From nobody Mon Sep 26 14:20:15 2022 X-Original-To: freebsd-current@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4MblK907KRz4XBNF for ; Mon, 26 Sep 2022 14:20:29 +0000 (UTC) (envelope-from wlosh@bsdimp.com) Received: from mail-ua1-x931.google.com (mail-ua1-x931.google.com [IPv6:2607:f8b0:4864:20::931]) (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 client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "smtp.gmail.com", Issuer "GTS CA 1D4" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4MblK7646Zz3xKS for ; Mon, 26 Sep 2022 14:20:27 +0000 (UTC) (envelope-from wlosh@bsdimp.com) Received: by mail-ua1-x931.google.com with SMTP id p17so2467919uao.11 for ; Mon, 26 Sep 2022 07:20:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bsdimp-com.20210112.gappssmtp.com; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date; bh=FalTkhh3952KWYuCSngkEOhw0AHxDD/CvyQkOdr/ZmA=; b=nxUMClzgo9wYnUWyT4YJA258k4PeHPtYw2jCnV61cv3NdLJicXkZnYMInkABmEC69U hMCMJ+IbUEhCmUGfJ37xo/8fxYap18GMWJQVROZ7pkf8SeO+sO2mfko/QARfC/9ebKW4 xcaJT14juAQN40wnpj3B4VNlZO3ySixTWYl3sULEGF29rDW1CSH1TrqgmFu4bb5fkuIY 1EUcp/zTmUEtlZ6+pV4zCmM/HVLeklxkGRmUlDeQBsnyV1nHa9hHwVAKaLOxgs2Vn8qN 5+vkvLgcq1EKxy+Cz0lyb4x9tnlpdEuCiRDkkXO3NsCRvxVvtATU8FyN/d8S2rAwEuyR bdlg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date; bh=FalTkhh3952KWYuCSngkEOhw0AHxDD/CvyQkOdr/ZmA=; b=t1zYz5BniyTWnQxWXgAkZg8NGDTIAIPuabLOwhtJdOh6VLqdPpcBBM/dnfwtKQfy1l whmV+YziieSe6nzKTPQ0+ZHTHUFIO0L7bswcBfCyL6CZTUapB6RfFZNL4OyxoxLOro/L JGQjiENmMDZp+d78GZCMFsi3tt3p4x1lJ/Fdk7kKlgkt25yWRglppttlGCs2+V/c8aCm 5W9eGKMZylbisyx8BqAKUVlnYFM/VZZufJv9sqZvo8ZEgNZ62RG0d/l8fy33D5ITtccn 5eS+n/hmC/1GgbSzPFWN7KBmPEYvspmjrTc0ml7ciXZ/xEEcxffmldSTMAGROGI6+DAt bvZQ== X-Gm-Message-State: ACrzQf2rIT447anl9V4x70xaX2Iuuvb1esV3HXW/JRc6S04GFU4OiaOw SmojwERQsMSc8yuzEGHhq0UW/+ypGGDr1N0wHSuEGedno1M= X-Google-Smtp-Source: AMsMyM4eXXPE3mtqA2ZqII3kz0+Z/AlVZc7Yqig8jvYmpR+8VlbC4ciMi8S1vQDsyY7GjrCH/rBeuwgq5WLVcruYPBw= X-Received: by 2002:ab0:3734:0:b0:3cd:9399:44b9 with SMTP id s20-20020ab03734000000b003cd939944b9mr2571037uag.60.1664202026903; Mon, 26 Sep 2022 07:20:26 -0700 (PDT) List-Id: Discussions about the use of FreeBSD-current List-Archive: https://lists.freebsd.org/archives/freebsd-current List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-current@freebsd.org MIME-Version: 1.0 References: <1A903FD8-D904-4B91-ABC4-2F704F0E2CF4@FreeBSD.org> <430A830E-3473-4EF4-9605-039F8254999C@FreeBSD.org> <8cd08b95-396a-b8a3-e33a-b0482a7f23e5@FreeBSD.org> In-Reply-To: <8cd08b95-396a-b8a3-e33a-b0482a7f23e5@FreeBSD.org> From: Warner Losh Date: Mon, 26 Sep 2022 08:20:15 -0600 Message-ID: Subject: Re: Did clang 14 lose some intrinsics support? To: Lev Serebryakov Cc: FreeBSD Current Content-Type: multipart/alternative; boundary="000000000000a5fec005e9953a5b" X-Rspamd-Queue-Id: 4MblK7646Zz3xKS X-Spamd-Bar: - Authentication-Results: mx1.freebsd.org; dkim=pass header.d=bsdimp-com.20210112.gappssmtp.com header.s=20210112 header.b=nxUMClzg; dmarc=none; spf=none (mx1.freebsd.org: domain of wlosh@bsdimp.com has no SPF policy when checking 2607:f8b0:4864:20::931) smtp.mailfrom=wlosh@bsdimp.com X-Spamd-Result: default: False [-1.99 / 15.00]; SUBJECT_ENDS_QUESTION(1.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000]; NEURAL_HAM_SHORT(-1.00)[-1.000]; NEURAL_HAM_LONG(-0.99)[-0.993]; FORGED_SENDER(0.30)[imp@bsdimp.com,wlosh@bsdimp.com]; R_DKIM_ALLOW(-0.20)[bsdimp-com.20210112.gappssmtp.com:s=20210112]; MIME_GOOD(-0.10)[multipart/alternative,text/plain]; MLMMJ_DEST(0.00)[freebsd-current@freebsd.org]; R_SPF_NA(0.00)[no SPF record]; RCVD_TLS_LAST(0.00)[]; RCVD_COUNT_TWO(0.00)[2]; MIME_TRACE(0.00)[0:+,1:+,2:~]; RCVD_IN_DNSWL_NONE(0.00)[2607:f8b0:4864:20::931:from]; DKIM_TRACE(0.00)[bsdimp-com.20210112.gappssmtp.com:+]; ASN(0.00)[asn:15169, ipnet:2607:f8b0::/32, country:US]; FROM_HAS_DN(0.00)[]; ARC_NA(0.00)[]; RCPT_COUNT_TWO(0.00)[2]; PREVIOUSLY_DELIVERED(0.00)[freebsd-current@freebsd.org]; TO_MATCH_ENVRCPT_SOME(0.00)[]; DMARC_NA(0.00)[bsdimp.com]; TO_DN_ALL(0.00)[]; FROM_NEQ_ENVFROM(0.00)[imp@bsdimp.com,wlosh@bsdimp.com] X-ThisMailContainsUnwantedMimeParts: N --000000000000a5fec005e9953a5b Content-Type: text/plain; charset="UTF-8" On Mon, Sep 26, 2022, 7:54 AM Lev Serebryakov wrote: > On 26.09.2022 13:03, Dimitry Andric wrote: > > > Sure, but if you are compiling without -mavx, why would you want the AVX > > intrinsics? You cannot use AVX intrinsics anyway, if AVX is not enabled. > Because autovectorization (generation of SSE or AVX instructions by > compiler itself, without intrinsics) can pessimize code. > > Sometimes it is valuable to know exactly where AVX is used. I don't > have examples on hands, but I've seen situations, when autovectorized code > was much slower than scalar code. > The detection method that dim@ outline will work just fine for the autodetect script. It just replaces the internal, charging undocumented names for standard ones. How you later compile individual bits of code is orthogonal. Warner > --000000000000a5fec005e9953a5b Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable


On Mon, Sep 26, 2022, 7:54 AM Lev Serebryakov <lev@freebsd.org> wrote:
On 26.09.2022 13:03, Dimitry Andric wrote:

> Sure, but if you are compiling without -mavx, why would you want the A= VX
> intrinsics? You cannot use AVX intrinsics anyway, if AVX is not enable= d.
=C2=A0 =C2=A0Because autovectorization (generation of SSE or AVX instructio= ns by compiler itself, without intrinsics) can pessimize code.

=C2=A0 =C2=A0Sometimes it is valuable to know exactly where AVX is used. I = don't have examples on hands, but I've seen situations, when autove= ctorized code was much slower than scalar code.

The detection method that di= m@ outline will work just fine for the autodetect script. It just replaces = the internal, charging undocumented names for standard ones.

How you later compile individual bits= of code is orthogonal.=C2=A0

Warner
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