From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 7454 invoked by alias); 4 Oct 2006 20:43:19 -0000 Received: (qmail 7444 invoked by uid 22791); 4 Oct 2006 20:43:19 -0000 X-Spam-Check-By: sourceware.org Received: from igw2.watson.ibm.com (HELO igw2.watson.ibm.com) (129.34.20.6) by sourceware.org (qpsmtpd/0.31) with ESMTP; Wed, 04 Oct 2006 20:43:13 +0000 Received: from sp1n294en1.watson.ibm.com (sp1n294en1.watson.ibm.com [129.34.20.40]) by igw2.watson.ibm.com (8.13.1/8.13.1/8.13.1-2005-04-25 igw) with ESMTP id k94Ki1cc025967; Wed, 4 Oct 2006 16:44:01 -0400 Received: from sp1n294en1.watson.ibm.com (localhost [127.0.0.1]) by sp1n294en1.watson.ibm.com (AIX5.2/8.11.6p2/8.11.7/01-14-2004_2) with ESMTP id k94Kh63160028; Wed, 4 Oct 2006 16:43:06 -0400 Received: from mgsmtp00.watson.ibm.com (mgsmtp00.watson.ibm.com [9.2.40.58]) by sp1n294en1.watson.ibm.com (AIX5.2/8.11.6p2/8.11.7/01-14-2004_1) with ESMTP id k94Kh5P14660; Wed, 4 Oct 2006 16:43:05 -0400 Received: from makai.watson.ibm.com (makai.watson.ibm.com [9.2.216.144]) by mgsmtp00.watson.ibm.com (8.12.11/8.12.11/2005/09/01) with ESMTP id k94KevG6026831; Wed, 4 Oct 2006 16:40:57 -0400 Received: from watson.ibm.com (localhost [127.0.0.1]) by makai.watson.ibm.com (AIX5.3/8.11.6p2/8.11.0/03-06-2002) with ESMTP id k94Kh4V28680; Wed, 4 Oct 2006 16:43:04 -0400 Message-Id: <200610042043.k94Kh4V28680@makai.watson.ibm.com> To: Janani Janakiraman , gdb-patches@sourceware.org, pgilliam@us.ibm.com, Alan Modra Subject: Re: [patch] Pushing Inferior Function Arguments onto Stack on PowerPC64 machines In-Reply-To: Message from Daniel Jacobowitz of "Wed, 04 Oct 2006 16:26:38 EDT." <20061004202638.GA6253@nevyn.them.org> References: <20061004191056.GA4000@nevyn.them.org> <20061004202638.GA6253@nevyn.them.org> Date: Wed, 04 Oct 2006 20:43:00 -0000 From: David Edelsohn Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org X-SW-Source: 2006-10/txt/msg00022.txt.bz2 >>>>> Daniel Jacobowitz writes: >> From reading the PPC64 Platform ABI at >> http://www.freestandards.org/spec/ELF/ppc64/PPC-elf64abi-1.9.html >> ( see section 3.1.7) it appears that on Big Endian machines, >> values are left aligned. But looks like GCC has different rules and right >> aligns the values which are put on the >> registers. This matches Andrew Cagney comment in the code, that says that >> ABI specifies that the values >> should be left aligned. But like I said in my earlier note, GCC appears to >> want the values to be >> right aligned. Would appreciate another set of eyes looking at it as I >> don't have too much experience >> in this area. The PPC64 Linux ABI changed. AIX always pads upwards. PPC64 Linux pads aggregates smaller than a doubleword downward. "An aggregate or union smaller than one doubleword in size is padded so that it appears in the least significant bits of the doubleword. All others are padded, if necessary, at their tail." David