From patchwork Wed Mar 30 17:59:25 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Matheus K. Ferst" X-Patchwork-Id: 12796152 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id B7052C433FE for ; Wed, 30 Mar 2022 18:07:26 +0000 (UTC) Received: from localhost ([::1]:48936 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nZcj7-0001Gc-KO for qemu-devel@archiver.kernel.org; Wed, 30 Mar 2022 14:07:25 -0400 Received: from eggs.gnu.org ([209.51.188.92]:41470) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nZcbc-0000Fp-Av; Wed, 30 Mar 2022 13:59:40 -0400 Received: from [187.72.171.209] (port=21948 helo=outlook.eldorado.org.br) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nZcbb-0004ik-0M; Wed, 30 Mar 2022 13:59:40 -0400 Received: from p9ibm ([10.10.71.235]) by outlook.eldorado.org.br over TLS secured channel with Microsoft SMTPSVC(8.5.9600.16384); Wed, 30 Mar 2022 14:59:34 -0300 Received: from eldorado.org.br (unknown [10.10.70.45]) by p9ibm (Postfix) with ESMTP id BCDC180060F; Wed, 30 Mar 2022 14:59:33 -0300 (-03) From: matheus.ferst@eldorado.org.br To: qemu-devel@nongnu.org, qemu-ppc@nongnu.org Subject: [RFC PATCH 1/8] qemu/int128: avoid undefined behavior in int128_lshift Date: Wed, 30 Mar 2022 14:59:25 -0300 Message-Id: <20220330175932.6995-2-matheus.ferst@eldorado.org.br> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220330175932.6995-1-matheus.ferst@eldorado.org.br> References: <20220330175932.6995-1-matheus.ferst@eldorado.org.br> MIME-Version: 1.0 X-OriginalArrivalTime: 30 Mar 2022 17:59:34.0183 (UTC) FILETIME=[E9C23370:01D8445F] X-Host-Lookup-Failed: Reverse DNS lookup failed for 187.72.171.209 (failed) Received-SPF: pass client-ip=187.72.171.209; envelope-from=matheus.ferst@eldorado.org.br; helo=outlook.eldorado.org.br X-Spam_score_int: -4 X-Spam_score: -0.5 X-Spam_bar: / X-Spam_report: (-0.5 / 5.0 requ) BAYES_00=-1.9, PDS_HP_HELO_NORDNS=0.659, RDNS_NONE=0.793, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=no 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: , Cc: danielhb413@gmail.com, richard.henderson@linaro.org, groug@kaod.org, clg@kaod.org, Matheus Ferst , david@gibson.dropbear.id.au Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Matheus Ferst Avoid the left shift of negative values in int128_lshift by casting a/a.hi to unsigned. Signed-off-by: Matheus Ferst --- include/qemu/int128.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/include/qemu/int128.h b/include/qemu/int128.h index 2c4064256c..2a19558ac6 100644 --- a/include/qemu/int128.h +++ b/include/qemu/int128.h @@ -85,7 +85,7 @@ static inline Int128 int128_rshift(Int128 a, int n) static inline Int128 int128_lshift(Int128 a, int n) { - return a << n; + return (__uint128_t)a << n; } static inline Int128 int128_add(Int128 a, Int128 b) @@ -305,7 +305,7 @@ static inline Int128 int128_lshift(Int128 a, int n) if (n >= 64) { return int128_make128(0, l); } else if (n > 0) { - return int128_make128(l, (a.hi << n) | (a.lo >> (64 - n))); + return int128_make128(l, ((uint64_t)a.hi << n) | (a.lo >> (64 - n))); } return a; }