From nobody Wed Nov 19 13:25:20 2025 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 1706464544516652.615609280687; Sun, 28 Jan 2024 09:55:44 -0800 (PST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rU9It-0002Rx-S3; Sun, 28 Jan 2024 12:50:51 -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 1rU9I5-0001s5-MD; Sun, 28 Jan 2024 12:50:07 -0500 Received: from isrv.corpit.ru ([86.62.121.231]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rU9I3-0000Uc-Ty; Sun, 28 Jan 2024 12:49:57 -0500 Received: from tsrv.corpit.ru (tsrv.tls.msk.ru [192.168.177.2]) by isrv.corpit.ru (Postfix) with ESMTP id 7FB7D480F3; Sun, 28 Jan 2024 20:49:46 +0300 (MSK) Received: from tls.msk.ru (mjt.wg.tls.msk.ru [192.168.177.130]) by tsrv.corpit.ru (Postfix) with SMTP id 140E26D51A; Sun, 28 Jan 2024 20:48:55 +0300 (MSK) Received: (nullmailer pid 811729 invoked by uid 1000); Sun, 28 Jan 2024 17:48:46 -0000 From: Michael Tokarev To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, Peter Maydell , Richard Henderson , Michael Tokarev Subject: [Stable-8.1.5 36/36] target/arm: Fix A64 scalar SQSHRN and SQRSHRN Date: Sun, 28 Jan 2024 20:48:41 +0300 Message-Id: <20240128174845.811654-12-mjt@tls.msk.ru> X-Mailer: git-send-email 2.39.2 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=86.62.121.231; envelope-from=mjt@tls.msk.ru; helo=isrv.corpit.ru X-Spam_score_int: -68 X-Spam_score: -6.9 X-Spam_bar: ------ X-Spam_report: (-6.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_HI=-5, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 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: 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: 1706464546115100005 Content-Type: text/plain; charset="utf-8" From: Peter Maydell In commit 1b7bc9b5c8bf374dd we changed handle_vec_simd_sqshrn() so that instead of starting with a 0 value and depositing in each new element from the narrowing operation, it instead started with the raw result of the narrowing operation of the first element. This is fine in the vector case, because the deposit operations for the second and subsequent elements will always overwrite any higher bits that might have been in the first element's result value in tcg_rd. However in the scalar case we only go through this loop once. The effect is that for a signed narrowing operation, if the result is negative then we will now return a value where the bits above the first element are incorrectly 1 (because the narrowfn returns a sign-extended result, not one that is truncated to the element size). Fix this by using an extract operation to get exactly the correct bits of the output of the narrowfn for element 1, instead of a plain move. Cc: qemu-stable@nongnu.org Fixes: 1b7bc9b5c8bf374dd3 ("target/arm: Avoid tcg_const_ptr in handle_vec_s= imd_sqshrn") Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2089 Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 20240123153416.877308-1-peter.maydell@linaro.org (cherry picked from commit 6fffc8378562c7fea6290c430b4f653f830a4c1a) Signed-off-by: Michael Tokarev diff --git a/target/arm/tcg/translate-a64.c b/target/arm/tcg/translate-a64.c index 7267f172d7..4e54cb7502 100644 --- a/target/arm/tcg/translate-a64.c +++ b/target/arm/tcg/translate-a64.c @@ -8116,7 +8116,7 @@ static void handle_vec_simd_sqshrn(DisasContext *s, b= ool is_scalar, bool is_q, narrowfn(tcg_rd_narrowed, cpu_env, tcg_rd); tcg_gen_extu_i32_i64(tcg_rd, tcg_rd_narrowed); if (i =3D=3D 0) { - tcg_gen_mov_i64(tcg_final, tcg_rd); + tcg_gen_extract_i64(tcg_final, tcg_rd, 0, esize); } else { tcg_gen_deposit_i64(tcg_final, tcg_final, tcg_rd, esize * i, e= size); } --=20 2.39.2