From patchwork Fri Jan 15 16:49:19 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Richard Sandiford X-Patchwork-Id: 1427150 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=gcc.gnu.org (client-ip=8.43.85.97; helo=sourceware.org; envelope-from=gcc-patches-bounces@gcc.gnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=gcc.gnu.org Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=gcc.gnu.org header.i=@gcc.gnu.org header.a=rsa-sha256 header.s=default header.b=Bf5Ijqq2; dkim-atps=neutral Received: from sourceware.org (unknown [8.43.85.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4DHRwk2JQ2z9sWQ for ; Sat, 16 Jan 2021 03:49:26 +1100 (AEDT) Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 493A539874D2; Fri, 15 Jan 2021 16:49:24 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 493A539874D2 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1610729364; bh=CgakW2CzL9/9h7o67e+/2ki73+POstkJEg5/ADINc6I=; h=To:Subject:Date:List-Id:List-Unsubscribe:List-Archive:List-Post: List-Help:List-Subscribe:From:Reply-To:From; b=Bf5Ijqq2evBajhfz2nnllmrmDRnMQb7SjRjkt+7h1E2XgZMcMq6DCOFbgjFW0D6ZE TT/os7zZGmcrjwYmg59erlHaVULQKssWH0I2mdK4FhzICXT0GxDDuNJ3PvkOSfXaKm QSjPBHo7Nv4NgYwUAqrUgF1lO69k+ViSlBUoUD04= X-Original-To: gcc-patches@gcc.gnu.org Delivered-To: gcc-patches@gcc.gnu.org Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by sourceware.org (Postfix) with ESMTP id 1B111398643A for ; Fri, 15 Jan 2021 16:49:22 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 1B111398643A Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id C3402D6E for ; Fri, 15 Jan 2021 08:49:21 -0800 (PST) Received: from localhost (e121540-lin.manchester.arm.com [10.32.98.126]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 6C00F3F719 for ; Fri, 15 Jan 2021 08:49:21 -0800 (PST) To: gcc-patches@gcc.gnu.org Mail-Followup-To: gcc-patches@gcc.gnu.org, richard.sandiford@arm.com Subject: [pushed] recog: Fix insn_change_watermark destructor Date: Fri, 15 Jan 2021 16:49:19 +0000 Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.3 (gnu/linux) MIME-Version: 1.0 X-Spam-Status: No, score=-12.8 required=5.0 tests=BAYES_00, GIT_PATCH_0, KAM_DMARC_STATUS, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) 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: Richard Sandiford via Gcc-patches From: Richard Sandiford Reply-To: Richard Sandiford Errors-To: gcc-patches-bounces@gcc.gnu.org Sender: "Gcc-patches" Noticed while working on something else that the insn_change_watermark destructor could call cancel_changes for changes that no longer exist. The loop in cancel_changes is a nop in that case, but: num_changes = num; can mess things up. I think this would only affect nested uses of insn_change_watermark. Tested on aarch64-linux-gnu, aarch64_be-elf and x86_64-linux-gnu, pushed as obvious. Richard gcc/ * recog.h (insn_change_watermark::~insn_change_watermark): Avoid calling cancel_changes for changes that no longer exist. --- gcc/recog.h | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/gcc/recog.h b/gcc/recog.h index 269094a30f1..e96e66e99f2 100644 --- a/gcc/recog.h +++ b/gcc/recog.h @@ -547,13 +547,19 @@ class insn_change_watermark { public: insn_change_watermark () : m_old_num_changes (num_validated_changes ()) {} - ~insn_change_watermark () { cancel_changes (m_old_num_changes); } + ~insn_change_watermark (); void keep () { m_old_num_changes = num_validated_changes (); } private: int m_old_num_changes; }; +inline insn_change_watermark::~insn_change_watermark () +{ + if (m_old_num_changes < num_validated_changes ()) + cancel_changes (m_old_num_changes); +} + #endif #endif /* GCC_RECOG_H */