From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 1216 invoked by alias); 14 Apr 2002 15:33:54 -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 1209 invoked from network); 14 Apr 2002 15:33:54 -0000 Received: from unknown (HELO localhost.redhat.com) (24.112.240.27) by sources.redhat.com with SMTP; 14 Apr 2002 15:33:54 -0000 Received: from cygnus.com (localhost [127.0.0.1]) by localhost.redhat.com (Postfix) with ESMTP id 873BA3CEB; Sun, 14 Apr 2002 11:33:49 -0400 (EDT) Message-ID: <3CB9A15D.8030807@cygnus.com> Date: Sun, 14 Apr 2002 08:33:00 -0000 From: Andrew Cagney User-Agent: Mozilla/5.0 (X11; U; NetBSD macppc; en-US; rv:0.9.9) Gecko/20020328 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Daniel Jacobowitz Cc: gdb@sources.redhat.com Subject: Re: Switch ARM, SPARC and i386 to generic dummy frames (PC_IN_CALL_DUMMY)? References: <3CB99778.4050403@cygnus.com> <20020414111854.A4874@nevyn.them.org> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-SW-Source: 2002-04/txt/msg00241.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? Sorry, you've lost me. BTW, the line: >> - generic: looks for the FP in the list of dummy frames isn't a typo. Andrew