From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2D6DEC433E1 for ; Tue, 18 Aug 2020 18:46:49 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id DA57E206B5 for ; Tue, 18 Aug 2020 18:46:48 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DA57E206B5 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bugs.launchpad.net Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:56068 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1k86dE-00007I-2Q for qemu-devel@archiver.kernel.org; Tue, 18 Aug 2020 14:46:48 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:49478) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1k86c9-0007LO-Eo for qemu-devel@nongnu.org; Tue, 18 Aug 2020 14:45:41 -0400 Received: from indium.canonical.com ([91.189.90.7]:36980) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1k86c7-0000MZ-HS for qemu-devel@nongnu.org; Tue, 18 Aug 2020 14:45:41 -0400 Received: from loganberry.canonical.com ([91.189.90.37]) by indium.canonical.com with esmtp (Exim 4.86_2 #2 (Debian)) id 1k86c6-0002rB-Dg for ; Tue, 18 Aug 2020 18:45:38 +0000 Received: from loganberry.canonical.com (localhost [127.0.0.1]) by loganberry.canonical.com (Postfix) with ESMTP id 60D982E80DC for ; Tue, 18 Aug 2020 18:45:38 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Date: Tue, 18 Aug 2020 18:37:13 -0000 From: Ahmed Karaman <1892081@bugs.launchpad.net> To: qemu-devel@nongnu.org X-Launchpad-Notification-Type: bug X-Launchpad-Bug: product=qemu; status=New; importance=Undecided; assignee=None; X-Launchpad-Bug-Information-Type: Public X-Launchpad-Bug-Private: no X-Launchpad-Bug-Security-Vulnerability: no X-Launchpad-Bug-Commenters: ahmedkrmn X-Launchpad-Bug-Reporter: Ahmed Karaman (ahmedkrmn) X-Launchpad-Bug-Modifier: Ahmed Karaman (ahmedkrmn) References: <159777580973.2034.8843080316751302000.malonedeb@chaenomeles.canonical.com> Message-Id: <159777583339.15880.666813501795760984.malone@soybean.canonical.com> Subject: [Bug 1892081] Re: Performance improvement when using "QEMU_FLATTEN" with softfloat type conversions X-Launchpad-Message-Rationale: Subscriber (QEMU) @qemu-devel-ml X-Launchpad-Message-For: qemu-devel-ml Precedence: bulk X-Generated-By: Launchpad (canonical.com); Revision="99c2d833c8d727fd05148486920aca032e908071"; Instance="production" X-Launchpad-Hash: abc096b965f10341936b37f31eaa196ed1d3e956 Received-SPF: none client-ip=91.189.90.7; envelope-from=bounces@canonical.com; helo=indium.canonical.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/08/18 14:45:37 X-ACL-Warn: Detected OS = Linux 3.11 and newer [fuzzy] X-Spam_score_int: -58 X-Spam_score: -5.9 X-Spam_bar: ----- X-Spam_report: (-5.9 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=1, RCVD_IN_DNSWL_HI=-5, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_NONE=0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Bug 1892081 <1892081@bugs.launchpad.net> Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" ** Attachment added: "before.png" https://bugs.launchpad.net/qemu/+bug/1892081/+attachment/5402578/+files/= before.png -- = You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1892081 Title: Performance improvement when using "QEMU_FLATTEN" with softfloat type conversions Status in QEMU: New Bug description: Attached below is a matrix multiplication program for double data types. The program performs the casting operation "(double)rand()" when generating random numbers. This operation calls the integer to float softfloat conversion function "int32_to_float_64". Adding the "QEMU_FLATTEN" attribute to the function definition decreases the instructions per call of the function by about 63%. Attached are before and after performance screenshots from KCachegrind. To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1892081/+subscriptions