Mercurial > jdk8-mips64-public > hotspot / file revision

 /*

  * 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

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  */

 /**

  * @test

  * @bug 6603011

  * @summary long/int division by constant

  *

  * @run main/othervm -Xcomp -Xbatch -XX:-Inline Test

  */

 //

 // -XX:-Inline is essential to this test so that verification functions

 //   divi, modi, divl and modl generate "plain" divides.

 // -Xcomp -Xbatch are also useful to ensure the full range of

 //   dividend and divisor combinations are tested

 //

 import java.net.*;

 class s {

   static int  divi(int  dividend, int  divisor) { return dividend / divisor; }

   static int  modi(int  dividend, int  divisor) { return dividend % divisor; }

   static long divl(long dividend, long divisor) { return dividend / divisor; }

   static long modl(long dividend, long divisor) { return dividend % divisor; }

 }

 public class Test implements Runnable {

   // Report verbose messages on failure; turn off to suppress

   // too much output with gross numbers of failures.

   static final boolean VERBOSE = true;

   // Initailize DIVISOR so that it is final in this class.

   static final int DIVISOR;

   static {

     int value = 0;

     try {

       value = Integer.decode(System.getProperty("divisor"));

     } catch (Throwable e) {

     }

     DIVISOR = value;

   }

   // The methods of interest. We want the JIT to compile these

   // and convert the divide into a multiply.

   public int divbyI (int dividend)   { return dividend / DIVISOR; }

   public int modbyI (int dividend)   { return dividend % DIVISOR; }

   public long divbyL (long dividend) { return dividend / DIVISOR; }

   public long modbyL (long dividend) { return dividend % DIVISOR; }

   public int divisor() { return DIVISOR; }

   public boolean checkI (int dividend) {

     int quo = divbyI(dividend);

     int rem = modbyI(dividend);

     int quo0 = s.divi(dividend, divisor());

     int rem0 = s.modi(dividend, divisor());

     if (quo != quo0 || rem != rem0) {

       if (VERBOSE) {

         System.out.println("Computed: " + dividend + " / " + divisor() + " = " +

                            quo  + ", " + dividend + " % " + divisor() + " = " + rem );

         System.out.println("expected: " + dividend + " / " + divisor() + " = " +

                            quo0 + ", " + dividend + " % " + divisor() + " = " + rem0);

         // Report sign of rem failure

         if (rem != 0 && (rem ^ dividend) < 0) {

           System.out.println("  rem & dividend have different signs");

         }

         // Report range of rem failure

         if (java.lang.Math.abs(rem) >= java.lang.Math.abs(divisor())) {

           System.out.println("  remainder out of range");

         }

         // Report quo/rem identity relationship failure

         if ((quo * divisor()) + rem != dividend) {

           System.out.println("  quotien/remainder invariant broken");

         }

       }

       return false;

     }

     return true;

   }

   public boolean checkL (long dividend) {

     long quo = divbyL(dividend);

     long rem = modbyL(dividend);

     long quo0 = s.divl(dividend, divisor());

     long rem0 = s.modl(dividend, divisor());

     if (quo != quo0 || rem != rem0) {

       if (VERBOSE) {

         System.out.println("  " + dividend + " / " + divisor() + " = " +

                            quo + ", " + dividend + " % " + divisor() + " = " + rem);

         // Report sign of rem failure

         if (rem != 0 && (rem ^ dividend) < 0) {

           System.out.println("  rem & dividend have different signs");

         }

         // Report range of rem failure

         if (java.lang.Math.abs(rem) >= java.lang.Math.abs(divisor())) {

           System.out.println("  remainder out of range");

         }

         // Report quo/rem identity relationship failure

         if ((quo * divisor()) + rem != dividend) {

           System.out.println(" (" + quo + " * " + divisor() + ") + " + rem + " != "

                              + dividend);

         }

       }

       return false;

     }

     return true;

   }

   public void run() {

     // Don't try to divide by zero

     if (divisor() == 0) return;

     // Range of dividends to check. Try dividends from start to end

     // inclusive, as well as variations on those values as shifted

     // left.

     int start = -1024;

     int end = 1024;

     // Test int division using a variety of dividends.

     int wrong = 0;

     int total = 0;

     outerloop:

     for (int i = start; i <= end; i++) {

       for (int s = 0; s < 32; s += 4) {

         total++;

         int dividend = i << s;

         if (!checkI(dividend)) {

           wrong++;

           // Stop on the first failure

           // break outerloop;

         }

       }

     }

     if (wrong > 0) {

       System.out.println("divisor " + divisor() + ": " +

                          wrong + "/" + total + " wrong int divisions");

     }

     // Test long division using a variety of dividends.

     wrong = 0;

     total = 0;

     outerloop:

     for (int i = start; i <= end; i++) {

       for (int s = 0; s < 64; s += 4) {

         total++;

         long dividend = i << s;

         if (!checkL(dividend)) {

           wrong++;

           // Stop on the first failure

           // break outerloop;

         }

       }

     }

     if (wrong > 0) {

       System.out.println("divisor " + divisor() + ": " +

                          wrong + "/" + total + " wrong long divisions");

     }

   }

   // Reload this class with the "divisor" property set to the input parameter.

   // This allows the JIT to see q.DIVISOR as a final constant, and change

   // any divisions or mod operations into multiplies.

   public static void test_divisor(int divisor,

                                   URLClassLoader apploader) throws Exception {

     System.setProperty("divisor", "" + divisor);

     ClassLoader loader = new URLClassLoader(apploader.getURLs(),

                                             apploader.getParent());

     Class c = loader.loadClass("Test");

     Runnable r = (Runnable)c.newInstance();

     r.run();

   }

   public static void main(String[] args) throws Exception {

     Class cl = Class.forName("Test");

     URLClassLoader apploader = (URLClassLoader)cl.getClassLoader();

     // Test every divisor between -100 and 100.

     for (int i = -100; i <= 100; i++) {

       test_divisor(i, apploader);

     }

     // Try a few divisors outside the typical range.

     // The values below have been observed in rt.jar.

     test_divisor(101, apploader);

     test_divisor(400, apploader);

     test_divisor(1000, apploader);

     test_divisor(3600, apploader);

     test_divisor(9973, apploader);

     test_divisor(86400, apploader);

     test_divisor(1000000, apploader);

   }

 }