re PR tree-optimization/19831 (Missing DSE/malloc/free optimization)

2009-07-01  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/19831
	* tree-ssa-dce.c (propagate_necessity): Calls to functions
	that only act as barriers do not make any previous stores
	necessary.
	* tree-ssa-structalias.c (handle_lhs_call): Delay making
	HEAP variables global, do not add a constraint from nonlocal.
	(find_func_aliases): Handle escapes through return statements.
	(compute_points_to_sets): Make escaped HEAP variables global.

	* gcc.dg/tree-ssa/20041122-1.c: Enable TBAA, scan FRE dump,
	make allocated memory escape.  Un-XFAIL.
	* gcc.dg/vect/pr21591.c: Make allocated memory escape.
	* gcc.dg/vect/pr31699.c: Likewise.
	* gcc.dg/tree-ssa/ssa-dce-7.c: New testcase.

	libmudflap/
	* testsuite/libmudflap.c/fail11-frag.c: Make allocated memory
	escape.
	* testsuite/libmudflap.c/fail12-frag.c: Likewise.
	* testsuite/libmudflap.c/fail16-frag.c: Likewise.
	* testsuite/libmudflap.c/fail31-frag.c: Likewise.

From-SVN: r149140