Conversion of std_logic to integer

tgt-vhdl/cast.cc

@@ -70,7 +70,15 @@ vhdl_expr *vhdl_expr::cast(const vhdl_type *to)
       }
    }
    else if (to->get_name() == VHDL_TYPE_INTEGER) {
-      vhdl_fcall *conv = new vhdl_fcall("To_Integer", new vhdl_type(*to));
+      vhdl_fcall *conv;
+      if (type_->get_name() == VHDL_TYPE_STD_LOGIC) {
+         require_support_function(SF_LOGIC_TO_INTEGER);
+         conv = new vhdl_fcall(support_function::function_name(SF_LOGIC_TO_INTEGER),
+                               vhdl_type::integer());
+      }
+      else
+         conv = new vhdl_fcall("To_Integer", new vhdl_type(*to));
+      
       conv->add_expr(this);
 
       return conv;

tgt-vhdl/support.cc

@@ -43,6 +43,7 @@ const char *support_function::function_name(support_function_t type)
    case SF_TERNARY_LOGIC:       return "Ternary_Logic";
    case SF_TERNARY_UNSIGNED:    return "Ternary_Unsigned";
    case SF_TERNARY_SIGNED:      return "Ternary_Signed";
+   case SF_LOGIC_TO_INTEGER:    return "Logic_To_Integer";
    default:
       assert(false);
    }
@@ -60,6 +61,8 @@ vhdl_type *support_function::function_type(support_function_t type)
    case SF_REDUCE_XOR:
    case SF_TERNARY_LOGIC:
       return vhdl_type::std_logic();
+   case SF_LOGIC_TO_INTEGER:
+      return vhdl_type::integer();
    default:
       assert(false);
    }
@@ -141,6 +144,12 @@ void support_function::emit(std::ostream &of, int level) const
          << nl_string(level);
       emit_ternary(of, level);
       break;
+   case SF_LOGIC_TO_INTEGER:
+      of << "(X : std_logic) return integer is" << nl_string(level)
+         << "begin" << nl_string(indent(level))
+         << "if X = '1' then return 1; else return 0; end if;"
+         << nl_string(level);
+      break;
    default:
       assert(false);
    }

tgt-vhdl/support.hh

@@ -33,6 +33,7 @@ enum support_function_t {
    SF_TERNARY_LOGIC,
    SF_TERNARY_UNSIGNED,
    SF_TERNARY_SIGNED,
+   SF_LOGIC_TO_INTEGER,
 };
 
 class support_function : public vhdl_function {