re PR tree-optimization/63476 (ICE: tree check: expected ssa_name, have var_decl in walk_aliased_vdefs_1, at tree-ssa-alias.c:2689)

2014-10-10  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/63476
	* tree-ssa-pre.c (struct bb_bitmap_sets): Add vop_on_exit member.
	(BB_LIVE_VOP_ON_EXIT): New define.
	(create_expression_by_pieces): Assign VUSEs to stmts.
	(compute_avail): Track BB_LIVE_VOP_ON_EXIT.
	(pass_pre::execute): Assert virtual SSA form is up-to-date
	after insertion.

	* g++.dg/torture/pr63476.C: New testcase.

From-SVN: r216065