From d37126bda5a99b67a557b68658f1750f1b2892e0 Mon Sep 17 00:00:00 2001
From: Stephen Williams <steve@icarus.com>
Date: Fri, 5 Nov 2010 19:49:28 -0700
Subject: [PATCH] Implement enum first/last/num methods.

---
 elab_expr.cc | 28 ++++++++++++++++++++++++++++
 netenum.cc   | 23 +++++++++++++++++++----
 netenum.h    | 12 +++++++++++-
 netmisc.cc   |  8 ++++++++
 netmisc.h    |  1 +
 5 files changed, 67 insertions(+), 5 deletions(-)

diff --git a/elab_expr.cc b/elab_expr.cc
index ebb1bd951..e8aa19abd 100644
--- a/elab_expr.cc
+++ b/elab_expr.cc
@@ -26,6 +26,7 @@
 
 # include  "pform.h"
 # include  "netlist.h"
+# include  "netenum.h"
 # include  "discipline.h"
 # include  "netmisc.h"
 # include  "util.h"
@@ -2214,9 +2215,36 @@ NetExpr* PEIdent::elaborate_expr(Design*des, NetScope*scope,
 				     net, par, eve, ex1, ex2);
 
 	    if (net != 0) {
+		    // Special case: The net is an enum, and the
+		    // method name is "num".
+		  netenum_t*netenum = net->enumeration();
+		  if (netenum && method_name == "num") {
+			NetEConst*tmp = make_const_val(netenum->size());
+			tmp->set_line(*this);
+			return tmp;
+		  }
+
+		    // Special case: The net is an enum, and the
+		    // method name is "first".
+		  if (netenum && method_name == "first") {
+			netenum_t::iterator item = netenum->first_name();
+			NetEConstEnum*tmp = new NetEConstEnum(scope,  item->first,
+							      netenum, item->second);
+			tmp->set_line(*this);
+			return tmp;
+		  }
+		  if (netenum && method_name == "last") {
+			netenum_t::iterator item = netenum->last_name();
+			NetEConstEnum*tmp = new NetEConstEnum(scope,  item->first,
+							      netenum, item->second);
+			tmp->set_line(*this);
+			return tmp;
+		  }
+
 		  const char*func_name = 0;
 		  if (method_name == "name") {
 			func_name = "$ivl_method$name";
+
 		  } else {
 			cerr << get_fileline() << ": error: "
 			     << "Unknown method name `" << method_name << "'"
diff --git a/netenum.cc b/netenum.cc
index 1821e9385..0dee3dd80 100644
--- a/netenum.cc
+++ b/netenum.cc
@@ -30,16 +30,31 @@ netenum_t::~netenum_t()
 
 bool netenum_t::insert_name(perm_string name, const verinum&val)
 {
-      names_[name] = verinum(val, msb_-lsb_+1);
-      return true;
+      std::pair<std::map<perm_string,verinum>::iterator, bool> res;
+
+      res = names_map_.insert( make_pair(name,val) );
+	// Only add the name to the list if it is not there already.
+      if (res.second) names_.push_back(name);
+
+      return res.second;
 }
 
 netenum_t::iterator netenum_t::find_name(perm_string name) const
 {
-      return names_.find(name);
+      return names_map_.find(name);
 }
 
 netenum_t::iterator netenum_t::end_name() const
 {
-      return names_.end();
+      return names_map_.end();
+}
+
+netenum_t::iterator netenum_t::first_name() const
+{
+      return names_map_.find(names_.front());
+}
+
+netenum_t::iterator netenum_t::last_name() const
+{
+      return names_map_.find(names_.back());
 }
diff --git a/netenum.h b/netenum.h
index 34843ef37..d299bcd05 100644
--- a/netenum.h
+++ b/netenum.h
@@ -22,6 +22,7 @@
 # include  "ivl_target.h"
 # include  "verinum.h"
 # include  "StringHeap.h"
+# include  <list>
 # include  <map>
 
 class netenum_t {
@@ -31,18 +32,27 @@ class netenum_t {
 			 long msb, long lsb);
       ~netenum_t();
 
+      size_t size() const;
+
       bool insert_name(perm_string name, const verinum&val);
 
       typedef std::map<perm_string,verinum>::const_iterator iterator;
       iterator find_name(perm_string name) const;
       iterator end_name() const;
 
+	// These methods roughly match the .first() and .last() methods.
+      iterator first_name() const;
+      iterator last_name() const;
+
     private:
       ivl_variable_type_t base_type_;
       bool signed_flag_;
       long msb_, lsb_;
 
-      std::map<perm_string,verinum> names_;
+      std::map<perm_string,verinum> names_map_;
+      std::list<perm_string> names_;
 };
 
+inline size_t netenum_t::size() const { return names_.size(); }
+
 #endif
diff --git a/netmisc.cc b/netmisc.cc
index 73d1f3b58..11d042f83 100644
--- a/netmisc.cc
+++ b/netmisc.cc
@@ -24,6 +24,7 @@
 # include  "netmisc.h"
 # include  "PExpr.h"
 # include  "pform_types.h"
+# include  "compiler.h"
 # include  "ivl_assert.h"
 
 NetNet* add_to_net(Design*des, NetNet*sig, long val)
@@ -393,6 +394,13 @@ NetEConst* make_const_0(unsigned long wid)
       return resx;
 }
 
+NetEConst* make_const_val(unsigned long value)
+{
+      verinum tmp (value, integer_width);
+      NetEConst*res = new NetEConst(tmp);
+      return res;
+}
+
 NetNet* make_const_x(Design*des, NetScope*scope, unsigned long wid)
 {
       verinum xxx (verinum::Vx, wid);
diff --git a/netmisc.h b/netmisc.h
index b7618f7ed..5c4ae014c 100644
--- a/netmisc.h
+++ b/netmisc.h
@@ -116,6 +116,7 @@ extern NetNet*sub_net_from(Design*des, NetScope*scope, long val, NetNet*sig);
  */
 extern NetEConst*make_const_x(unsigned long wid);
 extern NetEConst*make_const_0(unsigned long wid);
+extern NetEConst*make_const_val(unsigned long val);
 
 /*
  * Make A const net