From: Bernardo Innocenti <bernie@develer.com>
To: Linus Torvalds <torvalds@osdl.org>, Andrew Morton <akpm@digeo.com>
Cc: <linux-kernel@vger.kernel.org>, <torvalds@transmeta.com>
Subject: Re: [PATCH] Kill div64.h dupes, parenthesize do_div() macro params
Date: Wed, 2 Jul 2003 09:02:05 +0200 [thread overview]
Message-ID: <200307020902.05522.bernie@develer.com> (raw)
In-Reply-To: <Pine.LNX.4.44.0307012206530.2047-100000@home.osdl.org>
On Wednesday 02 July 2003 07:09, Linus Torvalds wrote:
> > Why 64-bit divides in particular were victimised in this manner is a
> > matter for speculation ;)
>
> Because gcc historically _cannot_ generate an efficient 64/32->64
> divide. It ends up doing a full 64/64 divide thing.
You're right here. I've been too quick in putting my faith in gcc ;-)
Shouldn't we complain to the gcc people? The 64/32 division is a
rather common operation in many applications besides the kernel, so
you'd expect gcc to get it right without polluting every single
project with reimplementations of do_div().
--
// Bernardo Innocenti - Develer S.r.l., R&D dept.
\X/ http://www.develer.com/
Please don't send Word attachments - http://www.gnu.org/philosophy/no-word-attachments.html
next prev parent reply other threads:[~2003-07-02 6:48 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-07-02 0:32 Bernardo Innocenti
[not found] ` <20030701173612.280d1296.akpm@digeo.com>
2003-07-02 2:24 ` Bernardo Innocenti
2003-07-02 2:32 ` Andrew Morton
2003-07-02 3:15 ` Bernardo Innocenti
2003-07-02 5:12 ` Linus Torvalds
2003-07-02 7:53 ` Russell King
2003-07-02 8:14 ` Ian Molton
2003-07-02 5:09 ` Linus Torvalds
2003-07-02 7:02 ` Bernardo Innocenti [this message]
2003-07-02 7:54 ` Matti Aarnio
2003-07-02 3:36 ` Peter Chubb
2003-07-02 4:37 ` Bernardo Innocenti
2003-07-02 5:57 ` Andrea Arcangeli
2003-07-02 6:52 ` Bernardo Innocenti
2003-07-02 7:19 ` Andrea Arcangeli
2003-07-02 7:28 ` Bernardo Innocenti
2003-07-02 8:38 ` Andrea Arcangeli
2003-07-02 16:16 ` Linus Torvalds
2003-07-03 10:43 ` [PATCH] Fix do_div() for all architectures Bernardo Innocenti
2003-07-02 7:56 ` [PATCH] Kill div64.h dupes, parenthesize do_div() macro params Russell King
2003-07-02 5:06 ` Linus Torvalds
2003-07-02 14:23 ` Geert Uytterhoeven
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