backport: [multiple changes]

backport: [multiple changes]

2012-01-04  Richard Guenther  <rguenther@suse.de>

	Backport from mainline
	2012-01-04  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/49651
	* tree-ssa-structalias.c (type_can_have_subvars): New function.
	(var_can_have_subvars): Use it.
	(get_constraint_for_1): Only consider subfields if there
	can be any.

	2011-07-14  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/49651
	* tree-ssa-structalias.c (get_constraint_for_1): Properly
	handle dereferences with subvariables.

	* gcc.dg/torture/pr49651.c: New testcase.

From-SVN: r182870