool dll_target::proc_trigger(const NetEvTrig*net)
{
      assert(stmt_cur_);
      assert(stmt_cur_->type_ == IVL_ST_NONE);

      stmt_cur_->type_ = IVL_ST_TRIGGER;
      stmt_cur_->u_.wait_.nevent = 1;

        /* Locate the event by name. Save the ivl_event_t in the
           statement so that the generator can find it easily. */
      const NetEvent*ev = net->event();
      ivl_scope_t ev_scope = lookup_scope_(ev->scope());

      for (unsigned idx = 0 ;  idx < ev_scope->nevent_ ;  idx += 1) {
            const char*ename = ivl_event_basename(ev_scope->event_[idx]);
            if (strcmp(ev->name(), ename) == 0) {
                  stmt_cur_->u_.wait_.event = ev_scope->event_[idx];
                  break;
            }
      }


      return true;
}

void dll_target::proc_utask(const NetUTask*net)
{
      assert(stmt_cur_);
      assert(stmt_cur_->type_ == IVL_ST_NONE);

      stmt_cur_->type_ = IVL_ST_UTASK;
      stmt_cur_->u_.utask_.def = lookup_scope_(net->task());
}

bool dll_target::proc_wait(const NetEvWait*net)
{
      assert(stmt_cur_);
      assert(stmt_cur_->type_ == IVL_ST_NONE);

      stmt_cur_->type_ = IVL_ST_WAIT;
      stmt_cur_->u_.wait_.stmt_ = (struct ivl_statement_s*)
            calloc(1, sizeof(struct ivl_statement_s));

      stmt_cur_->u_.wait_.nevent = net->nevents();
      if (net->nevents() > 1) {
            stmt_cur_->u_.wait_.events = (ivl_event_t*)
                  calloc(net->nevents(), sizeof(ivl_event_t*));
      }

      for (unsigned edx = 0 ;  edx < net->nevents() ;  edx += 1) {

              /* Locate the event by name. Save the ivl_event_t in the
                 statement so that the generator can find it easily. */
            const NetEvent*ev = net->event(edx);
            ivl_scope_t ev_scope = lookup_scope_(ev->scope());
            ivl_event_t ev_tmp=0;

            assert(ev_scope);
            assert(ev_scope->nevent_ > 0);
            for (unsigned idx = 0 ;  idx < ev_scope->nevent_ ;  idx += 1) {
                  const char*ename = ivl_event_basename(ev_scope->event_[idx]);
                  if (strcmp(ev->name(), ename) == 0) {
                        ev_tmp = ev_scope->event_[idx];
                        break;
                  }
            }
            // XXX should we assert(ev_tmp)?

            if (net->nevents() == 1)
                  stmt_cur_->u_.wait_.event = ev_tmp;
            else
                  stmt_cur_->u_.wait_.events[edx] = ev_tmp;

              /* If this is an event with a probe, then connect up the
                 pins. This wasn't done during the ::event method because
                 the signals weren't scanned yet. */

            if (ev->nprobe() >= 1) {
                  unsigned iany = 0;
                  unsigned ineg = ev_tmp->nany;
                  unsigned ipos = ineg + ev_tmp->nneg;

                  for (unsigned idx = 0 ;  idx < ev->nprobe() ;  idx += 1) {
                        const NetEvProbe*pr = ev->probe(idx);
                        unsigned base = 0;

                        switch (pr->edge()) {
                            case NetEvProbe::ANYEDGE:
                              base = iany;
                              iany += pr->pin_count();
                              break;
                            case NetEvProbe::NEGEDGE:
                              base = ineg;
                              ineg += pr->pin_count();
                              break;
                            case NetEvProbe::POSEDGE:
                              base = ipos;
                              ipos += pr->pin_count();
                              break;
                        }

                        for (unsigned bit = 0
                                   ; bit < pr->pin_count()
                                   ; bit += 1) {
                              ivl_nexus_t nex = (ivl_nexus_t)
                                    pr->pin(bit).nexus()->t_cookie();
                              assert(nex);
                              ev_tmp->pins[base+bit] = nex;
                        }
                  }
            }
      }

        /* The ivl_statement_t for the wait statement is not complete
           until we calculate the sub-statement. */

      ivl_statement_t save_cur_ = stmt_cur_;
      stmt_cur_ = stmt_cur_->u_.wait_.stmt_;
      bool flag = net->emit_recurse(this);
      if (flag && (stmt_cur_->type_ == IVL_ST_NONE))
            stmt_cur_->type_ = IVL_ST_NOOP;

      stmt_cur_ = save_cur_;

      return flag;
}

void dll_target::proc_while(const NetWhile*net)
{
      assert(stmt_cur_);
      assert(stmt_cur_->type_ == IVL_ST_NONE);

      stmt_cur_->type_ = IVL_ST_WHILE;
      stmt_cur_->u_.while_.stmt_ = (struct ivl_statement_s*)
            calloc(1, sizeof(struct ivl_statement_s));

      assert(expr_ == 0);
      net->expr()->expr_scan(this);
      stmt_cur_->u_.while_.cond_ = expr_;
      expr_ = 0;

        /* Now generate the statement of the while loop. We know it is
           a single statement, and we know that the
           emit_proc_recurse() will call emit_proc() for it. */

      ivl_statement_t save_cur_ = stmt_cur_;
      stmt_cur_ = save_cur_->u_.while_.stmt_;
      net->emit_proc_recurse(this);
      stmt_cur_ = save_cur_;
}