Trying to merge java.lang.Float, java.lang.Double with Classpath -- help wanted
Dalibor Topic
robilad@kaffe.org
Mon Sep 22 11:50:00 GMT 2003
Andrew Haley wrote:
> Nathanael Nerode writes:
> > >They are only GCJ-specific because they use CNI. There is nothing that
> > >is specific to any given VM implementation, ie a JNI implementation in
> > >classpath should work anywhere.
> >
> > They depend on the bit encoding of doubles and floats. This is not
> > specified on the Java Virtual Machine specification;
>
> Yes it is; the Java VM requires IEEE-754.
>
> http://java.sun.com/docs/books/vmspec/2nd-edition/html/Concepts.doc.html#33377
Yep, and the underlying C native code [1] may not be offering IEEE-754,
as the ISO C standard doesn't specify a floating format, AFAIK. So you
*may* need some abstraction/conversison layer between the OS
representation of floating points and Java's representation of floating
points.
At least if you're interested in portability to non-IEEE754 machines ;)
That's why I like Classpath's design better, but then, I'm not a gcj
developer yet, maybe next year ;)
cheers,
dalibor topic
[1] If you are using C, of course. Things may be different for other
languages.
More information about the Java-patches
mailing list