Path: csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!news.glorb.com!news-out.readnews.com!news-xxxfer.readnews.com!news.misty.com!news.iecc.com!.POSTED!nerds-end From: glen herrmannsfeldt Newsgroups: comp.compilers Subject: Re: Green Compiler ? Date: Wed, 2 Jan 2013 05:11:40 +0000 (UTC) Organization: Aioe.org NNTP Server Lines: 23 Sender: johnl@iecc.com Approved: comp.compilers@iecc.com Message-ID: <13-01-004@comp.compilers> References: <12-12-010@comp.compilers> <12-12-012@comp.compilers> <12-12-022@comp.compilers> <12-12-028@comp.compilers> <12-12-034@comp.compilers> <12-12-037@comp.compilers> <13-01-002@comp.compilers> NNTP-Posting-Host: news.iecc.com X-Trace: leila.iecc.com 1357150677 24560 64.57.183.58 (2 Jan 2013 18:17:57 GMT) X-Complaints-To: abuse@iecc.com NNTP-Posting-Date: Wed, 2 Jan 2013 18:17:57 +0000 (UTC) Keywords: architecture, performance, comment Posted-Date: 02 Jan 2013 13:17:56 EST X-submission-address: compilers@iecc.com X-moderator-address: compilers-request@iecc.com X-FAQ-and-archives: http://compilers.iecc.com Xref: csiph.com comp.compilers:827 George Neuner wrote: (snip) > My opinions are colored by experience with DSPs, but I have long > thought that it would be helpful to have a few K-words of non-cache > scratchpad memory very close (1..2 cycles) to the CPU. You mean like the vector registers of the Cray-1? It seems that vector processors are not out of fashion, though not so obvious that they couldn't come back. They work especially well with the pipelined ALU that the Cray series used. -- glen [It is my impression that vector processors went out of fashion when they figured out how to build instruction pipelines deep enough to keep execution units busy with scalar code. The context switch problems were and are severe, unless you want to manage a pool of scratchpads for active processes, and spill as needed, sort of like the way x86 processors do floating point register management. -John]