From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-il1-x132.google.com (mail-il1-x132.google.com [IPv6:2607:f8b0:4864:20::132]) by sourceware.org (Postfix) with ESMTPS id A8DA2385B523 for ; Fri, 17 Mar 2023 16:33:24 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org A8DA2385B523 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=adacore.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=adacore.com Received: by mail-il1-x132.google.com with SMTP id h7so3041037ila.5 for ; Fri, 17 Mar 2023 09:33:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=adacore.com; s=google; t=1679070804; h=mime-version:message-id:date:user-agent:references:in-reply-to :subject:cc:to:from:from:to:cc:subject:date:message-id:reply-to; bh=TL/lsTizkhWSogh6RIsA1vDWFJrvea+yHSs9Le3pxh4=; b=US/YSHacXYffCYLDlti+hn+wsFeOayGO6UPH/GdS9zdDIWIUButzblxUM4ssnmvne9 izkYg78+uqdXs9o4I03E2A/qHQQ1rhq5w+Djn8KErA7YdU2Vd/yr3nXb8dtUskbhMGLk EyfcacUkMBZgG3KwLknjOMOVmkLZH47pDWKbPKijsRjBNibwHtluKZENOL8rhB0zyzVR XgJu+d8mVPXuWL8wcpfv5Tm92jMkq76LFdSrjNmBZfX4VTCw1pcktZCf6hEdtCItJJFy 3rUTT9lnYLsCSbppbdpdMcGEratX5ZTjtTA8KmpmQrt0KZ02ylw8lBMx4tsbLYa34+X/ 3nMg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1679070804; h=mime-version:message-id:date:user-agent:references:in-reply-to :subject:cc:to:from:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=TL/lsTizkhWSogh6RIsA1vDWFJrvea+yHSs9Le3pxh4=; b=X1Vho9EDBsjKxs0/uN5JyY/7mV198sjrsPW2WP4EXgLnU1sAWN33VnN38kZxAT2X5Q gK3b6YlMc6CHNAlj9/SZTdcJuCPT96UvVwjbegOFOhgmAttmtQ6cLgANzZeRC39/pY9r dEqGUjzdsKgX/enX/ZmHzq0ctjaZar93k2yy2H/PCSDLO48swoDHhsOAJsPUlpJunIhI 7pVkhUsTDu9yss+odfsn0KvZ2PIQ2HdDTM67FS5Y/xJiXtqQat/8EwjQP22CxCzPGgjP JFh1OnTQTcO4d5jOyqBDLNHO5m/n38sFrA/T5p0dnt9C8LeNmXLi/gl5DEFmc8t/FaL6 i5Rw== X-Gm-Message-State: AO0yUKUGgfmkJs1zFOcdmpFcDx45dNDNqqgtpEWiJrPBuS2jyk3akuxM 6SmgHohIXRLewQuhMai8Tuih+A== X-Google-Smtp-Source: AK7set+T0jzpGa2rgpK08IH7z2KZppLL7W2mlDIX4u1PT11dzRVBYkDG9O7adEMocJyR23R25FACcg== X-Received: by 2002:a92:d98d:0:b0:316:e453:5372 with SMTP id r13-20020a92d98d000000b00316e4535372mr69567iln.1.1679070803879; Fri, 17 Mar 2023 09:33:23 -0700 (PDT) Received: from murgatroyd (71-211-185-113.hlrn.qwest.net. [71.211.185.113]) by smtp.gmail.com with ESMTPSA id y10-20020a927d0a000000b003179b81610csm718507ilc.17.2023.03.17.09.33.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 17 Mar 2023 09:33:23 -0700 (PDT) From: Tom Tromey To: Segher Boessenkool Cc: Alexandre Oliva , gcc-patches@gcc.gnu.org, Tom Tromey , David Edelsohn , Kewen Lin , Jason Merrill , Cary Coutant , Jakub Jelinek Subject: Re: [PATCH] [rs6000] adjust return_pc debug attrs In-Reply-To: <20230313143043.GA25951@gate.crashing.org> (Segher Boessenkool's message of "Mon, 13 Mar 2023 09:30:43 -0500") References: <20230313143043.GA25951@gate.crashing.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.2 (gnu/linux) X-Attribution: Tom Date: Fri, 17 Mar 2023 10:33:22 -0600 Message-ID: <87fsa3ibhp.fsf@tromey.com> MIME-Version: 1.0 Content-Type: text/plain X-Spam-Status: No, score=-3.2 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=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: >>>>> "Segher" == Segher Boessenkool writes: Segher> Yes. On most architectures you can get multiple machine instructions of Segher> course (for long calls for example), but on rs6000 (with some ABIs, in Segher> some circumstances) we generate a nop insn after calls, so that the Segher> linker has a spot to insert fixup code after calls (typically to restore Segher> the r2 contents, but it could be anything). FWIW I sent a gdb patch to work around this bug. However, in my examples, I only ever saw a nop following the call instruction -- so I had gdb check for this. Patch is here: https://sourceware.org/pipermail/gdb-patches/2023-March/197951.html ... but I suppose I should change it to drop the nop check? It would of course be better not to have to have gdb work around this problem. Tom