re PR tree-optimization/39207 (Strict aliasing warnings in libstdc++ headers)

re PR tree-optimization/39207 (Strict aliasing warnings in libstdc++ headers)

2009-02-19  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/39207
	PR tree-optimization/39074
	* tree-ssa-structalias.c (storedanything_id, var_storedanything,
	storedanything_tree): New.
	(do_ds_constraint): Simplify ANYTHING shortcutting.  Update
	the STOREDANYTHING solution if the lhs solution contains
	ANYTHING.
	(build_succ_graph): Add edges from STOREDANYTHING to all
	non-direct nodes.
	(init_base_vars): Initialize STOREDANYTHING.
	(compute_points_to_sets): Free substitution info after
	building the succ graph.
	(ipa_pta_execute): Likewise.

	* gcc.dg/torture/pr39074.c: New testcase.
	* gcc.dg/torture/pr39074-2.c: Likewise.
	* gcc.dg/torture/pr39074-3.c: Likewise.

	* tree-ssa-structalias.c (struct variable_info): Add may_have_pointers
	field.
	(do_ds_constraint): Do not add to special var or non-pointer
	field solutions.
	(type_could_have_pointers): Split out from ...
	(could_have_pointers): ... here.  For arrays use the element type.
	(create_variable_info_for): Initialize may_have_pointers.
	(new_var_info): Likewise.
	(handle_lhs_call): Make the HEAP variable unknown-sized.
	(intra_create_variable_infos): Use a type with pointers for
	PARM_NOALIAS, make it unknown-sized.

From-SVN: r144292