[EMAIL PROTECTED] wrote on 06/05/2005 10:48:29 PM:
> - The machine code concatinating technique consumes much memory. > In my experience, generated machine code is about 10 times larger > than the original instructions in Java bytecode. > > In the paper, the authors have not mentioned memory consumption of the > technique. We cannot guess how much it is precisely, but it is > possible to be a big drawback. Yes, we can say the same for the > approach taking a baseline compiler instead of an interpreter (like > Jikes RVM). Memory consumption of the baseline compiler of Jike RVM > is very interesting. It's platform dependent of course, but on IA32 isn't too horrible. For example, running SPECjvm98 we see a 6.23x expansion from the Jikes RVM baseline compiler machine code bytes over bytecode bytes. One thing to note is that a threaded interpreter would see something like a 2-4x expansion over "normal" bytecodes when it converts from bytecodes to its internal form (arrays of function pointers). So, a 6x expansion is probably only roughly 2x worse than some interpreted systems would actually see in practice. You can get this data out of Jikes RVM for your platform/program with -X:vm:measureCompilation=true. --dave
