From: Alexander Monakov <amonakov@ispras.ru>
To: Jakub Jelinek <jakub@redhat.com>
Cc: Martin Uecker <muecker@gwdg.de>,
Richard Biener <richard.guenther@gmail.com>,
Florian Weimer <fweimer@redhat.com>,
gcc@gcc.gnu.org
Subject: Re: Concerns regarding the -ffp-contract=fast default
Date: Mon, 18 Sep 2023 14:43:21 +0300 (MSK) [thread overview]
Message-ID: <2ef1dbd0-8a67-6a25-50e3-16c7ca3676b6@ispras.ru> (raw)
In-Reply-To: <ZQg1U4QDetoy56rj@tucnak>
On Mon, 18 Sep 2023, Jakub Jelinek wrote:
> Perhaps we should add some initial hammer approach for the pragma, like
> if you ever use the pragma to turn it somewhere off, it is turned off
> globally, or ditto per function. Might be far easier than trying to
> make it precise that contraction is allowed in this expression and not in
> this subexpression of that etc. Of course, making it precise is the
> ultimate goal.
When implementing -ffp-contract=standard I looked into implementing the
pragma (in a precise manner) and I didn't get the impression it would be
hard to implement for C. But I was somewhat discouraged by the lack of
front-end maintainers reaction to the patch implementing the =standard,
so I didn't pursue that.
The hardest part would be popping the pragma state when leaving a block,
which didn't seem difficult (at least for C).
Alexander
next prev parent reply other threads:[~2023-09-18 11:43 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-14 16:48 Florian Weimer
2023-09-14 17:09 ` Alexander Monakov
2023-09-18 7:50 ` Alexander Monakov
2023-09-18 8:06 ` Richard Biener
2023-09-18 10:10 ` Florian Weimer
2023-09-18 10:37 ` Richard Biener
2023-09-18 11:37 ` Florian Weimer
2023-09-18 11:12 ` Alexander Monakov
2023-09-18 11:34 ` Florian Weimer
2023-09-18 11:55 ` Alexander Monakov
2023-09-18 16:41 ` Florian Weimer
2023-09-18 17:31 ` Alexander Monakov
2023-09-18 17:39 ` Joseph Myers
2023-09-18 11:26 ` Martin Uecker
2023-09-18 11:32 ` Jakub Jelinek
2023-09-18 11:43 ` Alexander Monakov [this message]
2023-09-18 12:13 ` Martin Uecker
2023-09-18 15:38 ` Alexander Monakov
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