From: malc <av1474@comtv.ru>
To: Andriy Gapon <avg@FreeBSD.org>
Cc: qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] bug in popcnt emulation with some register operand(s)?
Date: Mon, 8 Oct 2012 11:52:30 +0400 (MSK) [thread overview]
Message-ID: <alpine.LNX.2.00.1210081152040.2993@linmac> (raw)
In-Reply-To: <50720C75.30109@FreeBSD.org>
On Mon, 8 Oct 2012, Andriy Gapon wrote:
>
> I am running Qemu (plain, no kvm, etc) on an AMD 10h machine that
> provides popcnt instruction. Qemu advertises availability of pocnt
> to a guest as well. What I see in the guest that popcnt
> 0x20(%r12),%r8 instruction actually placed its result into %rax.
> With %rdi and %rax operands the instruction worked fine though.
>
>
Does following work?
diff --git a/target-i386/translate.c b/target-i386/translate.c
index e896abf..c36cc3e 100644
--- a/target-i386/translate.c
+++ b/target-i386/translate.c
@@ -7818,7 +7818,7 @@ static target_ulong disas_insn(DisasContext *s, target_ulong pc_start)
goto illegal_op;
modrm = cpu_ldub_code(cpu_single_env, s->pc++);
- reg = ((modrm >> 3) & 7);
+ reg = ((modrm >> 3) & 7) | rex_r;
if (s->prefix & PREFIX_DATA)
ot = OT_WORD;
--
mailto:av1474@comtv.ru
next prev parent reply other threads:[~2012-10-08 7:52 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-07 23:12 [Qemu-devel] bug in popcnt emulation with some register operand(s)? Andriy Gapon
2012-10-08 7:52 ` malc [this message]
2012-10-08 9:02 ` Andriy Gapon
2012-10-10 21:03 ` Andriy Gapon
2012-10-10 21:09 ` malc
2012-10-14 10:25 ` Andriy Gapon
2012-10-14 10:56 ` malc
2012-10-14 11:01 ` Andriy Gapon
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