From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-3.4 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FROM,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED, RCVD_IN_MSPIKE_H3,RCVD_IN_MSPIKE_WL autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 6854 invoked from network); 1 Mar 2021 19:27:03 -0000 Received: from mother.openwall.net (195.42.179.200) by inbox.vuxu.org with ESMTPUTF8; 1 Mar 2021 19:27:03 -0000 Received: (qmail 17525 invoked by uid 550); 1 Mar 2021 19:26:59 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Reply-To: musl@lists.openwall.com Received: (qmail 17506 invoked from network); 1 Mar 2021 19:26:58 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1614626806; bh=REn6dGWpkP2URkBVG9Jd+iTE3usA1RS0el4prrKF+b8=; h=X-UI-Sender-Class:Date:From:To:Subject:References:In-Reply-To; b=kikEEkpRf8DLR9EbbcW3gxy0jdxxhYFvJanxqfFGZuAg561G90Q3sImkuP6N8J9yl 4zQNcDC+rVdRgs6tJ8xzm+OaroAvhjYO7M3OYhexgWYb8U94CWnA4pYQ40Fbzstorj 9ST2DwW1puhuJ3VqphdXR1DMjhT3MwAJq6YWoueY= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Date: Mon, 1 Mar 2021 20:26:46 +0100 From: Markus Wichmann To: musl@lists.openwall.com Message-ID: <20210301192646.GA2766@voyager> References: <20210228150912.1532943-1-maandree@kth.se> <20210228192210.1665554-1-maandree@kth.se> <20210228192210.1665554-2-maandree@kth.se> <20210228193733.GF354034@port70.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) X-Provags-ID: V03:K1:MgJFojXrwMJE9WBxwyijGRt2hLKwXndJNcHKPKI2/OEsxKrgeQm WKdI49P1fa47oJSIahkqkC4ShqH39j71KcyNkBeOOexF2U8y+SjZlSs1OKhQhVF747EGH5Z zTLZJArWADOVc+YbLcoGKmG5NAMs8FNgct1QkoDF12WLVbhkXnJDrvw+CWq/U0PC4WGWgkq EM3FaITXUZ6nlERpPvUhQ== X-UI-Out-Filterresults: notjunk:1;V03:K0:fQ7PCn1+PTg=:OjT1SIsgclQnDvaAohizv2 Bsgz90772uWpv62esSCb7N+LW/kZLCNHuc6YaE2KlwFvDuTyBRfXNyaoePDiVqkTNdFsLV9RT zoSf+BJ3SrH5msjh3faNKeCwcP0pmrq4nhw4a/Qk4N2yMYOsCzWbGRnJNretx1bSCCpE+NTAf AdSlPvVc33X1Lophu4NohuM5tXkbcqez4V3H4gL5x5/EvpSEvH9Pnsy4kEH5LwGYC5d2jdpX2 8uyZSnGeA1Z9to1rCdAnta1LomG8un5wSPuGZ81F3/fv54r4vVpvgrXf/EMyMA0/3iqxvUnS5 S9ghAGmXDjpbf5oP6vgV6K9syLTLKoE9BmopSaCmuLb/TgonAqv3adRuwnNNf2k/o79elck0D +sABzhDpIJPAuVWQAYhN+fwugGetP4didn/Qg32QKnOzLVH2WOnGPIhefrp2zDwMga3p1vAFO QSGWIhTdOfcS/nGsuXNRuPpIyPBHngqGt+FcpU+FhHRluYGggO8Sjw0AfhJD0ULS0gFOIsA0a V1BnltEZc2NHavgP03AfOMNmLCpnbSOeF3LW/6bkhbYoIkn/4W1BFbYM3v/HHvq1IK7TT3uw1 DlNd+jer4O5DeKh5EcC2WOJbIfKfZrw434kXPyOq2udx/L9jf0feKWusuMqsjIh0rX8NlPcQU 1OB4fNc1aq09IP1Ys2DWoVX9JB5EbPmIoYdIhndP50peZI3YcTMqTU9i4jgLtyYE3GPZItq7i Zlmi3KzzWw5i9ifhOi0hF/GyIqLAJZFINJXgFB+k7ZjlbTDOBjdxKDOww3WAzoAXDnl01jqBV i9bMlAGh3xajqZJS7BdoksX87ezcdIwK1jSSC1FInUCXyh00o6WNEscGM6P+zV9rKIA9fTt7Z 30IXh92LcW5NEjWWFjIQ== Content-Transfer-Encoding: quoted-printable Subject: Re: [musl] [PATCH v2 2/2] Use modulo instead of mul+sub in __secs_to_tm On Sun, Feb 28, 2021 at 07:58:27PM +0000, Jon Chesterfield wrote: > Note that module coming for free with division doesn't make it cheap. > Integer division is far more expensive that integer multiply on ~ every > architecture. Several architectures implement division in software. It's > not cheap on x86, despite the dedicated instruction. > > Cheers And then there's PowerPC, which does have a divide instruction but no modulo. The manual explicitly states that if you need a modulo, you are supposed to divide, multiply, and subtract. Ciao, Markus