Re: Optimization techniques

From	"Derek M. Jones" <derek@_NOSPAM_knosof.co.uk>
Newsgroups	comp.compilers
Subject	Re: Optimization techniques
Date	2019-04-26 13:39 +0100
Organization	virginmedia.com
Message-ID	<19-04-026@comp.compilers> (permalink)
References	<19-04-004@comp.compilers> <19-04-012@comp.compilers>

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All,

On 19/04/2019 23:27, Hans-Peter Diettrich wrote:
> I'm always a bit sceptic when C/C++ and "safe" occur in the same
> sentence. AFAIR a C compiler is allowed to ignore parentheses when
> reordering expressions, what can lead to numeric instabilities.

Not true:
"In the abstract machine, all expressions are evaluated as specified by
the semantics. "

https://c0x.coding-guidelines.com/5.1.2.3.html

--
Derek M. Jones
blog:shape-of-code.coding-guidelines.com
[Keeping in mind the "as if" rule which lets the compiler do whatever
it wants so long as the result is the same. -John]

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Optimization techniques "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2019-04-17 09:42 -0400
  Re: Optimization techniques Hans Aberg <haberg-news@telia.com> - 2019-04-17 18:11 +0200
  Re: Optimization techniques George Neuner <gneuner2@comcast.net> - 2019-04-18 04:07 -0400
    Re: Optimization techniques "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2019-04-18 11:22 -0400
      Re: Optimization techniques George Neuner <gneuner2@comcast.net> - 2019-04-19 15:48 -0400
    Re: Optimization techniques Hans Aberg <haberg-news@telia.com> - 2019-04-19 00:52 +0200
  Re: Optimization techniques Kaz Kylheku <847-115-0292@kylheku.com> - 2019-04-19 08:49 +0000
    Re: Optimization techniques "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2019-04-19 11:48 -0400
      Re: Optimization techniques David Brown <david.brown@hesbynett.no> - 2019-04-23 09:38 +0200
    Re: Optimization techniques David Brown <david.brown@hesbynett.no> - 2019-04-23 09:18 +0200
  Re: Optimization techniques Hans-Peter Diettrich <DrDiettrich1@netscape.net> - 2019-04-20 00:27 +0200
    Re: Optimization techniques "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2019-04-19 16:11 -0700
      Re: Optimization techniques Hans-Peter Diettrich <DrDiettrich1@netscape.net> - 2019-04-20 19:47 +0200
        Re: Optimization techniques "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2019-04-24 10:16 -0400
    Re: Optimization techniques George Neuner <gneuner2@comcast.net> - 2019-04-20 18:59 -0400
    Re: Optimization techniques David Brown <david.brown@hesbynett.no> - 2019-04-23 09:43 +0200
      Re: Optimization techniques Martin Ward <martin@gkc.org.uk> - 2019-04-26 20:10 +0100
        Re: Optimization techniques Kaz Kylheku <847-115-0292@kylheku.com> - 2019-04-26 21:11 +0000
        Re: Optimization techniques David Brown <david.brown@hesbynett.no> - 2019-04-28 17:22 +0200
          Re: Optimization techniques Gene Wirchenko <genew@telus.net> - 2019-04-30 18:07 -0700
            Re: Optimization techniques David Brown <david.brown@hesbynett.no> - 2019-05-01 09:03 +0200
    Re: Optimization techniques "Derek M. Jones" <derek@_NOSPAM_knosof.co.uk> - 2019-04-26 13:39 +0100
  Re: Optimization techniques rockbrentwood@gmail.com - 2019-09-26 20:35 -0700

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