linuxppc-dev.lists.ozlabs.org archive mirror
 help / color / mirror / Atom feed
From: Michael Neuling <mikey@neuling.org>
To: ananth@in.ibm.com
Cc: linuxppc-dev@ozlabs.org, Paul Mackerras <paulus@samba.org>,
	Srikar Dronamraju <srikar@linux.vnet.ibm.com>,
	"K.Prasad" <prasad@linux.vnet.ibm.com>
Subject: Re: [RFC PATCH] powerpc: Emulate nop too
Date: Fri, 28 May 2010 14:23:30 +1000	[thread overview]
Message-ID: <7278.1275020610@neuling.org> (raw)
In-Reply-To: <20100528041645.GB25946@in.ibm.com>



In message <20100528041645.GB25946@in.ibm.com> you wrote:
> On Fri, May 28, 2010 at 12:28:43PM +1000, Michael Neuling wrote:
> > 
> > 
> > In message <20100527141203.GA20770@in.ibm.com> you wrote:
> > > Hi Paul,
> > > 
> > > While we are at it, can we also add nop to the list of emulated
> > > instructions?
> > > 
> > > Ananth
> > > ---
> > > From: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
> > > 
> > > Emulate ori 0,0,0 (nop).
> > > 
> > > The long winded way is to do:
> > > 
> > >         case 24:
> > >                 rd = (instr >> 21) & 0x1f;
> > >                 if (rd != 0)
> > >                         break;
> > >                 rb = (instr >> 11) & 0x1f;
> > >                 if (rb != 0)
> > >                         break;
> > 
> > Don't we just need rb == rd?
> 
> Sure. But for this case, just checking against the opcode seems simple
> enough.

Simple, sure.  You could not emulate anything and remove the code
altogether.  That would be truly simple. :-P

Why not eliminate as much as possible?

Anyway, sounds like paulus as a better solution.

Mikey

  reply	other threads:[~2010-05-28  4:23 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-05-20 12:49 [RFC PATCH] powerpc: Emulate most load and store instructions in emulate_step() Paul Mackerras
2010-05-21 16:35 ` Milton Miller
2010-05-27 14:12 ` [RFC PATCH] powerpc: Emulate nop too Ananth N Mavinakayanahalli
2010-05-27 20:22   ` Kumar Gala
2010-05-28  3:52     ` Ananth N Mavinakayanahalli
2010-05-28  2:05   ` Paul Mackerras
2010-05-28  5:19     ` powerpc: remove resume_execution() in kprobes Ananth N Mavinakayanahalli
2010-05-28  2:28   ` [RFC PATCH] powerpc: Emulate nop too Michael Neuling
2010-05-28  4:16     ` Ananth N Mavinakayanahalli
2010-05-28  4:23       ` Michael Neuling [this message]
2010-05-28  5:54         ` Ananth N Mavinakayanahalli
2010-06-02  5:25 ` [RFC PATCH] powerpc: Emulate most load and store instructions in emulate_step() K.Prasad
2010-06-02  6:00   ` Paul Mackerras

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=7278.1275020610@neuling.org \
    --to=mikey@neuling.org \
    --cc=ananth@in.ibm.com \
    --cc=linuxppc-dev@ozlabs.org \
    --cc=paulus@samba.org \
    --cc=prasad@linux.vnet.ibm.com \
    --cc=srikar@linux.vnet.ibm.com \
    /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).