diff test/compiler/6800154/Test6800154.java @ 567:bbef4344adb2

6800154: Add comments to long_by_long_mulhi() for better understandability Summary: This patch adds a comment pointing to the Hacker's Delight version of the algorithm plus a verbatim copy of it. Furthermore it adds inline comments. Reviewed-by: kvn, jrose
author twisti
date Fri, 13 Feb 2009 09:09:35 -0800
parents
children c18cbe5936b8
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/compiler/6800154/Test6800154.java	Fri Feb 13 09:09:35 2009 -0800
@@ -0,0 +1,109 @@
+/*
+ * Copyright 2009 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+/**
+ * @test
+ * @bug 6800154
+ * @summary Add comments to long_by_long_mulhi() for better understandability
+ *
+ * @run main/othervm -Xcomp -XX:CompileOnly=Test6800154.divcomp Test6800154
+ */
+
+import java.net.URLClassLoader;
+
+public class Test6800154 implements Runnable {
+    static final long[] DIVIDENDS = {
+        0,
+        1,
+        2,
+        1423487,
+        4444441,
+        4918923241323L,
+        -1,
+        -24351,
+        0x3333,
+        0x0000000080000000L,
+        0x7fffffffffffffffL,
+        0x8000000000000000L
+    };
+
+    static final long[] DIVISORS = {
+        1,
+        2,
+        17,
+        12342,
+        24123,
+        143444,
+        123444442344L,
+        -1,
+        -2,
+        -4423423234231423L,
+        0x0000000080000000L,
+        0x7fffffffffffffffL,
+        0x8000000000000000L
+    };
+
+    // Initialize DIVISOR so that it is final in this class.
+    static final long DIVISOR;
+
+    static {
+        long value = 0;
+        try {
+            value = Long.decode(System.getProperty("divisor"));
+        } catch (Throwable e) {
+        }
+        DIVISOR = value;
+    }
+
+    public static void main(String[] args) throws Exception
+    {
+        Class cl = Class.forName("Test6800154");
+        URLClassLoader apploader = (URLClassLoader) cl.getClassLoader();
+
+        // Iterate over all divisors.
+        for (int i = 0; i < DIVISORS.length; i++) {
+            System.setProperty("divisor", "" + DIVISORS[i]);
+            ClassLoader loader = new URLClassLoader(apploader.getURLs(), apploader.getParent());
+            Class c = loader.loadClass("Test6800154");
+            Runnable r = (Runnable) c.newInstance();
+            r.run();
+        }
+    }
+
+    public void run()
+    {
+        // Iterate over all dividends.
+        for (int i = 0; i < DIVIDENDS.length; i++) {
+            long dividend = DIVIDENDS[i];
+
+            long expected = divint(dividend);
+            long result = divcomp(dividend);
+
+            if (result != expected)
+                throw new InternalError(dividend + " / " + DIVISOR + " failed: " + result + " != " + expected);
+        }
+    }
+
+    static long divint(long a)  { return a / DIVISOR; }
+    static long divcomp(long a) { return a / DIVISOR; }
+}