From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 27554 invoked by alias); 14 Apr 2002 15:18:41 -0000 Mailing-List: contact gdb-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sources.redhat.com Received: (qmail 27541 invoked from network); 14 Apr 2002 15:18:36 -0000 Received: from unknown (HELO nevyn.them.org) (128.2.145.6) by sources.redhat.com with SMTP; 14 Apr 2002 15:18:36 -0000 Received: from drow by nevyn.them.org with local (Exim 3.35 #1 (Debian)) id 16wlmI-0001Jo-00 for ; Sun, 14 Apr 2002 11:18:54 -0400 Date: Sun, 14 Apr 2002 08:18:00 -0000 From: Daniel Jacobowitz To: gdb@sources.redhat.com Subject: Re: Switch ARM, SPARC and i386 to generic dummy frames (PC_IN_CALL_DUMMY)? Message-ID: <20020414111854.A4874@nevyn.them.org> Mail-Followup-To: gdb@sources.redhat.com References: <3CB99778.4050403@cygnus.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3CB99778.4050403@cygnus.com> User-Agent: Mutt/1.3.23i X-SW-Source: 2002-04/txt/msg00240.txt.bz2 On Sun, Apr 14, 2002 at 10:51:36AM -0400, Andrew Cagney wrote: > Hello, > > If I remember one of those unwritten ``grand plans'' correctly, the > intent is to have all targets switched to ``generic dummy frames''. True? > > Among other things, generic dummy frames do not save/restore registers > on the target stack (instead they are cached locally) and this should > improve the overall performance of an inferior function call. > > Anyway, the thing that prompts this is PC_IN_CALL_DUMMY(PC, SP, FP). > There are several implementations. Only two: > > - generic: looks for the FP in the list of dummy frames > - stack: looks for PC in [FP..SP) > > require the SP/FP parameters. I've a patch to fix the first one (search > for the PC). If the ARM, SPARC and i386 can switch to generic dummy > frames then those parameters can be eliminated and all calls simplified. Wait a second. Switch to searching for the PC? Does that work reliably if the PC being searched for is in more than one dummy frame? I guess it does for PC_IN_CALL_DUMMY (a predicate), but does anything else use the search code? -- Daniel Jacobowitz Carnegie Mellon University MontaVista Software Debian GNU/Linux Developer