Elaborate logical and/or to account for special properties.

The arguments of logical and/or are self determined, and the width is
fixed as 1 bit. Account for this special behavior by creating the
PEBLogic class.

PExpr.cc

@@ -73,6 +73,16 @@ PEBComp::~PEBComp()
 {
 }
 
+PEBLogic::PEBLogic(char op, PExpr*l, PExpr*r)
+: PEBinary(op, l, r)
+{
+      assert(op == 'a' || op == 'o');
+}
+
+PEBLogic::~PEBLogic()
+{
+}
+
 PEBShift::PEBShift(char op, PExpr*l, PExpr*r)
 : PEBinary(op, l, r)
 {

PExpr.h

@@ -497,6 +497,25 @@ class PEBComp  : public PEBinary {
       NetExpr*elaborate_pexpr(Design*des, NetScope*sc) const;
 };
 
+/*
+ * This derived class is for handling logical expressions: && and ||.
+*/
+class PEBLogic  : public PEBinary {
+
+    public:
+      explicit PEBLogic(char op, PExpr*l, PExpr*r);
+      ~PEBLogic();
+
+      virtual unsigned test_width(Design*des, NetScope*scope,
+				  unsigned min, unsigned lval,
+				  ivl_variable_type_t&expr_type,
+				  bool&flag);
+
+      NetExpr* elaborate_expr(Design*des, NetScope*scope,
+			      int expr_width, bool sys_task_arg) const;
+      NetExpr*elaborate_pexpr(Design*des, NetScope*sc) const;
+};
+
 class PEBShift  : public PEBinary {
 
     public:

elab_expr.cc

@@ -294,11 +294,12 @@ NetExpr* PEBinary::elaborate_expr_base_(Design*des,
 
 	  case 'a':
 	  case 'o':
-	    lp = condition_reduce(lp);
-	    rp = condition_reduce(rp);
-	    tmp = new NetEBLogic(op_, lp, rp);
-	    tmp->set_line(*this);
-	    break;
+	    cerr << get_fileline() << ": internal error: "
+		 << "Elaboration of " << human_readable_op(op_)
+		 << " Should have been handled in NetEBLogic::elaborate."
+		 << endl;
+	    des->errors += 1;
+	    return 0;
 
 	  case 'p':
 	    tmp = new NetEBPow(op_, lp, rp);
@@ -799,6 +800,54 @@ NetExpr* PEBComp::elaborate_expr(Design*des, NetScope*scope,
       return tmp;
 }
 
+unsigned PEBLogic::test_width(Design*des, NetScope*scope,
+			      unsigned min, unsigned lval,
+			      ivl_variable_type_t&expr_type_out,
+			      bool&unsized_flag)
+{
+      expr_type_ = IVL_VT_LOGIC;
+      expr_width_ = 1;
+      expr_type_out = expr_type_;
+      return expr_width_;
+}
+
+NetExpr*PEBLogic::elaborate_expr(Design*des, NetScope*scope,
+				 int expr_width_dummp, bool sys_task_arg) const
+{
+      assert(left_);
+      assert(right_);
+
+	// The left and right expressions are self-determined and
+	// independent. Run their test_width methods independently. We
+	// don't need the widths here, but we do need the expressions
+	// to calculate their self-determined width and type.
+
+      bool left_flag = false;
+      ivl_variable_type_t left_type = IVL_VT_NO_TYPE;
+      left_->test_width(des, scope, 0, 0, left_type, left_flag);
+
+      bool right_flag = false;
+      ivl_variable_type_t right_type = IVL_VT_NO_TYPE;
+      right_->test_width(des, scope, 0, 0, right_type, right_flag);
+
+      NetExpr*lp = elab_and_eval(des, scope, left_, -1);
+      NetExpr*rp = elab_and_eval(des, scope, right_, -1);
+      if ((lp == 0) || (rp == 0)) {
+	    delete lp;
+	    delete rp;
+	    return 0;
+      }
+
+      lp = condition_reduce(lp);
+      rp = condition_reduce(rp);
+
+      NetEBLogic*tmp = new NetEBLogic(op_, lp, rp);
+      tmp->set_line(*this);
+      tmp->set_width(1);
+
+      return tmp;
+}
+
 unsigned PEBShift::test_width(Design*des, NetScope*scope,
 			      unsigned min, unsigned lval,
 			      ivl_variable_type_t&expr_type__,

elab_pexpr.cc

@@ -81,6 +81,28 @@ NetExpr*PEBComp::elaborate_pexpr(Design*des, NetScope*scope) const
       return tmp;
 }
 
+NetExpr*PEBLogic::elaborate_pexpr(Design*des, NetScope*scope) const
+{
+      NetExpr*lp = left_->elaborate_pexpr(des, scope);
+      NetExpr*rp = right_->elaborate_pexpr(des, scope);
+      if ((lp == 0) || (rp == 0)) {
+	    delete lp;
+	    delete rp;
+	    return 0;
+      }
+
+      NetEBLogic*tmp = new NetEBLogic(op_, lp, rp);
+      tmp->set_line(*this);
+      bool flag = tmp->set_width(1);
+      if (flag == false) {
+	    cerr << get_fileline() << ": internal error: "
+		  "expression bit width of comparison != 1." << endl;
+	    des->errors += 1;
+      }
+
+      return tmp;
+}
+
 /*
  * Event though parameters are not generally sized, parameter
  * expressions can include concatenation expressions. This requires

netlist.h

@@ -3270,7 +3270,7 @@ class NetEBLogic : public NetEBinary {
       NetEBLogic(char op, NetExpr*l, NetExpr*r);
       ~NetEBLogic();
 
-      virtual bool set_width(unsigned w, bool last_chance);
+      virtual bool set_width(unsigned w, bool last_chance =false);
       virtual NetEBLogic* dup_expr() const;
       virtual NetEConst* eval_tree(int prune_to_width = -1);
       virtual NetNet* synthesize(Design*, NetScope*scope);

parse.y

@@ -1034,12 +1034,12 @@ expression
 		  $$ = tmp;
 		}
 	| expression K_LOR expression
-		{ PEBinary*tmp = new PEBinary('o', $1, $3);
+		{ PEBinary*tmp = new PEBLogic('o', $1, $3);
 		  FILE_NAME(tmp, @2);
 		  $$ = tmp;
 		}
 	| expression K_LAND expression
-		{ PEBinary*tmp = new PEBinary('a', $1, $3);
+		{ PEBinary*tmp = new PEBLogic('a', $1, $3);
 		  FILE_NAME(tmp, @2);
 		  $$ = tmp;
 		}