hotspot/test/compiler/floatingpoint/ModNaN.java
changeset 24319 457a79645387
child 30028 ac021a11a31b
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/compiler/floatingpoint/ModNaN.java	Mon Apr 28 15:09:39 2014 -0400
@@ -0,0 +1,168 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. 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 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.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/**
+ * @test
+ * @bug 8015396
+ * @summary double a%b returns NaN for some (a,b) (|a| < inf, |b|>0) (on Core i7 980X)
+ *
+ * @run main ModNaN
+ */
+public class ModNaN {
+    /* This bug was seen in the field for a particular version of the VM,
+     * but never reproduced internally, and the reason was never known,
+     * nor were the exact circumstances of the failure.
+     */
+    /*
+     * Failed on Windows 7/Core i7 980X/1.6.0_38 (64-bit):
+     *
+     * NaNs (i.e., when it fails, this is what we expect to see):
+     *
+     * 8.98846567431158E307 % 1.295163E-318 = NaN
+     * (0x7FE0000000000000L % 0x0000000000040000L)
+     *
+     * 1.7976931348623157E308 % 2.59032E-318 = NaN
+     * (0x7FEFFFFFFFFFFFFFL % 0x000000000007FFFFL)
+     *
+     * 1.7976931348623157E308 % 1.060997895E-314 = NaN
+     * (0x7FEFFFFFFFFFFFFFL % 0x000000007FFFFFFFL)
+     *
+     * 1.7976931348623157E308 % 6.767486E-317 = NaN
+     * (0x7FEFFFFFFFFFFFFFL % 0x0000000000d10208L)
+     *
+     * 1.7976931348623157E308 % 7.528725E-318 = NaN
+     * (0x7FEFFFFFFFFFFFFFL % 0x0000000000174077L)
+     *
+     * These cases did not fail, even when the previous five did:
+     * 8.98846567431158E307 % 1.29516E-318 = 2.53E-321
+     * (0x7fe0000000000000L % 0x000000000003ffffL)
+     *
+     * 1.7976931348623157E308 % 2.590327E-318 = 0.0
+     * (0x7fefffffffffffffL % 0x0000000000080000L)
+     *
+     * 1.7976931348623157E308 % 1.060965516E-314 = 9.35818525E-315
+     * (0x7fefffffffffffffL % 0x000000007ffeffffL)
+     *
+     */
+
+    static double[][] bad = new double[][] {
+            /*
+             * These hex numbers correspond to the base-10 doubles in the
+             * comment above; this can be checked by observing the output
+             * of testWithPrint.
+             */
+            new double[] { Double.longBitsToDouble(0x7FE0000000000000L),
+                    Double.longBitsToDouble(0x0000000000040000L) },
+            new double[] { Double.longBitsToDouble(0x7FEFFFFFFFFFFFFFL),
+                    Double.longBitsToDouble(0x000000000007FFFFL) },
+            new double[] { Double.longBitsToDouble(0x7FEFFFFFFFFFFFFFL),
+                    Double.longBitsToDouble(0x000000007FFFFFFFL) },
+            new double[] { Double.longBitsToDouble(0x7FEFFFFFFFFFFFFFL),
+                    6.767486E-317 },
+            new double[] { Double.longBitsToDouble(0x7FEFFFFFFFFFFFFFL),
+                    7.528725E-318 }, };
+
+    static double[][] good = new double[][] {
+            new double[] { Double.longBitsToDouble(0x7FE0000000000000L),
+                    Double.longBitsToDouble(0x000000000003FFFFL) },
+            new double[] { Double.longBitsToDouble(0x7FEFFFFFFFFFFFFFL),
+                    Double.longBitsToDouble(0x0000000000080000L) },
+            new double[] { Double.longBitsToDouble(0x7FEFFFFFFFFFFFFFL),
+                    Double.longBitsToDouble(0x000000007FFEFFFFL) }, };
+
+    public static void main(String[] args) throws InterruptedException {
+        int N = 10000;
+        testWithPrint();
+        for (int i = 0; i < N; i++)
+            testStrict();
+        for (int i = 0; i < N; i++)
+            test();
+        Thread.sleep(1000); // pause to let the compiler work
+        for (int i = 0; i < 10; i++)
+            testStrict();
+        for (int i = 0; i < 10; i++)
+            test();
+    }
+
+    public strictfp static void testWithPrint() {
+        for (double[] ab : bad) {
+            double a = ab[0];
+            double b = ab[1];
+            double mod = a % b;
+            System.out.println("" + a + "("+toHexRep(a)+") mod " +
+                                    b + "("+toHexRep(b)+") yields " +
+                                    mod + "("+toHexRep(mod)+")");
+        }
+
+        for (double[] ab : good) {
+            double a = ab[0];
+            double b = ab[1];
+            double mod = a % b;
+            System.out.println("" + a + "("+toHexRep(a)+") mod " +
+                                    b + "("+toHexRep(b)+") yields " +
+                                    mod + "("+toHexRep(mod)+")");
+        }
+    }
+
+    public strictfp static void testStrict() {
+        for (double[] ab : bad) {
+            double a = ab[0];
+            double b = ab[1];
+            double mod = a % b;
+            check(mod);
+        }
+
+        for (double[] ab : good) {
+            double a = ab[0];
+            double b = ab[1];
+            double mod = a % b;
+            check(mod);
+        }
+    }
+
+    public static void test() {
+        for (double[] ab : bad) {
+            double a = ab[0];
+            double b = ab[1];
+            double mod = a % b;
+            check(mod);
+        }
+
+        for (double[] ab : good) {
+            double a = ab[0];
+            double b = ab[1];
+            double mod = a % b;
+            check(mod);
+        }
+    }
+
+    static String toHexRep(double d) {
+        return "0x" + Long.toHexString(Double.doubleToRawLongBits(d)) + "L";
+    }
+
+    static void check(double mod) {
+        if (Double.isNaN(mod)) {
+            throw new Error("Saw a NaN, fail");
+        }
+    }
+}