-- --
-- S p e c --
-- --
--- Copyright (C) 2004-2005, Free Software Foundation, Inc. --
+-- Copyright (C) 2004-2006, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- points to a 16-byte boundary. The compiler is responsible for aligning
-- vector data types on 16-byte boundaries."
- VECTOR_ALIGNMENT : constant := 16;
+ VECTOR_ALIGNMENT : constant := Natural'Min (16, Standard'Maximum_Alignment);
+ -- This value is used to set the alignment of vector datatypes in both the
+ -- hard and the soft binding implementations.
+ --
+ -- We want this value to never be greater than 16, because none of the
+ -- binding implementations requires larger alignments and such a value
+ -- would cause useless space to be allocated/wasted for vector objects.
+ -- Furthermore, the alignment of 16 matches the hard binding leading to
+ -- a more faithful emulation.
+ --
+ -- It needs to be exactly 16 for the hard binding, and the initializing
+ -- expression is just right for this purpose since Maximum_Alignment is
+ -- expected to be 16 for the real Altivec ABI.
+ --
+ -- The soft binding doesn't rely on strict 16byte alignment, and we want
+ -- the value to be no greater than Standard'Maximum_Alignment in this case
+ -- to ensure it is supported on every possible target.
-------------------------------------------------------
-- [PIM-2.1] Data Types - Interpretation of contents --