From nobody Tue Feb 10 09:01:59 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; 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 Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1770066387198311.18187566313236; Mon, 2 Feb 2026 13:06:27 -0800 (PST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1vn14B-00054H-A8; Mon, 02 Feb 2026 16:02:39 -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 ) id 1vn13S-0002ak-Me; Mon, 02 Feb 2026 16:01:55 -0500 Received: from isrv.corpit.ru ([212.248.84.144]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1vn13Q-0004WJ-W9; Mon, 02 Feb 2026 16:01:54 -0500 Received: from tsrv.corpit.ru (tsrv.tls.msk.ru [192.168.177.2]) by isrv.corpit.ru (Postfix) with ESMTP id 723AC1851B0; Mon, 02 Feb 2026 23:57:54 +0300 (MSK) Received: from think4mjt.tls.msk.ru (mjtthink.wg.tls.msk.ru [192.168.177.146]) by tsrv.corpit.ru (Postfix) with ESMTP id 3BF4835B327; Mon, 02 Feb 2026 23:58:36 +0300 (MSK) From: Michael Tokarev To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, Laurent Vivier , Richard Henderson , Michael Tokarev Subject: [Stable-10.1.4 36/74] m68k: fix CAS2 writeback when Dc1==Dc2 Date: Mon, 2 Feb 2026 23:57:47 +0300 Message-ID: <20260202205833.941615-36-mjt@tls.msk.ru> X-Mailer: git-send-email 2.47.3 In-Reply-To: References: 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=212.248.84.144; envelope-from=mjt@tls.msk.ru; helo=isrv.corpit.ru X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_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 development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZM-MESSAGEID: 1770066389948154100 Content-Type: text/plain; charset="utf-8" From: Laurent Vivier According to Programmer's Reference Manual, if Dc1 and Dc2 specify the same data register and the comparison fails, memory operand 1 is stored in the data register. The current helpers wrote Dc1 then Dc2, leaving operand 2 in the shared register. Swap the writeback order for cas2w/cas2l so memory operand 1 wins. Signed-off-by: Laurent Vivier Reviewed-by: Richard Henderson Message-ID: <20251226213707.331741-1-laurent@vivier.eu> (cherry picked from commit 11dac41f2e830bcd7ba74969dc50f5740e3ce7e7) Signed-off-by: Michael Tokarev diff --git a/target/m68k/op_helper.c b/target/m68k/op_helper.c index f29ae12af8..b40cc02c65 100644 --- a/target/m68k/op_helper.c +++ b/target/m68k/op_helper.c @@ -777,8 +777,8 @@ void HELPER(cas2w)(CPUM68KState *env, uint32_t regs, ui= nt32_t a1, uint32_t a2) env->cc_v =3D c2; } env->cc_op =3D CC_OP_CMPW; - env->dregs[Dc1] =3D deposit32(env->dregs[Dc1], 0, 16, l1); env->dregs[Dc2] =3D deposit32(env->dregs[Dc2], 0, 16, l2); + env->dregs[Dc1] =3D deposit32(env->dregs[Dc1], 0, 16, l1); } =20 static void do_cas2l(CPUM68KState *env, uint32_t regs, uint32_t a1, uint32= _t a2, @@ -839,8 +839,8 @@ static void do_cas2l(CPUM68KState *env, uint32_t regs, = uint32_t a1, uint32_t a2, env->cc_v =3D c2; } env->cc_op =3D CC_OP_CMPL; - env->dregs[Dc1] =3D l1; env->dregs[Dc2] =3D l2; + env->dregs[Dc1] =3D l1; } =20 void HELPER(cas2l)(CPUM68KState *env, uint32_t regs, uint32_t a1, uint32_t= a2) --=20 2.47.3