// logging utility
  template <class Container>
  string ToString(const Container& v) {
    std::stringstream ss;
    ss << "{";
    size_t i = 0;
    for (const auto& e : v) {
      if (i != 0) {
        ss << ", ";
      }
      ss << e.ToString();
      ++i;
    }
    ss << "}";
    return ss.str();
  }

  void VerifyFDefNodes(const tensorflow::FunctionDef& fdef,

-	    return s;
-	} while (--n4 > 0);
-      n &= 3;
-    }
+  size_t ss = __strnlen (s2, n);
 
-  while (n > 0)
-    {
-      c = *s2++;
-      *++s1 = c;
-      if (c == '\0')
-	return s;
-      n--;
-    }
-
-  if (c != '\0')
-    *++s1 = '\0';
+  s1[ss] = '\0';
+  memcpy (s1, s2, ss);
 
   return s;
 }
+