From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt1-x82c.google.com (mail-qt1-x82c.google.com [IPv6:2607:f8b0:4864:20::82c]) by sourceware.org (Postfix) with ESMTPS id 8AD63385AC27 for ; Thu, 11 Nov 2021 03:31:49 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 8AD63385AC27 Received: by mail-qt1-x82c.google.com with SMTP id j17so4169690qtx.2 for ; Wed, 10 Nov 2021 19:31:49 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=BgXs/9Q3vvTTkowid0a8l2VyprQQ1KjSq8gERVWxAHk=; b=1YXP87u6IERRg6jm/hQm6butXnmVR/sIa3PFXlTAQLdrkYCvV4Zh6Tu8EmY2pY57Q4 kJ3CCFUGqh1HYe7drzq85vSA6652jAtL1mIRcdZBr7gEDUbqN6elvRzjgObiFDCcwso2 tuTxa4TH+gA/cYbVIK1eUeBOMDzMNqbf/aepNqVASZs4fGsqC/ygW56Ce06GcDpR3XM+ hKXn6iHP8KeVECnl9Qdz+kYE1GYH6xQL3GXSghr/qkvpq2iWXIk3PY7nn8cBiAYEpmX3 fTvVePCNHNbsem4NFasKCk1AB4JjrpiwFfcd3+yGxdUpfIBmpJacYyZ7gYU1garWXSfG kb2A== X-Gm-Message-State: AOAM533dxnY7C3MenpnRNV13ZVQ5ZAozl0dd1ct6JE/oIdjTsiWCSKfK IVFMCToyUHnOD5N/0tK4Di/epA4WXNj9aS1KdG1fjcjBy3A= X-Google-Smtp-Source: ABdhPJx4gGSgSKXR1F8cMBoWfq5t7/bvtFPDHMcNqqgQbuvvqw+9rjH1VZ9YNjBPnPkkJSZTJD7KrOpTTvS40HlQ4G0= X-Received: by 2002:a05:622a:40a:: with SMTP id n10mr4408118qtx.161.1636601509222; Wed, 10 Nov 2021 19:31:49 -0800 (PST) MIME-Version: 1.0 References: <20211110030726.2468302-1-skpgkp2@gmail.com> <20211110030726.2468302-6-skpgkp2@gmail.com> In-Reply-To: From: Sunil Pandey Date: Wed, 10 Nov 2021 19:31:13 -0800 Message-ID: Subject: Re: [PATCH 5/6] x86-64: Add pow/powf to libmvec microbenchmark To: Joseph Myers Cc: GNU C Library , andrey.kolesov@intel.com X-Spam-Status: No, score=-2.4 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, FREEMAIL_ENVFROM_END_DIGIT, FREEMAIL_FROM, HK_RANDOM_ENVFROM, HK_RANDOM_FROM, HTML_MESSAGE, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=no autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Content-Filtered-By: Mailman/MimeDel 2.1.29 X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 11 Nov 2021 03:31:51 -0000 On Wed, Nov 10, 2021 at 12:27 PM Joseph Myers wrote: > On Tue, 9 Nov 2021, Sunil K Pandey via Libc-alpha wrote: > > > +# Random inputs in [a=3D0.01,b=3D100.00], [c=3D0.01,d=3D10.00] > > I think there should be a reasonable proportion of negative exponents, > unless you have evidence that negative exponents are rarely used in > practice. (The *first* argument of pow being negative is of use (produce= s > finite results) in much more limited cases, so may well be much rarer.) > Negative exponents not used in the input file to avoid denormal processing. Negative exponent may hit the underflow domain when pow(x, -y) produces denormals as results or as intermediate values. Both going to touch very slow special pow() path and invokes Intel software assist for denormals processing. All of this will distort the overall performance result of the main path. Also the base argument should be small so that it doesn=E2=80=99t produce d= enormals. > -- > Joseph S. Myers > joseph@codesourcery.com >