Hi, all:

I've been trying to understand the pro= cess of binary translation inside TCG.

= If I haven't misunderstood, qemu_ld/st are the operations that will call=20 helper function(ld_mmu) to let softmmu translate the GVA->GPA for the guest load/store instructions.

So there are some points that I hope you c= an help me out:

1. Is every guest load/store instruction would be translate= d to qemu_ld/st IR?

2. What about another TCG IR "ld/st"? What kind of gue= st instructions would cause TCG generates that IRs and for what purpose?

Any reply would be helpful to me. Thanks in advance.

<= /html> ------=_Part_306256_322467562.1432383983547-- From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41433) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YwHpV-00054L-7s for qemu-devel@nongnu.org; Sat, 23 May 2015 18:23:42 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YwHpS-0001JW-2h for qemu-devel@nongnu.org; Sat, 23 May 2015 18:23:41 -0400 Received: from mail-pa0-x22a.google.com ([2607:f8b0:400e:c03::22a]:33472) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YwHpR-0001JS-Ry for qemu-devel@nongnu.org; Sat, 23 May 2015 18:23:38 -0400 Received: by padbw4 with SMTP id bw4so45188784pad.0 for ; Sat, 23 May 2015 15:23:37 -0700 (PDT) Sender: Richard Henderson Message-ID: <5560FD66.4040400@twiddle.net> Date: Sat, 23 May 2015 15:21:26 -0700 From: Richard Henderson MIME-Version: 1.0 References: <636961558.306257.1432383983549.JavaMail.yahoo@mail.yahoo.com> In-Reply-To: <636961558.306257.1432383983549.JavaMail.yahoo@mail.yahoo.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Subject: Re: [Qemu-devel] What's the difference between "ld/st" and "qemu_ld/st" in TCG IR? List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: =?UTF-8?B?5rWp5YCrIOmtjw==?= , "qemu-devel@nongnu.org" On 05/23/2015 05:26 AM, 浩倫魏 wrote: > So there are some points that I hope you can help me out: > 1. Is every guest load/store instruction would be translated to qemu_ld/st IR? Yes. > 2. What about another TCG IR "ld/st"? What kind of guest instructions would > cause TCG generates that IRs and for what purpose? For instance, vector instructions are often implemented without TCG temporaries, but instead using ld/st to load the data from the ENV pointer directly. You can see that in the ARM and i386 targets. Otherwise, there are sometimes less-used system values that do not warrent a TCG temporary. You can see that in the alpha target. r~ From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48826) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YwJVU-0007xN-PB for qemu-devel@nongnu.org; Sat, 23 May 2015 20:11:12 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YwJVN-0003HZ-Qs for qemu-devel@nongnu.org; Sat, 23 May 2015 20:11:08 -0400 Received: from nm5-vm0.bullet.mail.tp2.yahoo.com ([203.188.200.216]:59827) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YwJVN-0003H4-9E for qemu-devel@nongnu.org; Sat, 23 May 2015 20:11:01 -0400 Date: Sun, 24 May 2015 00:10:58 +0000 (UTC) From: =?UTF-8?B?5rWp5YCrIOmtjw==?= Message-ID: <1311292936.348274.1432426258425.JavaMail.yahoo@mail.yahoo.com> In-Reply-To: <5560FD66.4040400@twiddle.net> References: <5560FD66.4040400@twiddle.net> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_348273_1483325644.1432426258423" Subject: Re: [Qemu-devel] What's the difference between "ld/st" and "qemu_ld/st" in TCG IR? Reply-To: =?UTF-8?B?5rWp5YCrIOmtjw==?= List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Richard Henderson , "qemu-devel@nongnu.org" ------=_Part_348273_1483325644.1432426258423 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Dear Richard: Now I get it, thanks for the help! :-) =20 Richard Henderson =E6=96=BC 2015/5/24 (=E9=80=B1=E6= =97=A5) 6:21 AM =E5=AF=AB=E9=81=93=EF=B9=95 =20 On 05/23/2015 05:26 AM, =E6=B5=A9=E5=80=AB =E9=AD=8F wrote: > So there are some points that I hope you can help me out: > 1. Is every guest load/store instruction would be translated to qemu_ld/s= t IR? Yes. > 2. What about another TCG IR "ld/st"? What kind of guest instructions wou= ld > cause TCG generates that IRs and for what purpose? For instance, vector instructions are often implemented without TCG=20 temporaries, but instead using ld/st to load the data from the ENV pointer= =20 directly.=C2=A0 You can see that in the ARM and i386 targets. Otherwise, there are sometimes less-used system values that do not warrent = a=20 TCG temporary.=C2=A0 You can see that in the alpha target. r~ ------=_Part_348273_1483325644.1432426258423 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable

Dear Richard:

Now I get it, thanks for the help! :-)

Richa= rd Henderson <rth@twiddle.net> =E6=96=BC 2015/5/24 (=E9=80=B1=E6=97= =A5) 6:21 AM =E5=AF=AB=E9=81=93=EF=B9=95

On 05/23/2015 05:26 AM, =E6=B5=A9=E5=80=AB =E9=AD= =8F wrote:
> So there are some points that I hope you = can help me out:
> 1. Is every guest load/store instru= ction would be translated to qemu_ld/st IR?

Yes.

> 2. What about another = TCG IR "ld/st"? What kind of guest instructions would
>= ; cause TCG generates that IRs and for what purpose?

For instance, vector instructions are often implemented with= out TCG
temporaries, but instead using ld/st to load the= data from the ENV pointer
directly. You can see t= hat in the ARM and i386 targets.

Other= wise, there are sometimes less-used system values that do not warrent a TCG temporary. You can see that in the alpha target.<= div class=3D"yqt7881444963" id=3D"yqtfd90548">

r~

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