re PR tree-optimization/65650 (CCP does not propgate copies)

re PR tree-optimization/65650 (CCP does not propgate copies)

2015-04-21  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/65650
	* tree-ssa-ccp.c (valid_lattice_transition): Allow lattice
	transitions involving copies.
	(set_lattice_value): Adjust for copy lattice state.
	(ccp_lattice_meet): Do not merge UNDEFINED and a copy to the copy
	if that doesn't dominate the merge point.
	(bit_value_unop): Adjust what we treat as varying mask.
	(bit_value_binop): Likewise.
	(bit_value_assume_aligned): Likewise.
	(evaluate_stmt): When we simplified to a SSA name record a copy
	instead of dropping to varying.
	(visit_assignment): Simplify.

	* gimple-match.h (gimple_simplify): Add another callback.
	* gimple-fold.c (fold_stmt_1): Adjust caller.
	(gimple_fold_stmt_to_constant_1): Likewise - pass valueize
	for the 2nd callback.
	* gimple-match-head.c (gimple_simplify): Add a callback that is
	used to valueize the stmt operands and use it that way.

	* gcc.dg/tree-ssa/ssa-ccp-37.c: New testcase.
	* gcc.dg/tree-ssa/forwprop-11.c: Adjust.
	* gcc.dg/tree-ssa/ssa-fre-3.c: Likewise.
	* gcc.dg/tree-ssa/ssa-fre-4.c: Likewise.
	* gcc.dg/tree-ssa/ssa-fre-5.c: Likewise.
	* gcc.dg/tree-ssa/ssa-fre-32.c: Likewise.

From-SVN: r222267