Path: csiph.com!xmission!news.alt.net!feeder.usenetexpress.com!tr2.iad1.usenetexpress.com!border1.nntp.dca1.giganews.com!border2.nntp.dca1.giganews.com!nntp.giganews.com!news.iecc.com!.POSTED.news.iecc.com!nerds-end From: Richard Harnden Newsgroups: comp.compilers Subject: Re: Algorithm Optimization Date: Wed, 16 Sep 2020 22:45:04 +0100 Organization: A noiseless patient Spider Lines: 11 Sender: news@iecc.com Approved: comp.compilers@iecc.com Message-ID: <20-09-041@comp.compilers> References: <20-09-032@comp.compilers> <20-09-035@comp.compilers> <20-09-036@comp.compilers> Reply-To: nospam.harnden@gmail.com Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Info: gal.iecc.com; posting-host="news.iecc.com:2001:470:1f07:1126:0:676f:7373:6970"; logging-data="36082"; mail-complaints-to="abuse@iecc.com" Keywords: errors Posted-Date: 16 Sep 2020 21:20:14 EDT X-submission-address: compilers@iecc.com X-moderator-address: compilers-request@iecc.com X-FAQ-and-archives: http://compilers.iecc.com In-Reply-To: <20-09-036@comp.compilers> Xref: csiph.com comp.compilers:2612 On 16/09/2020 06:25, JL wrote > [Back when people cared about Whetstone and Dyrystone benchmarks, > compilers recognized code sequences from those benchmarks for, uh, > special processing. But it doesn't generalize very well. -John] And can backfire badly for the company involved ... many VW cars being sold in America had a "defeat device" - or software - in diesel engines that could detect when they were being tested, changing the performance accordingly to improve results.