From: Paul Brook <paul@codesourcery.com>
To: qemu-devel@nongnu.org
Cc: Rodrigo Vivi <rodrigo.vivi@gmail.com>,
Lauro Ramos Venancio <lauro.venancio@indt.org.br>
Subject: Re: [Qemu-devel] qemu-arm: wrong execution of post-indexed loads when Rm and Rd are the same register
Date: Thu, 15 Mar 2007 21:10:39 +0000 [thread overview]
Message-ID: <200703152110.39814.paul@codesourcery.com> (raw)
In-Reply-To: <bdb0025f0703151332j36d31aa7i6ee2cea9bfb29a94@mail.gmail.com>
> > This is still wrong.
>
> So, is this a known bug?
Still wrong implies it's a bug, and your patch does not fix it properly.
> > The writeback must happen after the load.
>
> We code like this because
> - we didn't find this restriction in arm reference manual
It's the Abort model section you mention below.
> - the LLVM uses this instruction expecting a result like this
The compiler knows nothing about the abort behavior. The difference is only
visible if the load faults.
> - That was the result that we got running these instructions in an OMAP1710
I suggest you check again. I'm fairly sure the arm926 implements the Base
Restored abort model.
Paul
next prev parent reply other threads:[~2007-03-15 21:11 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-03-15 19:35 [Qemu-devel] qemu-arm: wrong execution of post-indexed loads when Rm and Rd are the same register Lauro Ramos Venancio
2007-03-15 19:43 ` [Qemu-devel] " Lauro Ramos Venancio
2007-03-15 20:03 ` [Qemu-devel] " Paul Brook
2007-03-15 20:32 ` Rodrigo Vivi
2007-03-15 21:10 ` Paul Brook [this message]
2007-03-15 21:19 ` Rodrigo Vivi
2007-03-15 21:55 ` Laurent Desnogues
2007-03-15 22:04 ` Paul Brook
2007-03-16 20:42 ` Lauro Ramos Venancio
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