From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 16590 invoked by alias); 10 Aug 2003 06:55:21 -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 16583 invoked from network); 10 Aug 2003 06:55:20 -0000 Received: from unknown (HELO mta1.wss.scd.yahoo.com) (66.218.85.32) by sources.redhat.com with SMTP; 10 Aug 2003 06:55:20 -0000 Received: from tuliptree.org (67.161.44.241) by mta1.wss.scd.yahoo.com (7.0.016) (authenticated as jim@tuliptree.org) id 3F0B40B900ADD46B; Sat, 9 Aug 2003 23:51:34 -0700 Message-ID: <3F35EB93.3020500@tuliptree.org> Date: Sun, 10 Aug 2003 08:06:00 -0000 From: Jim Wilson User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.0.2) Gecko/20030716 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Richard Kenner CC: gcc@gcc.gnu.org Subject: Re: Problem in split_basic_block References: <10308080152.AA10195@vlsi1.ultra.nyu.edu> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-SW-Source: 2003-08/txt/msg00546.txt.bz2 Richard Kenner wrote: > Interesting. I don't know the ia64 instruction set, but I'd always > thought of the addp4 stuff as a horrible kludge. I'm kind of curious > about this myself now. The upper three bits of an IA-64 address indicate the segment (region). This is somewhat similar to the VAX I believe. If you don't want segments you can define them in the obvious way to get a flat address space. addp4 does a 32-bit add and then copies the 2 most significant bits of the 32-bit result (31 and 30) into the 2 most significant bits of the target register (63 and 62). This gives you access to 4 segments (regions). You really should have some understanding of the IA-64 ISA if you are trying to do a port. IA-64 architecture manuals are available here: http://developer.intel.com/design/itanium/manuals.htm See Vol 2 Section 4.1.9 32-bit Virtual Addressing. This documents how to do zero-extend, sign-extend, or pointer-swizzling addressing via addp4. All 3 are supported by the architecture. -- Jim Wilson, GNU Tools Support, http://www.SpecifixInc.com