Linux PARISC architecture development
 help / color / mirror / Atom feed
From: Grant Grundler <grundler@parisc-linux.org>
To: Joel Soete <joel.soete@tiscali.be>
Cc: parisc-linux@lists.parisc-linux.org
Subject: Re: [parisc-linux] a fast fls also for 2.6?
Date: Fri, 5 Sep 2003 13:29:27 -0600	[thread overview]
Message-ID: <20030905192927.GD10216@dsl2.external.hp.com> (raw)
In-Reply-To: <20030905182621.GC10216@dsl2.external.hp.com>

On Fri, Sep 05, 2003 at 12:26:21PM -0600, Grant Grundler wrote:
> > Without any remark, I don't know if you could also be interested to 
> > include it in 2.6.
> 
> no - becuase fls() and ffs() return the same values for given input.
> (I see comments in include/asm-ppc/bitops.h to that effect).

James Bottomley privately corrected me. fls() != ffs().
fls() returns most significant bit set.

The examples provided:
	* Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.

have the same value for ffs() and fls(). I didn't read the rest.
Good examples for showing bit numbering though.

I'll work on adding 64-bit support to your __fls() and commit that.

sorry for the confusion,
grant

  parent reply	other threads:[~2003-09-05 19:29 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <3F58838A.9010203@tiscali.be>
     [not found] ` <3F5888F3.5060609@tiscali.be>
2003-09-05 18:26   ` [parisc-linux] a fast fls also for 2.6? Grant Grundler
2003-09-05 19:26     ` Joel Soete
2003-09-05 19:29     ` Grant Grundler [this message]
2003-09-05 19:54       ` Joel Soete
2003-08-07 15:37 Joel Soete

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=20030905192927.GD10216@dsl2.external.hp.com \
    --to=grundler@parisc-linux.org \
    --cc=joel.soete@tiscali.be \
    --cc=parisc-linux@lists.parisc-linux.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