tree-ssa-loop-niter.c (number_of_iterations_lt_to_ne, [...]): Use integer_zerop/integer_nonzerop instead of...

	* tree-ssa-loop-niter.c (number_of_iterations_lt_to_ne,
	assert_no_overflow_lt, assert_loop_rolls_lt,
	number_of_iterations_lt, number_of_iterations_le,
	number_of_iterations_cond, number_of_iterations_exit):
	Use integer_zerop/integer_nonzerop instead of
	null_or_integer_zerop/nonnull_and_integer_nonzerop.
	* tree.h (null_or_integer_zerop, nonnull_and_integer_nonzerop):
	Removed.
	* tree-scalar-evolution.c (simple_iv): Return zero for step of
	an invariant.
	* tree-ssa-loop-ivopts.c (alloc_iv): Do not set step of invariants
	to zero.
	(get_iv): Return NULL for non-scalar types.  Use zero as a step
	of an invariant.
	(determine_biv_step, find_interesting_uses_op,
	find_interesting_uses_cond, find_interesting_uses_stmt,
	add_old_ivs_candidates, determine_use_iv_cost_condition,
	rewrite_use_compare, remove_unused_ivs):
	Use integer_zerop instead of null_or_integer_zerop.
	(struct ifs_ivopts_data): Replace step_p field with step field.
	(idx_find_step): Use zero as a step of an invariant.  Modify
	step instead of *step_p.
	(find_interesting_uses_address): Use zero as a step of an invariant.
	Use integer_zerop instead of null_or_integer_zerop.
	(find_interesting_uses_outside): Call find_interesting_uses_op only
	for phi nodes for real operands.
	(add_candidate_1): Expect step to be non-NULL.
	* tree-ssa-loop-prefetch.c (idx_analyze_ref): Expect step to be
	non-NULL.

From-SVN: r120179