re PR tree-optimization/64084 (match-and-simplify prefers complex matches)

re PR tree-optimization/64084 (match-and-simplify prefers complex matches)

2014-11-28  Richard Biener  <rguenther@suse.de>

	PR middle-end/64084
	* genmatch.c (dt_node::gen_kids_1): New function, split out
	from dt_node::gen_kids.
	(decision_tree::cmp_node): DT_TRUE are generally not equal.
	(decision_tree::find_node): Treat DT_TRUE as barrier for
	node CSE on the same level.
	(dt_node::append_node): Do not keep DT_TRUE last.
	(dt_node::gen_kids): Emit code after each DT_TRUE node seen.

	* gcc.dg/tree-ssa/ssa-ccp-34.c: New testcase.
	* gcc.dg/tree-ssa/forwprop-31.c: Likewise.

From-SVN: r218141