From nobody Sun May 11 22:20:50 2025
Delivered-To: importer@patchew.org
Authentication-Results: mx.zohomail.com;
dkim=pass;
spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as
permitted sender)
smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org;
dmarc=pass(p=none dis=none) header.from=redhat.com
ARC-Seal: i=1; a=rsa-sha256; t=1734253733; cv=none;
d=zohomail.com; s=zohoarc;
b=UDKBalMLrKfuVpZAjUiWeSxJOl2m3efZD7xBzVuvrs2U7/yAbVcTPuthzhGyhXLHMpc4kmWHW9xqM2xN5vhwhAqZbMTQLGbOhpqILHMy2RHLUISs1p6RrsrLS2CxsDXGrGuPcXmtDHHPcAhOppmR1v5X3qvYEVL+WAtzarGemmQ=
ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com;
s=zohoarc;
t=1734253733;
h=Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:Subject:To:To:Message-Id:Reply-To;
bh=OyQ9wLbCKDjV+T8LPYPoAogaZ9aobQT720NgGO1dskY=;
b=VHeLULxL79OgIRg4hd1AvHcSqTw5bdhJDo4FxZapVVh9VHNkqa4BGCu9y2G0J9oIxKjSzuFZYwnl6ZjE0hKso6kXCrPvyLeXLvrqfca1R9OBGwsyV2ZnKivKsR3whTlT02GY9ktFMBdEDC6Fj456w+MkhsBfdfsQxxktfaspK0k=
ARC-Authentication-Results: i=1; mx.zohomail.com;
dkim=pass;
spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as
permitted sender)
smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org;
dmarc=pass header.from=<pbonzini@redhat.com> (p=none dis=none)
Return-Path: <qemu-devel-bounces+importer=patchew.org@nongnu.org>
Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by
mx.zohomail.com
with SMTPS id 1734253733458419.2110151133877;
Sun, 15 Dec 2024 01:08:53 -0800 (PST)
Received: from localhost ([::1] helo=lists1p.gnu.org)
by lists.gnu.org with esmtp (Exim 4.90_1)
(envelope-from <qemu-devel-bounces@nongnu.org>)
id 1tMkaM-0004ZE-JF; Sun, 15 Dec 2024 04:06:46 -0500
Received: from eggs.gnu.org ([2001:470:142:3::10])
by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256)
(Exim 4.90_1) (envelope-from <pbonzini@redhat.com>)
id 1tMkaL-0004Yd-4x
for qemu-devel@nongnu.org; Sun, 15 Dec 2024 04:06:45 -0500
Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124])
by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256)
(Exim 4.90_1) (envelope-from <pbonzini@redhat.com>)
id 1tMkaJ-0006yq-GW
for qemu-devel@nongnu.org; Sun, 15 Dec 2024 04:06:44 -0500
Received: from mail-wm1-f70.google.com (mail-wm1-f70.google.com
[209.85.128.70]) by relay.mimecast.com with ESMTP with STARTTLS
(version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id
us-mta-630-2KNboUw-PR--IDjg476Y2g-1; Sun, 15 Dec 2024 04:06:41 -0500
Received: by mail-wm1-f70.google.com with SMTP id
5b1f17b1804b1-436228ebc5eso345425e9.3
for <qemu-devel@nongnu.org>; Sun, 15 Dec 2024 01:06:40 -0800 (PST)
Received: from [192.168.10.3] ([151.81.118.45])
by smtp.gmail.com with ESMTPSA id
5b1f17b1804b1-436255531b1sm106296625e9.2.2024.12.15.01.06.37
(version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256);
Sun, 15 Dec 2024 01:06:37 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com;
s=mimecast20190719; t=1734253602;
h=from:from:reply-to:subject:subject:date:date:message-id:message-id:
to:to:cc:cc:mime-version:mime-version:
content-transfer-encoding:content-transfer-encoding:
in-reply-to:in-reply-to:references:references;
bh=OyQ9wLbCKDjV+T8LPYPoAogaZ9aobQT720NgGO1dskY=;
b=O/uXSGAHbif23rhze7e/ZQxQww8XsPuB4nsqbpSptcN0IKBrY17I5trTGpFX4Et1UkCdXY
TfQwOENm6uLJj/JB/Zset72kECySws11l6P4O4Bp9s4dmVXVldrJGmqh8y6B36ZduANCyR
fXLUEvCBYgkOmoM/fBBx0eSxnB4ebPw=
X-MC-Unique: 2KNboUw-PR--IDjg476Y2g-1
X-Mimecast-MFC-AGG-ID: 2KNboUw-PR--IDjg476Y2g
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
d=1e100.net; s=20230601; t=1734253599; x=1734858399;
h=content-transfer-encoding:mime-version:references:in-reply-to
:message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc
:subject:date:message-id:reply-to;
bh=OyQ9wLbCKDjV+T8LPYPoAogaZ9aobQT720NgGO1dskY=;
b=Z1DKw44bcrLbrX1FchkTc4jc7JsyYZthpXhOuNX+n3B9NaGNuwTSjJUGTgfsBSHTN4
4AiivCqmwKePPD09Bc3O7v6yczzj5ZyRI0iD/oj7BG3Ql/bW/A+EcHkxHBR90B+taPuw
LhYVSBp8LnX0tSUIQ9Mrq4R4CEO2dymDLchjeoCWhSkegzBSW3EU6LhQgoR6rqjKS5+r
kKNiZW8PYd2uMeU6Y3v7xaNz5INxEP2cfF7xeYAwok1ljj4aLVNrOESeWlfDLXIg3yuA
YJJwzcB0qq9cbVTZ6eFJlBbqCVMi54YJcn9KrakidOQvo+sWhais/hOxRZck0lS3pii8
6EFg==
X-Gm-Message-State: AOJu0YyFXwry+feK/u1BEQxIRd3XQ9w+XkrXpURT/bnEVeckXEXsQU1N
iod4vmxPvn1K8d2/MqW9t9bsoOWMekdwEUDwEDRqAr/wFgB4/bo/sKQQv3sGURpku8NIh20wLnj
JkdrVYGExVN6Xegjcvdx84XQ9ktrEu3QMyT2w6ui/lwPm+9NDxYSECTyT9c7gxxDG2e6tu7sSa6
EMoCQRTW1TbdEaatWPwAjpxttk8ayuIAhcSx3X
X-Gm-Gg: ASbGncvqUCBwp3M+4g+HCop/qkmnKP8l24WygozvB6iA4/o+X9eq9OXbhWp/jp8PLvM
kc5tn8btTR4z6IxVXiXJ9zkWeXnZVSsPwwZpmii07L2UyNbkYRM+/G8puXBvVUKyMfcT1PoyLD0
KMCJfi36ERpMlR8Z/FtcVCYIoAB7ImfLi5W0bfd2hII4b4/KIWhRRg7m5Hyz2eFLBmxNFcgjxZm
RWSKsu+T3M+wLF5LNYtUlTHpUA3+fWpYrlLA05thGFSlEZGCn6hv7k4jBU=
X-Received: by 2002:a05:600c:1e87:b0:436:2923:d23a with SMTP id
5b1f17b1804b1-4362aaaacdemr67798715e9.33.1734253599047;
Sun, 15 Dec 2024 01:06:39 -0800 (PST)
X-Google-Smtp-Source:
AGHT+IEY6XxQ1kkFUAQYQchIxSuLl6sJEOV/OkesHZY8hxwQkH9d9IWdxbWI4eM49e+N9LO5rrofOA==
X-Received: by 2002:a05:600c:1e87:b0:436:2923:d23a with SMTP id
5b1f17b1804b1-4362aaaacdemr67798335e9.33.1734253598557;
Sun, 15 Dec 2024 01:06:38 -0800 (PST)
From: Paolo Bonzini <pbonzini@redhat.com>
To: qemu-devel@nongnu.org
Cc: richard.henderson@linaro.org
Subject: [PATCH 08/13] target/i386: make cc_op handling more explicit for
repeated string instructions.
Date: Sun, 15 Dec 2024 10:06:07 +0100
Message-ID: <20241215090613.89588-9-pbonzini@redhat.com>
X-Mailer: git-send-email 2.47.1
In-Reply-To: <20241215090613.89588-1-pbonzini@redhat.com>
References: <20241215090613.89588-1-pbonzini@redhat.com>
MIME-Version: 1.0
Content-Transfer-Encoding: quoted-printable
Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17
as permitted sender) client-ip=209.51.188.17;
envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org;
helo=lists.gnu.org;
Received-SPF: pass client-ip=170.10.133.124;
envelope-from=pbonzini@redhat.com;
helo=us-smtp-delivery-124.mimecast.com
X-Spam_score_int: -23
X-Spam_score: -2.4
X-Spam_bar: --
X-Spam_report: (-2.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.292,
DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1,
RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001,
RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001,
RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001,
SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no
X-Spam_action: no action
X-BeenThere: qemu-devel@nongnu.org
X-Mailman-Version: 2.1.29
Precedence: list
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: <https://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>
Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org
Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org
X-ZohoMail-DKIM: pass (identity @redhat.com)
X-ZM-MESSAGEID: 1734253735509116600
Content-Type: text/plain; charset="utf-8"
Since the cost of gen_update_cc_op() must be paid anyway, it's easier
to place them manually and not rely on spilling that is buried under
multiple levels of function calls.
And since cc_op will have been spilled at the point of a fault, just
make the whole insn CC_OP_DYNAMIC. Once repz_opt is reintroduced,
a fault could happen either before or after the first execution of
CMPS/SCAS, and CC_OP_DYNAMIC sidesteps the complicated matter of what
x86_restore_state_to_opc would do.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
target/i386/tcg/translate.c | 17 ++++++++++++++++-
1 file changed, 16 insertions(+), 1 deletion(-)
diff --git a/target/i386/tcg/translate.c b/target/i386/tcg/translate.c
index 4ff0ccf71cb..4b53a47000e 100644
--- a/target/i386/tcg/translate.c
+++ b/target/i386/tcg/translate.c
@@ -1345,14 +1345,29 @@ static void do_gen_rep(DisasContext *s, MemOp ot,
*/
s->flags &=3D ~HF_RF_MASK;
=20
+ /*
+ * For CMPS/SCAS, the CC_OP after a memory fault could come from either
+ * the previous instruction or the string instruction; but because we
+ * arrange to keep CC_OP up to date all the time, just mark the whole
+ * insn as CC_OP_DYNAMIC.
+ *
+ * It's not a problem to do this even for instructions that do not
+ * modify the flags, so do it unconditionally.
+ */
gen_update_cc_op(s);
+ tcg_set_insn_start_param(s->base.insn_start, 1, CC_OP_DYNAMIC);
+
+ /* Any iteration at all? */
gen_op_jz_ecx(s, done);
=20
fn(s, ot);
gen_op_add_reg_im(s, s->aflag, R_ECX, -1);
+ gen_update_cc_op(s);
+
+ /* Leave if REP condition fails. */
if (is_repz_nz) {
int nz =3D (s->prefix & PREFIX_REPNZ) ? 1 : 0;
- gen_jcc(s, (JCC_Z << 1) | (nz ^ 1), done);
+ gen_jcc_noeob(s, (JCC_Z << 1) | (nz ^ 1), done);
}
=20
/*
--=20
2.47.1