From: malc <av1474@comtv.ru>
To: Richard Henderson <rth@twiddle.net>
Cc: Vic3Dexe <vic3dexe@gmail.com>,
qemu-devel@nongnu.org, Bug 600589 <600589@bugs.launchpad.net>
Subject: Re: [Qemu-devel] [Bug 600589] [NEW] xchg r8,rax treated as nop
Date: Thu, 1 Jul 2010 20:43:06 +0400 (MSD) [thread overview]
Message-ID: <alpine.LNX.2.00.1007012042260.17554@linmac> (raw)
In-Reply-To: <4C2CBF86.4060100@twiddle.net>
On Thu, 1 Jul 2010, Richard Henderson wrote:
> On 07/01/2010 05:04 AM, Vic3Dexe wrote:
> > Public bug reported:
> >
> > xchg r8,rax (49h 90h) executed as nop (90h) in long mode, in other words
> > REX not used.
> >
> > qemu 0.12.4, host Win 7 x64, running qemu-system-x86_64.exe.
> >
> > ** Affects: qemu
> > Importance: Undecided
> > Status: New
> >
>
> Verified. Test case for x86_64-linux-user:
>
> .globl main
> .type main, @function
> main:
> movl $0, %r8d
> movl $1, %eax
> xchgq %r8, %rax
> ret
>
> Expected result is exit status 0.
>
No surprise really:
target-i386/translate.c lines 6665-...
case 0x90: /* nop */
/* XXX: xchg + rex handling */
/* XXX: correct lock test for all insn */
The code to handle that just isn't there.
--
mailto:av1474@comtv.ru
next prev parent reply other threads:[~2010-07-01 16:43 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-07-01 12:04 [Qemu-devel] [Bug 600589] [NEW] xchg r8,rax treated as nop Vic3Dexe
2010-07-01 16:17 ` Richard Henderson
2010-07-01 16:42 ` [Qemu-devel] [PATCH] target-i386: Fix xchg rax,r8 Richard Henderson
2010-07-01 21:52 ` Aurelien Jarno
2010-07-01 16:43 ` malc [this message]
2010-07-02 19:13 ` [Qemu-devel] [Bug 600589] [NEW] xchg r8,rax treated as nop vic3dexe
2010-07-02 20:08 ` Richard Henderson
2010-07-06 13:00 ` [Qemu-devel] [Bug 600589] " Jes Sorensen
2011-02-20 17:13 ` Aurelien Jarno
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