From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Vibhav Pant Newsgroups: gmane.emacs.devel Subject: Re: HAVE_FAST_UNALIGNED_ACCESS Date: Thu, 30 Mar 2023 17:08:16 +0530 Message-ID: <94d3de92c50a96d9172f88462bf3bc9c2792600c.camel@gmail.com> References: <87sfdmlgzx.fsf@gmail.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg="pgp-sha256"; protocol="application/pgp-signature"; boundary="=-DNs9YD5deqKH12B/bgE2" Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="30411"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Evolution 3.46.4 Cc: Po Lu To: Robert Pluim , emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Thu Mar 30 13:39:25 2023 Return-path: Envelope-to: ged-emacs-devel@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1phqcn-0007pD-L8 for ged-emacs-devel@m.gmane-mx.org; Thu, 30 Mar 2023 13:39:25 +0200 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1phqc1-0003t1-P1; Thu, 30 Mar 2023 07:38:38 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1phqbx-0003sP-JJ for emacs-devel@gnu.org; Thu, 30 Mar 2023 07:38:34 -0400 Original-Received: from mail-wr1-x430.google.com ([2a00:1450:4864:20::430]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1phqbu-0001E8-AZ for emacs-devel@gnu.org; Thu, 30 Mar 2023 07:38:32 -0400 Original-Received: by mail-wr1-x430.google.com with SMTP id l27so18745385wrb.2 for ; Thu, 30 Mar 2023 04:38:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1680176304; h=mime-version:user-agent:references:in-reply-to:date:cc:to:from :subject:message-id:from:to:cc:subject:date:message-id:reply-to; bh=Dm1oPYSN9y6mS2+W++lVqmHGSfeRXW6iZMNzpC4e4o0=; b=MtMfdiHlo6v/tZWmA35ZUnfoxTzKQ9RPeGjZ0eiK+TLspSYf5hHw0DqShDq4WWCkVF z0Ap0mHarTPz8NZ0vICJNKwePFEE9SYHd5biIWffjx6JOZzwTSmCzDHg0EbI5FbO0fq9 hipTy4bDvfZR614GNRKvxHHbTjqF88Y314gHzTTrB1HsKwMJoXJ/S9mOMLHZz06KxWO0 fgdH3AvAVG0HfzpJsre/g0rj+NDrxSllozLokXkrzRj+5dsmDO9/zGnzFMUMrI4gfC+Y J15z14G5Bnphi0ZFQfVIwIyd1e2LSmArFAQAo4dY0dNPLaKd76sAJcdQJluUD3+dppJA hN3Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1680176304; h=mime-version:user-agent:references:in-reply-to:date:cc:to:from :subject:message-id:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=Dm1oPYSN9y6mS2+W++lVqmHGSfeRXW6iZMNzpC4e4o0=; b=O3sALKozdxY2wNR6tyKvIBXfqqYGYAirjJrMVLepQ1sNZrvoWFCc0ElN75FArSnFhF 6zruMfgWQEYKka4WrSte23xYsdbTDaQ3QWW+LB+jIlYrcq81SoDzAg1L966qjNdwweev zSx3b3PqXkSCta7sssEjJV1/9Wl4r0IYWiQSwsM9pYok2AkYXmXwzE7/eij9PuMqdvzi EZexvPPzI5h8bQRLXyDWQrakUiWLjbuo7u8So7BJXvHYx+XbV7eyWeCnAcxisUlk+rkw mZjZmpBYGiawTzT90QmcmSN+ujb2bcO8nWcKmK4XhqL6L1SGqQPvYcVlH6W0RLWOVk8A Z3Ew== X-Gm-Message-State: AAQBX9fiz4oUqL2QKQBLGJs7bFsYF/rtvyBcDTtV7rPx8PXFTQ+6ImzK bNspX7F5afeaPP+Fkc+A3j+Kr3EvxQHWpA== X-Google-Smtp-Source: AKy350Zm+Q4+4cO9IFMa09dZXExK2MEXLBDCZWXCD2s/9vaiuhVZLnVMpQ2cbxnyJpDboOL3pGuzFQ== X-Received: by 2002:adf:ee08:0:b0:2d0:58f9:a6b with SMTP id y8-20020adfee08000000b002d058f90a6bmr4468966wrn.13.1680176303843; Thu, 30 Mar 2023 04:38:23 -0700 (PDT) Original-Received: from vibhavp-mbp.local ([2401:4900:1c54:2c58::2]) by smtp.gmail.com with ESMTPSA id a3-20020adffb83000000b002c561805a4csm32615542wrr.45.2023.03.30.04.38.21 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 30 Mar 2023 04:38:23 -0700 (PDT) In-Reply-To: <87sfdmlgzx.fsf@gmail.com> Received-SPF: pass client-ip=2a00:1450:4864:20::430; envelope-from=vibhavp@gmail.com; helo=mail-wr1-x430.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.devel:304861 Archived-At: --=-DNs9YD5deqKH12B/bgE2 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Thu, 2023-03-30 at 11:34 +0200, Robert Pluim wrote: > Instead, HAVE_FAST_UNALIGNED_ACCESS and UNALIGNED_LOAD_SIZE should be > removed and memcpy used instead: >=20 > =C2=A0 word_t a, c; >=20 > =C2=A0 memcpy (&a, w1 + b / ws, sizeof a); > =C2=A0 memcpy (&c, w2 + b / ws, sizeof c); >=20 I had recently made a few modifications to this on master. There, Fstring_lessp in uses the macro UNALIGNED_LOAD_SIZE instead, which is defined to __sanitizer_unaligned_loadXX in lisp.h if: * We're building with AddressSaniziter, * is available, and * USE_SANITIZER_UNALIGNED_LOAD is defined. > I would like to install such a change on emacs-29.=C2=A0 Emacs currently > crashes when built with various compilers performing pointer > alignment > checks. Instead of removing the code entirely, you could try modifying the macro definition by getting rid of the AddressSanitizer ifdef, and building with USE_SANITIZER_UNALIGNED_LOAD. In theory, this should make the load not crash with other sanitizers as well. If that works, I imagine that would be a slightly more acceptable change to install into emacs-29. Best, Vibhav --=20 Vibhav Pant vibhavp@gmail.com GPG: 7ED1 D48C 513C A024 BE3A 785F E3FB 28CB 6AB5 9598 --=-DNs9YD5deqKH12B/bgE2 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- iQEzBAABCAAdFiEEftHUjFE8oCS+Onhf4/soy2q1lZgFAmQldKgACgkQ4/soy2q1 lZjIaQgAyVOFsMft9voClMNI4b+P31Z7H/4u1iyXLOFV7/MPnzqPCLGadQO9wYxD zbJIVXFCvogm87VOWdsFwAELvw0gAf57dVcManqnXzviNizDhiOw11Uc6aw0MLv8 qD87A1y71TKxvqfn16Glxlpd+4AZ8fxvxuFtUzbBwqLaUVCjxeX3LHBMh5QNwGA7 vOmSudR8+yXmvp7xCyvTOPoaLXNnwS0nRfXs81RIMdL8t8DlELWL5bTQnlgBiNAq tgIK+7kcoIB73oMfhswEGHep5f+DAEo/QKELnuUzWVLB3lM6rT+gsx2iOSQZY0re 8PLYwZQBE9GYIbipfnjrBXHoKX+7CQ== =0pWj -----END PGP SIGNATURE----- --=-DNs9YD5deqKH12B/bgE2--