Path: ...!news.misty.com!weretis.net!feeder6.news.weretis.net!i2pn.org!i2pn2.org!.POSTED!not-for-mail From: mitchalsup@aol.com (MitchAlsup1) Newsgroups: comp.lang.c,comp.arch Subject: Re: Radians Or =?UTF-8?B?RGVncmVlcz8=?= Date: Sat, 16 Mar 2024 01:23:12 +0000 Organization: Rocksolid Light Message-ID: <55fdf9ae69cdafb285b26afba62f7d46@www.novabbs.org> References: <20240222015920.00000260@yahoo.com> <20240222233838.0000572f@yahoo.com> <3b2e86cdb0ee8785b4405ab10871c5ca@www.novabbs.org> <936a852388e7e4414cb7e529da7095ea@www.novabbs.org> <20240314112655.000011f8@yahoo.com> <20240315141552.00003d38@yahoo.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Info: i2pn2.org; logging-data="2133266"; mail-complaints-to="usenet@i2pn2.org"; posting-account="PGd4t4cXnWwgUWG9VtTiCsm47oOWbHLcTr4rYoM0Edo"; User-Agent: Rocksolid Light X-Rslight-Site: $2y$10$phv1M6hH8aB5zw/UxKQT8uYy4EpU2wzKMnnIh/k4veJ5eoJSuyLrS X-Rslight-Posting-User: ac58ceb75ea22753186dae54d967fed894c3dce8 X-Spam-Checker-Version: SpamAssassin 4.0.0 Bytes: 2332 Lines: 18 Michael S wrote: > To make it less tempting, you could try to push for inclusion of > rsqrt() into basic set. Long overdue, IMHO. Many Newton-Raphson iterations converge more rapidly with RSQRT than with SQRT, for reasons I never looked that deeply into. > Right now, I can't think of any other transcendental that I really want > to elevate to higher status. It seems to me that elevation of log2(x) > and of 2**x will do no harm, but I am not sure about usefulness. Ln2 and EXP2 are the basis of My 66000 log and EXP families, performed in HW function unit. Ln2 has the property that a binade [1..2) maps directly to another binade [2..4); exp2 has a similar property. Ln2 is easier to get good accuracy from than Ln or Log as a starting point. But in any event:: you are always within a high precision multiply of the correct result = round(53×106);