Re: Arithmetic overflow checking

Date	2011-07-12 12:38 -0700
From	Patricia Shanahan <pats@acm.org>
Newsgroups	comp.lang.java.programmer, comp.lang.c
Subject	Re: Arithmetic overflow checking
References	(4 earlier) <pPqdnbD2qr5G7ovTnZ2dnUVZ_qednZ2d@earthlink.com> <3797038f-22d1-40b2-8c12-60db5a0976b8@t5g2000yqj.googlegroups.com> <4e1bf1bc$0$15671$4fafbaef@reader2.news.tin.it> <e7b7711c-93d5-477e-a470-21386854ff6f@j15g2000yqf.googlegroups.com> <s15p17t8vlv6sd9jknplh1eknmq7jnsgts@4ax.com>
Message-ID	<jOSdnUKE6ZMiP4HTnZ2dnUVZ_sCdnZ2d@earthlink.com> (permalink)

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On 7/12/2011 11:39 AM, Gene Wirchenko wrote:
> On Tue, 12 Jul 2011 02:22:41 -0700 (PDT), tm<thomas.mertes@gmx.at>
> wrote:
>
> [snip]
>
>> Yes, but it must be checked after every operation.
>> A hardware that triggers an interrupt, would save this
>> extra checks.
>
>       No, it would not.  The check would simply be implemented in
> hardware. It will still take time.

It would not necessarily directly take time. It could be done in
parallel with the stage that writes results back to register files, or
bypasses them to other instructions.

As has already been pointed out, there may be a tiny performance cost
because the space taken by the check logic might have been used for
something else.

Patricia

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Thread

Re: Arithmetic overflow checking tm <thomas.mertes@gmx.at> - 2011-07-10 01:47 -0700
  Re: Arithmetic overflow checking China Blue Dolls <chine.bleu@yahoo.com> - 2011-07-10 02:47 -0700
    Re: Arithmetic overflow checking pete <pfiland@mindspring.com> - 2011-07-10 06:04 -0400
      Re: Arithmetic overflow checking China Blue Dolls <chine.bleu@yahoo.com> - 2011-07-10 03:29 -0700
        Re: Arithmetic overflow checking Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-07-10 20:52 +0300
        Re: Arithmetic overflow checking pete <pfiland@mindspring.com> - 2011-07-10 23:29 -0400
    Re: Arithmetic overflow checking tm <thomas.mertes@gmx.at> - 2011-07-10 04:44 -0700
      Re: Arithmetic overflow checking "BartC" <bc@freeuk.com> - 2011-07-12 11:33 +0100
        Re: Arithmetic overflow checking tm <thomas.mertes@gmx.at> - 2011-07-12 04:17 -0700
          Re: Arithmetic overflow checking "BartC" <bc@freeuk.com> - 2011-07-12 12:33 +0100
            Re: Arithmetic overflow checking tm <thomas.mertes@gmx.at> - 2011-07-12 05:24 -0700
              Re: Arithmetic overflow checking Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-07-12 21:45 -0400
          Re: Arithmetic overflow checking Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-07-12 05:25 -0700
            Re: Arithmetic overflow checking tm <thomas.mertes@gmx.at> - 2011-07-12 10:21 -0700
              Re: Arithmetic overflow checking Thomas Boell <tboell@domain.invalid> - 2011-07-12 22:39 +0200
                Re: Arithmetic overflow checking tm <thomas.mertes@gmx.at> - 2011-07-12 14:15 -0700
                Re: Arithmetic overflow checking Keith Thompson <kst-u@mib.org> - 2011-07-12 14:18 -0700
                Re: Arithmetic overflow checking tm <thomas.mertes@gmx.at> - 2011-07-12 23:54 -0700
            Re: Arithmetic overflow checking "BartC" <bc@freeuk.com> - 2011-07-12 19:14 +0100
              Re: Arithmetic overflow checking Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-07-13 00:20 -0700
        Re: Arithmetic overflow checking markspace <-@.> - 2011-07-12 09:26 -0700
          Re: Arithmetic overflow checking Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2011-07-12 10:52 -0600
            Re: Arithmetic overflow checking Keith Thompson <kst-u@mib.org> - 2011-07-12 10:48 -0700
              Re: Arithmetic overflow checking Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2011-07-12 12:36 -0600
                Re: Arithmetic overflow checking Keith Thompson <kst-u@mib.org> - 2011-07-12 12:16 -0700
                Re: Arithmetic overflow checking Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2011-07-12 14:09 -0600
                Re: Arithmetic overflow checking Keith Thompson <kst-u@mib.org> - 2011-07-12 14:16 -0700
              Re: Arithmetic overflow checking, not so hard after all "Greg A. Woods" <woods@robohack.org> - 2011-07-12 21:52 -0700
                Re: Arithmetic overflow checking, not so hard after all Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-07-13 12:50 +0100
                Re: Arithmetic overflow checking, not so hard after all "Greg A. Woods" <woods@robohack.org> - 2011-07-13 11:10 -0700
                Re: Arithmetic overflow checking, not so hard after all Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-07-14 01:34 +0100
                Re: Arithmetic overflow checking, not so hard after all "Greg A. Woods" <woods@robohack.org> - 2011-07-19 17:10 -0700
                Re: Arithmetic overflow checking, not so hard after all Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2011-07-19 20:47 -0600
                Re: Arithmetic overflow checking, not so hard after all Keith Thompson <kst-u@mib.org> - 2011-07-19 20:23 -0700
                Re: Arithmetic overflow checking, not so hard after all Todd Carnes <toddcarnes@gmail.com> - 2011-07-20 03:48 +0000
                Re: Arithmetic overflow checking, not so hard after all Keith Thompson <kst-u@mib.org> - 2011-07-13 09:27 -0700
              Re: Arithmetic overflow checking "MikeP" <mp011011@some.org> - 2011-07-14 23:55 -0500
          Re: Arithmetic overflow checking Martin Gregorie <martin@address-in-sig.invalid> - 2011-07-12 16:54 +0000
            Re: Arithmetic overflow checking Gene Wirchenko <genew@ocis.net> - 2011-07-12 11:35 -0700
          Re: Arithmetic overflow checking tm <thomas.mertes@gmx.at> - 2011-07-12 10:13 -0700
          Re: Arithmetic overflow checking Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-07-12 21:53 -0400
        Re: Arithmetic overflow checking "MikeP" <mp011011@some.org> - 2011-07-14 23:41 -0500
          Re: Arithmetic overflow checking Gene Wirchenko <genew@ocis.net> - 2011-07-15 10:56 -0700
            Re: Arithmetic overflow checking "MikeP" <mp011011@some.org> - 2011-07-15 21:27 -0500
      Re: Arithmetic overflow checking bugbear <bugbear@trim_papermule.co.uk_trim> - 2011-07-20 09:22 +0100
        Re: Arithmetic overflow checking tm <thomas.mertes@gmx.at> - 2011-07-20 10:51 -0700
          Re: Arithmetic overflow checking gordonb.3urm7@burditt.org (Gordon Burditt) - 2011-07-20 15:39 -0500
          Re: Arithmetic overflow checking "BartC" <bc@freeuk.com> - 2011-07-21 12:12 +0100
    Re: Arithmetic overflow checking Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-07-10 09:28 -0400
      Re: Arithmetic overflow checking Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-07-10 06:52 -0700
        Re: Arithmetic overflow checking Keith Thompson <kst-u@mib.org> - 2011-07-10 14:47 -0700
        Re: Arithmetic overflow checking gordonb.u8vng@burditt.org (Gordon Burditt) - 2011-07-11 18:45 -0500
      Re: Arithmetic overflow checking "MikeP" <mp011011@some.org> - 2011-07-14 23:07 -0500
    Re: Arithmetic overflow checking Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-07-10 12:25 -0400
  Re: Arithmetic overflow checking Robert Wessel <robertwessel2@yahoo.com> - 2011-07-10 10:47 -0500
  Re: Arithmetic overflow checking Gene Wirchenko <genew@ocis.net> - 2011-07-11 07:58 -0700
    Re: Arithmetic overflow checking Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-07-11 10:48 -0700
      Re: Arithmetic overflow checking Gene Wirchenko <genew@ocis.net> - 2011-07-11 14:40 -0700
    Re: Arithmetic overflow checking tm <thomas.mertes@gmx.at> - 2011-07-11 14:54 -0700
      Re: Arithmetic overflow checking Gene Wirchenko <genew@ocis.net> - 2011-07-11 15:55 -0700
      Re: Arithmetic overflow checking Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-07-11 21:51 -0400
        Re: Arithmetic overflow checking Gene Wirchenko <genew@ocis.net> - 2011-07-11 21:31 -0700
          Re: Arithmetic overflow checking Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-07-11 23:16 -0700
          Re: Arithmetic overflow checking James Kuyper <jameskuyper@verizon.net> - 2011-07-12 06:28 -0400
          Re: Arithmetic overflow checking David Thompson <dave.thompson2@verizon.net> - 2011-07-24 22:13 -0400
  Re: Arithmetic overflow checking "io_x" <a@b.c.invalid> - 2011-07-12 09:05 +0200
    Re: Arithmetic overflow checking tm <thomas.mertes@gmx.at> - 2011-07-12 02:22 -0700
      Re: Arithmetic overflow checking "io_x" <a@b.c.invalid> - 2011-07-12 11:34 +0200
        Re: Arithmetic overflow checking Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-07-12 03:04 -0700
          Re: Arithmetic overflow checking "Greg A. Woods" <woods@robohack.org> - 2011-07-12 19:55 -0700
            Re: Arithmetic overflow checking "Greg A. Woods" <woods@robohack.org> - 2011-07-12 21:54 -0700
            Re: Arithmetic overflow checking "MikeP" <mp011011@some.org> - 2011-07-14 23:28 -0500
              Re: Arithmetic overflow checking "Greg A. Woods" <woods@robohack.org> - 2011-07-19 17:16 -0700
        Re: Arithmetic overflow checking tm <thomas.mertes@gmx.at> - 2011-07-12 03:33 -0700
        Re: Arithmetic overflow checking David Lamb <dalamb@cs.queensu.ca> - 2011-07-12 08:29 -0400
      Re: Arithmetic overflow checking "io_x" <a@b.c.invalid> - 2011-07-12 13:18 +0200
      Re: Arithmetic overflow checking Gene Wirchenko <genew@ocis.net> - 2011-07-12 11:39 -0700
        Re: Arithmetic overflow checking Patricia Shanahan <pats@acm.org> - 2011-07-12 12:38 -0700
          Re: Arithmetic overflow checking markspace <-@.> - 2011-07-12 13:20 -0700
            Re: Arithmetic overflow checking Gene Wirchenko <genew@ocis.net> - 2011-07-12 13:23 -0700
              Re: Arithmetic overflow checking Martin Gregorie <martin@address-in-sig.invalid> - 2011-07-12 21:08 +0000
                Re: Arithmetic overflow checking lewbloch <lewbloch@gmail.com> - 2011-07-12 14:48 -0700
                Re: Arithmetic overflow checking Gene Wirchenko <genew@ocis.net> - 2011-07-12 15:24 -0700
                Re: Arithmetic overflow checking lewbloch <lewbloch@gmail.com> - 2011-07-12 16:09 -0700
                Re: Arithmetic overflow checking Gene Wirchenko <genew@ocis.net> - 2011-07-13 10:38 -0700
                Re: Arithmetic overflow checking Patricia Shanahan <pats@acm.org> - 2011-07-13 11:00 -0700
                Re: Arithmetic overflow checking lewbloch <lewbloch@gmail.com> - 2011-07-13 12:16 -0700
                Re: Arithmetic overflow checking Gene Wirchenko <genew@ocis.net> - 2011-07-13 13:10 -0700
                Re: Arithmetic overflow checking markspace <-@.> - 2011-07-13 13:21 -0700
                Re: Arithmetic overflow checking Keith Thompson <kst-u@mib.org> - 2011-07-13 13:41 -0700
                Re: Arithmetic overflow checking Robert Wessel <robertwessel2@yahoo.com> - 2011-07-14 21:10 -0500
                Re: Arithmetic overflow checking "io_x" <a@b.c.invalid> - 2011-07-15 11:57 +0200
                Re: Arithmetic overflow checking Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-07-15 04:36 -0700
      Re: Arithmetic overflow checking "Greg A. Woods" <woods@robohack.org> - 2011-07-12 20:03 -0700
        Re: Arithmetic overflow checking tm <thomas.mertes@gmx.at> - 2011-07-13 00:52 -0700
          Re: Arithmetic overflow checking Patricia Shanahan <pats@acm.org> - 2011-07-13 07:45 -0700
            Re: Arithmetic overflow checking "Greg A. Woods" <woods@robohack.org> - 2011-07-13 11:28 -0700
          Re: Arithmetic overflow checking "Greg A. Woods" <woods@robohack.org> - 2011-07-13 11:15 -0700

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