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From: Geert Bosch <bosch@gnat.com>
To: Segher Boessenkool <segher@kernel.crashing.org>
Cc: gcc@gcc.gnu.org, Scott Robert Ladd <coyote@coyotegulch.com>,
	Gabriel Dos Reis <gdr@integrable-solutions.net>,
	Roger Sayle <roger@eyesopen.com>
Subject: Re: GCC viciously beaten by ICC in trig test!
Date: Mon, 15 Mar 2004 17:44:00 -0000	[thread overview]
Message-ID: <6E19A0D4-76A8-11D8-8D76-000A959A128E@gnat.com> (raw)
In-Reply-To: <E6448D8F-768D-11D8-8673-000A95A4DC02@kernel.crashing.org>

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On Mar 15, 2004, at 09:34, Segher Boessenkool wrote:
> +/- 2**63, on i387.  Original pentium is supposed to be 1 ulp
> accurate for all valid inputs (no idea if it actually is).
>
> Don't know for other chips.

It's not. The argument reduction uses a 68-bit approximation
of pi, which means that for sin (pi) the argument retains
only about 4 significant bits and in this case results in
about 4 bits of precision in the output. We recently became
aware of this issue for Ada and are working on fixing this.

   -Geert

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  reply	other threads:[~2004-03-15 17:44 UTC|newest]

Thread overview: 74+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-03-14 23:40 Scott Robert Ladd
2004-03-14 23:49 ` Gabriel Dos Reis
2004-03-15  1:47   ` Scott Robert Ladd
2004-03-15  0:11 ` Paolo Carlini
2004-03-15  1:47   ` Scott Robert Ladd
2004-03-15  2:07     ` Daniel Berlin
2004-03-15  2:30       ` Scott Robert Ladd
2004-03-15  2:31         ` Daniel Berlin
2004-03-15  2:38           ` Scott Robert Ladd
2004-03-15 10:00             ` Sebastian Pop
2004-03-15  0:12 ` GCC beaten by ICC in stupid " Andrew Pinski
2004-03-15  0:32   ` Paolo Carlini
2004-03-15  1:31   ` Scott Robert Ladd
2004-03-15  2:36   ` Scott Robert Ladd
2004-03-15 11:25   ` Paolo Carlini
2004-03-15 11:31     ` Paolo Carlini
2004-03-15 13:29     ` Zdenek Dvorak
2004-03-15 13:42       ` Paolo Carlini
2004-03-15 13:51         ` Zdenek Dvorak
2004-03-15 13:55           ` Paolo Carlini
2004-03-15 14:00             ` Zdenek Dvorak
2004-03-15 14:05           ` Joseph S. Myers
2004-03-15 14:13             ` Paolo Carlini
2004-03-15 14:18               ` Zdenek Dvorak
2004-03-15 14:29                 ` Segher Boessenkool
2004-03-15 14:28               ` Joseph S. Myers
2004-03-15  1:55 ` GCC viciously beaten by ICC in " Roger Sayle
2004-03-15  2:22   ` Dan Nicolaescu
2004-03-15 12:05     ` Stelios Xanthakis
2004-03-15 18:22       ` Dan Nicolaescu
2004-03-15  2:41   ` Scott Robert Ladd
2004-03-15  3:05     ` Gabriel Dos Reis
2004-03-15 14:47       ` Segher Boessenkool
2004-03-15 17:44         ` Geert Bosch [this message]
2004-03-15 17:46           ` Geert Bosch
2004-03-15  2:41   ` Kaveh R. Ghazi
2004-03-15  6:06     ` Andreas Jaeger
2004-03-15  8:57       ` Gabriel Dos Reis
2004-03-15  3:01   ` Gabriel Dos Reis
2004-03-15  4:06     ` Scott Robert Ladd
2004-03-15  5:15   ` James Morrison
2004-03-15  8:20     ` Jakub Jelinek
2004-03-15 18:13       ` Joe Buck
2004-03-16 13:31         ` Jakub Jelinek
2004-03-15  7:42   ` Ranjit Mathew
2004-03-15 19:00   ` Toon Moene
2004-03-15 19:44     ` Laurent GUERBY
2004-03-15  3:19 Stephan T. Lavavej
2004-03-15  3:29 ` Gabriel Dos Reis
2004-03-15 12:40   ` Scott Robert Ladd
2004-03-15 12:53     ` Gabriel Dos Reis
2004-03-15 13:37       ` Scott Robert Ladd
2004-03-15 15:11     ` Ian Lance Taylor
2004-03-15 16:25       ` Stephan T. Lavavej
2004-03-15 16:40         ` Jakub Jelinek
2004-03-15 16:46         ` Ian Lance Taylor
2004-03-15 16:56           ` Paolo Carlini
2004-03-15 17:10             ` Gabriel Dos Reis
2004-03-15 17:15               ` Paolo Carlini
2004-03-15 17:58                 ` Gabriel Dos Reis
2004-03-15 16:59           ` Gabriel Dos Reis
2004-03-15 17:28             ` Ian Lance Taylor
2004-03-15 17:47               ` Gabriel Dos Reis
2004-03-15 17:52               ` Joe Buck
2004-03-15 17:53               ` Phil Edwards
2004-03-15 17:45     ` Joe Buck
2004-03-15 19:50       ` Scott Robert Ladd
2004-03-16  1:00     ` Zack Weinberg
2004-03-17  0:07       ` Kai Henningsen
2004-03-16 23:12   ` Kai Henningsen
2004-03-17  3:00     ` Ian Lance Taylor
2004-03-15 17:42 ` Joe Buck
2004-03-17  0:31 Stephan T. Lavavej
2004-03-17  3:30 ` Ian Lance Taylor

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