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Java example source code file (TestMultiplyLongHiZero.java)

This example Java source code file (TestMultiplyLongHiZero.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

not, numberformatexception, runtimeexception, testmultiplylonghizero, trigger

The TestMultiplyLongHiZero.java Java example source code

/*
 * Copyright 2010 Google, 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 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 6921969
 * @summary Tests shorter long multiply sequences when the high 32 bits of long operands are known to be zero on x86_32
 * @run main/othervm -Xbatch -XX:-Inline -XX:CompileOnly=.testNormal,.testLeftOptimized,.testRightOptimized,.testOptimized,.testLeftOptimized_LoadUI2L,.testRightOptimized_LoadUI2L,.testOptimized_LoadUI2L TestMultiplyLongHiZero
 */

// This test must run without any command line arguments.

public class TestMultiplyLongHiZero {

  private static void check(long leftFactor, long rightFactor, long optimizedProduct, long constantProduct) {
    long normalProduct = leftFactor * rightFactor; // unaffected by the new optimization
    if (optimizedProduct != constantProduct || normalProduct != constantProduct) {
      throw new RuntimeException("Not all three products are equal: " +
                                 Long.toHexString(normalProduct) + ", " +
                                 Long.toHexString(optimizedProduct) + ", " +
                                 Long.toHexString(constantProduct));
    }
  }

  private static int initInt(String[] args, int v) {
    if (args.length > 0) {
      try {
        return Integer.valueOf(args[0]);
      } catch (NumberFormatException e) { }
    }
    return v;
  }

  private static final long mask32 = 0x00000000FFFFFFFFL;

  private static void testNormal(int leftFactor, int rightFactor, long constantProduct) {
    check((long) leftFactor,
          (long) rightFactor,
          (long) leftFactor * (long) rightFactor, // unaffected by the new optimization
          constantProduct);
  }

  private static void testLeftOptimized(int leftFactor, int rightFactor, long constantProduct) {
    check((leftFactor & mask32),
          (long) rightFactor,
          (leftFactor & mask32) * (long) rightFactor, // left factor optimized
          constantProduct);
  }

  private static void testRightOptimized(int leftFactor, int rightFactor, long constantProduct) {
    check((long) leftFactor,
          (rightFactor & mask32),
          (long) leftFactor * (rightFactor & mask32), // right factor optimized
          constantProduct);
  }

  private static void testOptimized(int leftFactor, int rightFactor, long constantProduct) {
    check((leftFactor & mask32),
          (rightFactor & mask32),
          (leftFactor & mask32) * (rightFactor & mask32), // both factors optimized
          constantProduct);
  }

  private static void testLeftOptimized_LoadUI2L(int leftFactor, int rightFactor, long constantProduct, int[] factors) {
    check((leftFactor & mask32),
          (long) rightFactor,
          (factors[0] & mask32) * (long) rightFactor, // left factor optimized
          constantProduct);
  }

  private static void testRightOptimized_LoadUI2L(int leftFactor, int rightFactor, long constantProduct, int[] factors) {
    check((long) leftFactor,
          (rightFactor & mask32),
          (long) leftFactor * (factors[1] & mask32), // right factor optimized
          constantProduct);
  }

  private static void testOptimized_LoadUI2L(int leftFactor, int rightFactor, long constantProduct, int[] factors) {
    check((leftFactor & mask32),
          (rightFactor & mask32),
          (factors[0] & mask32) * (factors[1] & mask32), // both factors optimized
          constantProduct);
  }

  private static void test(int leftFactor, int rightFactor,
                           long normalConstantProduct,
                           long leftOptimizedConstantProduct,
                           long rightOptimizedConstantProduct,
                           long optimizedConstantProduct) {
    int[] factors = new int[2];
    factors[0] = leftFactor;
    factors[1] = rightFactor;
    testNormal(leftFactor, rightFactor, normalConstantProduct);
    testLeftOptimized(leftFactor, rightFactor, leftOptimizedConstantProduct);
    testRightOptimized(leftFactor, rightFactor, rightOptimizedConstantProduct);
    testOptimized(leftFactor, rightFactor, optimizedConstantProduct);
    testLeftOptimized_LoadUI2L(leftFactor, rightFactor, leftOptimizedConstantProduct, factors);
    testRightOptimized_LoadUI2L(leftFactor, rightFactor, rightOptimizedConstantProduct, factors);
    testOptimized_LoadUI2L(leftFactor, rightFactor, optimizedConstantProduct, factors);
  }

  public static void main(String[] args) {
    for (int i = 0; i < 100000; ++i) { // Trigger compilation
      int i0 = initInt(args, 1);
      int i1 = initInt(args, 3);
      int i2 = initInt(args, -1);
      int i3 = initInt(args, 0x7FFFFFFF);
      test(i0, i1, 3L, 3L, 3L, 3L);
      test(i0, i2, -1L, -1L, 0xFFFFFFFFL, 0xFFFFFFFFL);
      test(i0, i3, 0x7FFFFFFFL, 0x7FFFFFFFL, 0x7FFFFFFFL, 0x7FFFFFFFL);
      test(i1, i2, -3L, -3L, 0x2FFFFFFFDL, 0x2FFFFFFFDL);
      test(i1, i3, 0x17FFFFFFDL, 0x17FFFFFFDL, 0x17FFFFFFDL, 0x17FFFFFFDL);
      test(i2, i3, 0xFFFFFFFF80000001L, 0x7FFFFFFE80000001L,
           0xFFFFFFFF80000001L, 0x7FFFFFFE80000001L);
    }
  }
}

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