Okay, that helps.

I'm not a compiler expert but here's a couple factoids: 1) we're always working to improve performance, 2) the compiler team is always working on improving the compiler (fix bugs etc), 3) the generated byte codes can either exhibit certain bugs or performance gains/losses ... hence, hence I expect/assume the byte codes output to vary somewhat from release to relase.

I can't say how much or what specifically that would be.

- David

Caster wrote:

Greg Tassone wrote:

I think this statement is a little too broad to be considered correct.
The compiler can (and often does) make changes to the resulting binaries
that may be VM-level specific (e.g., targeted for a 1.5 VM).  Consider
the "-target" argument for javac, for example, which "Allow[s] javac to
use 1.5 specific features in the libraries and virtual
machine" (http://java.sun.com/j2se/1.5.0/docs/relnotes/features.html ).

David Herron wrote:

er... Caster, the bytecode does vary based on the compiler.  And the
class file format has varied a small amount from release to release with
the 1.5 class file format being the most different.

This is, as I understand it, the crux of the problem you guys are seeing
with adopting 1.5 ... yes?


Sorry, I wasn't clear enough. I didn't mean the class file format which
is indeed different and causes problems. I was trying to ask if there
are any (the compiled bytecode performance?) gains of using 1.5 compiler
for 1.4 source (without specifying --source and --target 1.4). This
source won't use any 1.5 specific features, but you say the bytecode
still can somehow?

Caster