Usage of shuJIT

last-modified: Jul 12 14:05 2001 JST

This page explains the method of installation and usage.

Installation (to JDK 1.2 and later)
Installation (to JDK 1.1.X)
Usage
Confirmation of running
Options to shuJIT

Installation (to JDK 1.2 and later)

Place the shared library libshujit.so on the following path:

<JDK installation path>/jre/lib/i386/

Installation (to JDK 1.1.X)

Place the shared library libshujit.so on any path in the followings.

The path in the environment variable LD_LIBRARY_PATH
<JDK installation path>/lib/<processor name>/<thread library name>/
ex. /usr/local/jdk1.1.8/lib/i686/green_threads/

Usage

There are some methods to utilize JIT compiler.

Specify an option to `java`, `jre` command.

Give the option

-Djava.compiler=shujit

i.e. type

% java -Djava.compiler=shujit <your class name>

Set environment variable.

We can avoid typing a long command such as -Djava... by setting an environment variable JAVA_COMPILER to `shujit'.

If you use C shell compliants (csh, tcsh), type

% setenv JAVA_COMPILER shujit

If you use bourne shell compliants (sh, ksh, zsh), type

% export JAVA_COMPILER=shujit

We can write this configuration in run command file of your shell (ex. .cshrc, .bashrc, .profile).

Confirmation of running

We'll see this message if the JIT compiler runs:

  shuJIT  for Sun Classic VM/x86  by Kazuyuki Shudo

Options to shuJIT

The JIT compiler receives options via an environment variable JAVA_COMPILER_OPT. Options can be concatenated with comma`,'.

The following options is provided.

quiet: The JIT compiler don't show start up message `shuJIT ...'.
igndisable: Ignore java.lang.Compiler#disable(), enable() which stop and resume compiling.
outcode: JIT writes generated native code of each methods to the file `code-<class_name>#<method_name>.S'.; You can assemble (gcc -c foo.S) and disassemble (objdump -d foo.o) to see assembly code.
codesize: JIT writes numeral attributes, the number and the size of bytecode instructions and the size of generated code, to the file `jit_codesize'
cmplatload: All methods of a class is compiled when the class is loaded into the JVM.
cmplclinit: Compile class initializers (ex. static {...}) which aren't compiled usually.
systhreshold=<a decimal number> (0.7.0 and posterior): Compile the method which is provided by JDK when it is called $lt;a number$gt; times.; The default value is 10.
userthreshold=<a decimal number> (0.7.0 and posterior): Compile the method which is provided by users when it is called $lt;a number$gt; times.; The default value is 1.
inlinemaxlen=<a decimal number>: Inline the method if it is shorter than this value. This value is expressed in the length of internal instructions, which is about the number of bytecode instructions + 5 or 6 + something. The default value is 20.
inlinedepth=<a decimal number>: The depth where recursive inlining is performed. The default value is 2.
ignstrictfp: Ignore strictfp modifiers. Every floating-point calculation is not FP-strict.; Default behavior of shuJIT is considering strictfp modifiers.
frcstrictfp: Force strictfp semantics on every method.
sched_fifo: Set the scheduling policy of the JVM process as FIFO (SCHED_FIFO).; cf. % man sched_setscheduler
sched_rr: Set the scheduling policy of the JVM process as round robin (SCHED_RR).
codedb: Save compiled codes in a database file named shujit-code.{db,page},; and restore the saved codes into JVM instead of compilation.

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