220 38133 <6528826.uWXH5iz4YB@tjmaciei-mobl1> article Path: news.gmane.org!.POSTED!not-for-mail From: Thiago Macieira Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: memcpy/memset/etc overloads for volatile memory Date: Fri, 18 May 2018 23:20:27 -0700 Lines: 26 Approved: news@gmane.org Message-ID: <6528826.uWXH5iz4YB@tjmaciei-mobl1> References: <2300193.1RphyUdPvq@tjmaciei-mobl1> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" X-Trace: blaine.gmane.org 1526710705 4590 195.159.176.226 (19 May 2018 06:18:25 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Sat, 19 May 2018 06:18:25 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBCB4TK757YBRBLUE77LQKGQE3EBMLTQ@isocpp.org Sat May 19 08:18:21 2018 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-qk0-f197.google.com ([209.85.220.197]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1fJvC8-00015Y-QE for gclcip-std-proposals@m.gmane.org; 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[2001:19f0:5:2221::1:3]) by mx.google.com with ESMTPS id l21-v6si8870039qvg.112.2018.05.18.23.20.29 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 18 May 2018 23:20:29 -0700 (PDT) Received-SPF: pass (google.com: domain of thiago@macieira.org designates 2001:19f0:5:2221::1:3 as permitted sender) client-ip=2001:19f0:5:2221::1:3; Original-Received: from tjmaciei-mobl1.localnet (unknown [IPv6:2601:1c0:4501:5f9f:bc1f:402:4b5e:fda5]) by smtp.macieira.info (Postfix) with ESMTPSA id A73A3E7D0 for ; Fri, 18 May 2018 23:20:28 -0700 (PDT) In-Reply-To: X-Original-Sender: thiago@macieira.org X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of thiago@macieira.org designates 2001:19f0:5:2221::1:3 as permitted sender) smtp.mailfrom=thiago@macieira.org Precedence: list Mailing-list: list std-proposals@isocpp.org; contact std-proposals+owners@isocpp.org List-ID: X-Spam-Checked-In-Group: std-proposals@isocpp.org X-Google-Group-Id: 399137483710 List-Post: , List-Help: , List-Archive: List-Subscribe: , List-Unsubscribe: , Xref: news.gmane.org gmane.comp.lang.c++.isocpp.proposals:38133 Archived-At: On Friday, 18 May 2018 18:24:37 PDT dgutson . wrote: > Oh yes you don't know how hard it can get... avoid prefetching, avoid > SSE/vectorization, ensure right order of operations (WC regions). > So there are lots of details that a too smart toolchain may mess. Even with volatile? It can't change the accesses you make if you use volatile. So no prefetching, no SSE. The order is exactly the one that you specify. > However I will think if an execution policy can help here in copy. I'm not > talking about copying but also memsetting. > The linux kernel has a nice memcpy_toio/fromio worth to look at. Does it work for other types of memory besides I/O/ -- Thiago Macieira - thiago (AT) macieira.info - thiago (AT) kde.org Software Architect - Intel Open Source Technology Center -- You received this message because you are subscribed to the Google Groups "ISO C++ Standard - Future Proposals" group. To unsubscribe from this group and stop receiving emails from it, send an email to std-proposals+unsubscribe@isocpp.org. To post to this group, send email to std-proposals@isocpp.org. To view this discussion on the web visit https://groups.google.com/a/isocpp.org/d/msgid/std-proposals/6528826.uWXH5iz4YB%40tjmaciei-mobl1. .