From: Markus Trippelsdorf <markus@trippelsdorf.de>
To: Marek Polacek <polacek@redhat.com>
Cc: Richard Biener <richard.guenther@gmail.com>,
Mikael Morin <mikael.morin@sfr.fr>, Jeff Law <law@redhat.com>,
gcc-patches <gcc-patches@gcc.gnu.org>,
Richard Sandiford <rdsandiford@googlemail.com>
Subject: Re: [Patch] sext_hwi: Avoid left shift of negative value undefined behaviour
Date: Thu, 13 Aug 2015 13:55:00 -0000 [thread overview]
Message-ID: <20150813135200.GC386@x4> (raw)
In-Reply-To: <20150813134032.GM3335@redhat.com>
On 2015.08.13 at 15:40 +0200, Marek Polacek wrote:
> On Thu, Aug 13, 2015 at 01:11:53PM +0200, Richard Biener wrote:
> > Rather ubsan should not complain about implementation defined behavior (or
> > should separate those cases out with a different switch compared to undefined
> > behavior).
>
> I think ubsan doesn't complain about implementation-defined behavior. It seems
> to me that in this thread it only (rightfully) complained about left-shifting of
> negative value.
There are two issues in the same location:
1) gcc/hwint.h:250:19: runtime error: left shift of 8589934588 by 32
places cannot be represented in type 'long int'
2) left-shifting of negative values
--
Markus
next prev parent reply other threads:[~2015-08-13 13:52 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-06 10:26 Mikael Morin
2015-08-11 19:49 ` Jeff Law
2015-08-12 11:01 ` Richard Biener
2015-08-12 11:07 ` Markus Trippelsdorf
2015-08-12 11:09 ` Richard Biener
2015-08-12 13:34 ` Mikael Morin
2015-08-12 17:02 ` Jeff Law
2015-08-12 17:12 ` Richard Biener
2015-08-12 18:07 ` Jeff Law
2015-08-12 18:32 ` Richard Biener
2015-08-12 18:41 ` Jeff Law
2015-08-12 20:07 ` Richard Sandiford
2015-08-12 20:53 ` Mike Stump
2015-08-13 10:11 ` Richard Biener
2015-08-13 18:01 ` Mike Stump
2015-08-14 7:31 ` Richard Biener
2015-08-18 15:35 ` Mikael Morin
2015-08-18 17:51 ` Jeff Law
2015-08-13 11:03 ` Mikael Morin
2015-08-13 11:06 ` Mikael Morin
2015-08-13 11:09 ` Markus Trippelsdorf
2015-08-13 11:20 ` Richard Biener
2015-08-13 13:48 ` Marek Polacek
2015-08-13 13:55 ` Markus Trippelsdorf [this message]
2015-08-13 13:57 ` Marek Polacek
2015-08-12 19:20 ` Mike Stump
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