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All Power to OpenJDK:
Porting the JDK to PowerPC and AIX

Steve Pool, IBM & Volker Simonis, SAP


The SAP JVM supports Java 1.4, 5, 6, 7 and runs on 15 platforms:

..and we provide support for any SAP JVM version until the end of days:)

The SAP JVM is derived from the Sun/Oracle code base:

We constantly integrate Oracle changes:

The OpenJDK Project

Announced at JavaOne 2006

SAP can't use OpenJDK directly:

It took 5 years until SAP "officially" joined the OpenJDK project:

Today, the OpenJDK is a playground and collaboration space for different implementers:

The OpenJDK Source Tree

The OpenJDK consists of two major building blocks

The HotSpot VM

The HotSpot VM first appeared in 2000 with Java 1.3 and is constantly evolving since then:

Porting the HotSpot VM - Effort

The C++Interpreter

One big challenge when porting the C++Interpreter is that you first have implement
a Macro Assembler for your architecture!

The C2 "Server" JIT Compiler

The C2 "Server" JIT Compiler is the biggest (and most complicated) part of the HotSpot VM.
It consists of three main parts:

For every new architecture the corresponding AD file has to be written which means:

Platform Specifics

The PowerPC architecture:

The AIX operating system:

Porting-Lessons Learned

During the last years we've ported HotSpot to quite some new platforms and we learned:

"Convergent Evolution" is evil:

Status and Next Steps

Complete the porting of our port:

Integrate our port as fast as possible into the main code line:


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