Path: csiph.com!xmission!news.snarked.org!border2.nntp.dca1.giganews.com!nntp.giganews.com!news.iecc.com!.POSTED.news.iecc.com!nerds-end From: Tom Crick Newsgroups: comp.compilers Subject: Re: Bit swizzling Date: Tue, 8 Sep 2020 09:35:29 +0100 Organization: Compilers Central Lines: 22 Sender: news@iecc.com Approved: comp.compilers@iecc.com Message-ID: <20-09-023@comp.compilers> References: <20-09-014@comp.compilers> <20-09-020@comp.compilers> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit Injection-Info: gal.iecc.com; posting-host="news.iecc.com:2001:470:1f07:1126:0:676f:7373:6970"; logging-data="45397"; mail-complaints-to="abuse@iecc.com" Keywords: optimize Posted-Date: 08 Sep 2020 22:34:55 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: <20-09-020@comp.compilers> Xref: csiph.com comp.compilers:2594 On Mon, 7 Sep 2020 at 18:57, Martin Ward wrote: > > On 05/09/2020 17:05, Rick C. Hodgin wrote: > > Are there any existing algorithms which examine the operations that > > must be conducted and then create an optimized / minimal sequence of > > mechanical steps to conduct it given a constrained set of features > > (such as those present on a given CPU)? > > The process you are describing is called "Superoptimization": > finding the optimal code sequence for one loop-free sequence > of instructions. ... Back in the distant past (2009), I did my PhD on superoptimisation — provably optimal code generation using answer set programming: https://proftomcrick.com/2012/02/18/three-papers-on-superoptimisation/ Still an area with lots of potential (IMHO)... Best wishes, Tom