2011-05-20  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/49079
	* tree-dfa.c (get_ref_base_and_extent): Handle view-converting
	MEM_REFs correctly for the trailing array access detection.
	Special case constants the same way as decls for overall size
	constraining.

	* gcc.dg/torture/pr49079.c: New testcase.

From-SVN: r173954