diff --git a/tgt-vhdl/expr.cc b/tgt-vhdl/expr.cc
index 10465684c..0bf7d7991 100644
--- a/tgt-vhdl/expr.cc
+++ b/tgt-vhdl/expr.cc
@@ -180,6 +180,10 @@ static vhdl_expr *translate_unary(ivl_expr_t e)
       return translate_reduction(SF_REDUCE_AND, true, operand);
    case '&':
       return translate_reduction(SF_REDUCE_AND, false, operand);
+   case '^':   // XOR
+      return translate_reduction(SF_REDUCE_XOR, false, operand);
+   case 'X':   // XNOR
+      return translate_reduction(SF_REDUCE_XNOR, false, operand);
    default:
       error("No translation for unary opcode '%c'\n",
             ivl_expr_opcode(e));
diff --git a/tgt-vhdl/support.cc b/tgt-vhdl/support.cc
index 9ad74a3ca..b299aa486 100644
--- a/tgt-vhdl/support.cc
+++ b/tgt-vhdl/support.cc
@@ -40,6 +40,7 @@ const char *support_function::function_name(support_function_t type)
    case SF_REDUCE_OR:           return "Reduce_OR";
    case SF_REDUCE_AND:          return "Reduce_AND";
    case SF_REDUCE_XOR:          return "Reduce_XOR";
+   case SF_REDUCE_XNOR:         return "Reduce_XNOR";
    case SF_TERNARY_LOGIC:       return "Ternary_Logic";
    case SF_TERNARY_UNSIGNED:    return "Ternary_Unsigned";
    case SF_TERNARY_SIGNED:      return "Ternary_Signed";
@@ -61,6 +62,7 @@ vhdl_type *support_function::function_type(support_function_t type)
    case SF_REDUCE_OR:
    case SF_REDUCE_AND:
    case SF_REDUCE_XOR:
+   case SF_REDUCE_XNOR:
    case SF_TERNARY_LOGIC:
    case SF_SIGNED_TO_LOGIC:
    case SF_UNSIGNED_TO_LOGIC:
@@ -146,6 +148,16 @@ void support_function::emit(std::ostream &of, int level) const
          << "end loop;" << nl_string(indent(level))
          << "return R;";
       break;
+   case SF_REDUCE_XNOR:
+      of << "(X : std_logic_vector) return std_logic is"
+         << nl_string(indent(level))
+         << "variable R : std_logic := '0';" << nl_string(level)
+         << "begin" << nl_string(indent(level))
+         << "for I in X'Range loop" << nl_string(indent(indent(level)))
+         << "R := X(I) xnor R;" << nl_string(indent(level))
+         << "end loop;" << nl_string(indent(level))
+         << "return R;";
+      break;
    case SF_TERNARY_LOGIC:
       of << "(T : Boolean; X, Y : std_logic) return std_logic is";
       emit_ternary(of, level);
diff --git a/tgt-vhdl/support.hh b/tgt-vhdl/support.hh
index 234831c24..a738b0691 100644
--- a/tgt-vhdl/support.hh
+++ b/tgt-vhdl/support.hh
@@ -30,6 +30,7 @@ enum support_function_t {
    SF_REDUCE_OR,
    SF_REDUCE_AND,
    SF_REDUCE_XOR,
+   SF_REDUCE_XNOR,
    SF_TERNARY_LOGIC,
    SF_TERNARY_UNSIGNED,
    SF_TERNARY_SIGNED,