2012-07-06 Tom de Vries <tom@codesourcery.com>

2012-07-06  Tom de Vries  <tom@codesourcery.com>

	PR tree-optimization/52009
	* tree-ssa-tail-merge.c (gimple_equal_p): For GIMPLE_ASSIGN, compare
	value numbers of gimple_vdef.
	* tree-ssa-sccvn.h (vn_reference_insert): Add vdef parameter to
	prototype.
	* tree-ssa-sccvn.c (copy_reference_ops_from_ref): Handle MODIFY_EXPR.
	(vn_reference_insert): Add and handle vdef parameter.
	(visit_reference_op_load): Add argument to vn_reference_insert call.
	(visit_reference_op_store): Find value number of vdef of store.  Insert
	value number of vdef of store.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@189321 138bc75d-0d04-0410-961f-82ee72b054a4