From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf1-x436.google.com (mail-pf1-x436.google.com [IPv6:2607:f8b0:4864:20::436]) by sourceware.org (Postfix) with ESMTPS id 82E74385DC23 for ; Thu, 8 Jul 2021 01:02:24 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 82E74385DC23 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=dabbelt.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=dabbelt.com Received: by mail-pf1-x436.google.com with SMTP id f17so3921008pfj.8 for ; Wed, 07 Jul 2021 18:02:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=dabbelt-com.20150623.gappssmtp.com; s=20150623; h=date:subject:in-reply-to:cc:from:to:message-id:mime-version :content-transfer-encoding; bh=Hwpsc8gX0a9r5VysjHI42EvppubebcCuw5SobfExxiU=; b=wXK1fakB0cz2M8YxGjJbUyQbkj6itIEwAfO+vm7d2Lbkl8IvlxlG19B2+Y2voBojHo ZIpNkqDPJrjOXV0HmdMBb5mvVqvE61pg6K0xjwG1Yb9/qBUe3vIOSOyuOt/uqt0RjTlE lmhrHBC10A+0oVSndNBCWV6gg85HNLCuqYo5KfSYifesAYjkiKny9VhV8NeaE169hJPJ mquZPzb19lFkJEpbTbkYV/YTF5vNNldq4jocaA1HO+jKSLG0NVlNkCfqA2pWOIOlhvTd jcSzK78XpDPbv5EAUI+C2e4Nprfch53nnvflS8oAJ/kqF/ZvpS3bHVNGc3dfzjAns6jT S3nw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:subject:in-reply-to:cc:from:to:message-id :mime-version:content-transfer-encoding; bh=Hwpsc8gX0a9r5VysjHI42EvppubebcCuw5SobfExxiU=; b=j4MYmJKnEFKX+U/NK1+BsjgeR2Iuh1g8vJcRSut0dgbDJLZyJq7XhiQEbtLfGiQFWv Z2L58QM4/3hvBf9vCKClqVHZRT2Crbu23Qilv13UJNgP0ox6EiohnvC+tuO3FIYebPOo O8cD46pkB9/q5TdJJ1WkM6oX9O3uutRbjI7GYg0DfwAy+LnNzxiEvLwKzgvy2x90nfl7 OecgPTk1iwE0BvWjGWt4bRjhCct5PSEPogZZ8OkxYWPQhHY2ckwynTe88K371BLiLWRq 6zVGlzMiCeG/Ie0SJ5sLyQNYSzBD3Y0Gsb1j79N29R5jN64YJBlsegZkq6stZSAuPVNH 6NCQ== X-Gm-Message-State: AOAM530GFPpwrF6KORYhzvupfj2wuwXAjZSaXkykhIi/sRWILPx+7MnJ tnFIO/UyvwSZ3U/Tn1TXuyaZQQ== X-Google-Smtp-Source: ABdhPJx3w3vpTd0wNxpChiKekarRCT1EJux0Y00oht3A798ontdASXIed2l/CPPa/ULcaEy2ne79dA== X-Received: by 2002:a63:7d5:: with SMTP id 204mr28769724pgh.309.1625706142892; Wed, 07 Jul 2021 18:02:22 -0700 (PDT) Received: from localhost (76-210-143-223.lightspeed.sntcca.sbcglobal.net. [76.210.143.223]) by smtp.gmail.com with ESMTPSA id c136sm415666pfc.201.2021.07.07.18.02.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 07 Jul 2021 18:02:22 -0700 (PDT) Date: Wed, 07 Jul 2021 18:02:22 -0700 (PDT) X-Google-Original-Date: Wed, 07 Jul 2021 18:02:14 PDT (-0700) Subject: Re: [PATCH] docs: Add 'S' to Machine Constraints for RISC-V In-Reply-To: <20210707232625.zntqg54rmxv6lj4n@gmail.com> CC: kito.cheng@sifive.com, gcc-patches@gcc.gnu.org, Kito Cheng From: Palmer Dabbelt To: i@maskray.me Message-ID: Mime-Version: 1.0 (MHng) Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-12.5 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, GIT_PATCH_0, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: gcc-patches@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 08 Jul 2021 01:02:26 -0000 On Wed, 07 Jul 2021 16:26:25 PDT (-0700), i@maskray.me wrote: > On 2021-07-02, Kito Cheng wrote: >>It was undocument before, but already used in linux kernel, so LLVM >>community suggest we should document that, so that make it become >>supported/documented/non-internal machine constraints. >> >>gcc/ChangeLog: >> >> PR target/101275 >> * doc/md.text (Machine Constraints): Document the 'S' constraints >> for RISC-V. >>--- >> gcc/doc/md.texi | 3 +++ >> 1 file changed, 3 insertions(+) >> >>diff --git a/gcc/doc/md.texi b/gcc/doc/md.texi >>index 00caf3844cc..b776623e8a5 100644 >>--- a/gcc/doc/md.texi >>+++ b/gcc/doc/md.texi >>@@ -3536,6 +3536,9 @@ A 5-bit unsigned immediate for CSR access instructions. >> @item A >> An address that is held in a general-purpose register. >> >>+@item S >>+A constant call address. >>+ >> @end table >> >> @item RX---@file{config/rx/constraints.md} >>-- >>2.31.1 >> > > Ping on this:) Thanks, I hadn't had time to look a this but it was on the list. > 'S' can be used on either a variable or a function. Does "A constant call address." need change? I think so: this can certainly be used to generate arbitrary constant addresses into assembly, but I don't remember if there was some reason it was listed as only applying to call addresses. It certainly could just be a historical artifact, as those strings tend to bit rot when they're internal, but I wanted to at least take a look. Also: IIUC we're supposed to remove the @internal when something is documented (though I remember having said that before, so I might be mistaken).