From: Alexander Monakov <amonakov@ispras.ru>
To: Richard Biener <richard.guenther@gmail.com>
Cc: Jeff Law <jeffreyalaw@gmail.com>, gcc-patches@gcc.gnu.org
Subject: Re: Should -ffp-contract=off the default on GCC?
Date: Wed, 22 Mar 2023 15:26:13 +0300 (MSK) [thread overview]
Message-ID: <435162cb-99b5-1204-d723-ec3800e78997@ispras.ru> (raw)
In-Reply-To: <CAFiYyc25j3vP0XFJfn_w3=6ph04s4yJTYrdpQqnnCSBp3xHCVQ@mail.gmail.com>
On Wed, 22 Mar 2023, Richard Biener wrote:
> I think it's even less realistic to expect users to know the details of
> floating-point math. So I doubt any such sentence will be helpful
> besides spreading some FUD?
I think it's closer to "fundamental notions" rather than "details". For
users who bother to read the GCC manual there's a decent chance it wouldn't
be for naught.
For documentation, I was thinking
Together with -fexcess-precision=standard, -ffp-contract=off
is necessary to ensure that rounding of intermediate results to precision
implied by the source code and the FLT_EVAL_METHOD macro is not
omitted by the compiler.
Alexander
next prev parent reply other threads:[~2023-03-22 12:26 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-16 16:24 Qing Zhao
2023-03-16 16:31 ` Andrew Pinski
2023-03-16 16:38 ` Qing Zhao
2023-03-16 16:53 ` Jakub Jelinek
2023-03-16 18:40 ` Qing Zhao
2023-03-20 22:05 ` Qing Zhao
2023-03-20 22:25 ` Jakub Jelinek
2023-03-21 12:49 ` Qing Zhao
2023-03-21 15:01 ` Qing Zhao
2023-03-21 16:56 ` Paul Koning
2023-03-21 17:00 ` Qing Zhao
2023-03-21 17:59 ` Jeff Law
2023-03-21 18:03 ` Paul Koning
2023-03-21 18:55 ` Toon Moene
2023-03-21 18:12 ` Alexander Monakov
2023-03-21 18:18 ` Jeff Law
2023-03-22 10:13 ` Richard Biener
2023-03-22 12:26 ` Alexander Monakov [this message]
2023-03-22 13:57 ` Richard Biener
2023-03-22 15:52 ` Qing Zhao
2023-03-24 7:12 ` Fangrui Song
2023-03-24 19:42 ` Andrew Pinski
2023-03-31 16:31 ` Qing Zhao
2023-03-21 19:01 ` Qing Zhao
2023-03-21 19:12 ` Jakub Jelinek
2023-03-21 23:28 ` Jeff Law
2023-03-21 23:31 ` Jakub Jelinek
2023-03-21 19:51 ` Jeff Law
2023-03-21 21:08 ` Qing Zhao
2023-03-22 12:33 ` Alexander Monakov
2023-03-22 14:33 ` Qing Zhao
2023-03-27 9:03 Zeson
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