--- /dev/null	2018-09-26 16:39:08.000000000 -0700
+++ new/test/jdk/java/lang/Floating/DoubleToStringChecker.java	2018-09-26 16:39:08.000000000 -0700
@@ -0,0 +1,91 @@
+/*
+ * Copyright (c) 2018, Raffaello Giulietti. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ * This particular file is subject to the "Classpath" exception as provided
+ * in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+import java.math.BigDecimal;
+
+/**
+ * @author Raffaello Giulietti
+ */
+class DoubleToStringChecker extends StringChecker {
+
+    private double v;
+
+    DoubleToStringChecker(double v, String s) {
+        super(s);
+        this.v = v;
+    }
+
+    @Override
+    BigDecimal toBigDecimal() {
+        return new BigDecimal(v);
+    }
+
+    @Override
+    boolean recovers(BigDecimal b) {
+        return b.doubleValue() == v;
+    }
+
+    @Override
+    boolean recovers(String s) {
+        return Double.parseDouble(s) == v;
+    }
+
+    @Override
+    int maxExp() {
+        return 309;
+    }
+
+    @Override
+    int minExp() {
+        return -323;
+    }
+
+    @Override
+    int maxLen10() {
+        return 17;
+    }
+
+    @Override
+    boolean isZero() {
+        return v == 0;
+    }
+
+    @Override
+    boolean isInfinity() {
+        return v == Double.POSITIVE_INFINITY;
+    }
+
+    @Override
+    void invert() {
+        v = -v;
+    }
+
+    @Override
+    boolean isNegative() {
+        return Double.doubleToRawLongBits(v) < 0;
+    }
+
+    @Override
+    boolean isNaN() {
+        return v != v;
+    }
+
+}