From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from EUR04-HE1-obe.outbound.protection.outlook.com (mail-he1eur04on2044.outbound.protection.outlook.com [40.107.7.44]) by sourceware.org (Postfix) with ESMTPS id 19D85385609B for ; Fri, 10 Nov 2023 10:17:55 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 19D85385609B Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=arm.com ARC-Filter: OpenARC Filter v1.0.0 sourceware.org 19D85385609B Authentication-Results: server2.sourceware.org; arc=pass smtp.remote-ip=40.107.7.44 ARC-Seal: i=3; a=rsa-sha256; d=sourceware.org; s=key; t=1699611485; cv=pass; b=afCke8pe2SOuSvjG9zdxBYj85Br4rn7MmNm/jZruZlR2mK4lbIIJTyZRxiLhIa3u4aDczoF+NdZv1caF4r2nV6SgjUMU/1K5XOn82TUjiO7FeaCs0be7Ek/IFG4KBiA3tknIhA9bCN3+6tBBo20AAOvgWv9AXlYiFmt6/swsCGU= ARC-Message-Signature: i=3; a=rsa-sha256; d=sourceware.org; s=key; t=1699611485; c=relaxed/simple; bh=cmj/WzQ0DrgQ4FELg8FkCX+MUfEeK+tBRxIjJDItXWY=; h=DKIM-Signature:DKIM-Signature:From:To:Subject:Date:Message-ID: MIME-Version; b=hyrG+F0QN42HRCFzk1Qh7TKTa/siLaVzyvTsU6wMjDD/pIr7HeyAd3BCIXqITlnX0/BBZWO7HKt50wGXN5E78NhLvdzVAqPap/B7qj4gvb4l7jsvAmh+QILndwfmoroScs2rOTIfUVkCwQ3wLXX9Pkigi/ynEKp5K4cJK0Z9++w= ARC-Authentication-Results: i=3; server2.sourceware.org ARC-Seal: i=2; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=pass; b=Ti+yxLvL3XpgaOepgvhC/lwYZhJxVjr79PLj2dWvKS1z2C5k2sJ+HamWGQNBiADEyRrt4Ik0PDjuPX/B7DLRJjtytHtitLBXu7KAQhbeMDEb9CQUwoLNmSz2hhsObhoCTOpv2oDwM23Ya2twRqiMFpLtEsmpxD2H+rFCHNZdekuAhqqMqguFck8nLgDstgByrOySYcWeA7t9Tx8RpWMS7c+R/ln9rRRqxyaoRdD06quqXAfiuJC/SInJbGYLVGXV0JGAAfTHyeZAeGXAWuScM+HBRC3TgqikCj/yEugjmHZB744gqLEgAEr4XDAj86aCe21QSsOg5PrhWe88UWqoDw== ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=cmj/WzQ0DrgQ4FELg8FkCX+MUfEeK+tBRxIjJDItXWY=; b=iWA4boR2WdDH8fHxxx3+iXoUNcuvZc+ULkGwQR03pThjNG+O+bcxtUhMBsLFrV+GUz3hJRU/QG51UwjPT+zpeU2Or724usuRgFEZ0XhCOwMsbD2P5Z+OLmQfIBCA4stZ5Wi4v0h4DO07R2fOSvoxfYw4hroetsKUKa6g+7LCTdWDSr2SuVAFjqPVmdmC/ZxbnxQgIVpDKajo60AGvleNuoHmcLMoo/9/VZmkuTeOzmZ2+LVTGqKsjYRS0n/YGuLgGHdIvXsNbQwTF971iP7SjQw2jp1sCZQEKEGG/dhYOHy7ITVDqovxDIDOc5qFnTaQ+I4YVUQe1Gd7a/nqjBDvsA== ARC-Authentication-Results: i=2; mx.microsoft.com 1; spf=pass (sender ip is 63.35.35.123) smtp.rcpttodomain=gcc.gnu.org smtp.mailfrom=arm.com; dmarc=pass (p=none sp=none pct=100) action=none header.from=arm.com; dkim=pass (signature was verified) header.d=armh.onmicrosoft.com; arc=pass (0 oda=1 ltdi=1 spf=[1,1,smtp.mailfrom=arm.com] dkim=[1,1,header.d=arm.com] dmarc=[1,1,header.from=arm.com]) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=armh.onmicrosoft.com; s=selector2-armh-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=cmj/WzQ0DrgQ4FELg8FkCX+MUfEeK+tBRxIjJDItXWY=; b=AI6pfUe68zWf0npLi5C8llU0sdW0znPZaU4KeGsx5Pt+6OJ7ixDFymHaD/sdRZp/bYXd+Vug33UGT0Jce4EThQ8LKRJRgYdNbpeT943h5x8pVwP/dLeC7IvWmKeKf/ruo4JnRwv2Vqdx+5Bzmfq0w0zuUfQzTEhSHJkYgIEzaOU= Received: from DB3PR06CA0025.eurprd06.prod.outlook.com (2603:10a6:8:1::38) by AS8PR08MB10195.eurprd08.prod.outlook.com (2603:10a6:20b:629::21) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.6954.29; Fri, 10 Nov 2023 10:17:49 +0000 Received: from DB5PEPF00014B95.eurprd02.prod.outlook.com (2603:10a6:8:1:cafe::cf) by DB3PR06CA0025.outlook.office365.com (2603:10a6:8:1::38) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.6977.19 via Frontend Transport; Fri, 10 Nov 2023 10:17:49 +0000 X-MS-Exchange-Authentication-Results: spf=pass (sender IP is 63.35.35.123) smtp.mailfrom=arm.com; dkim=pass (signature was verified) header.d=armh.onmicrosoft.com;dmarc=pass action=none header.from=arm.com; Received-SPF: Pass (protection.outlook.com: domain of arm.com designates 63.35.35.123 as permitted sender) receiver=protection.outlook.com; client-ip=63.35.35.123; helo=64aa7808-outbound-1.mta.getcheckrecipient.com; pr=C Received: from 64aa7808-outbound-1.mta.getcheckrecipient.com (63.35.35.123) by DB5PEPF00014B95.mail.protection.outlook.com (10.167.8.233) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.6977.16 via Frontend Transport; Fri, 10 Nov 2023 10:17:49 +0000 Received: ("Tessian outbound 7c4ecdadb9e7:v228"); Fri, 10 Nov 2023 10:17:48 +0000 X-CheckRecipientChecked: true X-CR-MTA-CID: d9a1b557d7d57a66 X-CR-MTA-TID: 64aa7808 Received: from 25ac34d0c451.2 by 64aa7808-outbound-1.mta.getcheckrecipient.com id B403F60F-214C-4885-88B9-50F6DBDE2490.1; Fri, 10 Nov 2023 10:17:42 +0000 Received: from EUR05-AM6-obe.outbound.protection.outlook.com by 64aa7808-outbound-1.mta.getcheckrecipient.com with ESMTPS id 25ac34d0c451.2 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384); Fri, 10 Nov 2023 10:17:42 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=a5P+GKV+f/9jpl3OA3jRle9kZGLSypgOTuHuTDckWxt01euhbzO7Bzir918wMU7hgAUvTh2bANNNuF2H9JsxXwyw8gmvAezM1dHc9VHuyF8WGtqcYPhLBYjn23y5gx93nNjxwSb4fJec2fqk5T2xsvp/pfvmLgbwXkIRR7813SbZfoYdFK8XQVRoxNTFP2MmXdG/0sPVYk4uyfH9fOw3u9yxsHr9qOBd02WUCS4BVJRIM7Nl6kcePZ3T6zeudlCmqaB366Yklj2cV+0A84MLzYUgRMJ8S9fFg+ZkgRp+jDmDRTwaeYmrdPk+2dxiuNBN8iztFN6io3/Sy/c/cMAHlA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=cmj/WzQ0DrgQ4FELg8FkCX+MUfEeK+tBRxIjJDItXWY=; b=JncPDtuaPvINciRiMn3ckXVd7Abc+LMZXE6o1a3egq11G9yQbOE2zUsfGpByLC40k+n5OroI7uD1qbG5qU4SuXde599EJ4xpPVaPDz7B+sPO2s+6LU4xIkuqtRg2UZ0KquUTYioz7nbGYhiVbooD/CVIjASq9FOIOj5vhyy/6ORtTAbQoSurKdPE/39hidOARRPyjUtghVFWAaVsHxUU1qQ9AH6AdpWoZbYPxjzbAD1CQChcpuTLZglopHdwZjnW34NaWW9YlZznNDOeoCofF/73xHp5w9jPDJqkPqJdsO5drPZLvzXEURwLVav/poTcLHYuaLXerX+APz7ICKL1Hg== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=arm.com; dmarc=pass action=none header.from=arm.com; dkim=pass header.d=arm.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=armh.onmicrosoft.com; s=selector2-armh-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=cmj/WzQ0DrgQ4FELg8FkCX+MUfEeK+tBRxIjJDItXWY=; b=AI6pfUe68zWf0npLi5C8llU0sdW0znPZaU4KeGsx5Pt+6OJ7ixDFymHaD/sdRZp/bYXd+Vug33UGT0Jce4EThQ8LKRJRgYdNbpeT943h5x8pVwP/dLeC7IvWmKeKf/ruo4JnRwv2Vqdx+5Bzmfq0w0zuUfQzTEhSHJkYgIEzaOU= Received: from PAWPR08MB8982.eurprd08.prod.outlook.com (2603:10a6:102:33f::20) by GV2PR08MB9400.eurprd08.prod.outlook.com (2603:10a6:150:dd::12) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.6954.28; Fri, 10 Nov 2023 10:17:39 +0000 Received: from PAWPR08MB8982.eurprd08.prod.outlook.com ([fe80::cfc5:acc1:cfc1:9704]) by PAWPR08MB8982.eurprd08.prod.outlook.com ([fe80::cfc5:acc1:cfc1:9704%5]) with mapi id 15.20.6954.028; Fri, 10 Nov 2023 10:17:36 +0000 From: Wilco Dijkstra To: Kyrylo Tkachov , GCC Patches CC: Richard Sandiford , Richard Earnshaw Subject: Re: [PATCH] AArch64: Cleanup memset expansion Thread-Topic: [PATCH] AArch64: Cleanup memset expansion Thread-Index: AQHaAonvDvOGXhWPREyotSkr/rO2DbBtT7FFgAYhwJCAAASmIQ== Date: Fri, 10 Nov 2023 10:17:36 +0000 Message-ID: References: In-Reply-To: Accept-Language: en-GB, en-US Content-Language: en-GB X-MS-Has-Attach: X-MS-TNEF-Correlator: msip_labels: Authentication-Results-Original: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=arm.com; x-ms-traffictypediagnostic: PAWPR08MB8982:EE_|GV2PR08MB9400:EE_|DB5PEPF00014B95:EE_|AS8PR08MB10195:EE_ X-MS-Office365-Filtering-Correlation-Id: 148dd5bd-7ac6-471f-0d55-08dbe1d64a66 x-checkrecipientrouted: true nodisclaimer: true X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam-Untrusted: BCL:0; X-Microsoft-Antispam-Message-Info-Original: 42dl4oM8CMnSbdBLeZ79g6bTh/OMxFmZcnNPq4HO7n1tp/rrtWp2lBFpcHt5IrsfeRkeosKglGwEpOKw3k+OOqtD+m5hAR36CBoilS7vJdMVWWM36I6bFZoEKIBwcDTwGSrZObEEz0GJR50SdbU5UNC/6eFQHFD9Z34rPtqYaHskGlHkeD9qZqVy6c18waetWlP/X26k8jQvOF9qRuFGB26M90fsVB/HOsXIeB2W9NpYCk/GbZg39e/NtcKJd1t3WdbowsA3YFu6Baep9ZlWhSoDLghb6L5CL+U+mcj7ZnvIzUXgV1BCY3kFZhyfTjokAVNqpHTEJJwmzfQwuz9E+4x5TVWSnNEG/ADxXTfKevLB4fYENX8qFeInMmf3xZF10Twmo8OmddWzzGlJpi4v92+DHG8kZ3WI05ypljXQ97uafjkJG1QovOxETUbVCNEpyBfwnOr6bGWXJuKBHS/h565OZ3ygt+SRwQDCHv4CwJArb/xTPeu9zH5bSc6mY8exeZt2XT1a0cEprt+O5D41dUwoTj0ap1fDz47hL2jaNOdO0oPzcqNA6ZjZ2b55PRdk0+jMfoJdNJXazBr5YXG0MV74WNaYrd5ZplUEbN/yr+LX/DDpnS41/HEjGtjvjwXC X-Forefront-Antispam-Report-Untrusted: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:PAWPR08MB8982.eurprd08.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230031)(396003)(366004)(136003)(346002)(376002)(39860400002)(230922051799003)(1800799009)(186009)(64100799003)(451199024)(5660300002)(6506007)(9686003)(71200400001)(478600001)(7696005)(4744005)(26005)(110136005)(66946007)(41300700001)(66556008)(76116006)(2906002)(64756008)(91956017)(8676002)(8936002)(4326008)(54906003)(52536014)(66476007)(66446008)(316002)(38070700009)(38100700002)(33656002)(122000001)(86362001)(55016003);DIR:OUT;SFP:1101; Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-MS-Exchange-Transport-CrossTenantHeadersStamped: GV2PR08MB9400 Original-Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=arm.com; X-EOPAttributedMessage: 0 X-MS-Exchange-Transport-CrossTenantHeadersStripped: DB5PEPF00014B95.eurprd02.prod.outlook.com X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id-Prvs: a9257085-036f-4303-b62a-08dbe1d642dc X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:63.35.35.123;CTRY:IE;LANG:en;SCL:1;SRV:;IPV:CAL;SFV:NSPM;H:64aa7808-outbound-1.mta.getcheckrecipient.com;PTR:ec2-63-35-35-123.eu-west-1.compute.amazonaws.com;CAT:NONE;SFS:(13230031)(4636009)(136003)(376002)(346002)(396003)(39860400002)(230922051799003)(82310400011)(451199024)(64100799003)(186009)(1800799009)(46966006)(36840700001)(40470700004)(86362001)(4744005)(2906002)(47076005)(5660300002)(9686003)(36860700001)(52536014)(316002)(8676002)(54906003)(4326008)(8936002)(55016003)(40480700001)(356005)(81166007)(41300700001)(33656002)(70586007)(70206006)(336012)(40460700003)(26005)(82740400003)(110136005)(6506007)(7696005)(478600001);DIR:OUT;SFP:1101; X-OriginatorOrg: arm.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 10 Nov 2023 10:17:49.0353 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 148dd5bd-7ac6-471f-0d55-08dbe1d64a66 X-MS-Exchange-CrossTenant-Id: f34e5979-57d9-4aaa-ad4d-b122a662184d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=f34e5979-57d9-4aaa-ad4d-b122a662184d;Ip=[63.35.35.123];Helo=[64aa7808-outbound-1.mta.getcheckrecipient.com] X-MS-Exchange-CrossTenant-AuthSource: DB5PEPF00014B95.eurprd02.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: AS8PR08MB10195 X-Spam-Status: No, score=-4.8 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,FORGED_SPF_HELO,KAM_DMARC_NONE,RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H2,SPF_HELO_PASS,SPF_NONE,TXREP,T_SCC_BODY_TEXT_LINE,UNPARSEABLE_RELAY autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: Hi Kyrill,=0A= =0A= > +=A0 /* Reduce the maximum size with -Os.=A0 */=0A= > +=A0 if (optimize_function_for_size_p (cfun))=0A= > +=A0=A0=A0 max_set_size =3D 96;=0A= > +=0A= =0A= > .... This is a new "magic" number in this code. It looks sensible, but ho= w did you arrive at it?=0A= =0A= We need 1 instruction to create the value to store (DUP or MOVI) and 1 STP= =0A= for every 32 bytes, so the 96 means 4 instructions for typical sizes (sizes= not=0A= a multiple of 16 can add one extra instruction).=0A= =0A= I checked codesize on SPECINT2017, and 96 had practically identical size.= =0A= Using 128 would also be a reasonable Os value with a very slight size incre= ase, =0A= and 384 looks good for O2 - however I didn't want to tune these values as t= his=0A= is a cleanup patch.=0A= =0A= Cheers,=0A= Wilco=