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=-3.9 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 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 398161F461 for ; Mon, 8 Jul 2019 18:31:37 +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:subject:to:cc:references:from:message-id:date :mime-version:in-reply-to:content-type :content-transfer-encoding; q=dns; s=default; b=mtg/buUwZ23fIWJo hlPv2k53sgmnSX2/FOGgUhBHWQgWZcLSStYZIXFc75CfSY6XQw2j993q+VUVr+Vx 2ll173vfQ5fWFSqErKPK1krzdxrrPEfvS5zpF75DwynG2zwsQl0kDErGPa4BrG8T 42w+bc04qmxPdTRGPqFOpEI8K0s= 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:subject:to:cc:references:from:message-id:date :mime-version:in-reply-to:content-type :content-transfer-encoding; s=default; bh=jZnjvVpJNngixb6XXjRoy4 6W0rU=; b=mQrPRFP179H4Y+IAqbJFK9FncDlpdXkswE/PvFRLMNY2fBSCBMn37Z hlJin9UTJv3R1sF2v1VfuB8/E3Lye06nhnnyw6jHDSRs96CiH10oF83wKRRDg7Vm qLcryZvHg7WSNE3LVt8NTpDgdZ1c05sYhIoxIYiQ+NWjFxMDnvUSw= Received: (qmail 87930 invoked by alias); 8 Jul 2019 18:31:33 -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 87575 invoked by uid 89); 8 Jul 2019 18:31:30 -0000 Authentication-Results: sourceware.org; auth=none X-HELO: mail-qk1-f195.google.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=subject:to:cc:references:from:openpgp:autocrypt:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=k57JR55Oy999taKB+rvC7qEhNRyADFyEEPCaibo/p+A=; b=Gl7C+QjGoyC5NaaP5TMBB9QynL/8WdK92t4ZRPD14PVQvcUBDNNC4W+u7twEvhh3db D9rgzsNdTOmaQH+NU7Mzaod61oYnJuXuXQkybpS8IvRC1l/olbiDo3zeDL1DFlx9FdeL 51fw5a69k0BotPeOPfYVAymnMukkDTjyfEjnXVNasIkVjyi2pVTRT/hDZmZFkE4t6VM3 qx6/Bt8ANz6OJmL4TdJnM2P/qp65QCzEExcZjhbRx8Maj7CNMKc2N1ayg/6i1CIsv9qC KCrx0FRnoLsN9AWcfwDJ0XzwHY6MGLP+5UkltFe/K+uJCEbdCxwZGJOYElGYkZx5HlLs w0wg== Subject: Re: [PATCH 28/28] powerpc: refactor logb{f,l} To: "Gabriel F. T. Gomes" Cc: libc-alpha@sourceware.org References: <20190329133529.22523-1-adhemerval.zanella@linaro.org> <20190329133529.22523-29-adhemerval.zanella@linaro.org> <20190705012404.GD7290@tereshkova> From: Adhemerval Zanella Openpgp: preference=signencrypt Message-ID: <983ba93d-c4e5-2b20-26c0-5185283914b4@linaro.org> Date: Mon, 8 Jul 2019 15:31:23 -0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.2 MIME-Version: 1.0 In-Reply-To: <20190705012404.GD7290@tereshkova> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit On 04/07/2019 22:24, Gabriel F. T. Gomes wrote: > On Fri, Mar 29 2019, Adhemerval Zanella wrote: >> The power7 logb implementation does not show a performance gain on >> ISA 2.07+ chips with faster floating-point to GRP instructions >> (currently POWER8 and POWER9). > > Looks good to me. Thanks. > > Reviewed-by: Gabriel F. T. Gomes > >> - asm ( >> - "xxland %x0,%x1,%x2\n" >> - "fcfid %0,%0" >> - : "=f" (ret) >> - : "f" (x), "f" (mask.d)); >> + asm ("xxland %x0,%x1,%x2\n" >> + "fcfid %0,%0" >> + : "=d" (ret) >> + : "d" (x), "d" (0x7ff0000000000000ULL)); > > OK. I don't actually understand when the 'f' constraint is supposed to > be used, but 'd' looks good to me. > >> -static const double two7m1 = -127.0; /* -2**7 + 1 */ >> [...] >> - if (__builtin_expect (ret > -two7m1, 0)) >> + if (ret > 127.0) > > OK. Double negative. > >> --- a/sysdeps/powerpc/powerpc64/fpu/multiarch/Makefile >> +++ /dev/null > > Hurray. :) > > Thanks, Adhemerval. > > Sorry for taking too long to review this patch set (I tried to review > them all before the freeze, but it wasn't so easy for me). > If no one opposes it, I will commit this shortly.