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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

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 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

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 * 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.

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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("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(" (" + 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 = ((long)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);

  }

}