From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 51967 invoked by alias); 11 Feb 2020 16:29:12 -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 51922 invoked by uid 89); 11 Feb 2020 16:29:12 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-29.4 required=5.0 tests=AWL,BAYES_00,ENV_AND_HDR_SPF_MATCH,GIT_PATCH_0,GIT_PATCH_1,GIT_PATCH_2,GIT_PATCH_3,RCVD_IN_DNSWL_NONE,SPF_PASS,USER_IN_DEF_SPF_WL autolearn=ham version=3.3.1 spammy= X-HELO: mail-ot1-f65.google.com Received: from mail-ot1-f65.google.com (HELO mail-ot1-f65.google.com) (209.85.210.65) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Tue, 11 Feb 2020 16:29:10 +0000 Received: by mail-ot1-f65.google.com with SMTP id j20so10694322otq.3 for ; Tue, 11 Feb 2020 08:29:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=nTMXKUnb/ytIC0saBnwu/fcrUcFAWwx2Wxn2Xb+B9OE=; b=Rg6uBlGSVyo/YDEntROQxWVi/6bhBTUmy9tV1Lij0Q3lsKDd7E/uDSDqD95ap+l11z 7Kr2RY96EKZgQ6GIfNA2XzgFqI0BlBkAO/J/Sqq69gAQNvn5yBAmr1R79WPJV0gyS1HD 0TlBf7Bd1hUH9bqJW41VJbIIRMEW9ovs/DW7eiA6QPeZT4ql6fzq7ts07tzb60LN8WGq o0ZplIBIpuFFT72rtcMhed1paOXTlupV3uTBEFuBnu2PiQSjXYFazapVw9RySKx0o0bP XcnTz3b+XCzbxmDhG2ftEQ+xuu3abpK52eWkJVOsybLCRG2UVRnDQ6wJXPfHeRWt6kjJ M5Zg== MIME-Version: 1.0 References: <20200210233558.83580-1-cbiesinger@google.com> <3a393049-bc2d-b8be-1b47-20114311d5b3@linaro.org> <73905855-549A-4BA8-9E6B-F9D567E3E2AC@arm.com> In-Reply-To: <73905855-549A-4BA8-9E6B-F9D567E3E2AC@arm.com> From: "Christian Biesinger via gdb-patches" Reply-To: Christian Biesinger Date: Tue, 11 Feb 2020 16:29:00 -0000 Message-ID: Subject: Re: [PATCH] Add a comment for the ARM_F{0..7}_REGNUM registers To: Alan Hayward Cc: Luis Machado , Richard Earnshaw , "gdb-patches\\@sourceware.org" , nd Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-IsSubscribed: yes X-SW-Source: 2020-02/txt/msg00401.txt.bz2 On Tue, Feb 11, 2020 at 3:20 AM Alan Hayward wrote: > > On 11 Feb 2020, at 00:32, Luis Machado wrote: > > > > On 2/10/20 8:35 PM, Christian Biesinger via gdb-patches wrote: > >> These are for the obsolete FPA architecture. > >> gdb/ChangeLog: > >> 2020-02-10 Christian Biesinger > >> * arch/arm.h (enum gdb_regnum): Add comment for the FP0..7 > >> registers. > >> Change-Id: I6920616318ee637493d4ca12b91fa2ebcd103d76 > >> --- > >> gdb/arch/arm.h | 1 + > >> 1 file changed, 1 insertion(+) > >> diff --git a/gdb/arch/arm.h b/gdb/arch/arm.h > >> index 13f030af82..2d9e87eb42 100644 > >> --- a/gdb/arch/arm.h > >> +++ b/gdb/arch/arm.h > >> @@ -31,6 +31,7 @@ enum gdb_regnum { > >> ARM_SP_REGNUM =3D 13, /* Contains address of top of s= tack */ > >> ARM_LR_REGNUM =3D 14, /* address to return to from a = function call */ > >> ARM_PC_REGNUM =3D 15, /* Contains program counter */ > >> + /* F0..F7 are the fp registers for the (obsolete) FPA architecture.= */ > >> ARM_F0_REGNUM =3D 16, /* first floating point registe= r */ > >> ARM_F3_REGNUM =3D 19, /* last floating point argument= register */ > >> ARM_F7_REGNUM =3D 23, /* last floating point register= */ > > > > This looks obvious enough. cc-ed Alan in case he has any thoughts. > > I=E2=80=99m happy for that to be pushed as is. But... Thanks, pushed. > My only problem here is the use of the word =E2=80=9Cobsolete=E2=80=9D. I= f it=E2=80=99s obsolete, why are > we still supporting it? > > Digging into it, I didn=E2=80=99t realise FPA was quite that old, but it = dates back to around 1995. > > Some good background information here (question was asked only 22 days ag= o!) > https://retrocomputing.stackexchange.com/questions/13400/history-of-arm-l= inux-and-fpa > > GCC support for FPA was removed back in 2012, in GCC 4.8. > And GDB has a history of removing features after GCC support has been rem= oved. > > I=E2=80=99d suggest it=E2=80=99s worth someone ripping out FPA support en= tirely in a follow on set of > patches. This leaves us with vfpv2, vfpv3, xscale-iwmmxt and no float. > > (cc-ing Richard who removed the FPA from GCC, on the off chance he has an= y objections). I'm not familiar enough with any of this to do this removal myself, fwiw. (I just wanted to fix a netbsd-arm build error, heh. Actually originally I just wanted to remove a deprecated function...) Christian