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=unavailable autolearn_force=no version=3.4.4 Path: eternal-september.org!reader01.eternal-september.org!.POSTED!not-for-mail From: "J-P. Rosen" Newsgroups: comp.lang.ada Subject: Re: GNAT vs Matlab - operation on multidimensional complex matrices Date: Wed, 1 Apr 2020 19:15:43 +0200 Organization: Adalog Message-ID: References: <6c2c0e35-af07-4169-8be5-464ec7fd0fd5@googlegroups.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Injection-Date: Wed, 1 Apr 2020 17:15:44 -0000 (UTC) Injection-Info: reader02.eternal-september.org; posting-host="6aa54230d58b3fd786b0883ca84d8abd"; logging-data="22832"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1+Ch/bM9i8NGX7C8KM8xXiU" User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.6.0 Cancel-Lock: sha1:V30EHmuVRnAj6QAsObhjx3twjts= In-Reply-To: Content-Language: fr Xref: reader01.eternal-september.org comp.lang.ada:58275 Date: 2020-04-01T19:15:43+02:00 List-Id: Le 01/04/2020 à 18:39, darek a écrit : > No, I did not evaluate it. This how I look at it:some of the > functions (i.e. FFT) (that have some local complex arrays inside), I > need to call ~320k-400k times per second (depends on the settings, > and this is for the simpler 4x4 MIMO). So, even if a single > allocation cost some microseconds, then the total time is > substantial. I still fail to see how using pointers would save you anything... Unless you are assuming that arrays are passed by copy, which would be extremely unlikely in your case! Note: compilers are free to pass arrays by copy or by reference, this is intended to let them choose the most efficient method. -- J-P. Rosen Adalog 2 rue du Docteur Lombard, 92441 Issy-les-Moulineaux CEDEX Tel: +33 1 45 29 21 52, Fax: +33 1 45 29 25 00 http://www.adalog.fr