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From: Joseph Myers <joseph@codesourcery.com>
To: Sujoy Saraswati <ssaraswati@gmail.com>
Cc: Richard Biener <richard.guenther@gmail.com>,
	GCC Patches	<gcc-patches@gcc.gnu.org>
Subject: Re: Fix 61441
Date: Wed, 16 Sep 2015 17:03:00 -0000	[thread overview]
Message-ID: <alpine.DEB.2.10.1509161637180.9502@digraph.polyomino.org.uk> (raw)
In-Reply-To: <CA+ZXfhU_JckpXiFNKjsVS3kiaW1dVmnwH-YggzVn8h=_WOJy3w@mail.gmail.com>

On Wed, 16 Sep 2015, Sujoy Saraswati wrote:

> > If -fsignaling-nans, then folding of expressions involving sNaNs should be
> > disabled, outside of static initializers - such expressions should not get
> > folded to return an sNaN (it's incorrect to fold sNaN + 1 to sNaN, for
> > example).  I think existing code may ensure that (the HONOR_SNANS check in
> > const_binop, for example).
> 
> Yes, with -fsignaling-nans, the const_binop will not fold since the
> HONOR_SNANS check is there. However, elsewhere, like const_unop, the
> code doesn't do this check.

Which would be a bug in the const_unop code, or the functions it calls 
(for operations for which such a check is appropriate - as noted, abs and 
negation should be folded unconditionally).

-- 
Joseph S. Myers
joseph@codesourcery.com

  reply	other threads:[~2015-09-16 16:39 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-09-01 10:23 Sujoy Saraswati
2015-09-01 12:21 ` Richard Biener
2015-09-02 11:36   ` Sujoy Saraswati
2015-09-02 11:56     ` Richard Biener
2015-09-02 12:16       ` Sujoy Saraswati
2015-09-10  7:33       ` Sujoy Saraswati
2015-09-14 13:50         ` Richard Biener
2015-09-14 20:39           ` Joseph Myers
2015-09-16 13:01             ` Sujoy Saraswati
2015-09-16 17:03               ` Joseph Myers [this message]
2015-10-13 10:46                 ` Sujoy Saraswati
2015-10-28 17:19                   ` Joseph Myers
2015-11-05 11:29                     ` Sujoy Saraswati
2015-11-05 16:58                       ` Joseph Myers
2015-11-06  4:56                         ` Sujoy Saraswati
2015-11-06 13:09                           ` Joseph Myers
2015-11-26  8:28                             ` Saraswati, Sujoy (OSTL)

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