From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by sourceware.org (Postfix) with ESMTPS id 9053A3858CDB for ; Wed, 18 Oct 2023 09:18:21 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 9053A3858CDB Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=redhat.com ARC-Filter: OpenARC Filter v1.0.0 sourceware.org 9053A3858CDB Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1697620703; cv=none; b=cQBM5L+uYrk/LPs3NnX3x9A3X2xT8yDJggyKRkhIWNYdZadbgy14oIVpuHqmXXa/KLSOdRvVk9CHX6KfI+5IIZxILeaVy+zc4Z2IPVu9ESC8f+J6uneOnfu9dF3F6awd8+DSOgMFG7rvhtiiFWoLUJa523JFXNz7ZUN+Fv/O4Ks= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1697620703; c=relaxed/simple; bh=98iVpN2M/Bf9sTgjO1dGvzKtfnNWrZ57ceF7KF8TE+E=; h=DKIM-Signature:From:To:Subject:Date:Message-ID:MIME-Version; b=svOSDc/glrCinOZxhaC1AycPyKHhi617RCEAFYkm19KFMGU5WTF4yl3DTU0pI85A6UplWSxQPQnpPGBIH1acoZlIyG0RSqtUbY/A0uGkxiyEW+tIp6fRWC+tqj5MU+e0Y8Mo08IOVfUcqh5qprp4PUOb2yF2TsDP8D9hO66CFuA= ARC-Authentication-Results: i=1; server2.sourceware.org DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1697620700; 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: in-reply-to:in-reply-to:references:references; bh=jKoqYIIM1JOI3mrGT0sQ+eFmltjaSyH46wmIHvnT6kU=; b=K7tHjiKCS/aDiaJtfP7g9C+hZfc/Fhfl5tddJEznGRvFa9BlnvkAqfrqQZgaq/TDqR1Nho pk87ujGtAGV44WK7HosPk5LaIv2VCj+TBQ6BKzrJaMif0kQ4P/xMC7aKCuud5A3AjfxEzJ j7l5fV+WHVq7HjMZJ/lPi5yRFNSZ5nM= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-338-P8ebYq13PR2m4-M3n9XMnA-1; Wed, 18 Oct 2023 05:18:17 -0400 X-MC-Unique: P8ebYq13PR2m4-M3n9XMnA-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id A241A3C0F429; Wed, 18 Oct 2023 09:18:16 +0000 (UTC) Received: from oldenburg.str.redhat.com (unknown [10.2.16.3]) by smtp.corp.redhat.com (Postfix) with ESMTPS id EE16A492BFA; Wed, 18 Oct 2023 09:18:15 +0000 (UTC) From: Florian Weimer To: Noah Goldstein Cc: libc-alpha@sourceware.org, hjl.tools@gmail.com, carlos@systemhalted.org Subject: Re: x86: Prepare `strrchr-evex` and `strrchr-evex512` for AVX10 References: <20230921143837.2903914-1-goldstein.w.n@gmail.com> <20231004184855.3517478-1-goldstein.w.n@gmail.com> Date: Wed, 18 Oct 2023 11:18:14 +0200 In-Reply-To: <20231004184855.3517478-1-goldstein.w.n@gmail.com> (Noah Goldstein's message of "Wed, 4 Oct 2023 13:48:55 -0500") Message-ID: <87fs28gug9.fsf@oldenburg.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.3 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.10 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain X-Spam-Status: No, score=-4.6 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,KAM_NUMSUBJECT,RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H3,RCVD_IN_MSPIKE_WL,SPF_HELO_NONE,SPF_NONE,TXREP 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: * Noah Goldstein: > This commit refactors `strrchr-evex` and `strrchr-evex512` to use a > common implementation: `strrchr-evex-base.S`. > > The motivation is `strrchr-evex` needed to be refactored to not use > 64-bit masked registers in preperation for AVX10. > > Once vec-width masked register combining was removed, the EVEX and > EVEX512 implementations can easily be implemented in the same file > without any major overhead. > > The net result is performance improvements (measured on TGL) for both > `strrchr-evex` and `strrchr-evex512`. Although, note there are some > regressions in the test suite and it may be many of the cases that > make the total-geomean of improvement/regression across bench-strrchr > are cold. The point of the performance measurement is to show there > are no major regressions, but the primary motivation is preperation > for AVX10. > > Benchmarks where taken on TGL: > https://www.intel.com/content/www/us/en/products/sku/213799/intel-core-i711850h-processor-24m-cache-up-to-4-80-ghz/specifications.html > > EVEX geometric_mean(N=5) of all benchmarks New / Original : 0.74 > EVEX512 geometric_mean(N=5) of all benchmarks New / Original: 0.87 > > Full check passes on x86. I believe this caused some sort of regression because when we upgraded glibc in the Fedora rawhide buildroot, a lot of things started failing: glibc-2.38.9000-13.fc40 broke rawhide buildroot on x86_64 The list of changes relative to the previous version is rather short: - stdlib: fix grouping verification with multi-byte thousands separator (bug 30964) - build-many-glibcs: Check for required system tools - x86: Prepare `strrchr-evex` and `strrchr-evex512` for AVX10 - aarch64: Optimise vecmath logs - aarch64: Cosmetic change in SVE exp routines - aarch64: Optimize SVE cos & cosf - aarch64: Improve vecmath sin routines - nss: Get rid of alloca usage in makedb's write_output. - debug: Add regression tests for BZ 30932 - Fix FORTIFY_SOURCE false positive - nss: Rearrange and sort Makefile variables - inet: Rearrange and sort Makefile variables - Fix off-by-one OOB write in iconv/tst-iconv-mt And this patch is the most likely one to cause issues. I will try to revert the patch and see if it fixes the observed issues. Thanks, Florian