From: Rasmus Villemoes <linux@rasmusvillemoes.dk>
To: Willy Tarreau <w@1wt.eu>
Cc: "Paul E. McKenney" <paulmck@kernel.org>,
linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] selftests/nolibc: add 7 tests for memcmp()
Date: Thu, 27 Oct 2022 11:09:55 +0200 [thread overview]
Message-ID: <0b8feeb2-6ec6-d2af-8aa7-0bf34e7ab4b2@rasmusvillemoes.dk> (raw)
In-Reply-To: <20221026195224.GA24197@1wt.eu>
On 26/10/2022 21.52, Willy Tarreau wrote:
> On Wed, Oct 26, 2022 at 11:08:41AM +0200, Rasmus Villemoes wrote:
>> On 26/10/2022 07.39, Willy Tarreau wrote:
>>>
>>> No more false positives nor false negatives anymore. I'm sending you
>>> the patch separately.
>>
>> While you're at it, may I suggest also adding a few test cases where the
>> buffers differ by 128, e.g. 0x0 v 0x80 and 0x40 v 0xc0.
>
> I initially thought about it but changed my mind for +/- 0xc0 that
> covered the same cases in my opinion. Do you have a particular error
> case in mind that would be caught by this one that the other one does
> not catch ?
Not really, but in a sense the opposite: for the +/- 0xc0 case, both
ways of comparison will give the wrong sign because -192 becomes +64 and
vice versa. For +/- 0x80, one way of doing the comparison will
"accidentally" produce the right answer, and I thought that might also
be a little interesting.
I'm fine for proposing a respin of the patch to improve
> it if it brings some value,
It's your call, you can respin, do an incremental patch, or just ignore
me :)
Rasmus
next prev parent reply other threads:[~2022-10-27 9:10 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-21 6:03 [PATCH] selftests/nolibc: add 7 tests for memcmp() Willy Tarreau
2022-10-21 15:56 ` Paul E. McKenney
2022-10-21 17:01 ` Willy Tarreau
2022-10-21 17:07 ` Paul E. McKenney
2022-10-21 17:20 ` Willy Tarreau
2022-10-21 18:00 ` Paul E. McKenney
2022-10-22 11:22 ` Willy Tarreau
2022-10-24 15:53 ` Paul E. McKenney
2022-10-26 5:39 ` Willy Tarreau
2022-10-26 9:08 ` Rasmus Villemoes
2022-10-26 19:52 ` Willy Tarreau
2022-10-27 9:09 ` Rasmus Villemoes [this message]
2022-10-27 17:20 ` Willy Tarreau
2022-10-26 13:57 ` Paul E. McKenney
2022-10-26 14:17 ` Willy Tarreau
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