Add XNOR logic device

tgt-vhdl/logic.cc

@@ -124,6 +124,8 @@ static vhdl_expr *translate_logic_inputs(vhdl_scope *scope, ivl_net_logic_t log)
       return inputs_to_expr(scope, VHDL_BINOP_NOR, log);
    case IVL_LO_XOR:
       return inputs_to_expr(scope, VHDL_BINOP_XOR, log);
+   case IVL_LO_XNOR:
+      return inputs_to_expr(scope, VHDL_BINOP_XNOR, log);
    case IVL_LO_BUF:
    case IVL_LO_BUFZ:
       return nexus_to_var_ref(scope, ivl_logic_pin(log, 1));

tgt-vhdl/vhdl_syntax.cc

@@ -725,7 +725,7 @@ void vhdl_binop_expr::emit(std::ostream &of, int level) const
       const char* ops[] = {
          "and", "or", "=", "/=", "+", "-", "*", "<",
          ">", "<=", ">=", "sll", "srl", "xor", "&",
-         "nand", "nor", NULL
+         "nand", "nor", "xnor", NULL
       };
 
       of << " " << ops[op_] << " ";

tgt-vhdl/vhdl_syntax.hh

@@ -83,6 +83,7 @@ enum vhdl_binop_t {
    VHDL_BINOP_CONCAT,
    VHDL_BINOP_NAND,
    VHDL_BINOP_NOR,
+   VHDL_BINOP_XNOR,
 };
 
 /*