Re: Arithmetic overflow checking

From:

Patricia Shanahan <pats@acm.org>

Newsgroups:

comp.lang.java.programmer

Date:

Thu, 07 Jul 2011 14:53:50 -0700

Message-ID:

<l_qdnfmZ-4tpt4vTnZ2dnUVZ_sqdnZ2d@earthlink.com>

On 7/7/2011 2:34 PM, Gene Wirchenko wrote:

On Wed, 06 Jul 2011 22:41:54 -0700, Roedy Green
<see_website@mindprod.com.invalid> wrote:

On Wed, 6 Jul 2011 08:35:01 -0700 (PDT), rop rop<rop049@gmail.com>
wrote, quoted or indirectly quoted someone who said :

If I want to have arithmetic-overflow checking in all parts of an
application,
what is the most practical, simple, efficient way to achieve this?
Id like to clutter the code as little a possible...
Is there any way to instruct the JVM to include it?

the JVM does not detect it because most hardware does not. You pretty
well have to use long instead of int and mask off and check overflow.

Which hardware does not have overflow detection?

x86 does have an overflow flag.

So far, every instruction set I have studied has included overflow
detection at the hardware level.

I think the problem is more a matter of software knowing when overflow
should and should not be treated as an error.

Patricia