From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from herc.mirbsd.org (bonn.mirbsd.org [217.91.129.195]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1CCAA1FD8; Sat, 20 Jan 2024 07:21:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.91.129.195 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705735274; cv=none; b=PhGZ8RrnflpQEiN4pCuqegCm6uftAGaWHkuTQKvmmPq/Ju6gDDVU3cp+onUA5fScAZuLJ2gvqY+9LxriMJpSxMdMK3TydJmYv/2xG820CEGPf9rUZjPRzk2Yxw8v1gYamM8rD5bFT3itJQfLe+tj7DZHC8E6csF/Inw7ou+VTfQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705735274; c=relaxed/simple; bh=AUtMTHlxtutjYSVB+7qK1W4n0GnyCXxkh/HEIBxUCKg=; h=Date:From:To:cc:Subject:In-Reply-To:Message-ID:References: MIME-Version:Content-Type; b=P7Jq3N24luuQfkryNTVnmgao6/o7ZH431IzXyk5Ctdks1bRJ2gUJIr0fuVpho0eQrWGI7SNN+BVS8kXJzJCeXrxc6jolSk5Fx+SouVzwOA+7J2SRxLXqnru09M3UF0RQVeA2tenradpodFRVENqM4/t87cIhFc9n7LlCNuRDQ8k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=debian.org; spf=none smtp.mailfrom=debian.org; arc=none smtp.client-ip=217.91.129.195 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=debian.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=debian.org Received: from herc.mirbsd.org (tg@herc.mirbsd.org [192.168.0.82]) by herc.mirbsd.org (8.14.9/8.14.5) with ESMTP id 40K6wuil000662 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Sat, 20 Jan 2024 06:59:05 GMT Date: Sat, 20 Jan 2024 06:58:56 +0000 (UTC) From: Thorsten Glaser X-X-Sender: tg@herc.mirbsd.org To: Peter Zijlstra cc: x86@kernel.org, rostedt@goodmis.org, hpa@zytor.com, torvalds@linuxfoundation.org, linux-kernel@vger.kernel.org, linux-toolchains@vger.kernel.org, jpoimboe@redhat.com, alexei.starovoitov@gmail.com, mhiramat@kernel.org Subject: Re: [PATCH 1/2] x86: Remove dynamic NOP selection In-Reply-To: <20210312115749.065275711@infradead.org> Message-ID: References: <20210312113253.305040674@infradead.org> <20210312115749.065275711@infradead.org> Content-Language: de-Zsym-DE-1901-u-em-text-rg-denw-tz-utc, en-Zsym-GB-u-cu-eur-em-text-fw-mon-hc-h23-ms-metric-mu-celsius-rg-denw-tz-utc-va-posix Precedence: bulk X-Mailing-List: linux-toolchains@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Peter Zijlstra dixit: >-/* generic versions from gas [=E2=80=A6] >- 3: leal 0x00(%esi),%esi >- 4: leal 0x00(,%esi,1),%esi >- 6: leal 0x00000000(%esi),%esi >- 7: leal 0x00000000(,%esi,1),%esi vs. >+ * Generic 32bit nops from GAS: [=E2=80=A6] >+ * 3: leal 0x0(%esi),%esi >+ * 4: leal 0x0(%esi,%eiz,1),%esi >+ * 5: leal %ds:0x0(%esi,%eiz,1),%esi >+ * 6: leal 0x0(%esi),%esi >+ * 7: leal 0x0(%esi,%eiz,1),%esi >+ * 8: leal %ds:0x0(%esi,%eiz,1),%esi I think there=E2=80=99s some mistake introduced. The BYTES_* are identical for e.g. #7, but %eiz must be wrong, it=E2=80=99s not a register. Indeed, gas (on Debian bullseye) does not assemble that either. (Awful AT&T syntax aside=E2=80=A6) bye, //mirabilos --=20 =E2=80=9ECool, /usr/share/doc/mksh/examples/uhr.gz ist ja ein Grund, mksh auf jedem System zu installieren.=E2=80=9C =09-- XTaran auf der OpenRheinRuhr, ganz begeistert (EN: =E2=80=9C[=E2=80=A6]uhr.gz is a reason to install mksh on every system= =2E=E2=80=9D)