From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.5-pre1 (2020-06-20) on ip-172-31-74-118.ec2.internal X-Spam-Level: X-Spam-Status: No, score=0.8 required=3.0 tests=BAYES_50,FREEMAIL_FROM autolearn=ham autolearn_force=no version=3.4.5-pre1 X-Received: by 2002:a05:6214:1227:: with SMTP id p7mr78399951qvv.31.1609793733925; Mon, 04 Jan 2021 12:55:33 -0800 (PST) X-Received: by 2002:a25:7449:: with SMTP id p70mr100436787ybc.363.1609793733634; Mon, 04 Jan 2021 12:55:33 -0800 (PST) Path: eternal-september.org!reader02.eternal-september.org!news.gegeweb.eu!gegeweb.org!fdn.fr!proxad.net!feeder1-2.proxad.net!209.85.160.216.MISMATCH!news-out.google.com!nntp.google.com!postnews.google.com!google-groups.googlegroups.com!not-for-mail Newsgroups: comp.lang.ada Date: Mon, 4 Jan 2021 12:55:33 -0800 (PST) In-Reply-To: Complaints-To: groups-abuse@google.com Injection-Info: google-groups.googlegroups.com; posting-host=192.160.103.146; posting-account=1tLBmgoAAAAfy5sC3GUezzrpVNronPA- NNTP-Posting-Host: 192.160.103.146 References: User-Agent: G2/1.0 MIME-Version: 1.0 Message-ID: <6489a95e-dae1-486e-9aee-78e9d6e50ecan@googlegroups.com> Subject: Re: Quick inverse square root From: Matt Borchers Injection-Date: Mon, 04 Jan 2021 20:55:33 +0000 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Xref: reader02.eternal-september.org comp.lang.ada:61029 List-Id: I never made any claims about the contemporary usefulness of this algorithm= . As I said, I turned a bunch of ugly C into a few lines of pretty Ada for= a skeptic. I'm sure there is no need for this now, but it is still histor= ically interesting. Trying to make a generic simply started as a thought e= xperiment of how to eliminate the need for the two types (float and modular= ) which I now concede is impossible in its most generic form. As computers get faster, storage gets larger, and code libraries get bigger= , it is unfortunate that most programmers do not need to be as clever as th= ey once were required to be. Thanks for finding and sharing the PDF paper! I'm amazed someone could wri= te so many pages on this. Out of curiosity, I need to compare my computed = magic number with theirs from their 64-bit float example. Matt