qemu-devel.nongnu.org archive mirror
 help / color / mirror / Atom feed
From: Paul Brook <paul@codesourcery.com>
To: qemu-devel@nongnu.org
Cc: Jun Koi <junkoi2004@gmail.com>
Subject: Re: [Qemu-devel] dummy field in CPUTLBEntry?
Date: Mon, 19 Apr 2010 23:43:26 +0100	[thread overview]
Message-ID: <201004192343.26621.paul@codesourcery.com> (raw)
In-Reply-To: <s2sfdaac4d51004160200ybd50cef7u949ab1625f889ac8@mail.gmail.com>

> I find the way we calculate the dummy field in CPUTLBEntry funny. What
> is the point of having:
> 
>                    ((-sizeof(target_ulong) * 3) & (sizeof(unsigned long) -
>  1))
> 
> in its size? Why shouldnt it be more simple, like below?
> 
>     uint8_t dummy[(1 << CPU_TLB_ENTRY_BITS) - (sizeof(target_ulong) *
> 3 + sizeof(unsigned long))];
> 

No, because of alignment.
Consider the case of 32-bit target_ulong and 64-bit unsigned long).

Paul

      reply	other threads:[~2010-04-19 22:43 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-04-16  9:00 [Qemu-devel] dummy field in CPUTLBEntry? Jun Koi
2010-04-19 22:43 ` Paul Brook [this message]

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=201004192343.26621.paul@codesourcery.com \
    --to=paul@codesourcery.com \
    --cc=junkoi2004@gmail.com \
    --cc=qemu-devel@nongnu.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;
as well as URLs for NNTP newsgroup(s).