From: Anthony Liguori <anthony@codemonkey.ws>
To: Richard Henderson <rth@twiddle.net>
Cc: Anthony Liguori <aliguori@us.ibm.com>,
QEMU Developers <qemu-devel@nongnu.org>,
Gleb Natapov <gleb@redhat.com>
Subject: Re: [Qemu-devel] [PATCH] Fix comparison which always returned false
Date: Wed, 16 Jun 2010 07:34:51 -0500 [thread overview]
Message-ID: <4C18C4EB.9070001@codemonkey.ws> (raw)
In-Reply-To: <4C181A7A.7040107@twiddle.net>
On 06/15/2010 07:27 PM, Richard Henderson wrote:
> On 06/15/2010 02:28 PM, Anthony Liguori wrote:
>
>> On 06/15/2010 04:03 PM, Stefan Weil wrote:
>>
>>> Comparing an 8 bit value with ~0 does not work as expected.
>>> Replace ~0 by UINT8_MAX in comparison and also in assignment
>>> (and fix coding style, too).
>>>
>>>
>> Because when the uint8_t gets promoted, it doesn't get zero filled. I'd
>> rather something a bit more obvious like HPET_INVALID_COUNT.
>>
> Er, yes it does. The problem is that it *did* get zero-extended,
> but ~0 is 0xffffffff, so the comparison fails.
>
Typo on my part. I meant one filled obviously.
Regards,
Anthony Liguori
> But I really agree with Jan Kiszka down-thread -- why do we need
> to signal this as a special case at all?
>
>
> r~
>
next prev parent reply other threads:[~2010-06-16 12:34 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-06-15 21:03 [Qemu-devel] [PATCH] Fix comparison which always returned false Stefan Weil
2010-06-15 21:28 ` Anthony Liguori
2010-06-16 0:27 ` Richard Henderson
2010-06-16 12:34 ` Anthony Liguori [this message]
2010-06-15 21:28 ` [Qemu-devel] " Jan Kiszka
2010-06-16 4:30 ` Gleb Natapov
2010-06-15 21:41 ` [Qemu-devel] " malc
2010-06-15 21:44 ` malc
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