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From: Ray Blaak <rAYblaaK@STRIPCAPStelus.net>
Subject: Re: GNAT Optimization of Constant Expressions
Date: Fri, 18 May 2007 16:25:14 GMT
Date: 2007-05-18T16:25:14+00:00	[thread overview]
Message-ID: <u1whep09x.fsf@STRIPCAPStelus.net> (raw)
In-Reply-To: f2ier6$c09$1@jacob-sparre.dk

"Randy Brukardt" <randy@rrsoftware.com> writes:
> One example is:
>      Y := (X - 0.5) - 0.5;
> 
> You might think that replacing this with
>     Y := X - 1.0;
> would be a good idea, but actually it reduces the accuracy of the result

I don't understand this. Both 0.5 and 1.0 have "exact" binary representations
right? 

Can you give a value of X where this would hold?

-- 
Cheers,                                        The Rhythm is around me,
                                               The Rhythm has control.
Ray Blaak                                      The Rhythm is inside me,
rAYblaaK@STRIPCAPStelus.net                    The Rhythm has my soul.



  parent reply	other threads:[~2007-05-18 16:25 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-05-16 22:37 GNAT Optimization of Constant Expressions David Smith
2007-05-17  4:50 ` Randy Brukardt
2007-05-17 20:03   ` Gautier
2007-05-17 20:46     ` Randy Brukardt
2007-05-17 22:49       ` David Smith
2007-05-17 23:38         ` Randy Brukardt
2007-05-18  7:58           ` Dmitry A. Kazakov
2007-05-18 11:27           ` Georg Bauhaus
2007-05-18 17:28             ` Randy Brukardt
2007-05-18 16:25       ` Ray Blaak [this message]
2007-05-18 17:40         ` Randy Brukardt
2007-05-18 22:51           ` Adam Beneschan
2007-05-19  2:44             ` Randy Brukardt
2007-05-18  9:05   ` Markus E Leypold
2007-05-18  9:47   ` Florian Weimer
2007-05-18 11:32     ` Duncan Sands
2007-05-18 17:20     ` Randy Brukardt
2007-05-18 17:35       ` Duncan Sands
     [not found]       ` <200705181935.23877.baldrick@free.fr>
2007-05-18 17:49         ` Duncan Sands
2007-05-17  5:30 ` Martin Krischik
2007-05-18  9:56 ` Duncan Sands
2007-05-18 15:39   ` David Smith
2007-05-18 17:08     ` Duncan Sands
     [not found]     ` <200705181908.54920.baldrick@free.fr>
2007-05-18 17:32       ` Duncan Sands
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