From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pj1-x1034.google.com (mail-pj1-x1034.google.com [IPv6:2607:f8b0:4864:20::1034]) by sourceware.org (Postfix) with ESMTPS id 32FCA385829B; Fri, 14 Oct 2022 20:39:41 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 32FCA385829B Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-pj1-x1034.google.com with SMTP id t12-20020a17090a3b4c00b0020b04251529so5773589pjf.5; Fri, 14 Oct 2022 13:39:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=in-reply-to:from:references:cc:to:content-language:subject :user-agent:mime-version:date:message-id:from:to:cc:subject:date :message-id:reply-to; bh=FCQopy9OL57G9iU5SYX/wI+7MTgd6iA3V1g3KjrFVQc=; b=QkgvocvfQ5gWan59j/OMjhYfO5kxErK2QoSk6d2xBleE/d9nUBfGbUWMUwsYJzdj2Y fy5pAA1VxfksyNWGloWA2nAcATy93BL4nVm+SLJoI3Xl+n+zf8oTmRAiLYUHosdm1uwN BdWuepCUNN9/llOQyZBZsflyOyPL1klQV+Mwh+AS5X/l9tXYeIOuV9qcQw/e7J10r9xt n/lkIferQX8mm5vv7ZhsiLoUfesUYGptXCIFc1y6RUldbAyqIotmuSSjQAjs7HBRr9CM FYMmUw0Lfr+QQyI4B/Qx7Y9Nzx7DbxJv6sR4R91H3rKKCn71h59OYPSM55sqXLQFFHny 8Hsw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:from:references:cc:to:content-language:subject :user-agent:mime-version:date:message-id:x-gm-message-state:from:to :cc:subject:date:message-id:reply-to; bh=FCQopy9OL57G9iU5SYX/wI+7MTgd6iA3V1g3KjrFVQc=; b=vaH3gRYqFcZa5XabJjUHo90AlkpQHMisXwzjCAN86Yb1RnhLbrOlhic6GN7+HzlDWg XY4FZPX8dOh5nXC50GtMLRhOxp+aihVXz80jBY0qj0jXb/EZBvjxBPcJbHRv8MdDvLZF lhmx5eJjk3VT0fp+/TDZgasEmlw9o4/nEaDEhaKBVcW/RM+cngZXNB6RjiIrCujDzwwh nUVMe/16NWpDVTkfFJqCcZZNHOXWGqMX2rvpu7MFIWSLexmKC9Mg/USJ6sRtEE6xDTQj GlmcYQELNJAoIIXbsuopZpcMgioBnjp7p16BQkA4o6jpJlLHnrSCrfMzl+u+qTtixa+F lDyQ== X-Gm-Message-State: ACrzQf0oedeioGVkYWrnonYiwRBEqF/A+aOlnOYC989sbX5vIzRoWpfc VSaNMyfidYMWmrWkd4QZBlBSuqYJ7CM= X-Google-Smtp-Source: AMsMyM6Tucvjas8EOSz6DqiM6iRVqpNljEELTxeO6SLavOXMMJ1OOairCeP/xPODthr//NFyWYCHBA== X-Received: by 2002:a17:90b:3ecc:b0:20d:9da6:56cd with SMTP id rm12-20020a17090b3ecc00b0020d9da656cdmr7508438pjb.246.1665779979887; Fri, 14 Oct 2022 13:39:39 -0700 (PDT) Received: from ?IPV6:2601:681:8600:13d0::f0a? ([2601:681:8600:13d0::f0a]) by smtp.gmail.com with ESMTPSA id c28-20020aa7953c000000b0053725e331a1sm2144319pfp.82.2022.10.14.13.39.35 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 14 Oct 2022 13:39:39 -0700 (PDT) Content-Type: multipart/alternative; boundary="------------uru8V3RaXMzAYhmAa1qcdlqM" Message-ID: <818c3a05-feec-4f0a-8268-48074af14ac6@gmail.com> Date: Fri, 14 Oct 2022 14:39:33 -0600 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.3.1 Subject: Re: [PATCH v2 00/10] [RISC-V] Atomics improvements [PR100265/PR100266] Content-Language: en-US To: =?UTF-8?Q?Christoph_M=c3=bcllner?= , Palmer Dabbelt Cc: gcc-patches@gcc.gnu.org, Vineet Gupta , Kito Cheng , gnu-toolchain@rivosinc.com, Philipp Tomsich , =?UTF-8?Q?Christoph_M=c3=bcllner?= References: <47124771-dbfe-82c4-2f70-4b8c9fb19aa6@gmail.com> From: Jeff Law In-Reply-To: X-Spam-Status: No, score=-4.1 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM,HTML_MESSAGE,NICE_REPLY_A,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: This is a multi-part message in MIME format. --------------uru8V3RaXMzAYhmAa1qcdlqM Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 10/14/22 05:03, Christoph Müllner wrote: > > My guess is people like the ISA mapping (more) because it has been > documented and reviewed. > And it is the product of a working group that worked out the > RVWMO specification. > This gives some confidence that we don't need to rework it massively > because of correctness issues in the future. This stuff can be hard and if someone with deep experience in memory models has reviewed the ISA mapping, then I'd prefer it over the GCC mapping.   It's just more likely the experts in the memory model space are more likely to get it right than a bunch of compiler junkies, no matter how smart we think we are :-) Maybe I'm being too optimistic, but it's not hard for me to see a path where GCC and LLVM both implement the ISA mapping by default.  Anything else is just a path of long term pain. Jeff --------------uru8V3RaXMzAYhmAa1qcdlqM--