re PR tree-optimization/77745 (Inconsistent application of aliasing rules)

2016-09-27  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/77745
	* tree-ssa-pre.c (eliminate_dom_walker::before_dom_children):
	When removing redundant stores make sure to check compatibility
	of the TBAA state for downstream accesses.
	* tree-ssa-sccvn.c (visit_reference_op_store): Likewise for when
	value-numbering virtual operands for store matches.

	* g++.dg/torture/pr77745.C: New testcase.

From-SVN: r240534