From: "Ulrich Weigand" <uweigand@de.ibm.com>
To: joseph@codesourcery.com (Joseph Myers)
Cc: libc-alpha@sourceware.org
Subject: Re: fmax/fmin sNaN compatibility question
Date: Tue, 10 Dec 2019 10:44:00 -0000 [thread overview]
Message-ID: <20191210104358.4F372D80305@oc3748833570.ibm.com> (raw)
In-Reply-To: <alpine.DEB.2.21.1912100058130.816@digraph.polyomino.org.uk> from "Joseph Myers" at Dec 10, 2019 01:00:07 AM
Joseph Myers wrote:
> On Mon, 9 Dec 2019, Ulrich Weigand wrote:
> > Do you know why the sample implementation was even updated then?
> > If FP_SNANS_ALWAYS_SIGNAL is false, shouldn't the C11 method then
> > still be OK?
>
> The canonicalize call is needed in general to avoid propagating
> noncanonical DFP encodings, though not relevant for binary FP.
But it does change the behavior for binary FP as well, as far
as I can see: e.g. if both inputs are sNaNs, the C11 method
would return one of those sNaNs unchanged, while the C2x method
will return a qNaN (as the canonicalize call will quiet the
sNaN it receives as input), right?
Bye,
Ulrich
--
Dr. Ulrich Weigand
GNU/Linux compilers and toolchain
Ulrich.Weigand@de.ibm.com
next prev parent reply other threads:[~2019-12-10 10:44 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-09 17:12 Ulrich Weigand
2019-12-09 17:23 ` Joseph Myers
2019-12-09 17:39 ` Ulrich Weigand
2019-12-10 1:00 ` Joseph Myers
2019-12-10 10:44 ` Ulrich Weigand [this message]
2019-12-10 18:05 ` Joseph Myers
2019-12-10 18:39 ` Ulrich Weigand
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