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  1. JDK
  2. JDK-4205008

inlining of division by zero constants results in huge class files

    Details

    • Subcomponent:
    • CPU:
      sparc
    • OS:
      solaris_2.5.1

      Description



      Name: laC46010 Date: 01/22/99



      The following 516Byte example is compiled by javac (versions 1.2.2b, 1.2fcs)
      into 2.6Mb classfile. See also bug #4184242 (Synopsis: poor performance of
      constant expression calculation)

      Test example and javac diagnostics follow:
      -------------------------------------------------------
      novo35% cat test.java
      class test {
          public static void main(String[] argv) {
              final int i0 = 1 / 0;
              final int i1 = i0 / i0;
              final int i2 = i1 / i1;
              final int i3 = i2 / i2;
              final int i4 = i3 / i3;
              final int i5 = i4 / i4;
              final int i6 = i5 / i5;
              final int i7 = i6 / i6;
              final int i8 = i7 / i7;
              final int i9 = i8 / i8;
              final int j0 = i9 / i9;
              final int j1 = j0 / j0;
              final int j2 = j1 / j1;
              final int j3 = j2 / j2;
              final int j4 = j3 / j3;
              final int j5 = j4 / j4;
              final int j6 = j5 / j5;
              final int j7 = j6 / j6;
          }
      }

      novo35% java -version
      java version "1.2.2"
      Classic VM (build JDK-1.2.2-C, green threads, sunwjit)
      novo35% javac -J-mx96M test.java
      test1.java:11: This code requires generating a method with more than 64K bytes. Virtual
      machines may refuse the resulting class file.
              final int i8 = i7 / i7;
                                ^
      1 warning
      novo35% java -verify test
      Exception in thread "main" java.lang.ClassFormatError: test (Code of a method longer than
      65535 bytes)
              at java.lang.ClassLoader.defineClass0(Native Method)
              at java.lang.ClassLoader.defineClass(Compiled Code)
              at java.security.SecureClassLoader.defineClass(Compiled Code)
              at java.net.URLClassLoader.defineClass(Compiled Code)
              at java.net.URLClassLoader.access$1(Compiled Code)
              at java.net.URLClassLoader$1.run(Compiled Code)
              at java.security.AccessController.doPrivileged(Native Method)
              at java.net.URLClassLoader.findClass(Compiled Code)
              at java.lang.ClassLoader.loadClass(Compiled Code)
              at sun.misc.Launcher$AppClassLoader.loadClass(Compiled Code)
              at java.lang.ClassLoader.loadClass(Compiled Code)
      -------------------------------------------------------

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

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            • Assignee:
              wmaddoxsunw William Maddox (Inactive)
              Reporter:
              leosunw Leo Leo (Inactive)
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              • Created:
                Updated:
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