From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham autolearn_force=no version=3.4.4 X-Google-Thread: a07f3367d7,98dc917fce16b418 X-Google-Attributes: gida07f3367d7,public,usenet X-Google-NewGroupId: yes X-Google-Language: ENGLISH,ASCII Path: g2news2.google.com!news3.google.com!fu-berlin.de!uni-berlin.de!individual.net!not-for-mail From: "(see below)" Newsgroups: comp.lang.ada Subject: Re: Performance of access type : a tiny mistake in the WikiBook ? Date: Thu, 08 Oct 2009 01:30:06 +0100 Message-ID: References: <91ad7397-27a8-4b9d-811e-6e62d485645c@v2g2000vbb.googlegroups.com> <31da5154-9739-4ead-8437-aaa5d70dc7e8@h30g2000vbr.googlegroups.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 8bit X-Trace: individual.net 3V5Jc6VrflxRXfE/VkjF5QI9ief0U7k78P8XzNLha4Eq6M/ZlV Cancel-Lock: sha1:PJkuWluJRv4CZUgXdZ+G2QpoYhI= User-Agent: Microsoft-Entourage/12.20.0.090605 Thread-Topic: Performance of access type : a tiny mistake in the WikiBook ? Thread-Index: AcpHrnvG6b/aYHshD0K7W6cPL03FmA== Xref: g2news2.google.com comp.lang.ada:8615 Date: 2009-10-08T01:30:06+01:00 List-Id: On 08/10/2009 00:30, in article 31da5154-9739-4ead-8437-aaa5d70dc7e8@h30g2000vbr.googlegroups.com, "Yannick Duch�ne Hibou57" wrote: > Hi Bill, and thanks for your reply > > On 8 oct, 00:38, "(see below)" wrote: >> surely it should indicate the likely effect of the "not null" >> and "access constant" options as well. > That's a relevant comment indeed > You're right with that point > > I came into it because I'm seeking about common performance > considerations. So I've found this article on WikiPedia. > > I'm also seeking about informations on the average impact of inlined > in generics. The same WikiBook states it has bad impact on > performance, in the way it prevents the compiler from using code > sharing. But I wonder if it applies only to the actually inlined > methods or to the whole package. > ... Do you have any solid reason to believe that such micromanagement has a significant effect on your program's performance? If it has, it might well be contrary to such generalized rules of thumb as the Wikibook propounds. I have a 14KSLOC program that runs three times as fast when I inline the appropriate (small, but heavily-used) subprograms. It runs *half* as fast if I replace the 3-statement body of one of these subprograms by 2 statements that seem "obviously" more efficient. The only way to answer such questions is to experiment with the alternatives, after you've done the really difficult stuff (i.e., getting it right, for now and for the foreseeable future), and then have a demonstrated need for better performance. -- Bill Findlay chez blueyonder.co.uk