From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by sourceware.org (Postfix) with ESMTPS id AB6C73858C2C for ; Fri, 8 Jul 2022 08:09:44 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org AB6C73858C2C Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=suse.cz Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=suse.cz 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-out1.suse.de (Postfix) with ESMTPS id 5E9DB21E4E; Fri, 8 Jul 2022 08:09:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1657267783; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=jr545GqH01cUidF8eF9yuNtm0fA2WErKM4B269fwTL4=; b=2DziJ17pw/ksc+mQUro7fpT1ifHqNgjsrQNL+GWgNu8zT6hwxzgU3l7LbO3TFZpPmqaZop 5/aSEkqJ9eRhaf6cIcKY5SKWdvp27/1WI+u/0hbsbuiUTbRwe4VDvLmYhJ9PZSoLKJXGLY QdbJ2KrYxid471SOnFwBmAW/c0Yv81A= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1657267783; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=jr545GqH01cUidF8eF9yuNtm0fA2WErKM4B269fwTL4=; b=S3jzIAut5ONrgqMj6GAIYEAI+7+0Yx44sI6+pmhINadkd/Z+4/74jgmFPMH3nq6ukKibcW cbOdFISpWcMdpUCg== 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 4DA5713A80; Fri, 8 Jul 2022 08:09:43 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id zNPUEUfmx2LyJQAAMHmgww (envelope-from ); Fri, 08 Jul 2022 08:09:43 +0000 Message-ID: Date: Fri, 8 Jul 2022 10:09:42 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.11.0 Subject: Re: Bad performance (with GCC 11.3.0 - O3) of a small etude in C Content-Language: en-US To: Georgi Marinov , "gcc@gcc.gnu.org" References: From: =?UTF-8?Q?Martin_Li=c5=a1ka?= In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-5.9 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, KAM_SHORT, NICE_REPLY_A, SPF_HELO_NONE, SPF_PASS, TXREP, T_SCC_BODY_TEXT_LINE 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@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 08 Jul 2022 08:09:46 -0000 On 7/8/22 06:31, Georgi Marinov via Gcc wrote: > Hi, > just wanted to let you know that I found that GCC 11.3.0 -O3 is generating code with many unnecessary jumps (while CLANG 14.0.1 -O3 not) in a small partitioning (for Quicksort) 15 lines of code etude. > In case you are interested I will submit the three disassembly outputs, plus ICL 19.0 -O3, ICL is horrible in that, ICL 15.0 was good but they ruined their legacy. > Generally, GCC is my target compiler, yet, CLANG is better in my usecases. I would like some of your coders to look it up, my wish is GCC to catch up. > > Regards Hi. Please file a bug here: https://gcc.gnu.org/bugzilla/ with a reproducer we can take a look. Thanks, Martin