From: Joseph Myers <joseph@codesourcery.com>
To: Szabolcs Nagy <szabolcs.nagy@arm.com>
Cc: DJ Delorie <dj@redhat.com>, <libc-alpha@sourceware.org>, <nd@arm.com>
Subject: Re: riscv: fmax/fmin sNaN fix
Date: Tue, 20 Feb 2018 23:11:47 +0000 [thread overview]
Message-ID: <alpine.DEB.2.20.1802202302400.7674@digraph.polyomino.org.uk> (raw)
In-Reply-To: <b680364d-83ef-48ba-1885-71e50ccc4845@arm.com>
On Tue, 20 Feb 2018, Szabolcs Nagy wrote:
> On 20/02/18 02:57, DJ Delorie wrote:
> >
> > RISC-V's FPU follows the IEEE spec, not the POSIX spec. This patch
> ^^^^^^^^^
> which one?
> (the next ieee revision will have different min/max operations)
The point (as per
<https://sourceware.org/ml/libc-alpha/2018-01/msg01084.html>) is that fmax
and fmin in TS 18661-1 bind to maxNum and minNum. Those operations are to
be removed in IEEE 754-2018 so the C functions will have semantics that no
longer have a corresponding IEEE operation (much like e.g. nextafter /
nexttoward, which correspond to the Nextafter operation recommended in
IEEE 754-1985 but removed in IEEE 754-2008). Instead, the new minimum,
minimumNumber, maximum and maximumNumber operations are proposed to have
new functions fminimum, fminimum_num, fmaximum, fmaximum_num (and likewise
*mag* functions) - but so far there is no public draft of those proposed
TS changes (which might in any case more likely be dealt with in the C2x
process rather than through a new revision of the TS being produced).
--
Joseph S. Myers
joseph@codesourcery.com
next prev parent reply other threads:[~2018-02-20 23:09 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-20 2:57 riscv: fmax/fmin sNaN fix DJ Delorie
2018-02-20 10:26 ` Szabolcs Nagy
2018-02-20 17:12 ` DJ Delorie
2018-02-20 17:22 ` DJ Delorie
2018-02-21 10:44 ` Szabolcs Nagy
2018-02-21 17:25 ` DJ Delorie
2018-02-21 23:24 ` Carlos O'Donell
2018-02-22 0:24 ` DJ Delorie
2018-02-22 20:28 ` Carlos O'Donell
2018-02-22 20:34 ` DJ Delorie
2018-02-22 20:42 ` Joseph Myers
2018-02-22 20:50 ` Joseph Myers
2018-02-23 1:58 ` DJ Delorie
2018-02-23 2:01 ` Joseph Myers
2018-02-23 2:08 ` DJ Delorie
2018-02-20 22:03 ` Richard Henderson
2018-02-20 23:11 ` Joseph Myers [this message]
2018-02-21 21:25 ` Palmer Dabbelt
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