Re: Trying to merge java.lang.Float, java.lang.Double with Classpath-- help wanted

[Andrew Haley <aph at redhat dot com>]

Dalibor Topic writes:
 > 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.

Let's cross that particular bridge when we come to it.

 > 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 ;)

Well, we all have to get used to the idea that gcj and Classpath don't
have exactly the same goals, so in some cases there will be
divergence.

Andrew.