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  1. JDK
  2. JDK-4085020

error of division of min integer by -1

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      Name: laC46010 Date: 10/09/97



      JDK1.1.4 with JIT v. 57 fails to pass the following JCK-114a test case:

      lang/EXPR/expr275/expr27501/expr27501.html

      because 0x80000000/-1 incorrectly throws "java.lang.ArithmeticException: / by zero"

      It's particularly strange that the test is passed on WinNT.

      JLS, [p. 352, 15.16.2 Division Operator / ] says:

      > There is one special case that does not satisfy this rule: if the
      > dividend is the negative integer of largest possible magnitude for its
      > type, and the divisor is -1, then integer overflow occurs and the
      > result is equal to the dividend. Despite the overflow, no exception is
      > thrown in this case. On the other hand, if the value of the divisor in
      > an integer division is 0, then an ArithmeticException is thrown.


      An example below (which is modified version of the JCK test)
      produces the following output:
      --------------output----------------
      before
      catched: java.lang.ArithmeticException: / by zero - / by zero
      failed 5
      ------------------------------------

      --------------modified expr27501.java--------------------
      //File: @(#)expr27501.java 1.1 96/10/06
      //Copyright 10/06/96 Sun Microsystems, Inc. All Rights Reserved


      //package javasoft.sqe.tests.lang.expr275.expr27501;


      import java.io.PrintStream;
      import java.lang.Exception;


      public class expr27501
      {
      public static void main(String args[])
      {
      System.exit(run(args, System.out) + 95/*STATUS_TEMP*/);
      }
       
      public static int run(String args[], PrintStream out)
      {
      int i=5, j = 0x80000000, k = -1;
      boolean was_exception = false;

      try {
      out.println("before");
      i = j / k;
      out.println("after");
      } catch (Exception e) {
      was_exception = true;
      out.println("catched: " + e + " - " + e.getMessage());
      }
      if (was_exception) {
      out.println("failed " + i);
      return 2;
      } else {
      out.println("passed");
      return 0;
      }
      }
      }

      ---------------------------------------------------------

      ======================================================================

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            Assignee:
            dviswanasunw Deepa Viswanathan (Inactive)
            Reporter:
            leosunw Leo Leo (Inactive)
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