Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > comp.lang.forth > #38285

Re: rhel 7 and kforth

Path csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!eternal-september.org!feeder.eternal-september.org!mx02.eternal-september.org!.POSTED!not-for-mail
From Paul Rubin <no.email@nospam.invalid>
Newsgroups comp.lang.forth
Subject Re: rhel 7 and kforth
Date Fri, 17 Apr 2015 10:33:46 -0700
Organization A noiseless patient Spider
Lines 51
Message-ID <87d232wtfp.fsf@jester.gateway.pace.com> (permalink)
References <a6948250-7543-4540-b455-e1693be2806a@googlegroups.com> <6b95db78-ff4c-42aa-9680-7e4e588f61a4@googlegroups.com> <fcc13b4b-8c59-4163-a15b-af0f419ab0be@googlegroups.com> <de194ec8-75d4-4f9d-ba5e-7c206a57416a@googlegroups.com> <29c7eb53-229e-40a4-9bad-0d14e953ebc3@googlegroups.com> <afa7fe19-fb96-49d4-be33-6f2677fcd1da@googlegroups.com> <87f18d43-a91e-4ae7-b98a-2cf4b7227c47@googlegroups.com> <87y4lrwpfo.fsf@jester.gateway.pace.com> <ee3a191f-4d42-45d1-9c8d-9883b46dcc24@googlegroups.com> <e0adb3c5-88e7-4600-a5fb-e2e72dcd5356@googlegroups.com> <87twwfwlm2.fsf@jester.gateway.pace.com> <eee4002b-a756-4d33-94ca-5abfec0c76b9@googlegroups.com> <c686b94d-a564-4a71-be2a-5b2eb635f34d@googlegroups.com> <87pp73wi24.fsf@jester.gateway.pace.com> <a1fb0719-580a-4252-b212-b343ddc42fa5@googlegroups.com> <87a8y695hs.fsf@jester.gateway.pace.com> <ea58125a-3cc2-41a4-8481-b84c730218b9@googlegroups.com>
Mime-Version 1.0
Content-Type text/plain
Injection-Info mx02.eternal-september.org; posting-host="bda44be170c76b3ef6d23fecd204a8fa"; logging-data="15410"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX18k2Ur46baTRLoSSX7YeYUr"
User-Agent Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux)
Cancel-Lock sha1:2Wmn8tRl/sYLG7INZPpmf9BCdw4= sha1:MCHrqTvxJ9RlzdAikOXPVRBRMCw=
Xref csiph.com comp.lang.forth:38285

Show key headers only | View raw


krishna.myneni@ccreweb.org writes:
> I'm not claiming there is universal practice for compiling this
> expression. In my experience with C compilers, I haven't seen any
> exceptions. 

You mean exceptions with a[i]=i++?  How many compilers did you try that
with?  If you mean exceptions with *sp-- = *(sp + 1), obviously you did
just encounter a different compilation than what you expected.  

> Obviously, I'm peeved at having my code unnecessarily broken by poor
> choices made by the compiler.

Whether it was a poor choice is necessarily somewhat subjective.  The
compiler writers take the view that the good-vs-poor decision was made
during the standardization process and if it was a poor choice, the
standard wouldn't have allowed it.  So when they're left with a set of
options neutrally allowed by the standard, they naturally pick the one
that generates the fastest code that they can.  If they generated
different (slower) code earlier, that only means last year's optimizers
were less advanced than this year's.

> But, the actual fix is relatively simple. I can't see that the fix was
> justified by the standard.

Did you micro-benchmark both versions?  If the "broken" code was faster,
that is the justification.

> The standard could have stated that the expression, "a[i] = i++;" uses
> the instantaneous value of i just before the expression, for every
> reference of i. But, perhaps this leads to consistency problems with
> other expressions.

I dunno about consistency problems but I can tell you from having gotten
in arguments with those guys, the #1 thing they cared about was fast
code, and they opted for it over an "err on the side of caution"
approach.  I'd agree that this has caused problems that are being
recognized somewhat in hindsight (one reason I'm terrified of anything
written in C today).  But, the choices made back then were at least
arguably a sane fit for the knowledge and priorities that existed at the
time.

GCC has various command line options to disable some of the more
surprising optimizations and I like Regehr's proposal of a less
aggressive dialect, that could be enabled by a single option or even
made the default.

>> > Yes, I see the compiler warnings for both examples with -Wall 

It's probably worth compiling the whole program with -Wall and checking
all the messages for other problems.  -Wall has apparently gotten pretty
good.

Back to comp.lang.forth | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread


Thread

rhel 7 and kforth krishna.myneni@ccreweb.org - 2015-04-15 11:20 -0700
  Re: rhel 7 and kforth krishna.myneni@ccreweb.org - 2015-04-15 19:09 -0700
  Re: rhel 7 and kforth krishna.myneni@ccreweb.org - 2015-04-16 04:13 -0700
    Re: rhel 7 and kforth krishna.myneni@ccreweb.org - 2015-04-16 04:55 -0700
      Re: rhel 7 and kforth anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-04-16 12:08 +0000
        Re: rhel 7 and kforth krishna.myneni@ccreweb.org - 2015-04-16 05:29 -0700
          Re: rhel 7 and kforth krishna.myneni@ccreweb.org - 2015-04-16 07:07 -0700
            Re: rhel 7 and kforth franck.bensusan@gmail.com - 2015-04-16 07:44 -0700
              Re: rhel 7 and kforth krishna.myneni@ccreweb.org - 2015-04-16 08:14 -0700
          Re: rhel 7 and kforth anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-04-16 14:02 +0000
            Re: rhel 7 and kforth krishna.myneni@ccreweb.org - 2015-04-16 08:12 -0700
      Re: rhel 7 and kforth krishna.myneni@ccreweb.org - 2015-04-16 12:25 -0700
        Re: rhel 7 and kforth krishna.myneni@ccreweb.org - 2015-04-16 17:02 -0700
          Re: rhel 7 and kforth krishna.myneni@ccreweb.org - 2015-04-16 17:06 -0700
            Re: rhel 7 and kforth foxaudioresearch@gmail.com - 2015-04-16 17:24 -0700
              Re: rhel 7 and kforth krishna.myneni@ccreweb.org - 2015-04-16 17:39 -0700
              Re: rhel 7 and kforth Paul Rubin <no.email@nospam.invalid> - 2015-04-16 17:47 -0700
                Re: rhel 7 and kforth krishna.myneni@ccreweb.org - 2015-04-16 18:44 -0700
                Re: rhel 7 and kforth krishna.myneni@ccreweb.org - 2015-04-16 18:50 -0700
                Re: rhel 7 and kforth Paul Rubin <no.email@nospam.invalid> - 2015-04-16 19:10 -0700
                Re: rhel 7 and kforth krishna.myneni@ccreweb.org - 2015-04-16 19:29 -0700
                Re: rhel 7 and kforth krishna.myneni@ccreweb.org - 2015-04-16 20:10 -0700
                Re: rhel 7 and kforth Paul Rubin <no.email@nospam.invalid> - 2015-04-16 20:27 -0700
                Re: rhel 7 and kforth krishna.myneni@ccreweb.org - 2015-04-17 02:04 -0700
                Re: rhel 7 and kforth anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-04-17 11:41 +0000
                Re: rhel 7 and kforth krishna.myneni@ccreweb.org - 2015-04-17 14:45 -0700
                Re: rhel 7 and kforth anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-04-18 14:01 +0000
                Re: rhel 7 and kforth Paul Rubin <no.email@nospam.invalid> - 2015-04-17 07:47 -0700
                Re: rhel 7 and kforth krishna.myneni@ccreweb.org - 2015-04-17 08:35 -0700
                Re: rhel 7 and kforth Paul Rubin <no.email@nospam.invalid> - 2015-04-17 10:33 -0700
                Re: rhel 7 and kforth krishna.myneni@ccreweb.org - 2015-04-17 11:15 -0700
                Re: rhel 7 and kforth Paul Rubin <no.email@nospam.invalid> - 2015-04-17 11:47 -0700
                Re: rhel 7 and kforth krishna.myneni@ccreweb.org - 2015-04-17 14:51 -0700
                Re: rhel 7 and kforth anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-04-18 14:41 +0000
                Re: rhel 7 and kforth Paul Rubin <no.email@nospam.invalid> - 2015-04-24 11:42 -0700
                Re: rhel 7 and kforth "Elizabeth D. Rather" <erather@forth.com> - 2015-04-24 09:02 -1000
                Re: rhel 7 and kforth anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-05-02 10:53 +0000
                Re: rhel 7 and kforth Paul Rubin <no.email@nospam.invalid> - 2015-05-03 17:22 -0700
                Re: rhel 7 and kforth anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-05-04 10:23 +0000
                Re: rhel 7 and kforth Bernd Paysan <bernd.paysan@gmx.de> - 2015-04-22 00:10 +0200
                Re: rhel 7 and kforth Paul Rubin <no.email@nospam.invalid> - 2015-04-21 17:45 -0700
                Re: rhel 7 and kforth anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-04-22 13:08 +0000
                Re: rhel 7 and kforth albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-04-17 20:27 +0000
                Re: rhel 7 and kforth krishna.myneni@ccreweb.org - 2015-04-17 14:41 -0700
                Re: rhel 7 and kforth anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-04-18 14:11 +0000
                Re: rhel 7 and kforth Paul Rubin <no.email@nospam.invalid> - 2015-04-17 15:47 -0700
                Re: rhel 7 and kforth anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-04-18 14:34 +0000
                Re: rhel 7 and kforth krishna.myneni@ccreweb.org - 2015-04-18 14:09 -0700
                Re: rhel 7 and kforth Paul Rubin <no.email@nospam.invalid> - 2015-04-19 20:31 -0700
                Re: rhel 7 and kforth anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-04-20 11:35 +0000
                Re: rhel 7 and kforth Paul Rubin <no.email@nospam.invalid> - 2015-04-21 18:07 -0700
                Re: rhel 7 and kforth anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-04-22 11:21 +0000
                Re: rhel 7 and kforth Paul Rubin <no.email@nospam.invalid> - 2015-04-24 19:34 -0700
                Re: rhel 7 and kforth anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-04-25 08:36 +0000
                Re: rhel 7 and kforth albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-04-25 11:36 +0000
                Re: rhel 7 and kforth anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-04-25 16:29 +0000
                Re: rhel 7 and kforth albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-04-19 10:08 +0000
                Re: rhel 7 and kforth krishna.myneni@ccreweb.org - 2015-04-19 20:11 -0700
                Re: rhel 7 and kforth anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-04-20 12:05 +0000
                Re: rhel 7 and kforth Bernd Paysan <bernd.paysan@gmx.de> - 2015-04-22 01:27 +0200
                Re: rhel 7 and kforth Paul Rubin <no.email@nospam.invalid> - 2015-04-21 18:18 -0700
                Re: rhel 7 and kforth anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-04-22 11:00 +0000
                Re: rhel 7 and kforth Paul Rubin <no.email@nospam.invalid> - 2015-04-24 11:28 -0700
                Re: rhel 7 and kforth Bernd Paysan <bernd.paysan@gmx.de> - 2015-04-25 01:34 +0200
                Re: rhel 7 and kforth Paul Rubin <no.email@nospam.invalid> - 2015-04-24 21:07 -0700
                Re: rhel 7 and kforth anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-04-25 16:41 +0000
                Re: rhel 7 and kforth krishna.myneni@ccreweb.org - 2015-04-25 10:06 -0700
                Re: rhel 7 and kforth anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-04-26 14:56 +0000
                Re: rhel 7 and kforth krishna.myneni@ccreweb.org - 2015-04-26 20:22 -0700
                Re: rhel 7 and kforth anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-04-27 09:02 +0000
                Re: rhel 7 and kforth mhx@iae.nl - 2015-04-27 03:59 -0700
                Re: rhel 7 and kforth albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-04-27 15:45 +0000
                Re: rhel 7 and kforth "Rod Pemberton" <bork@lllljunkqwer.cpm> - 2015-04-27 18:09 -0400
                Re: rhel 7 and kforth Bernd Paysan <bernd.paysan@gmx.de> - 2015-04-28 03:55 +0200
                Re: rhel 7 and kforth krishna.myneni@ccreweb.org - 2015-04-27 19:30 -0700
                Re: rhel 7 and kforth krishna.myneni@ccreweb.org - 2015-04-27 19:44 -0700
                Re: rhel 7 and kforth "Rod Pemberton" <bork@lllljunkqwer.cpm> - 2015-04-28 02:03 -0400
                Re: rhel 7 and kforth krishna.myneni@ccreweb.org - 2015-04-28 01:44 -0700
                Re: rhel 7 and kforth Mark Wills <markwills1970@gmail.com> - 2015-04-28 02:44 -0700
                Re: rhel 7 and kforth Paul Rubin <no.email@nospam.invalid> - 2015-04-28 16:47 -0700
                Re: rhel 7 and kforth krishna.myneni@ccreweb.org - 2015-04-28 17:00 -0700
                Re: rhel 7 and kforth Paul Rubin <no.email@nospam.invalid> - 2015-04-28 17:14 -0700
                Re: rhel 7 and kforth krishna.myneni@ccreweb.org - 2015-04-28 17:59 -0700
                Re: rhel 7 and kforth Paul Rubin <no.email@nospam.invalid> - 2015-04-28 21:41 -0700
                Re: rhel 7 and kforth Bernd Paysan <bernd.paysan@gmx.de> - 2015-04-29 03:07 +0200
                Re: rhel 7 and kforth krishna.myneni@ccreweb.org - 2015-04-28 18:13 -0700
                Re: rhel 7 and kforth albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-04-29 00:07 +0000
                Re: rhel 7 and kforth Bernd Paysan <bernd.paysan@gmx.de> - 2015-04-28 22:22 +0200
                Re: rhel 7 and kforth krishna.myneni@ccreweb.org - 2015-04-28 14:23 -0700
                Re: rhel 7 and kforth Bernd Paysan <bernd.paysan@gmx.de> - 2015-04-28 23:51 +0200
                Re: rhel 7 and kforth krishna.myneni@ccreweb.org - 2015-04-28 16:50 -0700
                Re: rhel 7 and kforth David Thompson <dave.thompson2@verizon.net> - 2015-05-10 12:24 -0400
                Re: rhel 7 and kforth mhx@iae.nl - 2015-04-26 22:16 -0700
                Re: rhel 7 and kforth anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-04-27 09:19 +0000
                Re: rhel 7 and kforth mhx@iae.nl - 2015-04-27 04:03 -0700
                Re: rhel 7 and kforth "Rod Pemberton" <bork@lllljunkqwer.cpm> - 2015-04-27 18:21 -0400
                Re: rhel 7 and kforth anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-05-01 14:46 +0000
                Re: rhel 7 and kforth Bernd Paysan <bernd.paysan@gmx.de> - 2015-04-23 16:46 +0200
                Re: rhel 7 and kforth albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-04-17 10:35 +0000
                Re: rhel 7 and kforth krishna.myneni@ccreweb.org - 2015-04-17 08:43 -0700
  Re: rhel 7 and kforth krishna.myneni@ccreweb.org - 2015-04-17 08:41 -0700

csiph-web