From: Eric Botcazou <botcazou@adacore.com>
To: Richard Biener <richard.guenther@gmail.com>
Cc: gcc-patches@gcc.gnu.org
Subject: Re: [PATCH] Fix artificial overflow during GENERIC folding
Date: Wed, 24 May 2023 16:41:05 +0200 [thread overview]
Message-ID: <2560513.Lt9SDvczpP@fomalhaut> (raw)
In-Reply-To: <CAFiYyc0wuR4J=pt5K9qjk5J-9qwfe9yTOUUf2ah9oRWv=vAMJg@mail.gmail.com>
> But nobody is going to understand why the INTEGER_CST case goes the
> other way.
I can add a fat comment to that effect of course. :-)
> As you say we don't have a good way to say we're doing
> this to avoid undefined behavior, but then a view-convert back would
> be a good way to indicate that? I can't come up with a better name
> for a custom operator we could also use,
>
> (convert_without_overflow (negate (convert:utype @1))))
>
> maybe? As said, if view_convert works I prefer that. Does it?
Well, VIEW_CONVERT_EXPR adds its own set of problems in GENERIC and it will
precisely survive when it is not needed, so I'm not sure that's any better.
--
Eric Botcazou
next prev parent reply other threads:[~2023-05-24 14:41 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-24 9:54 Eric Botcazou
2023-05-24 11:15 ` Richard Biener
2023-05-24 12:39 ` Eric Botcazou
2023-05-24 13:09 ` Richard Biener
2023-05-24 14:41 ` Eric Botcazou [this message]
2023-05-25 6:22 ` Richard Biener
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