DMARC-Filter: OpenDMARC Filter v1.4.2 delorie.com 60K92aJC629084 Authentication-Results: delorie.com; dmarc=pass (p=none dis=none) header.from=cygwin.com Authentication-Results: delorie.com; spf=pass smtp.mailfrom=cygwin.com DKIM-Filter: OpenDKIM Filter v2.11.0 delorie.com 60K92aJC629084 Authentication-Results: delorie.com; dkim=pass (1024-bit key, unprotected) header.d=cygwin.com header.i=@cygwin.com header.a=rsa-sha256 header.s=default header.b=gxVGOk8R X-Recipient: archive-cygwin AT delorie DOT com DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org CF6CF4BC7ECE DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cygwin.com; s=default; t=1768899755; bh=cujEAa9XgyJZUuneEX5Yp8peaCRK5i/syz9M5yIDf4c=; h=Date:To:Cc:In-Reply-To:Subject:References:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From:Reply-To:From; b=gxVGOk8RvLPiZMRT8oN8TJbxgo6wwpwAKu3d7nazOTXI1U/nhOE3h46UJJTqW1G93 Jvd9ABiy/6lQbeEv6+VbhhlkvPIpngVv1xTWX15UUFuksRLck0ypsQDSeGd57KBMma 9iCIOx5OPJbegpj1yJRn+zWaoxxZu7bRzRe+rL3k= X-Original-To: cygwin AT cygwin DOT com Delivered-To: cygwin AT cygwin DOT com DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 8A4654BA9001 ARC-Filter: OpenARC Filter v1.0.0 sourceware.org 8A4654BA9001 ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1768899736; cv=none; b=aSTlwFuZ8J6L748UjB5czE4y8jdOaoQWPQCe3Eld4NJUWXvtB4LczTZE6xo7fAsK30mvsNgR5VbUscoNcrLAf5jJ9rDh+Yke1MhQVBVHLlH3i5ZpfUxGNfliX51+ds94Od7UMsOBM6YfLYI/TK8Tsi/sNGaHn9P/7HGivY9NS3k= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1768899736; c=relaxed/simple; bh=B5qW2BbJK4BP3/+P+tCfictP4rp9BpcNagfCcuu9YLA=; h=DKIM-Signature:Date:Message-Id:From:To:Subject; b=CrbdhyL+zQXFwP41s3IsF+ip42Dd5aFjMte+bx/evmNT0sVWhBTfErqpWJYuLOgJ64HKlNICHmMWqqwbLMHIqlon3dbSlR8ERLdwgDVEyIywqrtG0PJpkJMWCA0SAGgpPJu7Molp+uYEj8dCKcAKTkzvW4ZaKPnTxC4vNzVXa9I= ARC-Authentication-Results: i=1; server2.sourceware.org DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 8A4654BA9001 X-CSE-ConnectionGUID: GxblrEIfSQyLMhcpSkGclQ== X-CSE-MsgGUID: bpjN4TOdTPG1R+xqm8vMsQ== Received-SPF: SoftFail (mail2-relais-roc.national.inria.fr: domain of Paul DOT Zimmermann AT inria DOT fr is inclined to not designate 152.81.2.78 as permitted sender) identity=mailfrom; client-ip=152.81.2.78; receiver=mail2-relais-roc.national.inria.fr; envelope-from="Paul DOT Zimmermann AT inria DOT fr"; x-sender="Paul DOT Zimmermann AT inria DOT fr"; x-conformance=spf_only; x-record-type="v=spf1"; x-record-text="v=spf1 include:mailout.safebrands.com a:basic-mail.safebrands.com a:basic-mail01.safebrands.com a:basic-mail02.safebrands.com ip4:128.93.142.0/24 ip4:192.134.164.0/24 ip4:128.93.162.160 ip4:128.93.162.3 ip4:128.93.162.88 ip4:89.107.174.7 mx ~all" Received-SPF: None (mail2-relais-roc.national.inria.fr: no sender authenticity information available from domain of postmaster AT araignee) identity=helo; client-ip=152.81.2.78; receiver=mail2-relais-roc.national.inria.fr; envelope-from="Paul DOT Zimmermann AT inria DOT fr"; x-sender="postmaster AT araignee"; x-conformance=spf_only X-IronPort-AV: E=Sophos;i="6.21,240,1763420400"; d="scan'208";a="259395971" Date: Tue, 20 Jan 2026 10:02:13 +0100 Message-Id: To: KENNON J CONRAD Cc: cygwin AT cygwin DOT com In-Reply-To: <335671721.621101.1768877396354@connect.xfinity.com> (message from KENNON J CONRAD on Mon, 19 Jan 2026 18:49:56 -0800 (PST)) Subject: Re: Log2 seems inefficient References: <226987210 DOT 591128 DOT 1768766440723 AT connect DOT xfinity DOT com> <3c56778a-870c-4bae-a855-6b96392870c8 AT SystematicSW DOT ab DOT ca> <335671721 DOT 621101 DOT 1768877396354 AT connect DOT xfinity DOT com> X-BeenThere: cygwin AT cygwin DOT com X-Mailman-Version: 2.1.30 Precedence: list List-Id: General Cygwin discussions and problem reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Paul Zimmermann via Cygwin Reply-To: Paul Zimmermann MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: cygwin-bounces~archive-cygwin=delorie DOT com AT cygwin DOT com Sender: "Cygwin" Hi Kennon, > Thank you, Paul. It looks like it would be worth a try as the current log2 implementation from Cygwin is clearly not optimal for either speed or accuracy. This may be a stupid question, but what would be the easiest way to incorporate this into open source software? Should I rename the function and copy the (slightly modified) source code into the distribution? yes, the file is self-content, just rename cr_log2() into log2(), making sure you keep the copyright paragraph at the beginning. For ease of maintenance, also indicate which commit of CORE-MATH you used, and document changes if you need some. Feel free to contact us (core-math AT inria DOT fr) in case of problem. Best regards, Paul -- Problem reports: https://cygwin.com/problems.html FAQ: https://cygwin.com/faq/ Documentation: https://cygwin.com/docs.html Unsubscribe info: https://cygwin.com/ml/#unsubscribe-simple