LLVM includes the JIT that can be used to speed up OpenJDK on all platforms that currently only have support by the platform independent Zero C++ hotspot port.
The JIT in LLVM have been redesigned from the ground up to use the same code path ways as used by the static compilation in LLVM by using the new MCJIT that in turn are based on the new direct Machine Code emission back-end. LLVM will over time drop support for the old “classic” jello-JIT.
OpenJDK Shark + LLVM 3.0 patches exist on zero-dev
I have posted some LLVM 3.0 patches to zero-dev that allows OpenJDK Shark to be built using this new MCJIT. Grab them all at: http://mail.openjdk.java.net/pipermail/zero-dev/2011-August/thread.html
Builds and testers are needed for MIPS, PPC and ARM
Shark are known to work stable on X86 hardware where all parts of LLVM have great community support. For all other architectures please check out the LLVM Target Feature Matrix.
According to this Target Feature Matrix table, MIPS JIT support are now GREEN! MIPS devs should try the OpenJDK + Shark + LLVM 3.0 combination, it could turn out to be really good. If you have a spare MIPS machine that are online 24/7 do consider adding it to the LLVM and IcedTea buildbot network!
For ARM the MACH-o JIT backend are supposed to be working, testers of OpenJDK + Shark + LLVM 3.0 on darwin based platforms like the iPhone and iPad please step forward, this combination looks to be working, at least on paper.
All ARM Linux users have to wait until the ELF MCJIT are stable before we can expect to run Shark using LLVM 3.0 and later.
PPC testers are also needed, LLVM support for PPC have been 90% good in the past.. it could be all broken or all working, no-one really know at least the LLVM darwin PPC buildbot shows some green lights but we currently do not have any IcedTea PPC buildbots to check if Shark + PPC work at all.