Re: Odd compiler behaviour?

From	Rainer Weikusat <rweikusat@talktalk.net>
Newsgroups	comp.unix.programmer
Subject	Re: Odd compiler behaviour?
Date	2016-03-10 15:57 +0000
Message-ID	<87shzytjex.fsf@doppelsaurus.mobileactivedefense.com> (permalink)
References	<nb3t47$19o6$1@gioia.aioe.org> <nbmt79$127e$1@gioia.aioe.org> <20160309114028.390@kylheku.com> <nbrf41$1p2f$1@gioia.aioe.org> <20160310073739.787@kylheku.com>

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Kaz Kylheku <330-706-9395@kylheku.com> writes:
> On 2016-03-10, spud@potato.field <spud@potato.field> wrote:
>> Kaz Kylheku <330-706-9395@kylheku.com> wrote:

[...]

>>>  (1 + 2) + 3.0  // leftmost + is integer addition
>>>
>>>  1 + (2 + 3.0)  // leftmost + is floating-addition
>>
>> I know you're trying your best, but your argument is really not working. Its 
>> still doing addition. It hasn't suddenly decided to write the numbers out to
>> a stream instead of adding. 
>
> It's overloaded; it's doing different kinds of addition.
>
> Without overloading, you need a different + operator for
> floating-point.

The sole reason why these are "different kinds of addition" is that
'usual CPUs' have special support for performing (limited width) integer
arithmetic as that's much faster than  'always use
floating-point'. While this is (again) also the case in math as + as
defined on the set of real numbers is rather different from + as used in
modular arithmetic (eg, defined on the residue module 65536), that's not
consistent with the 'naive view' on this issue were + means "add two
numbers".

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Odd compiler behaviour? spud@potato.field - 2016-03-01 11:06 +0000
  Re: Odd compiler behaviour? David Brown <david.brown@hesbynett.no> - 2016-03-01 12:57 +0100
    Re: Odd compiler behaviour? spud@potato.field - 2016-03-01 13:48 +0000
      Re: Odd compiler behaviour? David Brown <david.brown@hesbynett.no> - 2016-03-01 15:46 +0100
        Re: Odd compiler behaviour? spud@potato.field - 2016-03-01 15:08 +0000
          Re: Odd compiler behaviour? Keith Thompson <kst-u@mib.org> - 2016-03-01 08:36 -0800
            Re: Odd compiler behaviour? spud@potato.field - 2016-03-01 16:47 +0000
              Re: Odd compiler behaviour? Keith Thompson <kst-u@mib.org> - 2016-03-01 08:51 -0800
                Re: Odd compiler behaviour? spud@potato.field - 2016-03-01 17:05 +0000
                Re: Odd compiler behaviour? Geoff <geoff@invalid.invalid> - 2016-03-01 10:00 -0800
                Re: Odd compiler behaviour? Keith Thompson <kst-u@mib.org> - 2016-03-01 10:56 -0800
                Re: Odd compiler behaviour? spud@potato.field - 2016-03-02 09:42 +0000
                Re: Odd compiler behaviour? Keith Thompson <kst-u@mib.org> - 2016-03-01 10:55 -0800
                Re: Odd compiler behaviour? spud@potato.field - 2016-03-02 09:46 +0000
                Re: Odd compiler behaviour? Kaz Kylheku <330-706-9395@kylheku.com> - 2016-03-01 20:59 +0000
          Re: Odd compiler behaviour? Geoff <geoff@invalid.invalid> - 2016-03-01 10:09 -0800
  Re: Odd compiler behaviour? Richard Kettlewell <rjk@greenend.org.uk> - 2016-03-01 13:03 +0000
    Re: Odd compiler behaviour? spud@potato.field - 2016-03-01 13:54 +0000
      Re: Odd compiler behaviour? Kaz Kylheku <330-706-9395@kylheku.com> - 2016-03-01 14:15 +0000
        Re: Odd compiler behaviour? spud@potato.field - 2016-03-01 14:38 +0000
          Re: Odd compiler behaviour? Kaz Kylheku <330-706-9395@kylheku.com> - 2016-03-01 14:59 +0000
          Re: Odd compiler behaviour? Barry Margolin <barmar@alum.mit.edu> - 2016-03-01 11:20 -0500
          Re: Odd compiler behaviour? Keith Thompson <kst-u@mib.org> - 2016-03-01 08:45 -0800
            Re: Odd compiler behaviour? Richard Kettlewell <rjk@greenend.org.uk> - 2016-03-01 16:54 +0000
              Re: Odd compiler behaviour? Barry Margolin <barmar@alum.mit.edu> - 2016-03-01 13:14 -0500
                Re: Odd compiler behaviour? Richard Kettlewell <rjk@greenend.org.uk> - 2016-03-01 19:10 +0000
                Re: Odd compiler behaviour? Rainer Weikusat <rweikusat@talktalk.net> - 2016-03-01 19:26 +0000
                Re: Odd compiler behaviour? Richard Kettlewell <rjk@greenend.org.uk> - 2016-03-01 19:57 +0000
                Re: Odd compiler behaviour? Noob <root@127.0.0.1> - 2016-03-01 21:07 +0100
                Re: Odd compiler behaviour? Barry Margolin <barmar@alum.mit.edu> - 2016-03-01 15:40 -0500
                Re: Odd compiler behaviour? Richard Kettlewell <rjk@greenend.org.uk> - 2016-03-01 21:14 +0000
                Re: Odd compiler behaviour? Rainer Weikusat <rweikusat@talktalk.net> - 2016-03-01 21:20 +0000
                Re: Odd compiler behaviour? Kaz Kylheku <330-706-9395@kylheku.com> - 2016-03-01 21:59 +0000
                Re: Odd compiler behaviour? Rainer Weikusat <rweikusat@talktalk.net> - 2016-03-01 22:09 +0000
                Re: Odd compiler behaviour? Richard Kettlewell <rjk@greenend.org.uk> - 2016-03-01 23:04 +0000
                Re: Odd compiler behaviour? Barry Margolin <barmar@alum.mit.edu> - 2016-03-01 17:08 -0500
                Re: Odd compiler behaviour? Richard Kettlewell <rjk@greenend.org.uk> - 2016-03-01 22:59 +0000
                Re: Odd compiler behaviour? Barry Margolin <barmar@alum.mit.edu> - 2016-03-02 10:39 -0500
                Re: Odd compiler behaviour? Richard Kettlewell <rjk@greenend.org.uk> - 2016-03-02 16:19 +0000
                Re: Odd compiler behaviour? Barry Margolin <barmar@alum.mit.edu> - 2016-03-02 11:56 -0500
                Re: Odd compiler behaviour? Richard Kettlewell <rjk@greenend.org.uk> - 2016-03-02 17:21 +0000
                Re: Odd compiler behaviour? Barry Margolin <barmar@alum.mit.edu> - 2016-03-02 12:42 -0500
                Re: Odd compiler behaviour? Richard Kettlewell <rjk@greenend.org.uk> - 2016-03-02 18:03 +0000
                Re: Odd compiler behaviour? Keith Thompson <kst-u@mib.org> - 2016-03-02 10:41 -0800
                Re: Odd compiler behaviour? Richard Kettlewell <rjk@greenend.org.uk> - 2016-03-02 18:59 +0000
                Re: Odd compiler behaviour? Keith Thompson <kst-u@mib.org> - 2016-03-02 11:40 -0800
                Re: Odd compiler behaviour? Richard Kettlewell <rjk@greenend.org.uk> - 2016-03-02 20:05 +0000
                Re: Odd compiler behaviour? Barry Margolin <barmar@alum.mit.edu> - 2016-03-02 15:32 -0500
                Re: Odd compiler behaviour? Richard Kettlewell <rjk@greenend.org.uk> - 2016-03-02 20:51 +0000
                Re: Odd compiler behaviour? Barry Margolin <barmar@alum.mit.edu> - 2016-03-02 16:01 -0500
                Re: Odd compiler behaviour? Richard Kettlewell <rjk@greenend.org.uk> - 2016-03-02 21:10 +0000
                Re: Odd compiler behaviour? Barry Margolin <barmar@alum.mit.edu> - 2016-03-02 16:41 -0500
                Re: Odd compiler behaviour? Keith Thompson <kst-u@mib.org> - 2016-03-02 13:52 -0800
                Re: Odd compiler behaviour? Richard Kettlewell <rjk@greenend.org.uk> - 2016-03-02 22:14 +0000
                Re: Odd compiler behaviour? "James K. Lowden" <jklowden@speakeasy.net> - 2016-03-02 18:54 -0500
                Re: Odd compiler behaviour? gazelle@shell.xmission.com (Kenny McCormack) - 2016-03-02 21:30 +0000
                Re: Odd compiler behaviour? Keith Thompson <kst-u@mib.org> - 2016-03-02 13:34 -0800
                Re: Odd compiler behaviour? Jorgen Grahn <grahn+nntp@snipabacken.se> - 2016-03-05 16:48 +0000
                Re: Odd compiler behaviour? "James K. Lowden" <jklowden@speakeasy.net> - 2016-03-05 15:29 -0500
                Re: Odd compiler behaviour? Eric Sosman <esosman@comcast-dot-net.invalid> - 2016-03-05 15:41 -0500
                Re: Odd compiler behaviour? Barry Margolin <barmar@alum.mit.edu> - 2016-03-05 23:19 -0500
                Re: Odd compiler behaviour? Rainer Weikusat <rweikusat@talktalk.net> - 2016-03-06 12:44 +0000
                Re: Odd compiler behaviour? Barry Margolin <barmar@alum.mit.edu> - 2016-03-06 14:10 -0500
                Re: Odd compiler behaviour? spud@potato.field - 2016-03-07 09:53 +0000
                Re: Odd compiler behaviour? Rainer Weikusat <rweikusat@talktalk.net> - 2016-03-08 12:59 +0000
                Re: Odd compiler behaviour? spud@potato.field - 2016-03-08 13:59 +0000
                Re: Odd compiler behaviour? Rainer Weikusat <rweikusat@talktalk.net> - 2016-03-08 15:28 +0000
                Re: Odd compiler behaviour? Barry Margolin <barmar@alum.mit.edu> - 2016-03-08 10:42 -0500
                Re: Odd compiler behaviour? Kaz Kylheku <330-706-9395@kylheku.com> - 2016-03-08 17:09 +0000
                Re: Odd compiler behaviour? Rainer Weikusat <rweikusat@talktalk.net> - 2016-03-08 20:38 +0000
                Re: Odd compiler behaviour? Rainer Weikusat <rweikusat@talktalk.net> - 2016-03-08 22:15 +0000
                Re: Odd compiler behaviour? Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2016-03-08 16:21 -0700
                Re: Odd compiler behaviour? Eric Sosman <esosman@comcast-dot-net.invalid> - 2016-03-08 10:47 -0500
                Re: Odd compiler behaviour? spud@potato.field - 2016-03-08 16:04 +0000
                Re: Odd compiler behaviour? "James K. Lowden" <jklowden@speakeasy.net> - 2016-03-09 00:21 -0500
                Re: Odd compiler behaviour? spud@potato.field - 2016-03-09 09:40 +0000
                Re: Odd compiler behaviour? David Brown <david.brown@hesbynett.no> - 2016-03-09 11:31 +0100
                Re: Odd compiler behaviour? BartC <bc@freeuk.com> - 2016-03-09 11:21 +0000
                Re: Odd compiler behaviour? David Brown <david.brown@hesbynett.no> - 2016-03-09 12:57 +0100
                Re: Odd compiler behaviour? Kaz Kylheku <330-706-9395@kylheku.com> - 2016-03-09 15:32 +0000
                Re: Odd compiler behaviour? Robert Wessel <robertwessel2@yahoo.com> - 2016-03-09 11:13 -0600
                Re: Odd compiler behaviour? Les Cargill <lcargill99@comcast.com> - 2016-03-09 07:16 -0600
                Re: Odd compiler behaviour? spud@potato.field - 2016-03-09 13:19 +0000
                Re: Odd compiler behaviour? Jerry Stuckle <jstucklex@attglobal.net> - 2016-03-09 09:28 -0500
                Re: Odd compiler behaviour? Kaz Kylheku <330-706-9395@kylheku.com> - 2016-03-09 15:35 +0000
                Re: Odd compiler behaviour? Jerry Stuckle <jstucklex@attglobal.net> - 2016-03-09 11:08 -0500
                Re: Odd compiler behaviour? spud@potato.field - 2016-03-09 13:32 +0000
                Re: Odd compiler behaviour? Nicolas George <nicolas$george@salle-s.org> - 2016-03-09 13:34 +0000
                Re: Odd compiler behaviour? spud@potato.field - 2016-03-09 16:17 +0000
                Re: Odd compiler behaviour? Nicolas George <nicolas$george@salle-s.org> - 2016-03-09 16:54 +0000
                Re: Odd compiler behaviour? Kaz Kylheku <330-706-9395@kylheku.com> - 2016-03-09 19:45 +0000
                Re: Odd compiler behaviour? spud@potato.field - 2016-03-10 09:34 +0000
                Re: Odd compiler behaviour? Kaz Kylheku <330-706-9395@kylheku.com> - 2016-03-10 15:40 +0000
                Re: Odd compiler behaviour? Rainer Weikusat <rweikusat@talktalk.net> - 2016-03-10 15:57 +0000
                Re: Odd compiler behaviour? spud@potato.field - 2016-03-10 16:07 +0000
                Re: Odd compiler behaviour? "James K. Lowden" <jklowden@speakeasy.net> - 2016-03-10 14:12 -0500
                Re: Odd compiler behaviour? Rainer Weikusat <rweikusat@talktalk.net> - 2016-03-10 19:51 +0000
                Re: Odd compiler behaviour? Kaz Kylheku <330-706-9395@kylheku.com> - 2016-03-10 20:08 +0000
                Re: Odd compiler behaviour? Rainer Weikusat <rweikusat@talktalk.net> - 2016-03-10 22:31 +0000
                Re: Odd compiler behaviour? Rainer Weikusat <rweikusat@talktalk.net> - 2016-03-10 22:55 +0000
                Re: Odd compiler behaviour? "James K. Lowden" <jklowden@speakeasy.net> - 2016-03-10 17:25 -0500
                Re: Odd compiler behaviour? Rainer Weikusat <rweikusat@talktalk.net> - 2016-03-11 17:49 +0000
                Re: Odd compiler behaviour? Keith Thompson <kst-u@mib.org> - 2016-03-12 18:11 -0800
                Re: Odd compiler behaviour? spud@potato.field - 2016-03-14 09:43 +0000
                Re: Odd compiler behaviour? Kaz Kylheku <330-706-9395@kylheku.com> - 2016-03-14 15:57 +0000
                Re: Odd compiler behaviour? "James K. Lowden" <jklowden@speakeasy.net> - 2016-03-14 12:16 -0400
                Re: Odd compiler behaviour? spud@potato.field - 2016-03-14 17:00 +0000
                Re: Odd compiler behaviour? Rainer Weikusat <rweikusat@talktalk.net> - 2016-03-14 17:14 +0000
                Re: Odd compiler behaviour? Kaz Kylheku <330-706-9395@kylheku.com> - 2016-03-14 18:29 +0000
                Re: Odd compiler behaviour? Kaz Kylheku <330-706-9395@kylheku.com> - 2016-03-14 18:46 +0000
                Re: Odd compiler behaviour? "James K. Lowden" <jklowden@speakeasy.net> - 2016-03-14 18:16 -0400
                Re: Odd compiler behaviour? Ian Collins <ian-news@hotmail.com> - 2016-03-15 20:45 +1300
                Re: Odd compiler behaviour? spud@potato.field - 2016-03-15 09:25 +0000
                Re: Odd compiler behaviour? Ian Collins <ian-news@hotmail.com> - 2016-03-15 22:36 +1300
                Re: Odd compiler behaviour? spud@potato.field - 2016-03-15 10:23 +0000
                Re: Odd compiler behaviour? "James K. Lowden" <jklowden@speakeasy.net> - 2016-03-15 10:11 -0400
                Re: Odd compiler behaviour? Kaz Kylheku <330-706-9395@kylheku.com> - 2016-03-15 14:33 +0000
                Re: Odd compiler behaviour? spud@potato.field - 2016-03-15 15:41 +0000
                Re: Odd compiler behaviour? "James K. Lowden" <jklowden@speakeasy.net> - 2016-03-17 18:18 -0400
                Re: Odd compiler behaviour? Nicolas George <nicolas$george@salle-s.org> - 2016-03-17 23:01 +0000
                Re: Odd compiler behaviour? spud@potato.field - 2016-03-18 09:44 +0000
                Re: Odd compiler behaviour? Ian Collins <ian-news@hotmail.com> - 2016-03-29 11:31 +1300
                Re: Odd compiler behaviour? spud@potato.field - 2016-03-29 08:32 +0000
                Re: Odd compiler behaviour? Ian Collins <ian-news@hotmail.com> - 2016-03-29 21:46 +1300
                Re: Odd compiler behaviour? spud@potato.field - 2016-03-29 09:25 +0000
                Re: Odd compiler behaviour? scott@slp53.sl.home (Scott Lurndal) - 2016-03-29 13:22 +0000
                Re: Odd compiler behaviour? spud@potato.field - 2016-03-29 14:07 +0000
                Re: Odd compiler behaviour? Rainer Weikusat <rweikusat@talktalk.net> - 2016-03-29 15:59 +0100
                Re: Odd compiler behaviour? spud@potato.field - 2016-03-29 15:12 +0000
                Re: Odd compiler behaviour? Rainer Weikusat <rweikusat@talktalk.net> - 2016-03-29 17:27 +0100
                Re: Odd compiler behaviour? spud@potato.field - 2016-03-30 08:35 +0000
                Re: Odd compiler behaviour? scott@slp53.sl.home (Scott Lurndal) - 2016-03-29 16:29 +0000
                Re: Odd compiler behaviour? spud@potato.field - 2016-03-30 08:23 +0000
                Re: Odd compiler behaviour? scott@slp53.sl.home (Scott Lurndal) - 2016-03-30 13:14 +0000
                Re: Odd compiler behaviour? spud@potato.field - 2016-03-30 13:38 +0000
                Re: Odd compiler behaviour? scott@slp53.sl.home (Scott Lurndal) - 2016-03-30 15:20 +0000
                Re: Odd compiler behaviour? scott@slp53.sl.home (Scott Lurndal) - 2016-03-29 16:23 +0000
                Re: Odd compiler behaviour? Rainer Weikusat <rweikusat@talktalk.net> - 2016-03-18 15:58 +0000
                Re: Odd compiler behaviour? spud@potato.field - 2016-03-18 16:20 +0000
                Re: Odd compiler behaviour? "James K. Lowden" <jklowden@speakeasy.net> - 2016-03-19 02:46 -0400
                Re: Odd compiler behaviour? Rainer Weikusat <rweikusat@talktalk.net> - 2016-03-15 15:42 +0000
                Re: Odd compiler behaviour? Kaz Kylheku <330-706-9395@kylheku.com> - 2016-03-15 21:55 +0000
                Re: Odd compiler behaviour? scott@slp53.sl.home (Scott Lurndal) - 2016-03-15 13:37 +0000
                Re: Odd compiler behaviour? Jorgen Grahn <grahn+nntp@snipabacken.se> - 2016-03-31 19:25 +0000
                Re: Odd compiler behaviour? David Brown <david.brown@hesbynett.no> - 2016-03-09 15:17 +0100
                Re: Odd compiler behaviour? spud@potato.field - 2016-03-09 16:23 +0000
                Re: Odd compiler behaviour? David Brown <david.brown@hesbynett.no> - 2016-03-09 19:30 +0100
                Re: Odd compiler behaviour? Jerry Stuckle <jstucklex@attglobal.net> - 2016-03-09 14:40 -0500
                Re: Odd compiler behaviour? spud@potato.field - 2016-03-10 09:28 +0000
                Re: Odd compiler behaviour? David Brown <david.brown@hesbynett.no> - 2016-03-10 10:57 +0100
                Re: Odd compiler behaviour? spud@potato.field - 2016-03-10 10:29 +0000
                Re: Odd compiler behaviour? David Brown <david.brown@hesbynett.no> - 2016-03-10 12:50 +0100
                Re: Odd compiler behaviour? Rainer Weikusat <rweikusat@talktalk.net> - 2016-03-10 12:21 +0000
                Re: Odd compiler behaviour? spud@potato.field - 2016-03-10 12:22 +0000
                Re: Odd compiler behaviour? BartC <bc@freeuk.com> - 2016-03-10 13:01 +0000
                Re: Odd compiler behaviour? spud@potato.field - 2016-03-10 13:55 +0000
                Re: Odd compiler behaviour? Keith Thompson <kst-u@mib.org> - 2016-03-10 08:29 -0800
                Re: Odd compiler behaviour? gordonb.uf2r1@burditt.org (Gordon Burditt) - 2016-03-12 03:36 -0600
                Re: Odd compiler behaviour? Richard Damon <Richard@Damon-Family.org> - 2016-03-12 10:13 -0500
                Re: Odd compiler behaviour? David Brown <david.brown@hesbynett.no> - 2016-03-13 23:11 +0100
                Re: Odd compiler behaviour? Rainer Weikusat <rweikusat@talktalk.net> - 2016-03-13 22:12 +0000
                succint expressions (was: Odd compiler behaviour?) Rainer Weikusat <rweikusat@talktalk.net> - 2016-03-09 11:04 +0000
                Re: Odd compiler behaviour? BartC <bc@freeuk.com> - 2016-03-09 11:39 +0000
                Re: Odd compiler behaviour? "James K. Lowden" <jklowden@speakeasy.net> - 2016-03-09 19:51 -0500
                Re: Odd compiler behaviour? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-03-10 01:00 +0000
                Re: Odd compiler behaviour? Jerry Stuckle <jstucklex@attglobal.net> - 2016-03-09 09:27 -0500
                Re: Odd compiler behaviour? Kaz Kylheku <330-706-9395@kylheku.com> - 2016-03-09 15:24 +0000
                Re: Odd compiler behaviour? Jerry Stuckle <jstucklex@attglobal.net> - 2016-03-09 11:10 -0500
                Re: Odd compiler behaviour? Kaz Kylheku <330-706-9395@kylheku.com> - 2016-03-09 19:14 +0000
                Re: Odd compiler behaviour? scott@slp53.sl.home (Scott Lurndal) - 2016-03-09 20:18 +0000
                Re: Odd compiler behaviour? gordonb.2x965@burditt.org (Gordon Burditt) - 2016-03-14 23:45 -0500
                Re: Odd compiler behaviour? Rainer Weikusat <rweikusat@talktalk.net> - 2016-03-09 16:11 +0000
                Re: Odd compiler behaviour? David Brown <david.brown@hesbynett.no> - 2016-03-09 19:37 +0100
                Re: Odd compiler behaviour? Kaz Kylheku <330-706-9395@kylheku.com> - 2016-03-09 19:34 +0000
                Re: Odd compiler behaviour? Rainer Weikusat <rweikusat@talktalk.net> - 2016-03-09 20:05 +0000
                [OT] Re: Odd compiler behaviour? Eric Sosman <esosman@comcast-dot-net.invalid> - 2016-03-09 15:13 -0500
                Re: Odd compiler behaviour? "James K. Lowden" <jklowden@speakeasy.net> - 2016-03-09 19:51 -0500
                Re: Odd compiler behaviour? Rainer Weikusat <rweikusat@talktalk.net> - 2016-03-10 15:35 +0000
                Re: Odd compiler behaviour? "James K. Lowden" <jklowden@speakeasy.net> - 2016-03-09 00:21 -0500
                Re: Odd compiler behaviour? Kaz Kylheku <330-706-9395@kylheku.com> - 2016-03-01 21:01 +0000
          Re: Odd compiler behaviour? raltbos@xs4all.nl (Richard Bos) - 2016-03-02 12:09 +0000
      Re: Odd compiler behaviour? scott@slp53.sl.home (Scott Lurndal) - 2016-03-01 14:18 +0000
        Re: Odd compiler behaviour? raltbos@xs4all.nl (Richard Bos) - 2016-03-02 12:53 +0000
  Re: Odd compiler behaviour? Noob <root@127.0.0.1> - 2016-03-01 16:44 +0100
  Re: Odd compiler behaviour? Geoff <geoff@invalid.invalid> - 2016-03-01 09:22 -0800
    Re: Odd compiler behaviour? David Thompson <dave.thompson2@verizon.net> - 2016-03-20 07:12 -0400

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