elaborate complex l-values

design_dump.cc

@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: design_dump.cc,v 1.95 2000/09/02 20:54:20 steve Exp $"
+#ident "$Id: design_dump.cc,v 1.96 2000/09/10 02:18:16 steve Exp $"
 #endif
 
 /*
@@ -422,41 +422,43 @@ void NetProcTop::dump(ostream&o, unsigned ind) const
       statement_->dump(o, ind+2);
 }
 
+void NetAssignBase::dump_lval(ostream&o) const
+{
+      o << "" << "{" << lval_->name();
+      if (lval_->bmux())
+	    o << "[" << *lval_->bmux() << "]";
+
+      for (NetAssign_*cur = lval_->more ;  cur ;  cur = cur->more) {
+	    o << ", " << cur->name();
+	    if (cur->bmux())
+		  o << "[" << *cur->bmux() << "]";
+      }
+
+      o << "}";
+}
+
 /* Dump an assignment statement */
 void NetAssign::dump(ostream&o, unsigned ind) const
 {
       o << setw(ind) << "";
+      dump_lval(o);
 
-      if (l_val(0)->bmux()) {
+      o << " = ";
-	    o << l_val(0)->name() << "[" << *l_val(0)->bmux() << "] = ";
+      if (l_val(0)->rise_time())
-	    if (l_val(0)->rise_time())
+	    o << "#" << l_val(0)->rise_time() << " ";
-		  o << "#" << l_val(0)->rise_time() << " ";
+      o << *rval() << ";" << endl;
-	    o << *rval() << ";" << endl;
-
-      } else {
-	    o << l_val(0)->name() << " = ";
-	    if (l_val(0)->rise_time())
-		  o << "#" << l_val(0)->rise_time() << " ";
-	    o << *rval() << ";" << endl;
-      }
 }
 
 void NetAssignNB::dump(ostream&o, unsigned ind) const
 {
       o << setw(ind) << "";
+      dump_lval(o);
 
-      if (l_val(0)->bmux()) {
+      o << " <= ";
-	    o << l_val(0)->name() << "[" << *l_val(0)->bmux() << "] <= ";
+      if (l_val(0)->rise_time())
-	    if (l_val(0)->rise_time())
+	    o << "#" << l_val(0)->rise_time() << " ";
-		  o << "#" << l_val(0)->rise_time() << " ";
+      o << *rval() << ";" << endl;
-	    o << *rval() << ";" << endl;
 
-      } else {
-	    o << l_val(0)->name() << " <= ";
-	    if (l_val(0)->rise_time())
-		  o << "#" << l_val(0)->rise_time() << " ";
-	    o << *rval() << ";" << endl;
-      }
 }
 
 void NetAssignMem::dump(ostream&o, unsigned ind) const
@@ -967,6 +969,9 @@ void Design::dump(ostream&o) const
 
 /*
  * $Log: design_dump.cc,v $
+ * Revision 1.96  2000/09/10 02:18:16  steve
+ *  elaborate complex l-values
+ *
  * Revision 1.95  2000/09/02 20:54:20  steve
  *  Rearrange NetAssign to make NetAssign_ separate.
  *

elab_lval.cc

@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: elab_lval.cc,v 1.1 2000/09/09 15:21:26 steve Exp $"
+#ident "$Id: elab_lval.cc,v 1.2 2000/09/10 02:18:16 steve Exp $"
 #endif
 
 # include  "PExpr.h"
@@ -79,23 +79,31 @@ NetAssign_* PExpr::elaborate_lval(Design*des, NetScope*scope) const
 
 /*
  * Concatenation expressions can appear as l-values. Handle them here.
- * XXXX For now, cheat and use elaborate_net to cope.
  */
 NetAssign_* PEConcat::elaborate_lval(Design*des, NetScope*scope) const
 {
+#if 0
       NetNet*ll = elaborate_net(des, scope->name(), 0, 0, 0, 0,
 				Link::STRONG, Link::STRONG);
-      if (ll == 0) {
+      if (ll != 0) {
-	    cerr << get_line() << ": Assignment l-value too complex."
+	    NetAssign_*lv = new NetAssign_(scope->local_symbol(),
-		 << endl;
+					   ll->pin_count());
-	    return 0;
+	    for (unsigned idx = 0 ; idx < ll->pin_count() ;  idx += 1)
+		  connect(lv->pin(idx), ll->pin(idx));
+	    des->add_node(lv);
+	    return lv;
+      }
+#endif
+      NetAssign_*res = 0;
+      for (unsigned idx = 0 ;  idx < parms_.count() ;  idx += 1) {
+	    NetAssign_*tmp = parms_[idx]->elaborate_lval(des, scope);
+	    assert(tmp);
+
+	    tmp->more = res;
+	    res = tmp;
       }
 
-      NetAssign_*lv = new NetAssign_(scope->local_symbol(), ll->pin_count());
+      return res;
-      for (unsigned idx = 0 ; idx < ll->pin_count() ;  idx += 1)
-	    connect(lv->pin(idx), ll->pin(idx));
-      des->add_node(lv);
-      return lv;
 }
 
 /*
@@ -195,7 +203,7 @@ NetAssign_* PEIdent::elaborate_lval(Design*des, NetScope*scope) const
 		 NetAssign_ the width of the target reg and attach a
 		 bmux to select the target bit. */
 	    unsigned wid = reg->pin_count();
-	    lv = new NetAssign_(scope->local_symbol(), wid);
+	    lv = new NetAssign_(des->local_symbol(scope->name()), wid);
 
 	    for (unsigned idx = 0 ;  idx < wid ;  idx += 1)
 		  connect(lv->pin(idx), reg->pin(idx));
@@ -210,7 +218,7 @@ NetAssign_* PEIdent::elaborate_lval(Design*des, NetScope*scope) const
 	    unsigned wid = (msb >= lsb)? (msb-lsb+1) : (lsb-msb+1);
 	    assert(wid <= reg->pin_count());
 
-	    lv = new NetAssign_(scope->local_symbol(), wid);
+	    lv = new NetAssign_(des->local_symbol(scope->name()), wid);
 	    unsigned off = reg->sb_to_idx(lsb);
 	    assert((off+wid) <= reg->pin_count());
 	    for (unsigned idx = 0 ;  idx < wid ;  idx += 1)
@@ -226,6 +234,9 @@ NetAssign_* PEIdent::elaborate_lval(Design*des, NetScope*scope) const
 
 /*
  * $Log: elab_lval.cc,v $
+ * Revision 1.2  2000/09/10 02:18:16  steve
+ *  elaborate complex l-values
+ *
  * Revision 1.1  2000/09/09 15:21:26  steve
  *  move lval elaboration to PExpr virtual methods.
  *

net_assign.cc

@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: net_assign.cc,v 1.3 2000/09/07 00:06:53 steve Exp $"
+#ident "$Id: net_assign.cc,v 1.4 2000/09/10 02:18:16 steve Exp $"
 #endif
 
 # include  "netlist.h"
@@ -34,10 +34,12 @@ NetAssign_::NetAssign_(const string&n, unsigned w)
 	    pin(idx).set_name("P", idx);
       }
 
+      more = 0;
 }
 
 NetAssign_::~NetAssign_()
 {
+      assert( more == 0 );
       if (bmux_) delete bmux_;
 }
 
@@ -66,7 +68,12 @@ NetAssignBase::NetAssignBase(NetAssign_*lv, NetExpr*rv)
 NetAssignBase::~NetAssignBase()
 {
       if (rval_) delete rval_;
-      if (lval_) delete lval_;
+      while (lval_) {
+	    NetAssign_*tmp = lval_;
+	    lval_ = tmp->more;
+	    tmp->more = 0;
+	    delete tmp;
+      }
 }
 
 NetExpr* NetAssignBase::rval()
@@ -87,20 +94,40 @@ void NetAssignBase::set_rval(NetExpr*r)
 
 NetAssign_* NetAssignBase::l_val(unsigned idx)
 {
+      NetAssign_*cur = lval_;
+      while (idx > 0) {
+	    if (cur == 0)
+		  return cur;
+
+	    cur = cur->more;
+	    idx -= 1;
+      }
+
       assert(idx == 0);
-      return lval_;
+      return cur;
 }
 
 const NetAssign_* NetAssignBase::l_val(unsigned idx) const
 {
+      const NetAssign_*cur = lval_;
+      while (idx > 0) {
+	    if (cur == 0)
+		  return cur;
+
+	    cur = cur->more;
+	    idx -= 1;
+      }
+
       assert(idx == 0);
-      return lval_;
+      return cur;
 }
 
 unsigned NetAssignBase::lwidth() const
 {
-      assert(lval_);
+      unsigned sum = 0;
-      return lval_->lwidth();
+      for (NetAssign_*cur = lval_ ;  cur ;  cur = cur->more)
+	    sum += cur->lwidth();
+      return sum;
 }
 
 
@@ -124,6 +151,9 @@ NetAssignNB::~NetAssignNB()
 
 /*
  * $Log: net_assign.cc,v $
+ * Revision 1.4  2000/09/10 02:18:16  steve
+ *  elaborate complex l-values
+ *
  * Revision 1.3  2000/09/07 00:06:53  steve
  *  encapsulate access to the l-value expected width.
  *

netlist.h

@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: netlist.h,v 1.161 2000/09/07 00:06:53 steve Exp $"
+#ident "$Id: netlist.h,v 1.162 2000/09/10 02:18:16 steve Exp $"
 #endif
 
 /*
@@ -1128,6 +1128,11 @@ class NetProc : public LineInfo {
  * assignment has its effect. The NetAssign_ class is not to be
  * derived from. 
  *
+ * The collection is arranged from lsb up to msb, and represents the
+ * concatenation of l-values. The elaborator may collapse some
+ * concatenations into a single NetAssign_. The "more" member of the
+ * NetAssign_ object points to the next most significant bits of l-value.
+ *
  * NOTE: The elaborator will make an effort to match the width of the
  * r-value to the with of the l-value, but targets and functions
  * should know that this is not a guarantee.
@@ -1154,6 +1159,9 @@ class NetAssign_ : public NetNode {
       virtual bool emit_node(struct target_t*) const;
       virtual void dump_node(ostream&, unsigned ind) const;
 
+	// This pointer is for keeping simple lists.
+      NetAssign_* more;
+
     private:
       NetExpr*bmux_;
 };
@@ -1178,6 +1186,8 @@ class NetAssignBase : public NetProc {
 	// accounts for any grouping of NetAssign_ objects that might happen.
       unsigned lwidth() const;
 
+      void dump_lval(ostream&) const;
+
     private:
       NetAssign_*lval_;
       NetExpr   *rval_;
@@ -2752,6 +2762,9 @@ extern ostream& operator << (ostream&, NetNet::Type);
 
 /*
  * $Log: netlist.h,v $
+ * Revision 1.162  2000/09/10 02:18:16  steve
+ *  elaborate complex l-values
+ *
  * Revision 1.161  2000/09/07 00:06:53  steve
  *  encapsulate access to the l-value expected width.
  *

t-vvm.cc

@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: t-vvm.cc,v 1.172 2000/09/08 17:08:10 steve Exp $"
+#ident "$Id: t-vvm.cc,v 1.173 2000/09/10 02:18:16 steve Exp $"
 #endif
 
 # include  <iostream>
@@ -174,6 +174,10 @@ class target_vvm : public target_t {
       virtual void net_probe(const NetEvProbe*);
       virtual bool process(const NetProcTop*);
       virtual void proc_assign(const NetAssign*);
+              void proc_assign_rval(const NetAssign_*, const NetEConst*,
+				    unsigned off);
+              void proc_assign_rval(const NetAssign_*, const string&,
+				    unsigned wid, unsigned off);
       virtual void proc_assign_mem(const NetAssignMem*);
       virtual void proc_assign_nb(const NetAssignNB*);
       virtual void proc_assign_mem_nb(const NetAssignMemNB*);
@@ -2139,6 +2143,140 @@ void target_vvm::start_process(ostream&os, const NetProcTop*proc)
 	   << endl << "{" << endl;
 }
 
+/*
+ * This method handles the special case of the assignment of a
+ * constant r-value to the l-value. In this case, I can set specific
+ * values to each of the bits instead of calculating bit values or
+ * even reading values from a vpip_bit_t elsewhere.
+ */
+void target_vvm::proc_assign_rval(const NetAssign_*lv,
+				  const NetEConst*rv,
+				  unsigned off)
+{
+      const verinum value = rv->value();
+
+	/* This condition catches the special case of assigning to a
+	   non-constant bit select. This cal be something like:
+
+		a[idx] = x;
+
+	   For this sort of assignment, I only need a single bit of
+	   the r-value. That bit is written into a single bit of the
+	   target using a generated switch statement, where each case
+	   of the switch assignes to a specific nexus. This is not
+	   unreasonable because there aren't typically all that many
+	   bits in the l-value. */
+
+      if (lv->bmux()) {
+
+	      // This is a bit select. Assign the low bit of the
+	      // constant to the selected bit of the lval.
+
+	    const char*rval = vvm_val_name(value.get(off),
+					   Link::STRONG,
+					   Link::STRONG);
+
+	    string bval = emit_proc_rval(this, lv->bmux());
+
+	    defn << "      switch (" << bval
+		 << ".as_unsigned()) {" << endl;
+
+	    for (unsigned idx = 0; idx < lv->pin_count(); idx += 1) {
+
+		  string nexus = lv->pin(idx).nexus()->name();
+		  unsigned ncode = nexus_wire_map[nexus];
+
+		  defn << "      case " << idx << ":" << endl;
+
+		  defn << "        nexus_wire_table["<<ncode<<"]"
+		       << ".reg_assign(" << rval << ");" << endl;
+		  defn << "        break;" << endl;
+
+	    }
+
+	    defn << "      }" << endl;
+	    return;
+      }
+
+
+	/* We've handled the case of bit selects, so here we know that
+	   we are doing a good ol' assignment to an l-value. So for
+	   the entire width of the l-value, assign constant bit values
+	   to the appropriate nexus. */
+
+      for (unsigned idx = 0 ;  idx < lv->pin_count() ;  idx += 1) {
+	    string nexus = lv->pin(idx).nexus()->name();
+	    unsigned ncode = nexus_wire_map[nexus];
+
+	    verinum::V val = (idx+off) < value.len() 
+		  ? value.get(idx+off)
+		  : verinum::V0;
+	    const char*rval = vvm_val_name(val, Link::STRONG, Link::STRONG);
+
+	    defn << "      nexus_wire_table[" <<ncode<< "]"
+		 << ".reg_assign(" << rval << ");" << endl;
+      }
+}
+
+/*
+ * This method does the grunt work of generating an assignment given a
+ * generated rval result.
+ */
+void target_vvm::proc_assign_rval(const NetAssign_*lv,
+				  const string&rval,
+				  unsigned wid, unsigned off)
+{
+      assert(lv);
+
+	/* Now, if there is a mux on the l-value, generate a code to
+	   assign a single bit to one of the bits of the
+	   l-value. Otherwise, generate code for a complete
+	   assignment. */
+
+      if (lv->bmux()) {
+
+	      // This is a bit select. Assign the low bit of the rval
+	      // to the selected bit of the lval.
+	    string bval = emit_proc_rval(this, lv->bmux());
+
+	    defn << "      switch (" << bval << ".as_unsigned()) {" << endl;
+
+	    for (unsigned idx = 0 ;  idx < lv->pin_count() ;  idx += 1) {
+
+		  string nexus = lv->pin(idx).nexus()->name();
+		  unsigned ncode = nexus_wire_map[nexus];
+
+		  defn << "      case " << idx << ":" << endl;
+
+		  defn << "        nexus_wire_table["<<ncode<<"]"
+		       << ".reg_assign(" << rval << "["<<off<<"]);" << endl;
+		  defn << "        break;" << endl;
+
+	    }
+
+	    defn << "      }" << endl;
+
+      } else {
+	    unsigned min_count = lv->pin_count();
+	    if ((wid-off) < min_count)
+		  min_count = wid - off;
+
+	    for (unsigned idx = 0 ;  idx < min_count ;  idx += 1) {
+		  string nexus = lv->pin(idx).nexus()->name();
+		  unsigned ncode = nexus_wire_map[nexus];
+		  defn << "      nexus_wire_table["<<ncode<<"].reg_assign("
+		       << rval << "[" << (idx+off) << "]);" << endl;
+	    }
+
+	    for (unsigned idx = min_count; idx < lv->pin_count(); idx += 1) {
+		  string nexus = lv->pin(idx).nexus()->name();
+		  unsigned ncode = nexus_wire_map[nexus];
+		  defn << "      nexus_wire_table["<<ncode<<"]"
+		       << ".reg_assign(St0);" << endl;
+	    }
+      }
+}
+
 /*
  * This method generates code for a procedural assignment. The lval is
  * a signal, but the assignment should generate code to go to all the
@@ -2148,59 +2286,22 @@ void target_vvm::proc_assign(const NetAssign*net)
 {
 
 	/* Detect the very special (and very common) case that the
-	   rvalue is a constant in this assignment. I this case, there
+	   rvalue is a constant value. In this case, there is no
-	   is no reason to go scan the expression, and in the process
+	   reason to go scan the expression, and in the process
 	   generate bunches of temporaries. */
 
       if (const NetEConst*rc = dynamic_cast<const NetEConst*>(net->rval())) {
 
-	    const verinum value = rc->value();
+	    const NetAssign_*cur = net->l_val(0);
-
+	    unsigned off = 0;
-	    if (net->l_val(0)->bmux()) {
+	    unsigned idx = 0;
-
+	    while (cur != 0) {
-		    // This is a bit select. Assign the low bit of the
+		  proc_assign_rval(cur, rc, off);
-		    // constant to the selected bit of the lval.
+		  off += cur->lwidth();
-
+		  idx += 1;
-		  const char*rval = vvm_val_name(value.get(0),
+		  cur = net->l_val(idx);
-						 Link::STRONG,
-						 Link::STRONG);
-
-		  string bval = emit_proc_rval(this, net->l_val(0)->bmux());
-
-		  defn << "      switch (" << bval
-		       << ".as_unsigned()) {" << endl;
-
-		  for (unsigned idx = 0; idx < net->l_val(0)->pin_count(); idx += 1) {
-
-			string nexus = net->l_val(0)->pin(idx).nexus()->name();
-			unsigned ncode = nexus_wire_map[nexus];
-
-			defn << "      case " << idx << ":" << endl;
-
-			defn << "        nexus_wire_table["<<ncode<<"]"
-			     << ".reg_assign(" << rval << ");" << endl;
-			defn << "        break;" << endl;
-
-		  }
-
-		  defn << "      }" << endl;
-		  return;
 	    }
 
-	    for (unsigned idx = 0 ;  idx < net->l_val(0)->pin_count() ;  idx += 1) {
-		  string nexus = net->l_val(0)->pin(idx).nexus()->name();
-		  unsigned ncode = nexus_wire_map[nexus];
-
-		  verinum::V val = idx < value.len() 
-			? value.get(idx)
-			: verinum::V0;
-		  const char*rval = vvm_val_name(val,
- 						 Link::STRONG,
- 						 Link::STRONG);
-
-		  defn << "      nexus_wire_table[" <<ncode<< "]"
-		       << ".reg_assign(" << rval << ");" << endl;
-	    }
 	    return;
       }
 
@@ -2218,12 +2319,11 @@ void target_vvm::proc_assign(const NetAssign*net)
 
       if (const NetESignal*rs = dynamic_cast<const NetESignal*>(net->rval())) {
 
-	    if (net->l_val(0)->pin_count() > rs->pin_count()) {
+	    if (net->lwidth() > rs->pin_count()) {
 		  rval = emit_proc_rval(this, net->rval());
 
 	    } else {
-		  assert((net->l_val(0)->pin_count() <= rs->pin_count())
+
-			 || (net->l_val(0)->bmux() && (rs->pin_count() >= 1)));
 		  rval = mangle(rs->name()) + ".bits";
 	    }
 
@@ -2235,53 +2335,16 @@ void target_vvm::proc_assign(const NetAssign*net)
 
       defn << "      // " << net->get_line() << ": " << endl;
 
-
+      { const NetAssign_*cur = net->l_val(0);
-	/* Now, if there is a mux on the l-value, generate a code to
+        unsigned wid = net->rval()->expr_width();
-	   assign a single bit to one of the bits of the
+        unsigned off = 0;
-	   l-value. Otherwise, generate code for a complete
+	unsigned idx = 0;
-	   assignment. */
+	while (cur != 0) {
-
+	      proc_assign_rval(cur, rval, wid, off);
-      if (net->l_val(0)->bmux()) {
+	      off += cur->lwidth();
-
+	      idx += 1;
-	      // This is a bit select. Assign the low bit of the rval
+	      cur = net->l_val(idx);
-	      // to the selected bit of the lval.
+	}
-	    string bval = emit_proc_rval(this, net->l_val(0)->bmux());
-
-	    defn << "      switch (" << bval << ".as_unsigned()) {" << endl;
-
-	    for (unsigned idx = 0 ;  idx < net->l_val(0)->pin_count() ;  idx += 1) {
-
-		  string nexus = net->l_val(0)->pin(idx).nexus()->name();
-		  unsigned ncode = nexus_wire_map[nexus];
-
-		  defn << "      case " << idx << ":" << endl;
-
-		  defn << "        nexus_wire_table["<<ncode<<"]"
-		       << ".reg_assign(" << rval << "[0]);" << endl;
-		  defn << "        break;" << endl;
-
-	    }
-
-	    defn << "      }" << endl;
-
-      } else {
-	    unsigned min_count = net->l_val(0)->pin_count();
-	    if (net->rval()->expr_width() < min_count)
-		  min_count = net->rval()->expr_width();
-
-	    for (unsigned idx = 0 ;  idx < min_count ;  idx += 1) {
-		  string nexus = net->l_val(0)->pin(idx).nexus()->name();
-		  unsigned ncode = nexus_wire_map[nexus];
-		  defn << "      nexus_wire_table["<<ncode<<"].reg_assign("
-		       << rval << "[" << idx << "]);" << endl;
-	    }
-
-	    for (unsigned idx = min_count; idx < net->l_val(0)->pin_count(); idx += 1) {
-		  string nexus = net->l_val(0)->pin(idx).nexus()->name();
-		  unsigned ncode = nexus_wire_map[nexus];
-		  defn << "      nexus_wire_table["<<ncode<<"]"
-		       << ".reg_assign(St0);" << endl;
-	    }
       }
 }
 
@@ -2320,6 +2383,9 @@ void target_vvm::proc_assign_nb(const NetAssignNB*net)
       string rval = emit_proc_rval(this, net->rval());
       const unsigned long delay = net->l_val(0)->rise_time();
 
+	// XXXX I cannot handle this yet.
+      assert(net->l_val(1) == 0);
+
       if (net->l_val(0)->bmux()) {
 	      /* If the l-value has a bit select, set the output bit
 		 to only the desired bit. Evaluate the index and use
@@ -3116,6 +3182,9 @@ extern const struct target tgt_vvm = {
 };
 /*
  * $Log: t-vvm.cc,v $
+ * Revision 1.173  2000/09/10 02:18:16  steve
+ *  elaborate complex l-values
+ *
  * Revision 1.172  2000/09/08 17:08:10  steve
  *  initialize vlog info.
  *