extract_bit_field_1 tries to use vec_extract to extract part of a
vector.  However, if that pattern isn't defined or if the operands
aren't suitable, another good approach is to try a direct subreg
reference.  This is particularly useful for multi-vector modes on
SVE (e.g. when extracting one vector from an LD2 result).

The function would go on to try the same thing anyway, but only
if there is an integer mode with the same size as the vector mode,
which isn't true for SVE modes (and doesn't seem a good thing to
require in general).  Even when there is an integer mode, doing the
operation on the original modes avoids some unnecessary bitcasting.

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

gcc/
	* expmed.c (extract_bit_field_1): For vector extracts,
	fall back to extract_bit_field_as_subreg if vec_extract
	isn't available.

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

From-SVN: r256209

Once SVE is enabled, a general AArch64 spill slot offset will be

  A + B * VL

where A is a constant and B is a multiple of the SVE vector length.
The offsets in SVE load and store instructions are a multiple of VL
(and so can encode some values of B), while offsets for standard AArch64
load and store instructions aren't (and encode some values of A).

We therefore get better spill code if variable-sized slots are grouped
together separately from constant-sized slots, and if variable-sized
slots are not reused for constant-sized data.  Then, spills to the
constant-sized slots can add B * VL to the offset first, creating a
common anchor point for spills with the same B component but different
A components.  Similarly, spills to variable-sized slots can add A to
the offset first, creating a common anchor point for spills with the same
A component but different B components.

This patch implements the sorting and grouping side of the optimisation.
A later patch creates the anchor points.

The patch is a no-op on other targets.

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

gcc/
	* lra-spills.c (pseudo_reg_slot_compare): Sort slots by whether
	they are variable or constant sized.
	(assign_stack_slot_num_and_sort_pseudos): Don't reuse variable-sized
	slots for constant-sized data.

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

From-SVN: r256208

This patch allows us to recognise:

    ... = bool1 != bool2 ? x : y

as equivalent to:

    bool tmp = bool1 ^ bool2;
    ... = tmp ? x : y

For the latter we were already able to find the natural number
of vector units for tmp based on the types that feed bool1 and
bool2, whereas with the former we would simply treat bool1 and
bool2 as vectorised 8-bit values, possibly requiring them to
be packed and unpacked from their natural width.

This is used by a later SVE patch.

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

gcc/
	* tree-vect-patterns.c (vect_recog_mask_conversion_pattern): When
	handling COND_EXPRs with boolean comparisons, try to find a better
	basis for the mask type than the boolean itself.

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

From-SVN: r256207

The default value of MAX_BITSIZE_MODE_ANY_MODE is calculated
from the initial mode sizes specified in the modes.def file.
The target needs to be able to override it if ADJUST_BYTESIZE
& co. can choose a bigger size.

2018-01-03  Richard Sandiford  <richard.sandiford@linaro.org>

gcc/
	* doc/rtl.texi (MAX_BITSIZE_MODE_ANY_MODE): Describe how the default
	is calculated and how it can be overridden.
	* genmodes.c (max_bitsize_mode_any_mode): New variable.
	(create_modes): Initialize it from MAX_BITSIZE_MODE_ANY_MODE,
	if defined.
	(emit_max_int): Use it to set the output MAX_BITSIZE_MODE_ANY_MODE,
	if nonzero.

From-SVN: r256206

This patch reworks aarch64_simd_valid_immediate so that
it's easier to add SVE support.  The main changes are:

- make simd_immediate_info easier to construct
- replace the while (1) { ... break; } blocks with checks that use
  the full 64-bit value of the constant
- treat floating-point modes as integers if they aren't valid
  as floating-point values

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

gcc/
	* config/aarch64/aarch64-protos.h (aarch64_output_simd_mov_immediate):
	Remove the mode argument.
	(aarch64_simd_valid_immediate): Remove the mode and inverse
	arguments.
	* config/aarch64/iterators.md (bitsize): New iterator.
	* config/aarch64/aarch64-simd.md (*aarch64_simd_mov<mode>, and<mode>3)
	(ior<mode>3): Update calls to aarch64_output_simd_mov_immediate.
	* config/aarch64/constraints.md (Do, Db, Dn): Update calls to
	aarch64_simd_valid_immediate.
	* config/aarch64/predicates.md (aarch64_reg_or_orr_imm): Likewise.
	(aarch64_reg_or_bic_imm): Likewise.
	* config/aarch64/aarch64.c (simd_immediate_info): Replace mvn
	with an insn_type enum and msl with a modifier_type enum.
	Replace element_width with a scalar_mode.  Change the shift
	to unsigned int.  Add constructors for scalar_float_mode and
	scalar_int_mode elements.
	(aarch64_vect_float_const_representable_p): Delete.
	(aarch64_can_const_movi_rtx_p)
	(aarch64_simd_scalar_immediate_valid_for_move)
	(aarch64_simd_make_constant): Update call to
	aarch64_simd_valid_immediate.
	(aarch64_advsimd_valid_immediate_hs): New function.
	(aarch64_advsimd_valid_immediate): Likewise.
	(aarch64_simd_valid_immediate): Remove mode and inverse
	arguments.  Rewrite to use the above.  Use const_vec_duplicate_p
	to detect duplicated constants and use aarch64_float_const_zero_rtx_p
	and aarch64_float_const_representable_p on the result.
	(aarch64_output_simd_mov_immediate): Remove mode argument.
	Update call to aarch64_simd_valid_immediate and use of
	simd_immediate_info.
	(aarch64_output_scalar_simd_mov_immediate): Update call
	accordingly.

gcc/testsuite/
	* gcc.target/aarch64/vect-movi.c (movi_float_lsl24): New function.
	(main): Call it.

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

From-SVN: r256205

We already allow the target to change the size and alignment of a mode.
This patch does the same thing for the number of units, which is needed
to give command-line control of the SVE vector length.

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

gcc/
	* machmode.h (mode_precision): Prefix with CONST_MODE_PRECISION.
	(mode_nunits): Likewise CONST_MODE_NUNITS.
	* machmode.def (ADJUST_NUNITS): Document.
	* genmodes.c (mode_data::need_nunits_adj): New field.
	(blank_mode): Update accordingly.
	(adj_nunits): New variable.
	(print_maybe_const_decl): Replace CATEGORY with a NEEDS_ADJ
	parameter.
	(emit_mode_size_inline): Set need_bytesize_adj for all modes
	listed in adj_nunits.
	(emit_mode_nunits_inline): Set need_nunits_adj for all modes
	listed in adj_nunits.  Don't emit case statements for such modes.
	(emit_insn_modes_h): Emit definitions of CONST_MODE_NUNITS
	and CONST_MODE_PRECISION.  Make CONST_MODE_SIZE expand to
	nothing if adj_nunits is nonnull.
	(emit_mode_precision, emit_mode_nunits): Use print_maybe_const_decl.
	(emit_mode_unit_size, emit_mode_base_align, emit_mode_ibit)
	(emit_mode_fbit): Update use of print_maybe_const_decl.
	(emit_move_size): Likewise.  Treat the array as non-const
	if adj_nunits.
	(emit_mode_adjustments): Handle adj_nunits.

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

From-SVN: r256204

Originally the SVE port used the names for 256-bit vectors, as the
next available increment after Advanced SIMD.  However, that was
always a bit of a hack and is bound to confuse people new to the code.

Nothing actually requires vector modes to have names of the form
V<nunits><mode>, and after talking it over with the AArch64 maintainers,
we agreed to switch to things like:

    VNx16QI

instead.  This patch lets targets pick this kind of prefix.

2018-01-03  Richard Sandiford  <richard.sandiford@linaro.org>

gcc/
	* machmode.def (VECTOR_MODES_WITH_PREFIX): Document.
	* genmodes.c (VECTOR_MODES_WITH_PREFIX): New macro.
	(VECTOR_MODES): Use it.
	(make_vector_modes): Take the prefix as an argument.

From-SVN: r256203

This patch adds a new mode class to represent vectors of booleans.
GET_MODE_BITSIZE (m) / GET_MODE_NUNITS (m) determines the number
of bits that are used to represent each boolean; this can be 1
for a fully-packed representation or greater than 1 for an unpacked
representation.  In the latter case, the value of bits other than
the lowest is not significant.

These are used by the SVE port to represent predicates.

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

gcc/
	* mode-classes.def (MODE_VECTOR_BOOL): New mode class.
	* machmode.h (INTEGRAL_MODE_P, VECTOR_MODE_P): Return true
	for MODE_VECTOR_BOOL.
	* machmode.def (VECTOR_BOOL_MODE): Document.
	* genmodes.c (VECTOR_BOOL_MODE): New macro.
	(make_vector_bool_mode): New function.
	(complete_mode, emit_mode_wider, emit_mode_adjustments): Handle
	MODE_VECTOR_BOOL.
	* lto-streamer-in.c (lto_input_mode_table): Likewise.
	* rtx-vector-builder.c (rtx_vector_builder::find_cached_value):
	Likewise.
	* stor-layout.c (int_mode_for_mode): Likewise.
	* tree.c (build_vector_type_for_mode): Likewise.
	* varasm.c (output_constant_pool_2): Likewise.
	* emit-rtl.c (init_emit_once): Make sure that CONST1_RTX (BImode) and
	CONSTM1_RTX (BImode) are the same thing.  Initialize const_tiny_rtx
	for MODE_VECTOR_BOOL.
	* expr.c (expand_expr_real_1): Use VECTOR_MODE_P instead of a list
	of mode class checks.
	* tree-vect-generic.c (expand_vector_operation): Use VECTOR_MODE_P
	instead of a list of mode class checks.
	(expand_vector_scalar_condition): Likewise.
	(type_for_widest_vector_mode): Handle BImode as an inner mode.

gcc/c-family/
	* c-common.c (c_common_type_for_mode): Handle MODE_VECTOR_BOOL.

gcc/fortran/
	* trans-types.c (gfc_type_for_mode): Handle MODE_VECTOR_BOOL.

gcc/go/
	* go-lang.c (go_langhook_type_for_mode): Handle MODE_VECTOR_BOOL.

gcc/lto/
	* lto-lang.c (lto_type_for_mode): Handle MODE_VECTOR_BOOL.

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

From-SVN: r256202

This patch changes GET_MODE_SIZE from unsigned short to poly_uint16.
The non-mechanical parts were handled by previous patches.

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

gcc/
	* machmode.h (mode_size): Change from unsigned short to
	poly_uint16_pod.
	(mode_to_bytes): Return a poly_uint16 rather than an unsigned short.
	(GET_MODE_SIZE): Return a constant if ONLY_FIXED_SIZE_MODES,
	or if measurement_type is not polynomial.
	(fixed_size_mode::includes_p): Check for constant-sized modes.
	* genmodes.c (emit_mode_size_inline): Make mode_size_inline
	return a poly_uint16 rather than an unsigned short.
	(emit_mode_size): Change the type of mode_size from unsigned short
	to poly_uint16_pod.  Use ZERO_COEFFS for the initializer.
	(emit_mode_adjustments): Cope with polynomial vector sizes.
	* lto-streamer-in.c (lto_input_mode_table): Use bp_unpack_poly_value
	for GET_MODE_SIZE.
	* lto-streamer-out.c (lto_write_mode_table): Use bp_pack_poly_value
	for GET_MODE_SIZE.
	* auto-inc-dec.c (try_merge): Treat GET_MODE_SIZE as polynomial.
	* builtins.c (expand_ifn_atomic_compare_exchange_into_call): Likewise.
	* caller-save.c (setup_save_areas): Likewise.
	(replace_reg_with_saved_mem): Likewise.
	* calls.c (emit_library_call_value_1): Likewise.
	* combine-stack-adj.c (combine_stack_adjustments_for_block): Likewise.
	* combine.c (simplify_set, make_extraction, simplify_shift_const_1)
	(gen_lowpart_for_combine): Likewise.
	* convert.c (convert_to_integer_1): Likewise.
	* cse.c (equiv_constant, cse_insn): Likewise.
	* cselib.c (autoinc_split, cselib_hash_rtx): Likewise.
	(cselib_subst_to_values): Likewise.
	* dce.c (word_dce_process_block): Likewise.
	* df-problems.c (df_word_lr_mark_ref): Likewise.
	* dwarf2cfi.c (init_one_dwarf_reg_size): Likewise.
	* dwarf2out.c (multiple_reg_loc_descriptor, mem_loc_descriptor)
	(concat_loc_descriptor, concatn_loc_descriptor, loc_descriptor)
	(rtl_for_decl_location): Likewise.
	* emit-rtl.c (gen_highpart, widen_memory_access): Likewise.
	* expmed.c (extract_bit_field_1, extract_integral_bit_field): Likewise.
	* expr.c (emit_group_load_1, clear_storage_hints): Likewise.
	(emit_move_complex, emit_move_multi_word, emit_push_insn): Likewise.
	(expand_expr_real_1): Likewise.
	* function.c (assign_parm_setup_block_p, assign_parm_setup_block)
	(pad_below): Likewise.
	* gimple-fold.c (optimize_atomic_compare_exchange_p): Likewise.
	* gimple-ssa-store-merging.c (rhs_valid_for_store_merging_p): Likewise.
	* ira.c (get_subreg_tracking_sizes): Likewise.
	* ira-build.c (ira_create_allocno_objects): Likewise.
	* ira-color.c (coalesced_pseudo_reg_slot_compare): Likewise.
	(ira_sort_regnos_for_alter_reg): Likewise.
	* ira-costs.c (record_operand_costs): Likewise.
	* lower-subreg.c (interesting_mode_p, simplify_gen_subreg_concatn)
	(resolve_simple_move): Likewise.
	* lra-constraints.c (get_reload_reg, operands_match_p): Likewise.
	(process_addr_reg, simplify_operand_subreg, curr_insn_transform)
	(lra_constraints): Likewise.
	(CONST_POOL_OK_P): Reject variable-sized modes.
	* lra-spills.c (slot, assign_mem_slot, pseudo_reg_slot_compare)
	(add_pseudo_to_slot, lra_spill): Likewise.
	* omp-low.c (omp_clause_aligned_alignment): Likewise.
	* optabs-query.c (get_best_extraction_insn): Likewise.
	* optabs-tree.c (expand_vec_cond_expr_p): Likewise.
	* optabs.c (expand_vec_perm_var, expand_vec_cond_expr): Likewise.
	(expand_mult_highpart, valid_multiword_target_p): Likewise.
	* recog.c (offsettable_address_addr_space_p): Likewise.
	* regcprop.c (maybe_mode_change): Likewise.
	* reginfo.c (choose_hard_reg_mode, record_subregs_of_mode): Likewise.
	* regrename.c (build_def_use): Likewise.
	* regstat.c (dump_reg_info): Likewise.
	* reload.c (complex_word_subreg_p, push_reload, find_dummy_reload)
	(find_reloads, find_reloads_subreg_address): Likewise.
	* reload1.c (eliminate_regs_1): Likewise.
	* rtlanal.c (for_each_inc_dec_find_inc_dec, rtx_cost): Likewise.
	* simplify-rtx.c (avoid_constant_pool_reference): Likewise.
	(simplify_binary_operation_1, simplify_subreg): Likewise.
	* targhooks.c (default_function_arg_padding): Likewise.
	(default_hard_regno_nregs, default_class_max_nregs): Likewise.
	* tree-cfg.c (verify_gimple_assign_binary): Likewise.
	(verify_gimple_assign_ternary): Likewise.
	* tree-inline.c (estimate_move_cost): Likewise.
	* tree-ssa-forwprop.c (simplify_vector_constructor): Likewise.
	* tree-ssa-loop-ivopts.c (add_autoinc_candidates): Likewise.
	(get_address_cost_ainc): Likewise.
	* tree-vect-data-refs.c (vect_enhance_data_refs_alignment): Likewise.
	(vect_supportable_dr_alignment): Likewise.
	* tree-vect-loop.c (vect_determine_vectorization_factor): Likewise.
	(vectorizable_reduction): Likewise.
	* tree-vect-stmts.c (vectorizable_assignment, vectorizable_shift)
	(vectorizable_operation, vectorizable_load): Likewise.
	* tree.c (build_same_sized_truth_vector_type): Likewise.
	* valtrack.c (cleanup_auto_inc_dec): Likewise.
	* var-tracking.c (emit_note_insn_var_location): Likewise.
	* config/arc/arc.h (ASM_OUTPUT_CASE_END): Use as_a <scalar_int_mode>.
	(ADDR_VEC_ALIGN): Likewise.

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

From-SVN: r256201

This patch changes GET_MODE_BITSIZE from an unsigned short
to a poly_uint16.

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

gcc/
	* machmode.h (mode_to_bits): Return a poly_uint16 rather than an
	unsigned short.
	(GET_MODE_BITSIZE): Return a constant if ONLY_FIXED_SIZE_MODES,
	or if measurement_type is polynomial.
	* calls.c (shift_return_value): Treat GET_MODE_BITSIZE as polynomial.
	* combine.c (make_extraction): Likewise.
	* dse.c (find_shift_sequence): Likewise.
	* dwarf2out.c (mem_loc_descriptor): Likewise.
	* expmed.c (store_integral_bit_field, extract_bit_field_1): Likewise.
	(extract_bit_field, extract_low_bits): Likewise.
	* expr.c (convert_move, convert_modes, emit_move_insn_1): Likewise.
	(optimize_bitfield_assignment_op, expand_assignment): Likewise.
	(store_expr_with_bounds, store_field, expand_expr_real_1): Likewise.
	* fold-const.c (optimize_bit_field_compare, merge_ranges): Likewise.
	* gimple-fold.c (optimize_atomic_compare_exchange_p): Likewise.
	* reload.c (find_reloads): Likewise.
	* reload1.c (alter_reg): Likewise.
	* stor-layout.c (bitwise_mode_for_mode, compute_record_mode): Likewise.
	* targhooks.c (default_secondary_memory_needed_mode): Likewise.
	* tree-if-conv.c (predicate_mem_writes): Likewise.
	* tree-ssa-strlen.c (handle_builtin_memcmp): Likewise.
	* tree-vect-patterns.c (adjust_bool_pattern): Likewise.
	* tree-vect-stmts.c (vectorizable_simd_clone_call): Likewise.
	* valtrack.c (dead_debug_insert_temp): Likewise.
	* varasm.c (mergeable_constant_section): Likewise.
	* config/sh/sh.h (LOCAL_ALIGNMENT): Use as_a <fixed_size_mode>.

gcc/ada/
	* gcc-interface/misc.c (enumerate_modes): Treat GET_MODE_BITSIZE
	as polynomial.

gcc/c-family/
	* c-ubsan.c (ubsan_instrument_shift): Treat GET_MODE_BITSIZE
	as polynomial.

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

From-SVN: r256200

This patch makes the CONCAT handing in expand_assignment cope with
polynomial mode sizes.  The mode of the CONCAT must be complex,
so we can base the tests on the sizes of the real and imaginary
components.

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

gcc/
	* expr.c (expand_assignment): Cope with polynomial mode sizes
	when assigning to a CONCAT.

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

From-SVN: r256199

This patch changes GET_MODE_PRECISION from an unsigned short
to a poly_uint16.

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

gcc/
	* machmode.h (mode_precision): Change from unsigned short to
	poly_uint16_pod.
	(mode_to_precision): Return a poly_uint16 rather than an unsigned
	short.
	(GET_MODE_PRECISION): Return a constant if ONLY_FIXED_SIZE_MODES,
	or if measurement_type is not polynomial.
	(HWI_COMPUTABLE_MODE_P): Turn into a function.  Optimize the case
	in which the mode is already known to be a scalar_int_mode.
	* genmodes.c (emit_mode_precision): Change the type of mode_precision
	from unsigned short to poly_uint16_pod.  Use ZERO_COEFFS for the
	initializer.
	* lto-streamer-in.c (lto_input_mode_table): Use bp_unpack_poly_value
	for GET_MODE_PRECISION.
	* lto-streamer-out.c (lto_write_mode_table): Use bp_pack_poly_value
	for GET_MODE_PRECISION.
	* combine.c (update_rsp_from_reg_equal): Treat GET_MODE_PRECISION
	as polynomial.
	(try_combine, find_split_point, combine_simplify_rtx): Likewise.
	(expand_field_assignment, make_extraction): Likewise.
	(make_compound_operation_int, record_dead_and_set_regs_1): Likewise.
	(get_last_value): Likewise.
	* convert.c (convert_to_integer_1): Likewise.
	* cse.c (cse_insn): Likewise.
	* expr.c (expand_expr_real_1): Likewise.
	* lra-constraints.c (simplify_operand_subreg): Likewise.
	* optabs-query.c (can_atomic_load_p): Likewise.
	* optabs.c (expand_atomic_load): Likewise.
	(expand_atomic_store): Likewise.
	* ree.c (combine_reaching_defs): Likewise.
	* rtl.h (partial_subreg_p, paradoxical_subreg_p): Likewise.
	* rtlanal.c (nonzero_bits1, lsb_bitfield_op_p): Likewise.
	* tree.h (type_has_mode_precision_p): Likewise.
	* ubsan.c (instrument_si_overflow): Likewise.

gcc/ada/
	* gcc-interface/misc.c (enumerate_modes): Treat GET_MODE_PRECISION
	as polynomial.

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

From-SVN: r256198

This patch changes TYPE_VECTOR_SUBPARTS to a poly_uint64.  The value is
encoded in the 10-bit precision field and was previously always stored
as a simple log2 value.  The challenge was to use this 10 bits to
encode the number of elements in variable-length vectors, so that
we didn't need to increase the size of the tree.

In practice the number of vector elements should always have the form
N + N * X (where X is the runtime value), and as for constant-length
vectors, N must be a power of 2 (even though X itself might not be).
The patch therefore uses the low 8 bits to encode log2(N) and bit
8 to select between constant-length and variable-length vectors.
Targets without variable-length vectors continue to use the old scheme.

A new valid_vector_subparts_p function tests whether a given number
of elements can be encoded.  This is false for the vector modes that
represent an LD3 or ST3 vector triple (which we want to treat as arrays
of vectors rather than single vectors).

Most of the patch is mechanical; previous patches handled the changes
that weren't entirely straightforward.

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

gcc/
	* tree.h (TYPE_VECTOR_SUBPARTS): Turn into a function and handle
	polynomial numbers of units.
	(SET_TYPE_VECTOR_SUBPARTS): Likewise.
	(valid_vector_subparts_p): New function.
	(build_vector_type): Remove temporary shim and take the number
	of units as a poly_uint64 rather than an int.
	(build_opaque_vector_type): Take the number of units as a
	poly_uint64 rather than an int.
	* tree.c (build_vector_from_ctor): Handle polynomial
	TYPE_VECTOR_SUBPARTS.
	(type_hash_canon_hash, type_cache_hasher::equal): Likewise.
	(uniform_vector_p, vector_type_mode, build_vector): Likewise.
	(build_vector_from_val): If the number of units is variable,
	use build_vec_duplicate_cst for constant operands and
	VEC_DUPLICATE_EXPR otherwise.
	(make_vector_type): Remove temporary is_constant ().
	(build_vector_type, build_opaque_vector_type): Take the number of
	units as a poly_uint64 rather than an int.
	(check_vector_cst): Handle polynomial TYPE_VECTOR_SUBPARTS and
	VECTOR_CST_NELTS.
	* cfgexpand.c (expand_debug_expr): Likewise.
	* expr.c (count_type_elements, categorize_ctor_elements_1): Likewise.
	(store_constructor, expand_expr_real_1): Likewise.
	(const_scalar_mask_from_tree): Likewise.
	* fold-const-call.c (fold_const_reduction): Likewise.
	* fold-const.c (const_binop, const_unop, fold_convert_const): Likewise.
	(operand_equal_p, fold_vec_perm, fold_ternary_loc): Likewise.
	(native_encode_vector, vec_cst_ctor_to_array): Likewise.
	(fold_relational_const): Likewise.
	(native_interpret_vector): Likewise.  Change the size from an
	int to an unsigned int.
	* gimple-fold.c (gimple_fold_stmt_to_constant_1): Handle polynomial
	TYPE_VECTOR_SUBPARTS.
	(gimple_fold_indirect_ref, gimple_build_vector): Likewise.
	(gimple_build_vector_from_val): Use VEC_DUPLICATE_EXPR when
	duplicating a non-constant operand into a variable-length vector.
	* hsa-brig.c (hsa_op_immed::emit_to_buffer): Handle polynomial
	TYPE_VECTOR_SUBPARTS and VECTOR_CST_NELTS.
	* ipa-icf.c (sem_variable::equals): Likewise.
	* match.pd: Likewise.
	* omp-simd-clone.c (simd_clone_subparts): Likewise.
	* print-tree.c (print_node): Likewise.
	* stor-layout.c (layout_type): Likewise.
	* targhooks.c (default_builtin_vectorization_cost): Likewise.
	* tree-cfg.c (verify_gimple_comparison): Likewise.
	(verify_gimple_assign_binary): Likewise.
	(verify_gimple_assign_ternary): Likewise.
	(verify_gimple_assign_single): Likewise.
	* tree-pretty-print.c (dump_generic_node): Likewise.
	* tree-ssa-forwprop.c (simplify_vector_constructor): Likewise.
	(simplify_bitfield_ref, is_combined_permutation_identity): Likewise.
	* tree-vect-data-refs.c (vect_permute_store_chain): Likewise.
	(vect_grouped_load_supported, vect_permute_load_chain): Likewise.
	(vect_shift_permute_load_chain): Likewise.
	* tree-vect-generic.c (nunits_for_known_piecewise_op): Likewise.
	(expand_vector_condition, optimize_vector_constructor): Likewise.
	(lower_vec_perm, get_compute_type): Likewise.
	* tree-vect-loop.c (vect_determine_vectorization_factor): Likewise.
	(get_initial_defs_for_reduction, vect_transform_loop): Likewise.
	* tree-vect-patterns.c (vect_recog_bool_pattern): Likewise.
	(vect_recog_mask_conversion_pattern): Likewise.
	* tree-vect-slp.c (vect_supported_load_permutation_p): Likewise.
	(vect_get_constant_vectors, vect_transform_slp_perm_load): Likewise.
	* tree-vect-stmts.c (perm_mask_for_reverse): Likewise.
	(get_group_load_store_type, vectorizable_mask_load_store): Likewise.
	(vectorizable_bswap, simd_clone_subparts, vectorizable_assignment)
	(vectorizable_shift, vectorizable_operation, vectorizable_store)
	(vectorizable_load, vect_is_simple_cond, vectorizable_comparison)
	(supportable_widening_operation): Likewise.
	(supportable_narrowing_operation): Likewise.
	* tree-vector-builder.c (tree_vector_builder::binary_encoded_nelts):
	Likewise.
	* varasm.c (output_constant): Likewise.

gcc/ada/
	* gcc-interface/utils.c (gnat_types_compatible_p): Handle
	polynomial TYPE_VECTOR_SUBPARTS.

gcc/brig/
	* brigfrontend/brig-to-generic.cc (get_unsigned_int_type): Handle
	polynomial TYPE_VECTOR_SUBPARTS.
	* brigfrontend/brig-util.h (gccbrig_type_vector_subparts): Likewise.

gcc/c-family/
	* c-common.c (vector_types_convertible_p, c_build_vec_perm_expr)
	(convert_vector_to_array_for_subscript): Handle polynomial
	TYPE_VECTOR_SUBPARTS.
	(c_common_type_for_mode): Check valid_vector_subparts_p.
	* c-pretty-print.c (pp_c_initializer_list): Handle polynomial
	VECTOR_CST_NELTS.

gcc/c/
	* c-typeck.c (comptypes_internal, build_binary_op): Handle polynomial
	TYPE_VECTOR_SUBPARTS.

gcc/cp/
	* constexpr.c (cxx_eval_array_reference): Handle polynomial
	VECTOR_CST_NELTS.
	(cxx_fold_indirect_ref): Handle polynomial TYPE_VECTOR_SUBPARTS.
	* call.c (build_conditional_expr_1): Likewise.
	* decl.c (cp_finish_decomp): Likewise.
	* mangle.c (write_type): Likewise.
	* typeck.c (structural_comptypes): Likewise.
	(cp_build_binary_op): Likewise.
	* typeck2.c (process_init_constructor_array): Likewise.

gcc/fortran/
	* trans-types.c (gfc_type_for_mode): Check valid_vector_subparts_p.

gcc/lto/
	* lto-lang.c (lto_type_for_mode): Check valid_vector_subparts_p.
	* lto.c (hash_canonical_type): Handle polynomial TYPE_VECTOR_SUBPARTS.

gcc/go/
	* go-lang.c (go_langhook_type_for_mode): Check valid_vector_subparts_p.

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

From-SVN: r256197

The GET_MODE_NUNITS patch made vect_grouped_store_supported and
vect_grouped_load_supported check for a constant number of elements,
so vect_permute_store_chain and vect_permute_load_chain can assert
for that.  This patch adds commentary to that effect; the actual
asserts will be added by a later, more mechanical, patch.

The patch also reorganises the function so that the asserts
are linked specifically to code that builds permute vectors
element-by-element.  This allows a later patch to add support
for some variable-length permutes.

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

gcc/
	* tree-vect-data-refs.c (vect_permute_store_chain): Reorganize
	so that both the length == 3 and length != 3 cases set up their
	own permute vectors.  Add comments explaining why we know the
	number of elements is constant.
	(vect_permute_load_chain): Likewise.

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

From-SVN: r256196

This patch changes GET_MODE_NUNITS from unsigned char
to poly_uint16, although it remains a macro when compiling
target code with NUM_POLY_INT_COEFFS == 1.

We can handle permuted loads and stores for variable nunits if
the number of statements is a power of 2, but not otherwise.

The to_constant call in make_vector_type goes away in a later patch.

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

gcc/
	* machmode.h (mode_nunits): Change from unsigned char to
	poly_uint16_pod.
	(ONLY_FIXED_SIZE_MODES): New macro.
	(pod_mode::measurement_type, scalar_int_mode::measurement_type)
	(scalar_float_mode::measurement_type, scalar_mode::measurement_type)
	(complex_mode::measurement_type, fixed_size_mode::measurement_type):
	New typedefs.
	(mode_to_nunits): Return a poly_uint16 rather than an unsigned short.
	(GET_MODE_NUNITS): Return a constant if ONLY_FIXED_SIZE_MODES,
	or if measurement_type is not polynomial.
	* genmodes.c (ZERO_COEFFS): New macro.
	(emit_mode_nunits_inline): Make mode_nunits_inline return a
	poly_uint16.
	(emit_mode_nunits): Change the type of mode_nunits to poly_uint16_pod.
	Use ZERO_COEFFS when emitting initializers.
	* data-streamer.h (bp_pack_poly_value): New function.
	(bp_unpack_poly_value): Likewise.
	* lto-streamer-in.c (lto_input_mode_table): Use bp_unpack_poly_value
	for GET_MODE_NUNITS.
	* lto-streamer-out.c (lto_write_mode_table): Use bp_pack_poly_value
	for GET_MODE_NUNITS.
	* tree.c (make_vector_type): Remove temporary shim and make
	the real function take the number of units as a poly_uint64
	rather than an int.
	(build_vector_type_for_mode): Handle polynomial nunits.
	* dwarf2out.c (loc_descriptor, add_const_value_attribute): Likewise.
	* emit-rtl.c (const_vec_series_p_1): Likewise.
	(gen_rtx_CONST_VECTOR): Likewise.
	* fold-const.c (test_vec_duplicate_folding): Likewise.
	* genrecog.c (validate_pattern): Likewise.
	* optabs-query.c (can_vec_perm_var_p, can_mult_highpart_p): Likewise.
	* optabs-tree.c (expand_vec_cond_expr_p): Likewise.
	* optabs.c (expand_vector_broadcast, expand_binop_directly): Likewise.
	(shift_amt_for_vec_perm_mask, expand_vec_perm_var): Likewise.
	(expand_vec_cond_expr, expand_mult_highpart): Likewise.
	* rtlanal.c (subreg_get_info): Likewise.
	* tree-vect-data-refs.c (vect_grouped_store_supported): Likewise.
	(vect_grouped_load_supported): Likewise.
	* tree-vect-generic.c (type_for_widest_vector_mode): Likewise.
	* tree-vect-loop.c (have_whole_vector_shift): Likewise.
	* simplify-rtx.c (simplify_unary_operation_1): Likewise.
	(simplify_const_unary_operation, simplify_binary_operation_1)
	(simplify_const_binary_operation, simplify_ternary_operation)
	(test_vector_ops_duplicate, test_vector_ops): Likewise.
	(simplify_immed_subreg): Use GET_MODE_NUNITS on a fixed_size_mode
	instead of CONST_VECTOR_NUNITS.
	* varasm.c (output_constant_pool_2): Likewise.
	* rtx-vector-builder.c (rtx_vector_builder::build): Only include the
	explicit-encoded elements in the XVEC for variable-length vectors.

gcc/ada/
	* gcc-interface/misc.c (enumerate_modes): Handle polynomial
	GET_MODE_NUNITS.

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

From-SVN: r256195

Use partial_subreg_p in code that was added since the initial patch
that introduced this function.

2018-01-03  Richard Sandiford  <richard.sandiford@linaro.org>

gcc/
	* lra-constraints.c (curr_insn_transform): Use partial_subreg_p.

From-SVN: r256194

This patch adds a POD version of fixed_size_mode.  The only current use
is for storing the __builtin_apply and __builtin_result register modes,
which were made fixed_size_modes by the previous patch.

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

gcc/
	* coretypes.h (fixed_size_mode): Declare.
	(fixed_size_mode_pod): New typedef.
	* builtins.h (target_builtins::x_apply_args_mode)
	(target_builtins::x_apply_result_mode): Change type to
	fixed_size_mode_pod.
	* builtins.c (apply_args_size, apply_result_size, result_vector)
	(expand_builtin_apply_args_1, expand_builtin_apply)
	(expand_builtin_return): Update accordingly.

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

From-SVN: r256193

This patch makes some pieces of code operate directly on the new
CONST_VECTOR encoding.

2018-01-03  Richard Sandiford  <richard.sandiford@linaro.org>

gcc/
	* cse.c (hash_rtx_cb): Hash only the encoded elements.
	* cselib.c (cselib_hash_rtx): Likewise.
	* expmed.c (make_tree): Build VECTOR_CSTs directly from the
	CONST_VECTOR encoding.

From-SVN: r256192

	PR target/83641
	* config/i386/i386.c (ix86_adjust_stack_and_probe_stack_clash): For
	noreturn probe, use gen_pop instead of ix86_emit_restore_reg_using_pop,
	only set RTX_FRAME_RELATED_P on both the push and pop if cfa_reg is sp
	and add REG_CFA_ADJUST_CFA notes in that case to both insns.

	PR target/83641
	* config/i386/i386.c (ix86_adjust_stack_and_probe_stack_clash): Do not
	explicitly probe *sp in a noreturn function if there were any callee
	register saves or frame pointer is needed.

	PR target/83641
	* gcc.target/i386/stack-check-17.c: New test.
	* gcc.target/i386/stack-check-12.c: Drop unnecessary asm.

From-SVN: r256191

	PR debug/83621
	* cfgexpand.c (expand_debug_expr): Return NULL if mode is
	BLKmode for ternary, binary or unary expressions.

	* gcc.dg/pr83621.c: New test.

From-SVN: r256190

	PR debug/83645
	* var-tracking.c (delete_vta_debug_insn): New inline function.
	(delete_vta_debug_insns): Add USE_CFG argument, if true, walk just
	insns from get_insns () to NULL instead of each bb separately.
	Use delete_vta_debug_insn.  No longer static.
	(vt_debug_insns_local, variable_tracking_main_1): Adjust
	delete_vta_debug_insns callers.
	* rtl.h (delete_vta_debug_insns): Declare.
	* final.c (rest_of_handle_final): Call delete_vta_debug_insns
	instead of variable_tracking_main.

	* gcc.dg/pr83645.c: New test.

From-SVN: r256189

PR c/83559 - -Wsuggest-attribute=const conflicts with -Wattributes warning about const attribute on function returning void

gcc/ChangeLog:

	PR c/83559
	* doc/extend.texi (attribute const): Fix a typo.
	* ipa-pure-const.c ((warn_function_const, warn_function_pure): Avoid
	issuing -Wsuggest-attribute for void functions.

gcc/testsuite/ChangeLog:

	PR c/83559
	* gcc.dg/const-2.c: New test.
	* gcc.dg/pure-3.c: New test.

From-SVN: r256188

gimple-ssa-warn-restrict.c (builtin_memref::builtin_memref): Use offset_int::from instead of wide_int::to_shwi.


gcc/ChangeLog:

	* gimple-ssa-warn-restrict.c (builtin_memref::builtin_memref): Use
	offset_int::from instead of wide_int::to_shwi.
	(maybe_diag_overlap): Remove assertion.
	Use HOST_WIDE_INT_PRINT_DEC instead of %lli.
	* gimple-ssa-sprintf.c (format_directive): Same.
	(parse_directive): Same.
	(sprintf_dom_walker::compute_format_length): Same.
	(try_substitute_return_value): Same.

gcc/testsuite/ChangeLog:

	* gcc.dg/Wrestrict-3.c: New test.

From-SVN: r256187

	PR c++/83555
	* typeck.c (build_static_cast_1): For static casts to reference types,
	call build_base_path with flag_delete_null_pointer_checks as nonnull
	instead of always false.  When -fsanitize=null, call
	ubsan_maybe_instrument_reference on the NULL reference INTEGER_CST.
	* cp-gimplify.c (cp_genericize_r): Don't walk subtrees of UBSAN_NULL
	call if the first argument is INTEGER_CST with REFERENCE_TYPE.

	* g++.dg/opt/pr83555.C: New test.
	* g++.dg/ubsan/pr83555.C: New test.

From-SVN: r256186

* include/std/optional: Use the feature macro.

From-SVN: r256185

gcc/testsuite/ChangeLog:
	* gcc.dg/plugin/expensive-selftests-1.c: Update regexp to handle
	the !CHECKING_P case by expecting a note.
	* gcc.dg/plugin/expensive_selftests_plugin.c (plugin_init): Issue
	a note for the !CHECKING_P case, and move the return statement
	outside of #if CHECKING_P guard.

From-SVN: r256183

re PR middle-end/83654 (-fstack-clash-protection probes below the stack pointer for VLA with constant size)

	PR middle-end/83654
	* explow.c (anti_adjust_stack_and_probe_stack_clash): Test a
	non-constant residual for zero at runtime and avoid probing in
	that case.  Reorganize code for trailing problem to mirror handling
	of the residual.

	PR middle-end/83654
	* gcc.target/i386/stack-check-18.c: New test.
	* gcc.target/i386/stack-check-19.c: New test.

From-SVN: r256182

gcc/testsuite/ChangeLog:
	* c-c++-common/Warray-bounds-3.c: Remove xfail.

From-SVN: r256181

2018-01-03  Prathamesh Kulkarni  <prathamesh.kulkarni@linaro.org>

	PR tree-optimization/83501
	* tree-ssa-strlen.c (get_string_cst): New.
	(handle_char_store): Call get_string_cst.

testsuite/
	* gcc.dg/tree-ssa/pr83501.c: New test.

From-SVN: r256180

https://gcc.gnu.org/ml/gcc-patches/2018-01/msg00148.html
	PR c++/83667
	* method.c (make_alias_for): Copy DECL_CONTEXT.

	PR c++/83667
	* g++.dg/ipa/pr83667.C: New.

From-SVN: r256179

2018-01-03  Martin Liska  <mliska@suse.cz>

	PR tree-optimization/83593
	* tree-ssa-strlen.c: Include tree-cfg.h.
	(strlen_check_and_optimize_stmt): Add new argument cleanup_eh.
	(strlen_dom_walker): Add new member variable m_cleanup_cfg.
	(strlen_dom_walker::strlen_dom_walker): Initialize m_cleanup_cfg
	to false.
	(strlen_dom_walker::before_dom_children): Call
	gimple_purge_dead_eh_edges. Dump tranformation with details
	dump flags.
	(strlen_dom_walker::before_dom_children): Update call by adding
	new argument cleanup_eh.
	(pass_strlen::execute): Return TODO_cleanup_cfg if needed.
2018-01-03  Martin Liska  <mliska@suse.cz>

	PR tree-optimization/83593
	* gcc.dg/pr83593.c: New test.

From-SVN: r256178

2018-01-03  Martin Liska  <mliska@suse.cz>

	PR ipa/83549
	* cif-code.def (VARIADIC_THUNK): New enum value.
	* ipa-fnsummary.c (compute_fn_summary): Do not inline variadic
	thunks.
2018-01-03  Martin Liska  <mliska@suse.cz>

	PR ipa/83549
	* g++.dg/ipa/pr83549.C: New test.

From-SVN: r256177

	PR c++/83592
	* decl.c (grokdeclarator): Don't warn about MVP in typename context.

	* g++.dg/warn/mvp2.C: New test.

From-SVN: r256176

	PR preprocessor/83602
	* name-lookup.c (lookup_name_fuzzy): Don't use macro_use_before_def
	for builtin macros.

	* g++.dg/cpp/pr83602.C: New test.

From-SVN: r256175

	PR c++/83634
	* cp-gimplify.c (cp_fold) <case NOP_EXPR>: If the operand folds to
	error_mark_node, return error_mark_node.

	* g++.dg/parse/pr83634.C: New test.

From-SVN: r256174

2018-01-03  Thomas Koenig  <tkoenig@gcc.gnu.org>

	PR fortran/83664
	* check.c (gfc_check_eoshift): Error for missing boundary if array
	is not one of the standard types.

2018-01-03  Thomas Koenig  <tkoenig@gcc.gnu.org>

	PR fortran/83664
	* gfortran.dg/eoshift_7.f90: New test.

From-SVN: r256171

Simply mirror the MODE_XI logic of handling unaligned operands in
mov<mode>_internal into MODE_TI / MODE_OI handling.

gcc/
2018-01-03  Jan Beulich  <jbeulich@suse.com>

	* sse.md (mov<mode>_internal): Tighten condition for when to use
	vmovdqu<ssescalarsize> for TI and OI modes.

gcc/testsuite/
2018-01-03  Jan Beulich  <jbeulich@suse.com>

	* gcc.target/i386/avx512vl-no-vmovdqu8.c,
	gcc.target/i386/avx512vl-no-vmovdqu16.c: New.

From-SVN: r256170

From-SVN: r256169

From-SVN: r256168

2018-01-03  Martin Liska  <mliska@suse.cz>

	PR ipa/83594
	* ipa-visibility.c (function_and_variable_visibility): Skip
	functions with noipa attribure.
2018-01-03  Martin Liska  <mliska@suse.cz>

	PR ipa/83594
	* gcc.dg/ipa/pr83594.c: New test.

From-SVN: r256167