From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from fossa.birch.relay.mailchannels.net (fossa.birch.relay.mailchannels.net [23.83.209.62]) by sourceware.org (Postfix) with ESMTPS id F32ED3858D1E for ; Wed, 21 Dec 2022 23:38:58 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org F32ED3858D1E Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=gotplt.org Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=gotplt.org X-Sender-Id: dreamhost|x-authsender|siddhesh@gotplt.org Received: from relay.mailchannels.net (localhost [127.0.0.1]) by relay.mailchannels.net (Postfix) with ESMTP id 89C4D102187; Wed, 21 Dec 2022 23:38:57 +0000 (UTC) Received: from pdx1-sub0-mail-a305.dreamhost.com (unknown [127.0.0.6]) (Authenticated sender: dreamhost) by relay.mailchannels.net (Postfix) with ESMTPA id CBCCF10214B; Wed, 21 Dec 2022 23:38:56 +0000 (UTC) ARC-Seal: i=1; s=arc-2022; d=mailchannels.net; t=1671665936; a=rsa-sha256; cv=none; b=KVLIcuggPcGF9KLCRQC8A/6UHRWzVTn8b3e9K5MqY+gNCWpHhYm+wcGGRUNd8Rpy6dXTJb ZQrq/JgztMnTw4SC6/H/PCvKreoviUDaMbODz8qbDV2jvSLRDFCy93btLhJYBHxdSoI2ep l795GCIl99eDdGXlvDb9hYMEgBl66v04d1Ao29Ri8nQPgNTVEx4UTsiUNKfJTf/1rotUrP VDJOGNBsRCDcfiRpaUBcmlaO3XfZjU4oDMjLaW8vfOgFWVczL2tvVsUFpHk5XiGvE1pWc9 ixWeThgYzDa+Y09lR0A7/i8sbY6Xibl+86AP1zgIEE+xLcZGWJIegWyDkHvTzA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=mailchannels.net; s=arc-2022; t=1671665936; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=7D/NFU2XqsdmTG820ISP1hPuWLzgWCrUxshw1S6bXy0=; b=NZiauf8xEgAvTJiE1jRjNXSbguSLMZe9ssaG1LeS7w5Mo5PIeQXWJv8+wSN3jhcNCUfQ2w WrieceVGP5Yob+gq/JcEFS/KlZOg71bkiwbXHLZ5ylGLeerCR6YkenXuM4/Y/5Oa7Wp7Rc yFOxJmyLGGkGGvhiCTYSexn9cHov25Cff6H3B04nKmSLT1F9afGCloPU85GG7N+0H1/jW0 iQzJDtaYXSyDgpoFcsbe08FOpjL5DX3nrCSjN/LxvEWJJI/lJLb+rBPJk/ODiODh0pgR51 y98pd+W9+miMhG9S8XlPAVpaq6870Tg++KLYHEnlo9qK9Cqyy0838UbBADGGhg== ARC-Authentication-Results: i=1; rspamd-698c4479bb-q4tmz; auth=pass smtp.auth=dreamhost smtp.mailfrom=siddhesh@gotplt.org X-Sender-Id: dreamhost|x-authsender|siddhesh@gotplt.org X-MC-Relay: Neutral X-MailChannels-SenderId: dreamhost|x-authsender|siddhesh@gotplt.org X-MailChannels-Auth-Id: dreamhost X-Bored-Rock: 4cca52106fd2bb73_1671665937067_1755744154 X-MC-Loop-Signature: 1671665937067:3656971978 X-MC-Ingress-Time: 1671665937066 Received: from pdx1-sub0-mail-a305.dreamhost.com (pop.dreamhost.com [64.90.62.162]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384) by 100.103.24.117 (trex/6.7.1); Wed, 21 Dec 2022 23:38:57 +0000 Received: from [192.168.0.182] (bras-base-toroon4834w-grc-23-76-68-24-147.dsl.bell.ca [76.68.24.147]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: siddhesh@gotplt.org) by pdx1-sub0-mail-a305.dreamhost.com (Postfix) with ESMTPSA id 4Ncqdr2l9bzC3; Wed, 21 Dec 2022 15:38:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gotplt.org; s=dreamhost; t=1671665936; bh=7D/NFU2XqsdmTG820ISP1hPuWLzgWCrUxshw1S6bXy0=; h=Date:Subject:To:Cc:From:Content-Type:Content-Transfer-Encoding; b=QlU8rQl4pPIlGvV6Zr7ff/U2J/vyH38GJXvUiCUbYEo7BX2PgagnjM3VEbWkAPkKC eeDgPbvMYQhism3EOVpaTOApTntRtCGMz2Bkvg6f6eJRG2SHGDXSByvgTGeykiqLmr 2P4Hwhm4BJEF9IqBhL4k/NoQ/P3KDJ4qI3rYvR66KW56u1Rj/KMbkBHdwRv2gk+esp V3HxyMHNoE2+K83hxzF1RH/WoKYTckjXB6PF8hwu8CYCqPdpY1VEZH8YpnrbMcJw9n z7f1N+c4li51MGvcFx9KxXmR8hXuCCuJXiHpWC20f30cTSMTytmRBAPbsUxdV7Ztwb xKkratbLubdYQ== Message-ID: <5d1066f2-b8f3-c210-1fef-b5f38fb08be1@gotplt.org> Date: Wed, 21 Dec 2022 18:38:55 -0500 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.5.0 Subject: Re: [RFC]: Removing old Falkor ifuncs Content-Language: en-US To: Wilco Dijkstra Cc: 'GNU C Library' References: <8862bd85-24ef-42d7-e48a-acdb7ada73c9@gotplt.org> From: Siddhesh Poyarekar In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-3031.6 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,NICE_REPLY_A,RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_PASS,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: On 2022-12-21 12:27, Wilco Dijkstra wrote: > Hi Siddhesh, > >>> On 2022-12-09 10:14, Wilco Dijkstra wrote: >>>> Do we need the ifuncs for Falkor? The SIMD memcpy is now the default >>>> generic memcpy and that is quite similar to the Falkor one, so it seems >>>> time to remove the Falkor variants. Since you are the original author, >>>> what do you think? >>> >>> The key differentiator in memcpy/memmove at that time was the register >>> number usage since that affected how the hardware prefetcher performed. >>> Changing that might affect performance on falkor, although I don't >>> exactly remember by how much. >> >> If there was a difference, it would likely be on large copies. But it would be hard >> to test without access to a machine... > > I managed to get an old Falkor revived, so was able to finally run benchtests. > The new generic memcpy is about 10% faster on bench-memcpy-random test > when sizes fit in L1, and about 5% faster overall. Bench-memcpy-large and -walk > are very similar, so it doesn't seem to have any effect on prefetching in large copies. > > So it looks like the new generic memcpy is better overall. Great, I'd say go for it then :) Thanks, Sid