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[8.43.85.97]) by mx.google.com with ESMTPS id eq17-20020a170907291100b008b2c034ca3dsi19275448ejc.744.2023.02.23.04.55.15 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 23 Feb 2023 04:55:15 -0800 (PST) Received-SPF: pass (google.com: domain of gcc-patches-bounces+ouuuleilei=gmail.com@gcc.gnu.org designates 8.43.85.97 as permitted sender) client-ip=8.43.85.97; Authentication-Results: mx.google.com; dkim=pass header.i=@gcc.gnu.org header.s=default header.b=GxVjoUZr; spf=pass (google.com: domain of gcc-patches-bounces+ouuuleilei=gmail.com@gcc.gnu.org designates 8.43.85.97 as permitted sender) smtp.mailfrom="gcc-patches-bounces+ouuuleilei=gmail.com@gcc.gnu.org"; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=gnu.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id C8819385843D for ; Thu, 23 Feb 2023 12:55:14 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org C8819385843D DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1677156914; bh=LKU0SkWfiKJGSdHDv14IfJTONGQx7EXisV2rUn/kyZo=; h=Date:To:cc:Subject:List-Id:List-Unsubscribe:List-Archive: List-Post:List-Help:List-Subscribe:From:Reply-To:From; b=GxVjoUZrWOG+xI0xt/k1O5rNMg3QbrAsYIYABuKMBuszThjvi/gPtF3RF8f8mS8V0 MSMHFUdt+PGepuCF7lQDTGaXwNPj4xLDYIsEWd+tqVsXvVLmrwWpEuU4T+Io6pBsFw 9/8pPlHmnBJlnte457UTyCgd0TLUxVBBCQa0a8w8= X-Original-To: gcc-patches@gcc.gnu.org Delivered-To: gcc-patches@gcc.gnu.org Received: from smtp-out2.suse.de (smtp-out2.suse.de [IPv6:2001:67c:2178:6::1d]) by sourceware.org (Postfix) with ESMTPS id 137B73857C5A for ; Thu, 23 Feb 2023 12:54:29 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 137B73857C5A Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 04E875D913; Thu, 23 Feb 2023 12:54:28 +0000 (UTC) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id DA402139B5; Thu, 23 Feb 2023 12:54:27 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id zBMiNANi92OHYQAAMHmgww (envelope-from ); Thu, 23 Feb 2023 12:54:27 +0000 Date: Thu, 23 Feb 2023 13:54:27 +0100 (CET) To: gcc-patches@gcc.gnu.org cc: Jakub Jelinek Subject: [PATCH] Avoid default-initializing auto_vec storage MIME-Version: 1.0 Message-Id: <20230223125427.DA402139B5@imap2.suse-dmz.suse.de> X-Spam-Status: No, score=-11.7 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) 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 Biener via Gcc-patches From: Richard Biener Reply-To: Richard Biener Errors-To: gcc-patches-bounces+ouuuleilei=gmail.com@gcc.gnu.org Sender: "Gcc-patches" X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1758626490130889542?= X-GMAIL-MSGID: =?utf-8?q?1758626490130889542?= The following avoids default-initializing auto_vec storage for non-POD T since that's not what the allocated storage fallback will do and it's also not expected for existing cases like auto_vec, 64> elts; which exist to optimize the allocation. Bootstrapped and tested on x86_64-unknown-linux-gnu. It saves around 1kB of text size for cc1. OK for trunk? Thanks, Richard. * vec.h (auto_vec): Turn m_data storage into uninitialized unsigned char. --- gcc/vec.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/gcc/vec.h b/gcc/vec.h index a536b68732d..cee96254a31 100644 --- a/gcc/vec.h +++ b/gcc/vec.h @@ -1584,7 +1584,7 @@ public: private: vec m_auto; - T m_data[MAX (N - 1, 1)]; + alignas(T) unsigned char m_data[sizeof (T) * MAX (N - 1, 1)]; }; /* auto_vec is a sub class of vec whose storage is released when it is