From: Will Newton <will.newton@gmail.com>
To: Thiago Galesi <thiagogalesi@gmail.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>,
akpm@linux-foundation.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] crc32: remove useless __pure modifier from functions
Date: Tue, 3 Mar 2009 09:33:15 +0000 [thread overview]
Message-ID: <87a5b0800903030133y7bd22204y4995657cfd75950f@mail.gmail.com> (raw)
In-Reply-To: <82ecf08e0903020942i55e1a31bn983c2ce243e342e9@mail.gmail.com>
On Mon, Mar 2, 2009 at 5:42 PM, Thiago Galesi <thiagogalesi@gmail.com> wrote:
>>
>> Hmm. They're not marked as pure in the header files. Does GCC look it up
>> from the object file or something for this...?
>
> I just tested this, the answer is No :(
>
> It only works if it's marked in the header. But when it's marked, it
> works, and redundant calls are optimized.
Did you see any change in size of your kernel with this annotation? It
didn't seem to have any effect as far as I could tell.
There are a number of functions in lib/ code that could be marked
__pure or __attribute_const__ but I'm not sure if it's worth the
effort, for my compiler (gcc 4.2) at least.
next prev parent reply other threads:[~2009-03-03 9:33 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-03-02 15:18 Pekka Enberg
2009-03-02 15:50 ` Thiago Galesi
2009-03-02 17:28 ` Pekka Enberg
2009-03-02 17:42 ` Thiago Galesi
2009-03-03 9:33 ` Will Newton [this message]
2009-03-03 13:17 ` Thiago Galesi
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