From: Laurent Desnogues <laurent.desnogues@gmail.com>
To: Jakub Jermar <jakub@jermar.eu>
Cc: HelenOS development mailing list <helenos-devel@lists.modry.cz>,
qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [HelenOS-devel] [sparc64] Miscomputed minimum of a group of numbers in sparc64 emulation
Date: Fri, 1 Jul 2011 16:24:39 +0200 [thread overview]
Message-ID: <BANLkTi=f1tbZSx=tp9OUAOML+mFCWXmW2A@mail.gmail.com> (raw)
In-Reply-To: <4E0DD58C.2070001@jermar.eu>
On Fri, Jul 1, 2011 at 4:11 PM, Jakub Jermar <jakub@jermar.eu> wrote:
[...]
> Actually, the testcase can be further reduced into:
>
> .global _start
>
> .text
>
> .space 0x20
>
> _start:
> set 110393, %i1
> set 0x40, %i2
>
> cmp %i1, %i2
> udivx %g0, 1, %g0
> movgu %xcc, %i2, %i1
> cmp %i1, 512
> bgu %xcc, 0f
> nop
>
> succ:
> ta 0
>
> fail:
> 0:
> ta 1
>
> The presence of the `udivx` instruction seems to be essential. Even
> though it has no effect on the computation, removing it will make the
> testcase non-reproducible.
Could you try to replace udivx with sdivx? It looks wrong too.
Laurent
next prev parent reply other threads:[~2011-07-01 14:24 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-06-30 21:12 [Qemu-devel] [sparc64] Miscomputed minimum of a group of numbers in sparc64 emulation Jakub Jermar
2011-07-01 9:15 ` [Qemu-devel] [HelenOS-devel] " Artyom Tarasenko
2011-07-01 9:36 ` Jakub Jermar
2011-07-01 10:41 ` Artyom Tarasenko
2011-07-01 12:57 ` Jakub Jermar
2011-07-01 14:11 ` Jakub Jermar
2011-07-01 14:24 ` Laurent Desnogues [this message]
2011-07-01 14:28 ` Jakub Jermar
2011-07-01 15:08 ` Artyom Tarasenko
2011-07-01 14:15 ` Laurent Desnogues
2011-07-01 14:21 ` Jakub Jermar
2011-07-01 15:03 ` Artyom Tarasenko
2011-07-01 15:20 ` Laurent Desnogues
2011-07-01 15:53 ` Artyom Tarasenko
2011-07-01 16:14 ` Artyom Tarasenko
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