re PR tree-optimization/36945 (PRE/SCCVN do not handle aggregate function arguments correctly)

2008-07-29  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/36945
	* tree-ssa-sccvn.h (copy_reference_ops_from_ref): Declare.
	* tree-ssa-sccvn.c (copy_reference_ops_from_ref): Export.
	Record invariant addresses un-decomposed.
	(copy_reference_ops_from_call): Record reference call
	arguments properly.  Simplify.
	* tree-ssa-pre.c (create_component_ref_by_pieces_1): New
	helper split out from ...
	(create_component_ref_by_pieces): ... here.  Simplify.
	Prepare for recursive invocation for call arguments.
	(create_expression_by_pieces): Adjust call to
	create_component_ref_by_pieces.
	(compute_avail): Process operand 2 of reference ops.

	* gcc.dg/tree-ssa/ssa-pre-18.c: New testcase.

From-SVN: r138257