From: Aldy Hernandez <aldyh@redhat.com>
To: Toon Moene <toon@moene.org>, Jakub Jelinek <jakub@redhat.com>
Cc: gcc-patches <gcc-patches@gcc.gnu.org>
Subject: Re: [PATCH] Add support for floating point endpoints to frange.
Date: Mon, 29 Aug 2022 16:36:42 +0200 [thread overview]
Message-ID: <CAGm3qMWzs50Nk5a-0PEZ=4dEFRgpdBbV8Q1hkfJ=s+_Nka8rxg@mail.gmail.com> (raw)
In-Reply-To: <c8ba1f90-6ba9-e280-4398-aa042fd0c5d7@moene.org>
On Mon, Aug 29, 2022 at 4:30 PM Toon Moene <toon@moene.org> wrote:
>
> On 8/29/22 16:15, Aldy Hernandez wrote:
>
> > But even with -ffinite-math-only, is there any benefit to propagating
> > a known NAN? For example:
>
> The original intent (in 2002) for the option -ffinite-math-only was for
> the optimizers to ignore all the various exceptions to common
> optimizations because they might not work correctly when presented with
> a NaN or an Inf.
>
> I do not know what the effect for floating point range information would
> be - offhand.
>
> But in the *spirit* of this option would be to ignore that the range
> [5.0, 5.0] would "also" contain NaN, for instance.
Hmm, this is somewhat similar to what Jakub suggested. Perhaps we
could categorically set !NAN for !HONOR_NANS at frange construction
time?
For reference:
bool
HONOR_NANS (machine_mode m)
{
return MODE_HAS_NANS (m) && !flag_finite_math_only;
}
Thanks.
Aldy
next prev parent reply other threads:[~2022-08-29 14:36 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-23 11:42 Aldy Hernandez
2022-08-26 15:55 ` Aldy Hernandez
2022-08-26 17:40 ` Andrew Pinski
2022-08-26 18:11 ` Aldy Hernandez
2022-08-26 18:11 ` Aldy Hernandez
2022-08-26 19:16 ` Aldy Hernandez
2022-08-26 19:44 ` Andrew Pinski
2022-08-29 13:45 ` Aldy Hernandez
2022-08-29 13:54 ` Jakub Jelinek
2022-08-29 14:07 ` Toon Moene
2022-08-29 14:15 ` Aldy Hernandez
2022-08-29 14:30 ` Toon Moene
2022-08-29 14:36 ` Aldy Hernandez [this message]
2022-08-29 14:42 ` Toon Moene
2022-08-30 9:27 ` Aldy Hernandez
2022-08-31 15:22 ` Jeff Law
2022-08-31 15:19 ` Jeff Law
2022-08-29 14:08 ` Aldy Hernandez
2022-08-29 14:17 ` Jakub Jelinek
2022-08-29 14:20 ` Aldy Hernandez
2022-08-29 14:27 ` Jakub Jelinek
2022-08-29 14:30 ` Aldy Hernandez
2022-08-31 15:24 ` Jeff Law
2022-08-30 22:32 ` Joseph Myers
2022-08-31 15:16 ` Jeff Law
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