public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: "H. Peter Anvin" <hpa@zytor.com>
To: eranian@hpl.hp.com
Cc: linux-kernel@vger.kernel.org
Subject: Re: i386 and x86-64 bitops function prototypes differ
Date: Fri, 26 Jan 2007 09:49:54 -0800	[thread overview]
Message-ID: <45BA3F42.3020006@zytor.com> (raw)
In-Reply-To: <20070126143555.GL11525@frankl.hpl.hp.com>

Stephane Eranian wrote:
> Hello,
> 
> I ran into compiler warnings with the perfmon code when I tried
> using test() and __set_bit() on i386. 
> 
> For some reason, the i386 bitops functions use unsigned long * for
> the address whereas x86-64/ia64 use void *.
> 
> I do not quite understand why such difference?
> Is this just for historical reasons?
> 
> Thanks.
> 

Arguably void * is the right thing for a littleendian architecture.  For 
bigendian architectures it unfortunately matters what the chunk size is, 
regardless of if the chunks are numbered in bigendian (reverse) or 
littleendian (forward) order.

	-hpa

  reply	other threads:[~2007-01-26 17:54 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-01-26 14:35 i386 and x86-64 bitops function prototypes differ Stephane Eranian
2007-01-26 17:49 ` H. Peter Anvin [this message]
2007-02-01  9:15   ` Stephane Eranian
2007-02-01 22:55     ` Andrew Morton
2007-02-01 23:27       ` Stephane Eranian
2007-02-02  7:12       ` Andi Kleen

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=45BA3F42.3020006@zytor.com \
    --to=hpa@zytor.com \
    --cc=eranian@hpl.hp.com \
    --cc=linux-kernel@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox