From: Paolo Bonzini <pbonzini@redhat.com>
To: Peter Maydell <peter.maydell@linaro.org>
Cc: QEMU Developers <qemu-devel@nongnu.org>
Subject: Re: [Qemu-devel] [PATCH for 2.5] QEMU does not care about left shifts of signed negative values
Date: Tue, 17 Nov 2015 11:57:27 +0100 [thread overview]
Message-ID: <564B0817.1010704@redhat.com> (raw)
In-Reply-To: <CAFEAcA-4EYH_ZpxSGcmh_rcZoR-nsfVyLWG=xH-cTXQdcyKKRQ@mail.gmail.com>
On 17/11/2015 11:55, Peter Maydell wrote:
> If you pass clang -fwrapv then this causes -fsanitize=undefined to
> no longer complain about signed integer overflows from addition.
> However the sanitizer will still complain about left shifts of
> negative values. The conclusion I draw is that clang (as per
> the documentation) applies fwrapv only to addition &c, not to
> shifts.
Ok, I'll open a bug for this. It's probably unintended, they've already
fixed -fwrapv once for pointers.
Paolo
next prev parent reply other threads:[~2015-11-17 10:57 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-17 9:59 [Qemu-devel] [PATCH for 2.5] QEMU does not care about left shifts of signed negative values Paolo Bonzini
2015-11-17 10:19 ` Peter Maydell
2015-11-17 10:28 ` Paolo Bonzini
2015-11-17 10:36 ` Peter Maydell
2015-11-17 10:37 ` Paolo Bonzini
2015-11-17 10:42 ` Peter Maydell
2015-11-17 10:55 ` Peter Maydell
2015-11-17 10:57 ` Paolo Bonzini [this message]
2015-11-17 11:22 ` Peter Maydell
2015-11-17 12:10 ` Paolo Bonzini
2015-11-17 12:22 ` Peter Maydell
2015-11-17 10:41 ` Laszlo Ersek
2015-11-17 10:43 ` Paolo Bonzini
2015-11-17 10:52 ` Laszlo Ersek
2015-11-17 11:59 ` Markus Armbruster
2015-11-17 12:04 ` Peter Maydell
2015-11-17 12:17 ` Laszlo Ersek
2015-11-17 13:48 ` Paolo Bonzini
2015-11-17 12:18 ` Laszlo Ersek
2015-11-17 10:26 ` Markus Armbruster
2015-11-17 10:36 ` Laszlo Ersek
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