This patch makes ivopts handle polynomial address offsets
when recording potential IV uses.

2017-12-21  Richard Sandiford  <richard.sandiford@linaro.org>
	    Alan Hayward  <alan.hayward@arm.com>
	    David Sherwood  <david.sherwood@arm.com>

gcc/
	* tree-ssa-loop-ivopts.h (strip_offset): Return the offset as
	poly_uint64_pod rather than an unsigned HOST_WIDE_INT.
	* tree-loop-distribution.c (classify_builtin_st): Update accordingly.
	* tree-ssa-loop-ivopts.c (iv_use::addr_offset): Change from
	an unsigned HOST_WIDE_INT to a poly_uint64_pod.
	(group_compare_offset): Update accordingly.
	(split_small_address_groups_p): Likewise.
	(record_use): Take addr_offset as a poly_uint64 rather than
	an unsigned HOST_WIDE_INT.
	(strip_offset): Return the offset as a poly_uint64 rather than
	an unsigned HOST_WIDE_INT.
	(record_group_use, split_address_groups): Track polynomial offsets.
	(add_iv_candidate_for_use): Likewise.
	(addr_offset_valid_p): Take the offset as a poly_int64 rather
	than a HOST_WIDE_INT.
	(strip_offset_1): Return the offset as a poly_int64 rather than
	a HOST_WIDE_INT.

Co-Authored-By: Alan Hayward <alan.hayward@arm.com>
Co-Authored-By: David Sherwood <david.sherwood@arm.com>

From-SVN: r255933