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From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/60181] constant folding of complex number incorrect
Date: Fri, 14 Feb 2014 09:37:00 -0000	[thread overview]
Message-ID: <bug-60181-4-8WmI3Oweaf@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-60181-4@http.gcc.gnu.org/bugzilla/>

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60181

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
I think that it needs to be decided on a case-by-case basis whether the
runtime complex division routine is "precise enough".  But yes, you
generally cannot expect constant folding and runtime execution to produce
the exact same result.  This is FP after all ...

(I would expect it for operations that are specified to be rounded correctly
to 0.5ulp precision though)

Note that the goal we have instead is that cross-compiling from all hosts
produces the same constant folding results for a target (code generation
doesn't depend on the host).


  parent reply	other threads:[~2014-02-14  9:37 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-02-13 16:19 [Bug target/60181] New: " krebbel at gcc dot gnu.org
2014-02-13 18:09 ` [Bug target/60181] " joseph at codesourcery dot com
2014-02-14  9:37 ` rguenth at gcc dot gnu.org [this message]
2014-02-14 11:59 ` krebbel at gcc dot gnu.org
2014-02-14 15:34 ` pinskia at gcc dot gnu.org
2014-10-02 14:52 ` boger at us dot ibm.com
2014-10-02 15:38 ` boger at us dot ibm.com
2014-10-02 15:47 ` dje at gcc dot gnu.org
2014-10-02 16:10 ` pinskia at gcc dot gnu.org

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