From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from esa4.mentor.iphmx.com (esa4.mentor.iphmx.com [68.232.137.252]) by sourceware.org (Postfix) with ESMTPS id B46B83857C48 for ; Wed, 2 Sep 2020 19:35:57 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org B46B83857C48 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=codesourcery.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=Andrew_Stubbs@mentor.com IronPort-SDR: 2PiZ6ngFH6UJltU29icH759qknIqYVsjEgx9oiNRd8Zh30OkJSEDHWO/zACD7D1SxfYSZ71ysp 2tMEGXvAPXEENiAcGd1vKLgFxaugYNukcAZkGxeMfDgsZyCGwpX58BUhJj7SINBUMHGR2bq8Cv HuKxqg0b96Evlcm8e7yycsUSdcYsqjD51CyJqQEPeQZRydNFI/s/kTjKZkwj/mfnI8npAMUGIJ B7vB/qwhh6yEk17HGiqrpKPzixrt5TpzLL6zX/KGCKN6CWvE22072/FO5qCUk1hJcTcEbVKiVh Uu4= X-IronPort-AV: E=Sophos;i="5.76,384,1592899200"; d="scan'208";a="52642913" Received: from orw-gwy-02-in.mentorg.com ([192.94.38.167]) by esa4.mentor.iphmx.com with ESMTP; 02 Sep 2020 11:35:53 -0800 IronPort-SDR: 67/zfKyF3Nc3i6q1+6KbmMz+HItmgEPaN0eq8Kd8hqUkQjl7uVrt0No3iHCuYp9sE08otgq5jX cdjFzIpdOuqh4VSyM2IkzlBlnmfhB3k49noGl6Ce4/dhgNoEPjFKb0Afls9yhd4ywhXhPMU8ut txgFiib/Od4zay1d/mAlz/vt/QwKshT8zYWipXHNr2hNOvwbUzp6BSqjviKTySLZzAmc0ZzWQg WfKOtkrcDTxHlHelFstLxCxaHY5LdZSGG2ie0EBafyZ2yM3/gUlbRx+ufc7xU21cO3hnxgmzbc aMA= Subject: Re: [PATCH] dwarf: Multi-register CFI address support To: Tom Tromey CC: "gcc-patches@gcc.gnu.org" References: <363f6c4b-4c7f-9244-9bf1-dee7e7a42f8c@codesourcery.com> <87v9gwukzf.fsf@tromey.com> From: Andrew Stubbs Message-ID: <9b0cb151-b85c-1ef4-d867-cf5fdd1dd892@codesourcery.com> Date: Wed, 2 Sep 2020 20:35:48 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <87v9gwukzf.fsf@tromey.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit X-Originating-IP: [137.202.0.90] X-ClientProxiedBy: SVR-IES-MBX-04.mgc.mentorg.com (139.181.222.4) To SVR-IES-MBX-03.mgc.mentorg.com (139.181.222.3) X-Spam-Status: No, score=-7.1 required=5.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS, KAM_DMARC_STATUS, KAM_SHORT, NICE_REPLY_A, SPF_HELO_PASS, 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: 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: Wed, 02 Sep 2020 19:36:00 -0000 On 02/09/2020 18:49, Tom Tromey wrote: >>>>>> "Andrew" == Andrew Stubbs writes: > > Andrew> To be fair, the DWARF standard makes a similar assumption; the > Andrew> engineers working on LLVM and GDB, at AMD, have therefore invented > Andrew> some new DWARF operators that they plan to propose for a future > Andrew> standard. Only one is relevant here, however: > Andrew> DW_OP_LLVM_piece_end. (Unfortunately this clashes with an AArch64 > Andrew> extension, but I think we can cope using an alias -- only GCC dumps > Andrew> will be confusing.) > > Andrew> +/* AMD GCN extensions (originally for LLVM). */ > Andrew> +// This clashes with DW_OP_AARCH64_operation, so use an alias instead > Andrew> +// DW_OP (DW_OP_LLVM_piece_end, 0xea) > Andrew> +#define DW_OP_LLVM_piece_end DW_OP_AARCH64_operation > Andrew> DW_END_OP > > Is it too late to pick a non-clashing value? > > Also, we have tried pretty hard in recent years to document all of gcc's > DWARF extensions. Please add a link to the documentation for this one. > If there aren't docs -- I guess it would be ideal if you could write > them. Putting them on the GCC wiki is fine. I didn't select this number; I'm just following out-of-tree LLVM and GDB usage from AMD. It's allocated from the user extension range, so I imagine it'll enter the standard with a different number (and probably name). The documentation is here: http://llvm.org/docs/AMDGPUDwarfExtensionsForHeterogeneousDebugging.html#composite-location-description-operations Andrew