From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 70041 invoked by alias); 29 May 2015 10:36:16 -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 70031 invoked by uid 89); 29 May 2015 10:36:16 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-0.3 required=5.0 tests=AWL,BAYES_00,FREEMAIL_FROM,FROM_LOCAL_NOVOWEL,HK_RANDOM_ENVFROM,HK_RANDOM_FROM,RCVD_IN_DNSWL_LOW,SPF_PASS autolearn=no version=3.3.2 X-HELO: mail-ob0-f171.google.com Received: from mail-ob0-f171.google.com (HELO mail-ob0-f171.google.com) (209.85.214.171) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES128-GCM-SHA256 encrypted) ESMTPS; Fri, 29 May 2015 10:36:15 +0000 Received: by obbea2 with SMTP id ea2so54041320obb.3 for ; Fri, 29 May 2015 03:36:13 -0700 (PDT) MIME-Version: 1.0 X-Received: by 10.202.185.135 with SMTP id j129mr6010197oif.123.1432895773501; Fri, 29 May 2015 03:36:13 -0700 (PDT) Received: by 10.76.26.178 with HTTP; Fri, 29 May 2015 03:36:13 -0700 (PDT) In-Reply-To: <55683406.4080305@redhat.com> References: <1431904329-13965-1-git-send-email-jcmvbkbc@gmail.com> <55659984.90103@redhat.com> <55683406.4080305@redhat.com> Date: Fri, 29 May 2015 10:36:00 -0000 Message-ID: Subject: Re: [PATCH] xtensa: fix access to the last pseudo register From: Max Filippov To: Pedro Alves Cc: gdb-patches@sourceware.org, Maxim Grigoriev , Woody LaRue , Marc Gauthier Content-Type: text/plain; charset=UTF-8 X-SW-Source: 2015-05/txt/msg00709.txt.bz2 On Fri, May 29, 2015 at 12:40 PM, Pedro Alves wrote: > 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! Checked in. -- Max