All of lore.kernel.org
 help / color / mirror / Atom feed
From: HongWoo Lee <hongwoo7@gmail.com>
To: linuxppc-dev@lists.ozlabs.org
Subject: Question : about difference with bdnz and bdnz+
Date: Thu, 27 Aug 2009 14:04:35 +0900	[thread overview]
Message-ID: <4A9613E3.8020700@gmail.com> (raw)

Hi ~

I found the code in the linux kernel.

static __inline__ void clear_page(void *addr)
{
    unsigned long lines, line_size;
    line_size = cpu_caches.dline_size;
    lines = cpu_caches.dlines_per_page;

    __asm__ __volatile__(
            "mtctr  %1      # clear_page\n\
            1:  dcbz    0,%0\n\
            add     %0,%0,%3\n\
            bdnz+   1b"
            : "=r" (addr)
            : "r" (lines), "0" (addr), "r" (line_size)
            : "ctr", "memory");
}

And I have a question about bdnz+ instruction.
Through googling, I learned that bdnz does decrement count register and 
branch if it is still nonzero.
But I couldn't find what "bdnz+" is.
Can anybody explain to me what it is ??

Thanks in advance.

HongWoo.

             reply	other threads:[~2009-08-27  5:04 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-08-27  5:04 HongWoo Lee [this message]
2009-08-27  9:30 ` Question : about difference with bdnz and bdnz+ Benjamin Herrenschmidt

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=4A9613E3.8020700@gmail.com \
    --to=hongwoo7@gmail.com \
    --cc=linuxppc-dev@lists.ozlabs.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.