From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 33315 invoked by alias); 29 May 2015 09:40:30 -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 33303 invoked by uid 89); 29 May 2015 09:40:29 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.4 required=5.0 tests=AWL,BAYES_00,KAM_LAZY_DOMAIN_SECURITY,SPF_HELO_PASS,T_RP_MATCHES_RCVD autolearn=no version=3.3.2 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; Fri, 29 May 2015 09:40:29 +0000 Received: from int-mx13.intmail.prod.int.phx2.redhat.com (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26]) by mx1.redhat.com (Postfix) with ESMTPS id F1390374A1E; Fri, 29 May 2015 09:40:26 +0000 (UTC) Received: from [127.0.0.1] (ovpn01.gateway.prod.ext.ams2.redhat.com [10.39.146.11]) by int-mx13.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id t4T9eMlD004261; Fri, 29 May 2015 05:40:25 -0400 Message-ID: <55683406.4080305@redhat.com> Date: Fri, 29 May 2015 09:40:00 -0000 From: Pedro Alves User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.5.0 MIME-Version: 1.0 To: Max Filippov CC: gdb-patches@sourceware.org, Maxim Grigoriev , Woody LaRue , Marc Gauthier Subject: Re: [PATCH] xtensa: fix access to the last pseudo register References: <1431904329-13965-1-git-send-email-jcmvbkbc@gmail.com> <55659984.90103@redhat.com> In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-SW-Source: 2015-05/txt/msg00705.txt.bz2 On 05/27/2015 11:55 AM, Max Filippov wrote: > On Wed, May 27, 2015 at 1:16 PM, Pedro Alves wrote: >> On 05/18/2015 12:12 AM, Max Filippov wrote: >>> Currently access to the last pseudo register is aliased to a1. This is >>> done by little snippets in the beginning of xtensa_pseudo_register_read >>> and xtensa_pseudo_register_write that used to do such aliasing for FP >>> register since bdb4c075a29dd086f0868b394b488b1c94666be6, but then >>> FP_ALIAS was expanded into gdbarch_num_regs (current_gdbarch) + >>> gdbarch_num_pseudo_regs (current_gdbarch) (one register past the last >>> pseudo register) in 304fe2552d6e0821e8fdb7575f8e7ba6607a076d, which >>> then was changed to the last pseudo register in >>> 94a0e877111421d300d26b858bd3a0a27078d1e8. >> >> IIUC, the original intention was for FP to alias a1, and then through >> that series of patches (part of old current_gdbarch elimination) >> we ended up aliasing the wrong register. Instead of fixing the >> aliasing, you're just removing it altogether. Correct? > > I'm removing that aliasing to expose the last pseudoregister. > After that patch fp pseudo register still exists and it is a read only alias > for a1. I don't think that's right, because normally frame pointer is a7 or > a15, depending on ABI, but that's definitely a separate question. Ah, ok. FAOD, patch is still OK. :-) Thanks, Pedro Alves