net_nex_output.cc

   1 /*
   2  * Copyright (c) 2002 Stephen Williams (steve@icarus.com)
   3  *
   4  *    This source code is free software; you can redistribute it
   5  *    and/or modify it in source code form under the terms of the GNU
   6  *    General Public License as published by the Free Software
   7  *    Foundation; either version 2 of the License, or (at your option)
   8  *    any later version.
   9  *
  10  *    This program is distributed in the hope that it will be useful,
  11  *    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *    GNU General Public License for more details.
  14  *
  15  *    You should have received a copy of the GNU General Public License
  16  *    along with this program; if not, write to the Free Software
  17  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  18  */
  19 #ifdef HAVE_CVS_IDENT
  20 #ident "$Id: net_nex_output.cc,v 1.14 2007/04/17 04:34:23 steve Exp $"
  21 #endif
  22
  23 # include "config.h"
  24
  25 # include <iostream>
  26
  27 # include  <cassert>
  28 # include  <typeinfo>
  29 # include  "netlist.h"
  30 # include  "netmisc.h"
  31
  32 void NetProc::nex_output(NexusSet&out)
  33 {
  34       cerr << get_line()
  35            << ": internal error: NetProc::nex_output not implemented"
  36            << endl;
  37       cerr << get_line()
  38            << ":               : on object type " << typeid(*this).name()
  39            << endl;
  40 }
  41
  42 /*
  43  * Assignments have as output all the bits of the concatenated signals
  44  * of the l-value.
  45  */
  46 void NetAssignBase::nex_output(NexusSet&out)
  47 {
  48       for (NetAssign_*cur = lval_ ;  cur ;  cur = cur->more) {
  49             if (NetNet*lsig = cur->sig()) {
  50                   out.add(lsig->pin(0).nexus());
  51             } else {
  52                     /* Quoting from netlist.h comments for class NetMemory:
  53                      * "This is not a node because memory objects can only be
  54                      * accessed by behavioral code."
  55                      */
  56                   cerr << get_line() << ": internal error: "
  57                        << "NetAssignBase::nex_output on unsupported lval ";
  58                   dump_lval(cerr);
  59                   cerr << endl;
  60             }
  61       }
  62 }
  63
  64 void NetBlock::nex_output(NexusSet&out)
  65 {
  66       if (last_ == 0)
  67             return;
  68
  69       NetProc*cur = last_;
  70       do {
  71             cur = cur->next_;
  72             cur->nex_output(out);
  73       } while (cur != last_);
  74 }
  75
  76 void NetCase::nex_output(NexusSet&out)
  77 {
  78       for (unsigned idx = 0 ;  idx < nitems_ ;  idx += 1) {
  79
  80               // Empty statements clearly have no output.
  81             if (items_[idx].statement == 0)
  82                   continue;
  83
  84             assert(items_[idx].statement);
  85             items_[idx].statement->nex_output(out);
  86       }
  87
  88 }
  89
  90 void NetCondit::nex_output(NexusSet&out)
  91 {
  92       if (if_ != 0)
  93             if_->nex_output(out);
  94       if (else_ != 0)
  95             else_->nex_output(out);
  96 }
  97
  98 void NetEvWait::nex_output(NexusSet&out)
  99 {
 100       assert(statement_);
 101       statement_->nex_output(out);
 102 }
 103
 104 void NetPDelay::nex_output(NexusSet&out)
 105 {
 106       if (statement_) statement_->nex_output(out);
 107 }
 108
 109 /*
 110  * For the purposes of synthesis, system task calls have no output at
 111  * all. This is OK because most system tasks are not synthesizeable in
 112  * the first place.
 113  */
 114 void NetSTask::nex_output(NexusSet&out)
 115 {
 116 }
 117
 118 /*
 119 * Consider a task call to not have any outputs. This is not quite
 120 * right, we should be listing as outputs all the output ports, but for
 121 * the purposes that this method is used, this will do for now.
 122 */
 123 void NetUTask::nex_output(NexusSet&out)
 124 {
 125 }
 126
 127 void NetWhile::nex_output(NexusSet&out)
 128 {
 129       if (proc_ != 0)
 130             proc_->nex_output(out);
 131 }
 132
 133 /*
 134  * $Log: net_nex_output.cc,v $
 135  * Revision 1.14  2007/04/17 04:34:23  steve
 136  *  Fix handling calls to tasks in combinational always block
 137  *
 138  * Revision 1.13  2007/04/05 01:53:52  steve
 139  *  Probe of case statement inputs can skip nul statements.
 140  *
 141  * Revision 1.12  2005/02/14 04:58:50  steve
 142  *  l-value input may be a vector.
 143  *
 144  * Revision 1.11  2004/09/16 03:17:33  steve
 145  *  net_output handles l-value concatenations.
 146  *
 147  * Revision 1.10  2004/08/28 16:23:05  steve
 148  *  Fix use of system tasks in AT_STAR statements.
 149  *
 150  * Revision 1.9  2004/06/30 15:32:18  steve
 151  *  nex_output for NetPDelay statements.
 152  *
 153  * Revision 1.8  2003/12/20 00:59:31  steve
 154  *  Synthesis debug messages.
 155  *
 156  * Revision 1.7  2003/10/26 04:51:39  steve
 157  *  Output of While is output of while substatement.
 158  *
 159  * Revision 1.6  2002/09/17 04:39:20  steve
 160  *  Account for part select in l-value.
 161  *
 162  * Revision 1.5  2002/08/12 01:34:59  steve
 163  *  conditional ident string using autoconfig.
 164  *
 165  * Revision 1.4  2002/07/29 00:00:28  steve
 166  *  Asynchronous synthesis of sequential blocks.
 167  *
 168  * Revision 1.3  2002/07/07 22:32:15  steve
 169  *  Asynchronous synthesis of case statements.
 170  *
 171  * Revision 1.2  2002/07/01 00:54:21  steve
 172  *  synth_asych of if/else requires redirecting the target
 173  *  if sub-statements. Use NetNet objects to manage the
 174  *  situation.
 175  *
 176  * Revision 1.1  2002/06/30 02:21:32  steve
 177  *  Add structure for asynchronous logic synthesis.
 178  *
 179  */
 180