From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 26931 invoked by alias); 18 Apr 2003 01:16:11 -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 26911 invoked from network); 18 Apr 2003 01:16:09 -0000 Received: from unknown (HELO vlsi1.ultra.nyu.edu) (128.122.140.213) by sources.redhat.com with SMTP; 18 Apr 2003 01:16:09 -0000 Received: by vlsi1.ultra.nyu.edu (4.1/1.34) id AA15817; Thu, 17 Apr 03 21:20:24 EDT Date: Fri, 18 Apr 2003 08:06:00 -0000 From: kenner@vlsi1.ultra.nyu.edu (Richard Kenner) Message-Id: <10304180120.AA15817@vlsi1.ultra.nyu.edu> To: rth@redhat.com Subject: Re: DATA_ALIGNMENT vs. DECL_USER_ALIGNMENT Cc: gcc-patches@gcc.gnu.org, gcc@gcc.gnu.org X-SW-Source: 2003-04/txt/msg00894.txt.bz2 The fact of the matter is that this field is being overloaded for two meanings: No, it's being overloaded for two *other* meanings: (1) The user really did set the alignment of the object. (2) The user really did set the alignment of the object's *type*. The user REALLY DID set the alignment, and expects it to be honored exactly as stated Yes, but there's a fundamental ambiguity here. If the user says he wants an object aligned at a 4-byte boundary, is it an error to align it to a page boundary? Is there some requirement that we ensure that every such object is at an address that has *exactly* the number of low-order zeros as requested by the alignment and no more? What, precisely, does "honored" mean here? I'll have more to say about this, but tomorrow morning when I'm fresher.