poly_int: current_vector_size and TARGET_AUTOVECTORIZE_VECTOR_SIZES

This patch changes the type of current_vector_size to poly_uint64.
It also changes TARGET_AUTOVECTORIZE_VECTOR_SIZES so that it fills
in a vector of possible sizes (as poly_uint64s) instead of returning
a bitmask.  The documentation claimed that the hook didn't need to
include the default vector size (returned by preferred_simd_mode),
but that wasn't consistent with the omp-low.c usage.

2018-01-03  Richard Sandiford  <richard.sandiford@linaro.org>
	    Alan Hayward  <alan.hayward@arm.com>
	    David Sherwood  <david.sherwood@arm.com>

gcc/
	* target.h (vector_sizes, auto_vector_sizes): New typedefs.
	* target.def (autovectorize_vector_sizes): Return the vector sizes
	by pointer, using vector_sizes rather than a bitmask.
	* targhooks.h (default_autovectorize_vector_sizes): Update accordingly.
	* targhooks.c (default_autovectorize_vector_sizes): Likewise.
	* config/aarch64/aarch64.c (aarch64_autovectorize_vector_sizes):
	Likewise.
	* config/arc/arc.c (arc_autovectorize_vector_sizes): Likewise.
	* config/arm/arm.c (arm_autovectorize_vector_sizes): Likewise.
	* config/i386/i386.c (ix86_autovectorize_vector_sizes): Likewise.
	* config/mips/mips.c (mips_autovectorize_vector_sizes): Likewise.
	* omp-general.c (omp_max_vf): Likewise.
	* omp-low.c (omp_clause_aligned_alignment): Likewise.
	* optabs-query.c (can_vec_mask_load_store_p): Likewise.
	* tree-vect-loop.c (vect_analyze_loop): Likewise.
	* tree-vect-slp.c (vect_slp_bb): Likewise.
	* doc/tm.texi: Regenerate.
	* tree-vectorizer.h (current_vector_size): Change from an unsigned int
	to a poly_uint64.
	* tree-vect-stmts.c (get_vectype_for_scalar_type_and_size): Take
	the vector size as a poly_uint64 rather than an unsigned int.
	(current_vector_size): Change from an unsigned int to a poly_uint64.
	(get_vectype_for_scalar_type): Update accordingly.
	* tree.h (build_truth_vector_type): Take the size and number of
	units as a poly_uint64 rather than an unsigned int.
	(build_vector_type): Add a temporary overload that takes
	the number of units as a poly_uint64 rather than an unsigned int.
	* tree.c (make_vector_type): Likewise.
	(build_truth_vector_type): Take the number of units as a poly_uint64
	rather than an unsigned int.

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

From-SVN: r256131