tree-ssa-ccp.c (get_symbol_constant_value): Strip all conversions.

tree-ssa-ccp.c (get_symbol_constant_value): Strip all conversions.

2010-02-05  Richard Guenther  <rguenther@suse.de>

	* tree-ssa-ccp.c (get_symbol_constant_value): Strip all
	conversions.
	(fold_const_aggregate_ref): Likewise.
	(ccp_fold_stmt): Substitute loads.
	(maybe_fold_reference): Verify types before substituting.
	Unshare properly.
	(fold_gimple_assign): Unshare properly.
	(fold_stmt_1): Insert conversion if necessary before replacing
	the RHS.

	* gcc.dg/tree-ssa/ssa-ccp-28.c: New testcase.

From-SVN: r156519