From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 48523 invoked by alias); 28 Apr 2016 22:15:19 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Received: (qmail 48436 invoked by uid 89); 28 Apr 2016 22:15:09 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.9 required=5.0 tests=BAYES_00,RP_MATCHES_RCVD,SPF_HELO_PASS autolearn=ham version=3.3.2 spammy=art, article X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES256-GCM-SHA384 encrypted) ESMTPS; Thu, 28 Apr 2016 22:14:59 +0000 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 95BA6C05681D; Thu, 28 Apr 2016 22:14:58 +0000 (UTC) Received: from [127.0.0.1] (ovpn01.gateway.prod.ext.phx2.redhat.com [10.5.9.1]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u3SMEuVb022214; Thu, 28 Apr 2016 18:14:57 -0400 Subject: Re: [PING][PATCH 2/2] Involve gdbarch in taking DWARF register pieces To: Andreas Arnez References: <20160415180943.4FEE857EE@oc7340732750.ibm.com> <571134CD.8080507@redhat.com> <5714E6EA.8050905@redhat.com> <57150356.3090508@redhat.com> Cc: Ulrich Weigand , gdb-patches@sourceware.org From: Pedro Alves Message-ID: Date: Thu, 28 Apr 2016 22:15:00 -0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-SW-Source: 2016-04/txt/msg00648.txt.bz2 On 04/28/2016 05:51 PM, Andreas Arnez wrote: > On Thu, Apr 28 2016, Pedro Alves wrote: > >> I couldn't find any reference to "sub-register" in the codebase. >> I'd assume it's something like "eax" being a sub part of "rax" >> on x86-64. But I'm not certain that's the case here? On a machine with >> vector registers, is a FP register really a chunk of the vector >> register, or is it a real separate physical register? > > It's exactly comparable with eax and rax. Or consider the SSE registers > xmm0-xmm15, which are embedded in their double-wide AVX counterparts > ymm0-ymm15. With z/Architecture, each 64-bit FP register is just a > "chunk" ("sub-register" / "part" / "slice" / ...) of a 128-bit vector > register. The ASCII art in section 2.1 of this article illustrates > this: > > https://sourceware.org/ml/gdb/2016-01/msg00013.html Thanks, this helps a lot. > > (BTW, I still didn't get much feedback on that article...) > > And if there is a better (or wider used) term than "sub-register", I'll > be happy to change the wording. No, that's fine terminology. I was just confused because I wasn't very clear whether we're talking about completely different registers. Thanks, Pedro Alves