From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-il1-x144.google.com (mail-il1-x144.google.com [IPv6:2607:f8b0:4864:20::144]) by sourceware.org (Postfix) with ESMTPS id 8A0C938930C3 for ; Fri, 24 Apr 2020 06:43:59 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 8A0C938930C3 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=sifive.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=nelson.chu@sifive.com Received: by mail-il1-x144.google.com with SMTP id u5so8303874ilb.5 for ; Thu, 23 Apr 2020 23:43:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sifive.com; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=ZE0hNZ/b+vbOhJl5Oau8cYYILwMt4l0GtXwtsrZlR60=; b=iW8K3eA1vdICppJdyTg0tgqIzpKcnJmBzDWmfLYK+mara9U5rpRMzNbe7hZxer50wU lBm7vUHkJhnMcM+Gogq9bJjZfYttkWslYxAcd5P51DhPT69dQfT+R/X7FdWiP26y/TQD qpB2Lyam0tEBbEIgbh7ZJtX92USSO0BJcYF+DJ5qLPg/DZdN49M1mrlqB9eRSRTt4hiK CcCIYnERkkdWNvpAANAuxGYsCWQDRsrVpQI6LUCEvSEo1oHk6ihIwdeUvqXL55p+9zOd RjLzW8tdN8mrGDECki+HfbWXjo7UcnkDOKw6r5xva3Q67cZsQoHHWGOsgfyWzomLSWg5 sYHQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=ZE0hNZ/b+vbOhJl5Oau8cYYILwMt4l0GtXwtsrZlR60=; b=Swesue8WCfdP8QN50JC4O4uDJLlLJLqeT/RqwjvziLGcOLicn9xFd8ode7SsqnESY1 OSFCKEEA8Yw05q6h64kbs25SYV7BuLB3B5mU68LB8JU766034tYSdwqzcraswU1RLos0 k+s90i0xwU3FpQw2hZaJbl0lmichtlpWSKw4Vtd93brfGMDjLSM1+qA9frdIwe2ehSAn /3brpVBMT6h0lcQIuOJEKa9Z7oBeDRy8HlJdvDEc7UMt3EskzHLXsfBmad2dKkNuIAze RHutWfCaYCwkJKmqqIITWYACVERvKivfp0s0Ocsh2vEgksM/g7s5hsV8PSpikp8a2qpr eXEQ== X-Gm-Message-State: AGi0PubgKFaJwmH1zMPODbZrreiNdXHgweKe6VZkF7t4Zivk4m/LVwTS cBVrYusn+zyMOCgK3rdOKIG3rNpOAy9C5CqJWFoWag== X-Google-Smtp-Source: APiQypJmRcaepomK+K+foHmt3BgYsex3W3tBD4EJ/AGRKAsYnVsaxN6zD+HLUGh0E+08Vz8gY3rbpaChhwtsU/bDDiE= X-Received: by 2002:a92:dd09:: with SMTP id n9mr7490141ilm.132.1587710639049; Thu, 23 Apr 2020 23:43:59 -0700 (PDT) MIME-Version: 1.0 References: <1587208075-2462-4-git-send-email-nelson.chu@sifive.com> In-Reply-To: From: Nelson Chu Date: Fri, 24 Apr 2020 14:43:50 +0800 Message-ID: Subject: Re: [PATCH 3/7] RISC-V: Support new GAS options and configure options to set ISA versions. To: Palmer Dabbelt Cc: Binutils , gdb-patches@sourceware.org, Andrew Waterman , asb@lowrisc.org, Maxim Blinov , Kito Cheng Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Spam-Status: No, score=-2.9 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: gdb-patches@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gdb-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 24 Apr 2020 06:44:01 -0000 On Fri, Apr 24, 2020 at 10:37 AM Nelson Chu wrote: > > Hi Palmer, > > On Fri, Apr 24, 2020 at 6:59 AM Palmer Dabbelt wrote= : > > > * -mriscv-isa-version =3D > > > The syntax of is same as -march option, but without rv32= or rv64 > > > prefix. There are two reasons that you may need this option, > > > > > > 1. Some versions of extensions defined in the ISA spec are not matche= d to the > > > toolchain=E2=80=99s implementation. For example, V-ext is defined to= version 0.7 in > > > ISA spec, but we only have implementations for 0.8 and 0.9. Therefor= e, you > > > have to use this option to choose the correct version for V-ext. > > > > > > 2. You want to update the version for the specific standard extension= s if the > > > version are not set in the ELF arch attributes and -march option. > > > > I don't buy the argument for this. The V extension stuff isn't relevan= t: those > > are all draft versions, and this is a perfect reason why we don't want = to take > > drafts upstream. When we have a defined V ISA it'll be part of a vers= ioned > > RISC-V specification and any users that want it can just use at least t= hat ISA > > spec. > > I think I got your point, we all have reached consensus that it's > better not to take draft spec upstream. The v-extension might be a > little different, the latest released ISA spec defines the v-ext as > 0.7, even if the released riscv-v-spec is up to 0.8. According to our > consensus, we should accept the 0.8 and 0.9 v-ext on upstream until we > have a released ISA spec defining them. Otherwise, we can just accept > the 0.7 v-ext for now. I guess that is why we just have v-ext 0.8 and > 0.9 on riscv/riscv-binutils-gdb rather than upstream. This makes > sense, thank you :) Correct the information. The version of extensions before 2.0 should be draft, not release. > And we can still use -march to choose the version we want, including > v-ext. If users use the rvv-0.9.x in riscv/riscv-binutils-gdb, they > have to set the v-ext with version 0.9 by -march. Otherwise, we will > give them v0p0 if they only set -misa-spec=3D20191213. Give them v0p0, or we should give an error to make sure the valid version is set by march. The latter seems more safe. We give 0p0 when the user sets x extension without version. Thanks Nelson