JDK build questions

[Martin Buchholz]

On Fri, Apr 16, 2010 at 10:24, David Dabbs <dmdabbs at gmail.com> wrote:
>
> Hello. My apologies if these questions are OT for this list.
>
> On the premise that building my own binaries could yield performance
> improvements versus the Sun(Oracle)-provided binaries I've decided to
> tinker with building from source.
>
> * My first question is "Is this a reasonable premise?"

Unlikely, since the code that really counts is generated
by the JIT at runtime.  The most performance-sensitive
native code is probably the GC.

> * If so, is it possible to build using Intel's compiler?

You'll probably need to port, and to modify
some underlying assumptions.
I don't recommend it.

> * Now that Visual Studio 2010 has been released will there be an
>  option to use it to build the JDK under Windows?
>
> * If I build on a recent Xeon with "gcc -march=native ..." would one expect
>  to see performance differences versus the Sun(Oracle)-provided binary to
>  justify the effort?
>
> * I have recently been tinkering with Intel's memory allocator and TCMalloc,
> etc.
>  Would compiling with these be expected to a) even work and b) yield perf
>  improvements worth the effort.

The JDK doesn't malloc much.

I would welcome having more choice of compilers,
but I think it's a bigger project than it looks.

The IcedTea project has a "configure" infrastructure,
that would be more accommodating to your goals.

Martin