From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-4.1 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_EF,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,SPF_HELO_PASS,SPF_PASS, T_BULK_RE_SUSP_NTLD,T_FROM_SUSPICIOUS_NTLD shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from sourceware.org (server1.sourceware.org [209.132.180.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dcvr.yhbt.net (Postfix) with ESMTPS id BDA661F45F for ; Fri, 10 May 2019 01:01:14 +0000 (UTC) DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-type; q=dns; s=default; b=btvI d14Axj5gUlG/JRu6PPmGZc7lZquOvpIEGyFFgkP2wnSBQfDHqx3zAGCjLznVgSAf Kdb1pR8ELF41NySuFUy/mtFwHt1WUbZI0jD0j9DclBgWLuI6g2ePtwTijUQ39te1 OYKXevPRnzHzb3LOCXLKlT/4bSocbHCV1SsPc3I= 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:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-type; s=default; bh=isvvkXV6TB 6qbK+yGxgJWO+3gDU=; b=p3EwsYMv/bF8lXKOtvU4px4z8N6B0HPjLfBbRM4QWR kGhEuMbSTbLpP/CZ22VPLp09UI3PqW9d7wuCNPxOrzQNXa+vdu+SpotObWoGjWVE RI4JvfGormTQQU+JqStf8fvkMDXf7nadmB9uB05AJWtLpxrCRnBtmN7YBCijqsNf w= Received: (qmail 58874 invoked by alias); 10 May 2019 01:01:11 -0000 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: , Sender: libc-alpha-owner@sourceware.org Received: (qmail 58666 invoked by uid 89); 10 May 2019 01:00:58 -0000 Authentication-Results: sourceware.org; auth=none X-HELO: git.icu MIME-Version: 1.0 References: <20190505203438.28140-1-shawn@git.icu> <20190506203210.8536-1-shawn@git.icu> <878svfqu2d.fsf@linux.ibm.com> In-Reply-To: <878svfqu2d.fsf@linux.ibm.com> From: Shawn Landden Date: Thu, 9 May 2019 20:00:25 -0500 Message-ID: Subject: Re: [PATCH] powerpc: add libmvec implementations of log and logf To: Tulio Magno Quites Machado Filho Cc: Joseph Myers , libc-alpha@sourceware.org Content-Type: text/plain; charset="UTF-8" On Thu, May 9, 2019 at 2:58 PM Tulio Magno Quites Machado Filho wrote: > > Shawn Landden writes: > > > When I first looked at Bert's patch I saw all the scalar code for the > > special path and thought it wasn't a real vector implementation. > > Otherwise I wouldn't have tried to compete with him. > > > > HOWEVER, once I fixed the bugs in my benchmark programs, there is no > > performance advantage of doing either log or logf with vector > > operation, at least on this power 9 VPS---either mine or Bert's > > patches. I think this is because they require too many table lookups > > for the constants, and Power ISA 3.0 lacks both a gather instruction, > > and a permutexvar instruction, both of which could be used to > > vectorize these table lookups. (shufflevector can't do it) > > Base on this information and considering that you haven't a FSF copyright > assignment, which means I can't look at your patch, I plan to merge Bert's > patches. How do I do the assignment? The web site only provided guidance for what forms to send me, not how to do it myself. Also, did you read that I could not find a performance improvement in Bert's patches? > > Thank you! > > -- > Tulio Magno