From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 10404 invoked by alias); 25 Apr 2002 04:27:11 -0000 Mailing-List: contact gcc-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Archive: List-Post: List-Help: Sender: gcc-owner@gcc.gnu.org Received: (qmail 10393 invoked from network); 25 Apr 2002 04:27:07 -0000 Received: from unknown (HELO hiauly1.hia.nrc.ca) (132.246.100.193) by sources.redhat.com with SMTP; 25 Apr 2002 04:27:07 -0000 Received: from hiauly1.hia.nrc.ca (localhost [127.0.0.1]) by hiauly1.hia.nrc.ca (8.12.0.Beta16/8.12.0.Beta16) with ESMTP id g3P4R5FN019650; Thu, 25 Apr 2002 00:27:06 -0400 (EDT) Received: (from dave@localhost) by hiauly1.hia.nrc.ca (8.12.0.Beta16/8.12.0.Beta16) id g3P4R48w019648; Thu, 25 Apr 2002 00:27:04 -0400 (EDT) Message-Id: <200204250427.g3P4R48w019648@hiauly1.hia.nrc.ca> Subject: Re: PA specifies invalid T_ADAFLAGS To: willy@debian.org (Matthew Wilcox) Date: Wed, 24 Apr 2002 21:39:00 -0000 From: "John David Anglin" Cc: dewar@gnat.com, gcc@gcc.gnu.org, willy@debian.org In-Reply-To: <20020425040940.A32191@parcelfarce.linux.theplanet.co.uk> from "Matthew Wilcox" at Apr 25, 2002 04:09:40 am MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-SW-Source: 2002-04/txt/msg01280.txt.bz2 > PA has 8 space registers numbered 0 to 7. Most instructions allow you > to specify one of 1, 2 or 3, OR to select the space register to use based > on the top two bits of the virtual address. If the top two bits are 00, > use sr4, 01, use sr5, 10 uses 6 and 11 uses 7. HPUX takes advantage The first model is only available under hpux using assembly language. The standard code generated by gcc uses sr4 which causes the top two bits of a virtual address to select one of sr4, sr5, sr6, or sr7, respectively. Your comments that the base register can end up in the wrong segment still suggests a bug to me. I can't imagine the linker working with anything other than the standard runtime. As I said, a fix was done regarding which register becomes the base register. There were problems in the past with the index being selected as the base register and that didn't work with the segmented architecture of the PA. I agree with Matthew that "-mdisable-indexing" should not be used under linux as it has a flat memory model. There doesn't seem to be any documentation of why -mdisable-indexing is needed and nothing in the changelogs. If there is something special about the memory model used by ada, it would be good to have it documented. Dave -- J. David Anglin dave.anglin@nrc.ca National Research Council of Canada (613) 990-0752 (FAX: 952-6605)