Scala 2.7.4-rc1 released Thursday, Apr 16 2009 

Scala 2.7.4-rc1 has been released. It incorporates a few important fixes related to serialization of anonymous functions and generation of Java generics, but the big change is the improved Scala plugin Scala IDE for Eclipse. This means that my backport is now obsolete.

The announcement contains all the juicy information.


Twitter Wednesday, Apr 15 2009 

After resisting for a while, I have started using twitter. It’s useful to be able to contribute to some of the “conversations” that go on over there, even if I am not particularly fond of the character limit.

Load unsigned and better Compressed Oops Friday, Apr 3 2009 

The HotSpot engineers are constantly working on improving performance. I noticed two interesting commits recently:

Vladimir Kozlov improved Compressed Oops so that it doesn’t need to do encoding/decoding if the heap is smaller than 4GB and to reduce branches/checks if the heap is between 4GB and 32GB. The end result is that 64-bit now surpasses 32-bit performance in more situations. See my entry about Compressed Oops if you don’t know what I’m talking about. :)

Christian Thalinger added support for load unsigned in the -server JIT. This means that things like bytearray[i] & 0xFF and intarray[i] & 0xFFFFFFFF (necessary since JVM bytecode doesn’t support unsigned types) can be transformed into load unsigned operations to avoid the performance penalty. This can make a decent difference in some cases (e.g. charset operations).