From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Joseph Myers Newsgroups: gmane.comp.lib.glibc.alpha Subject: Re: [PATCH] v11 Improves __ieee754_exp() performance by greater than 5x on sparc/x86. Date: Wed, 14 Feb 2018 16:41:59 +0000 Message-ID: References: NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" X-Trace: blaine.gmane.org 1518626441 32449 195.159.176.226 (14 Feb 2018 16:40:41 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Wed, 14 Feb 2018 16:40:41 +0000 (UTC) User-Agent: Alpine 2.20 (DEB 67 2015-01-07) Cc: To: Patrick McGehearty Original-X-From: libc-alpha-return-90294-glibc-alpha=m.gmane.org@sourceware.org Wed Feb 14 17:40:36 2018 Return-path: Envelope-to: glibc-alpha@blaine.gmane.org DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:date:from:to:cc:subject:in-reply-to:message-id :references:mime-version:content-type; q=dns; s=default; b=yd4TT OYuLO+POtIubnR5He0hlbWFHwKkDi3ET0srPBoeu5N+oFmTtyFZQVPcaFO88uyDx /SR/NButKjGgOavkCqkW7LfA5+bVOYEgKOn8fiBI15YNiHj945oLEoCoRhCiQpDZ Ruv/DbXU2IGHgg6qi4g5JEuxu6V7SN1x1KhwtI= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:date:from:to:cc:subject:in-reply-to:message-id :references:mime-version:content-type; s=default; bh=ps28/OJQoG/ 2VwgSdD5MyypqsII=; b=pgbLq1V7pINq5oY8Mt8NdZj/tODNajFpW7BbAFjFXpO drUxHJcOHf9U6xzk1W9JTuu1lVPMM+YHv7HTud854L0TBVhny25FXPFyCu2f1QaI eYUow1k2OHf+8fzGOAMzTSEIcnlOF/RMYotvuEt9zvG+5SA3jV/89ZX2PXCg8K6A = Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Original-Sender: libc-alpha-owner@sourceware.org Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.0 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_NONE,SPF_PASS,URIBL_RED autolearn=ham version=3.3.2 spammy= X-HELO: relay1.mentorg.com In-Reply-To: X-ClientProxiedBy: svr-ies-mbx-01.mgc.mentorg.com (139.181.222.1) To svr-ies-mbx-01.mgc.mentorg.com (139.181.222.1) Xref: news.gmane.org gmane.comp.lib.glibc.alpha:82642 Archived-At: Received: from server1.sourceware.org ([209.132.180.131] helo=sourceware.org) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1em06G-0006K1-Eg for glibc-alpha@blaine.gmane.org; Wed, 14 Feb 2018 17:40:04 +0100 Received: (qmail 19688 invoked by alias); 14 Feb 2018 16:42:06 -0000 Received: (qmail 19361 invoked by uid 89); 14 Feb 2018 16:42:06 -0000 On Tue, 13 Feb 2018, Patrick McGehearty wrote: > Any thoughts on general principles on how to decide which patch > to accept, given both seem much more better than the existing code? My understanding would be that Szabolcs intends (as per and ) to eliminate rounding mode changes from the present exp, and possibly make other speedups there. Then the final result of such speedups would need comparing with a version of your patch that also eliminates rounding mode changes (and updates libm-test-ulps expectations for other functions in non-default rounding modes as needed to avoid introducing failures). It would be best to have a precise statement of what "both my throughput and latency benchmarks" are in , to make sure there is a common basis of comparison so we can see if it's really the case that one version is faster on some architectures and another on other architectures, or whether different people are measuring different things. -- Joseph S. Myers joseph@codesourcery.com