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To: kenner@vlsi1.ultra.nyu.edu (Richard Kenner)
cc: gcc-patches@gcc.gnu.org, gcc@gcc.gnu.org
Subject: Re: DATA_ALIGNMENT vs. DECL_USER_ALIGNMENT 
In-Reply-To: Message from kenner@vlsi1.ultra.nyu.edu (Richard Kenner) 
   of "Thu, 10 Apr 2003 18:01:18 EDT." <10304102201.AA03464@vlsi1.ultra.nyu.edu> 
Date: Thu, 10 Apr 2003 22:23:00 -0000
From: David Edelsohn <dje@watson.ibm.com>
X-SW-Source: 2003-04/txt/msg00485.txt.bz2

>>>>> Richard Kenner writes:

Richard> If only to objects, saying that an object is 1-byte aligned allows
Richard> *any* alignment.

	Yes.  64-bit S/390 requires 2-byte alignment.  The alignment can
be 2 or anything stricter than 2 for 64-bit S/390.  GNU Ada currently is
setting USER_ALIGN to 1 for some objects, which is breaking GNU Ada on
64-bit S/390.

Richard> But I can't find a macro that specifies an minimum alignment.  What is
Richard> it called?

	This would be a new macro, or result of querying an existing macro
with a test alignment of 1 byte to examine what modification to that
alignment a GCC port currently produces.

David