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From: Peter Maydell <peter.maydell@linaro.org>
To: Markus Armbruster <armbru@redhat.com>
Cc: QEMU Developers <qemu-devel@nongnu.org>,
	Paolo Bonzini <pbonzini@redhat.com>,
	Patch Tracking <patches@linaro.org>
Subject: Re: [Qemu-devel] [PATCH] configure: Always compile with -fwrapv
Date: Mon, 12 Sep 2016 17:22:55 +0100	[thread overview]
Message-ID: <CAFEAcA-xjk_rxouZcwJkjj53c1bM5iGg4bye72exPWkfa-oQfg@mail.gmail.com> (raw)
In-Reply-To: <87wpihtb0u.fsf@dusky.pond.sub.org>

On 12 September 2016 at 16:04, Markus Armbruster <armbru@redhat.com> wrote:
> If I remember correctly, we discussed -fno-strict-overflow (which the
> kernel uses), but in the end opted for the more stringent -fwrapv.

Yep. -fno-strict-overflow just says "don't do bad things on
integer overflow (but it's still a bug in the program if it
happens)", so overflows are still program bugs and
the compiler/sanitizer will still complain about them.
You need -fwrapv to say "overflows aren't bugs at all".

thanks
-- PMM

  reply	other threads:[~2016-09-12 16:24 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-09-12 13:10 [Qemu-devel] [PATCH] configure: Always compile with -fwrapv Peter Maydell
2016-09-12 15:04 ` Markus Armbruster
2016-09-12 16:22   ` Peter Maydell [this message]
2016-09-12 17:06 ` Paolo Bonzini
2016-09-13 15:41   ` Peter Maydell

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