re PR tree-optimization/31146 (forwprop does not look through casts)

re PR tree-optimization/31146 (forwprop does not look through casts)

2007-03-16  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/31146
	* tree-ssa-forwprop.c (forward_propagate_addr_expr_1): Restructure
	to allow recursion of forward_propagate_addr_expr.
	(forward_propagate_addr_into_variable_array_index): Likewise.
	(forward_propagate_addr_expr): Likewise.
	(tree_ssa_forward_propagate_single_use_vars): Likewise.
	(forward_propagate_addr_expr_1): Recurse on simple copies
	instead of propagating into them.  Do so for useless conversions
	as well.
	(forward_propagate_addr_expr): Clean up unused statements after
	recursion.

	* g++.dg/tree-ssa/pr31146.C: New testcase.

From-SVN: r122985