Re: Possible Loss of Precision - not caused by type conversion

From:

Lew <lew@lewscanon.nospam>

Newsgroups:

comp.lang.java.programmer

Date:

Sat, 07 Jul 2007 18:01:06 -0400

Message-ID:

<PYqdnfNxeYmnkA3bnZ2dnUVZ_vqpnZ2d@comcast.com>

Lew wrote:

If you have an array of long with 2 billion entries it will occupy
over 16GB of heap - the issue of your index will be moot.

Patricia Shanahan wrote:

Not if you have a 64 bit JVM and a server with a large memory.

(and -Xmx configured accordingly)

Good catch - even though I have a 64b machine for my own development I keep
forgetting what a huge difference it makes. I found
<http://msdn2.microsoft.com/en-us/vstudio/aa700838.aspx>
which examines the effect objectively for both .NET and Java (IBM WebSphere
with their JVMs).

I agree that an argument can be made that it was shortsighted of Sun to limit
array indexes to int, but the fact is that they did and it is documented in
the JLS. Does Sun have a plan to change this, or to introduce a large-array
type to Java? A sparse-array type?

I foresee when people will superciliously disparage those who once thought 64
bits provided enough address range, along the lines of those now parroting the
"and you thought 640K is enough" canard.

--
Lew