From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp.smtpout.orange.fr (smtp-26.smtpout.orange.fr [80.12.242.26]) by sourceware.org (Postfix) with ESMTPS id 54B5D3858C52 for ; Tue, 27 Sep 2022 09:26:31 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 54B5D3858C52 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=orange.fr Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=orange.fr Received: from [192.168.1.17] ([86.215.174.255]) by smtp.orange.fr with ESMTPA id d6r6ovNxgg7y2d6rCoddC9; Tue, 27 Sep 2022 11:26:28 +0200 X-ME-Helo: [192.168.1.17] X-ME-Auth: bW9yaW4tbWlrYWVsQG9yYW5nZS5mcg== X-ME-Date: Tue, 27 Sep 2022 11:26:28 +0200 X-ME-IP: 86.215.174.255 Message-ID: Date: Tue, 27 Sep 2022 11:26:20 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.2.2 Subject: Re: [COMMITTED] Optimize [0 = x & MASK] in range-ops. To: gcc-patches@gcc.gnu.org References: <20220926172441.3219466-1-aldyh@redhat.com> Content-Language: fr, en-US From: Mikael Morin In-Reply-To: <20220926172441.3219466-1-aldyh@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-5.0 required=5.0 tests=BAYES_00,FREEMAIL_FROM,JMQ_SPF_NEUTRAL,KAM_DMARC_STATUS,NICE_REPLY_A,RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H3,RCVD_IN_MSPIKE_WL,SPF_HELO_PASS,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 List-Id: Le 26/09/2022 à 19:24, Aldy Hernandez via Gcc-patches a écrit : > For [0 = x & MASK], we can determine that x is ~MASK. > Suggestion: as AND is a bitwise operator, a X non-zero bit can be cleared for every bit at which the result is cleared and the MASK is set, so what you do here can be extended to non-zero result values.