How Can I Inspect the JIT-Compiled Native Code in the JVM?

Inspecting JIT-Compiled Code in the JVM

Understanding the native code generated by the Just-In-Time (JIT) compiler is crucial for performance analysis and optimization in Java applications. This article explores methods for examining the JIT-compiled code in a Java Virtual Machine (JVM).

General Usage

To view the native code generated by the JIT, run the JVM with the following options:

-XX:+UnlockDiagnosticVMOptions -XX:+PrintAssembly

This will output the Assembly code for the compiled methods.

Filtering on a Specific Method

You can also filter the output to display the Assembly code for a specific method using the following syntax:

-XX:+UnlockDiagnosticVMOptions -XX:CompileCommand=print,*MyClass.myMethod

Note:

• Depending on your operating system, you may need to enclose the second argument in quotes.
• If the method is inlined, you may miss some optimizations.

Installation on Windows

For Windows users, you will need to install the required libraries before using the PrintAssembly options. Instructions for this task can be found here: [hsdis-amd64.dll and hsdis-i386.dll Installation](https://mergedoc.com/q/16723387/How-to-access-hsdis-amd64-dll-and-hsdis-i386-dll-files-for-NetBeans)

Additional Options

• -XX:PrintAssemblyOptions=intel: Specify Intel Assembly syntax instead of AT&T.

Benefits of Viewing JIT-Compiled Code

Inspecting JIT-compiled code allows you to:

• Analyze performance hotspots.
• Identify potential bottlenecks.
• Optimize code for specific hardware architectures.
• Compare code generation across different JIT compilers.
• Gain insights into the inner workings of the Java runtime environment.

By understanding the code produced by the JIT compiler, you can optimize Java applications and achieve better performance.

The above is the detailed content of How Can I Inspect the JIT-Compiled Native Code in the JVM?. For more information, please follow other related articles on the PHP Chinese website!