From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([208.118.235.92]:49387)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <agraf@suse.de>) id 1UZPVb-0006UU-A0
	for qemu-devel@nongnu.org; Mon, 06 May 2013 13:47:32 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <agraf@suse.de>) id 1UZPVZ-00021o-Vt
	for qemu-devel@nongnu.org; Mon, 06 May 2013 13:47:31 -0400
Message-ID: <5187ECAD.4050901@suse.de>
Date: Mon, 06 May 2013 19:47:25 +0200
From: Alexander Graf <agraf@suse.de>
MIME-Version: 1.0
References: <86sj20rql4.fsf@shell.gmplib.org>
In-Reply-To: <86sj20rql4.fsf@shell.gmplib.org>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Subject: Re: [Qemu-devel] Incorrect handling of PPC64 rldcl insn
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Torbjorn Granlund <tg@gmplib.org>
Cc: "<qemu-ppc@nongnu.org>" <qemu-ppc@nongnu.org>, qemu-devel@nongnu.org

On 05/06/2013 07:00 PM, Torbjorn Granlund wrote:
> I could finally make Debian GNU/Linux install and run under
> qemu-system-ppc64.  I used Debian 7.0.0 and qemu from the main git repo,
> updated a few days ago.
>
> While Debian runs well and not too slowly, GMP fails badly under all
> ABIs, and in many different ways.  I have isolated the first problem.
>
> Test case:
>
> #include<stdio.h>
> int
> main ()
> {
>    unsigned long r;
>    asm ("rldcl\t%0, %1, %2, 0" : "=r" (r) : "r" (0xcafebabedeadbeeful), "r" (16));
>    printf ("%lx\n", r);
>    return 0;
> }
>
> Expected output:
> babedeadbeefcafe
>
> Output under qemu:
> 0
>
> I have single stepped in gdb to determine that it is indeed rldcl that
> misbehaves.

Thanks a lot for the bug report and test case! Please CC qemu-ppc 
whenever you find issues or have patches for PPC. That makes filtering 
for important mails a lot easier.

Does the patch below fix the issue for you?


Alex

diff --git a/target-ppc/translate.c b/target-ppc/translate.c
index 0886f4d..a018616 100644
--- a/target-ppc/translate.c
+++ b/target-ppc/translate.c
@@ -1733,8 +1733,6 @@ static inline void gen_rldnm(DisasContext *ctx, 
uint32_t mb, uint32_t me)
  {
      TCGv t0;

-    mb = MB(ctx->opcode);
-    me = ME(ctx->opcode);
      t0 = tcg_temp_new();
      tcg_gen_andi_tl(t0, cpu_gpr[rB(ctx->opcode)], 0x3f);
      tcg_gen_rotl_tl(t0, cpu_gpr[rS(ctx->opcode)], t0);