Message ID | 20200210233558.83580-1-cbiesinger@google.com |
---|---|
State | New, archived |
Headers |
Received: (qmail 85421 invoked by alias); 10 Feb 2020 23:36:05 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: <gdb-patches.sourceware.org> List-Unsubscribe: <mailto:gdb-patches-unsubscribe-##L=##H@sourceware.org> List-Subscribe: <mailto:gdb-patches-subscribe@sourceware.org> List-Archive: <http://sourceware.org/ml/gdb-patches/> List-Post: <mailto:gdb-patches@sourceware.org> List-Help: <mailto:gdb-patches-help@sourceware.org>, <http://sourceware.org/ml/#faqs> Sender: gdb-patches-owner@sourceware.org Delivered-To: mailing list gdb-patches@sourceware.org Received: (qmail 85413 invoked by uid 89); 10 Feb 2020 23:36:04 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-21.4 required=5.0 tests=AWL, BAYES_00, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, RCVD_IN_DNSWL_NONE, SPF_PASS autolearn=ham version=3.3.1 spammy=HX-HELO:sk:mail-yw, HX-Spam-Relays-External:sk:mail-yw, H*RU:sk:mail-yw, H*r:sk:mail-yw X-HELO: mail-yw1-f74.google.com Received: from mail-yw1-f74.google.com (HELO mail-yw1-f74.google.com) (209.85.161.74) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Mon, 10 Feb 2020 23:36:03 +0000 Received: by mail-yw1-f74.google.com with SMTP id 206so7445217ywt.3 for <gdb-patches@sourceware.org>; Mon, 10 Feb 2020 15:36:03 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=CD/MEzAXvL8lBv/nj+BpGc6X+gMllZ6waYbpeIsQPPA=; b=KJOc9r+QxtNx8lbEseH8dvQC7/udodBuB7bdv4Y6aKbx3YLwY2eACGcu6IutQHaq+x KNw6xbbYCdwZ6mllUDAJRQmfwhKP4gHRvwdcIBPLk0Npxq/wbllj/YLam2RxOdBTCuxQ 7vft+cQv6BlmQsgCTAvVWadWLenuI1YWuaMA6Kaa4UkxlggFz9ZcPVzWd8063w6bUo9L tP5eCRC+YqcPzyTWdlSiUdQvBb/7IZxOTyfWQD3xWoS6gUOlrFr6bXWAg1zEC82xMCtg sUoSwxqRP8rsAhV1xO7iGrQVYiGDHwZxGhB6RNT3HwN20IV7LDAD5Bp3dpH8yz2QBDtz 6Zpw== Date: Mon, 10 Feb 2020 17:35:58 -0600 Message-Id: <20200210233558.83580-1-cbiesinger@google.com> Mime-Version: 1.0 Subject: [PATCH] Add a comment for the ARM_F{0..7}_REGNUM registers From: "Christian Biesinger via gdb-patches" <gdb-patches@sourceware.org> Reply-To: Christian Biesinger <cbiesinger@google.com> To: gdb-patches@sourceware.org Cc: Christian Biesinger <cbiesinger@google.com> Content-Type: text/plain; charset="UTF-8" X-IsSubscribed: yes |
Commit Message
Terekhov, Mikhail via Gdb-patches
Feb. 10, 2020, 11:35 p.m. UTC
These are for the obsolete FPA architecture. gdb/ChangeLog: 2020-02-10 Christian Biesinger <cbiesinger@google.com> * 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(+)
Comments
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 <cbiesinger@google.com> > > * 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 = 13, /* Contains address of top of stack */ > ARM_LR_REGNUM = 14, /* address to return to from a function call */ > ARM_PC_REGNUM = 15, /* Contains program counter */ > + /* F0..F7 are the fp registers for the (obsolete) FPA architecture. */ > ARM_F0_REGNUM = 16, /* first floating point register */ > ARM_F3_REGNUM = 19, /* last floating point argument register */ > ARM_F7_REGNUM = 23, /* last floating point register */ > This looks obvious enough. cc-ed Alan in case he has any thoughts.
> On 11 Feb 2020, at 00:32, Luis Machado <luis.machado@linaro.org> 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 <cbiesinger@google.com> >> * 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 = 13, /* Contains address of top of stack */ >> ARM_LR_REGNUM = 14, /* address to return to from a function call */ >> ARM_PC_REGNUM = 15, /* Contains program counter */ >> + /* F0..F7 are the fp registers for the (obsolete) FPA architecture. */ >> ARM_F0_REGNUM = 16, /* first floating point register */ >> ARM_F3_REGNUM = 19, /* last floating point argument register */ >> ARM_F7_REGNUM = 23, /* last floating point register */ > > This looks obvious enough. cc-ed Alan in case he has any thoughts. I’m happy for that to be pushed as is. But... My only problem here is the use of the word “obsolete”. If it’s obsolete, why are we still supporting it? Digging into it, I didn’t realise FPA was quite that old, but it dates back to around 1995. Some good background information here (question was asked only 22 days ago!) https://retrocomputing.stackexchange.com/questions/13400/history-of-arm-linux-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 removed. I’d suggest it’s worth someone ripping out FPA support entirely 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 any objections). Alan.
On Tue, Feb 11, 2020 at 3:20 AM Alan Hayward <Alan.Hayward@arm.com> wrote: > > On 11 Feb 2020, at 00:32, Luis Machado <luis.machado@linaro.org> 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 <cbiesinger@google.com> > >> * 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 = 13, /* Contains address of top of stack */ > >> ARM_LR_REGNUM = 14, /* address to return to from a function call */ > >> ARM_PC_REGNUM = 15, /* Contains program counter */ > >> + /* F0..F7 are the fp registers for the (obsolete) FPA architecture. */ > >> ARM_F0_REGNUM = 16, /* first floating point register */ > >> ARM_F3_REGNUM = 19, /* last floating point argument register */ > >> ARM_F7_REGNUM = 23, /* last floating point register */ > > > > This looks obvious enough. cc-ed Alan in case he has any thoughts. > > I’m happy for that to be pushed as is. But... Thanks, pushed. > My only problem here is the use of the word “obsolete”. If it’s obsolete, why are > we still supporting it? > > Digging into it, I didn’t realise FPA was quite that old, but it dates back to around 1995. > > Some good background information here (question was asked only 22 days ago!) > https://retrocomputing.stackexchange.com/questions/13400/history-of-arm-linux-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 removed. > > I’d suggest it’s worth someone ripping out FPA support entirely 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 any 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
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 = 13, /* Contains address of top of stack */ ARM_LR_REGNUM = 14, /* address to return to from a function call */ ARM_PC_REGNUM = 15, /* Contains program counter */ + /* F0..F7 are the fp registers for the (obsolete) FPA architecture. */ ARM_F0_REGNUM = 16, /* first floating point register */ ARM_F3_REGNUM = 19, /* last floating point argument register */ ARM_F7_REGNUM = 23, /* last floating point register */