From patchwork Fri Nov 5 22:19:57 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Hubicka X-Patchwork-Id: 47142 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 9E0203857C58 for ; Fri, 5 Nov 2021 22:20:28 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 9E0203857C58 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1636150828; bh=c7KV7HPs5bTuNWWgGJzgIlyVVHAj6rY4nzJ+FdRDKb0=; h=Date:To:Subject:List-Id:List-Unsubscribe:List-Archive:List-Post: List-Help:List-Subscribe:From:Reply-To:From; b=tV1Qo3QrEDYlNjFTQHfB1/kY+vlv/5shIiqtXPOVPh1run0bcNsRtb1fThqwJtAzS we8O2MOyq1DntzKLAMjC6OqMhcoqkVOCnTE+ozM02xCukiIl12cwixfqQqWo/Rr7EB pz/CVYzIdHQBCNkMhKyWNug7F5H/DpZ0/T45+5lc= X-Original-To: gcc-patches@gcc.gnu.org Delivered-To: gcc-patches@gcc.gnu.org Received: from nikam.ms.mff.cuni.cz (nikam.ms.mff.cuni.cz [195.113.20.16]) by sourceware.org (Postfix) with ESMTPS id 0595C3858421 for ; Fri, 5 Nov 2021 22:19:59 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 0595C3858421 Received: by nikam.ms.mff.cuni.cz (Postfix, from userid 16202) id 8A83A280768; Fri, 5 Nov 2021 23:19:57 +0100 (CET) Date: Fri, 5 Nov 2021 23:19:57 +0100 To: gcc-patches@gcc.gnu.org Subject: Avoid left shift of negative value in ipa-modref-tree.h Message-ID: <20211105221957.GE4548@kam.mff.cuni.cz> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.10.1 (2018-07-13) X-Spam-Status: No, score=-11.6 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, GIT_PATCH_0, RCVD_IN_MSPIKE_H3, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_NONE, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: gcc-patches@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-Patchwork-Original-From: Jan Hubicka via Gcc-patches From: Jan Hubicka Reply-To: Jan Hubicka Errors-To: gcc-patches-bounces+patchwork=sourceware.org@gcc.gnu.org Sender: "Gcc-patches" Hi, ubsan is complaining about left shift of negative value which is undefined in c++11..c++17. Replaced by multiplication. Bootstrapped/regtested x86_64-linux, comitted. Honza gcc/ChangeLog: PR ipa/103082 * ipa-modref-tree.h (struct modref_access_node): Avoid left shift of negative value diff --git a/gcc/ipa-modref-tree.h b/gcc/ipa-modref-tree.h index 9976e489697..bc428d193d2 100644 --- a/gcc/ipa-modref-tree.h +++ b/gcc/ipa-modref-tree.h @@ -116,8 +116,13 @@ struct GTY(()) modref_access_node if (!known_le (parm_offset, a.parm_offset) && !range_info_useful_p ()) return false; + /* We allow negative aoffset_adj here in case + there is an useful range. This is because adding + a.offset may result in non-ngative offset again. + Ubsan fails on val << LOG_BITS_PER_UNIT where val + is negative. */ aoffset_adj = (a.parm_offset - parm_offset) - << LOG2_BITS_PER_UNIT; + * BITS_PER_UNIT; } } if (range_info_useful_p ())