re PR middle-end/38533 (tree-ssa-reassoc.c increases register pressure several times)

re PR middle-end/38533 (tree-ssa-reassoc.c increases register pressure several times)

	PR middle-end/38533
	* tree-ssa-reassoc.c (remove_visited_stmt_chain): New function.
	(rewrite_expr_tree): Add moved argument, move stmts together if
	needed.  Call remove_visited_stmt_chain.
	(linearize_expr_tree): Don't move stmts here.
	(reassociate_bb): Call remove_visited_stmt_chain if num ops is 1.
	Adjust rewrite_expr_tree caller.

	* gcc.dg/tree-ssa/pr38533.c: New test.
	* gcc.c-torture/execute/pr38533.c: New test.

From-SVN: r142807