2015-10-01  Richard Biener  <rguenther@suse.de>

	* gimple-match.h (mprts_hook): Declare.
	* gimple-match.head.c (mprts_hook): Define.
	(maybe_push_res_to_seq): Use new hook.
	* gimple-fold.c (gimple_fold_stmt_to_constant_1): Likewise.
	* tree-ssa-sccvn.h (vn_ssa_aux::expr): Change to a gimple_seq.
	(vn_ssa_aux::has_constants): Remove.
	* tree-ssa-sccvn.c: Include gimple-match.h.
	(VN_INFO_GET): Assert we don't re-use SSA names.
	(vn_get_expr_for): Remove.
	(expr_has_constants): Likewise.
	(stmt_has_constants): Likewise.
	(simplify_binary_expression): Likewise.
	(simplify_unary_expression): Likewise.
	(vn_lookup_simplify_result): New hook.
	(visit_copy): Adjust.
	(visit_reference_op_call): Likewise.
	(visit_phi): Likewise.
	(visit_use): Likewise.
	(process_scc): Likewise.
	(init_scc_vn): Likewise.
	(visit_reference_op_load): Likewise.  Use match-and-simplify and
	a gimple seq for inserted expressions.
	(try_to_simplify): Remove GENERIC stmt combining code.
	(sccvn_dom_walker::before_dom_children): Use match-and-simplify.
	* tree-ssa-pre.c (eliminate_insert): Adjust.
	(eliminate_dom_walker::before_dom_children): Likewise.

	* gcc.dg/tree-ssa/ssa-fre-7.c: Adjust.
	* gcc.dg/tree-ssa/ssa-fre-8.c: Likewise.

From-SVN: r228320