simplify_exprt::expr2bits now independent of bitvector representation

Author: Daniel Kroening

src/util/simplify_expr.cpp

@@ -1575,7 +1575,9 @@ optionalt<std::string> simplify_exprt::expr2bits(
        type.id()==ID_floatbv ||
        type.id()==ID_fixedbv)
     {
-      std::string nat=id2string(to_constant_expr(expr).get_value());
+      const auto width = to_bitvector_type(type).get_width();
+      mp_integer int_value=bv2integer(id2string(to_constant_expr(expr).get_value()), width, false);
+      std::string nat=integer2binary(int_value, width);
       std::reverse(nat.begin(), nat.end());
 
       endianness_mapt map(type, little_endian, ns);