This patch prints a message to say how an alias check is being
implemented.

2019-11-16  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* tree-data-ref.c (create_intersect_range_checks_index)
	(create_intersect_range_checks): Print dump messages.

gcc/testsuite/
	* gcc.dg/vect/vect-alias-check-1.c: Test for the type of alias check.
	* gcc.dg/vect/vect-alias-check-8.c: Likewise.
	* gcc.dg/vect/vect-alias-check-9.c: Likewise.
	* gcc.dg/vect/vect-alias-check-10.c: Likewise.
	* gcc.dg/vect/vect-alias-check-11.c: Likewise.
	* gcc.dg/vect/vect-alias-check-12.c: Likewise.
	* gcc.dg/vect/vect-alias-check-13.c: Likewise.
	* gcc.dg/vect/vect-alias-check-14.c: Likewise.
	* gcc.dg/vect/vect-alias-check-15.c: Likewise.
	* gcc.dg/vect/vect-alias-check-16.c: Likewise.
	* gcc.dg/vect/vect-alias-check-17.c: Likewise.

From-SVN: r278353

This patch dumps the final (merged) list of alias pairs.  It also adds:

- WAW and RAW versions of vect-alias-check-8.c
- a "well-ordered" version of vect-alias-check-9.c (i.e. all reads
  before any writes)
- a test with mixed steps in the same alias pair

I also tweaked the test value in vect-alias-check-9.c so that the
result was less likely to be accidentally correct if the alias
isn't honoured.

2019-11-16  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* tree-data-ref.c (dump_alias_pair): New function.
	(prune_runtime_alias_test_list): Use it to dump each merged alias pair.

gcc/testsuite/
	* gcc.dg/vect/vect-alias-check-8.c: Test for the RAW flag.
	* gcc.dg/vect/vect-alias-check-9.c: Test for the ARBITRARY flag.
	(TEST_VALUE): Use a higher value for early iterations.
	* gcc.dg/vect/vect-alias-check-14.c: New test.
	* gcc.dg/vect/vect-alias-check-15.c: Likewise.
	* gcc.dg/vect/vect-alias-check-16.c: Likewise.
	* gcc.dg/vect/vect-alias-check-17.c: Likewise.

From-SVN: r278352

prune_runtime_alias_test_list can merge dr_with_seg_len_pair_ts that
have different steps for the first reference or different steps for the
second reference.  This patch adds a flag to record that.

I don't know whether the change to create_intersect_range_checks_index
fixes anything in practice.  It would have to be a corner case if so,
since at present we only merge two alias pairs if either the first or
the second references are identical and only the other references differ.
And the vectoriser uses VF-based segment lengths only if both references
in a pair have the same step.  Either way, it still seems wrong to use
DR_STEP when it doesn't represent all checks that have been merged into
the pair.

2019-11-16  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* tree-data-ref.h (DR_ALIAS_MIXED_STEPS): New flag.
	* tree-data-ref.c (prune_runtime_alias_test_list): Set it when
	merging data references with different steps.
	(create_intersect_range_checks_index): Take a
	dr_with_seg_len_pair_t instead of two dr_with_seg_lens.
	Bail out if DR_ALIAS_MIXED_STEPS is set.
	(create_intersect_range_checks): Take a dr_with_seg_len_pair_t
	instead of two dr_with_seg_lens.  Update call to
	create_intersect_range_checks_index.
	(create_runtime_alias_checks): Update call accordingly.

From-SVN: r278351

This patch adds a bunch of flags to dr_with_seg_len_pair_t,
for use by later patches.  The update to tree-loop-distribution.c
is conservatively correct, but might be tweakable later.

2019-11-16  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* tree-data-ref.h (DR_ALIAS_RAW, DR_ALIAS_WAR, DR_ALIAS_WAW)
	(DR_ALIAS_ARBITRARY, DR_ALIAS_SWAPPED, DR_ALIAS_UNSWAPPED): New flags.
	(dr_with_seg_len_pair_t::sequencing): New enum.
	(dr_with_seg_len_pair_t::flags): New member variable.
	(dr_with_seg_len_pair_t::dr_with_seg_len_pair_t): Take a sequencing
	parameter and initialize the flags member variable.
	* tree-loop-distribution.c (compute_alias_check_pairs): Update
	call accordingly.
	* tree-vect-data-refs.c (vect_prune_runtime_alias_test_list): Likewise.
	Ensure the two data references in an alias pair are in statement
	order, if there is a defined order.
	* tree-data-ref.c (prune_runtime_alias_test_list): Use
	DR_ALIAS_SWAPPED and DR_ALIAS_UNSWAPPED to record whether we've
	swapped the references in a dr_with_seg_len_pair_t.  OR together
	the flags when merging two dr_with_seg_len_pair_ts.  After merging,
	try to restore the original dr_with_seg_len order, updating the
	flags if that fails.

From-SVN: r278350

prune_runtime_alias_test_list swapped dr_as between two dr_with_seg_len
pairs before finally deciding whether to merge them.  Bailing out later
would therefore leave the pairs in an incorrect state.

IMO a better fix would be to split this out into a subroutine that
produces a temporary dr_with_seg_len on success, rather than changing
an existing one in-place.  It would then be easy to merge both the dr_as
and dr_bs if we wanted to, rather than requiring one of them to be equal.
But here I tried to do something that could be backported if necessary.

2019-11-16  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* tree-data-ref.c (prune_runtime_alias_test_list): Delay
	swapping the dr_as based on init values until we've decided
	whether to merge them.

From-SVN: r278349

The two users of tree-data-ref's runtime alias checks both canonicalise
the order of the dr_with_seg_lens in a pair before passing them to
prune_runtime_alias_test_list.  It's more convenient for later patches
if prune_runtime_alias_test_list does that itself.

2019-11-16  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* tree-data-ref.c (prune_runtime_alias_test_list): Sort the
	two accesses in each dr_with_seg_len_pair_t before trying to
	combine separate dr_with_seg_len_pair_ts.
	* tree-loop-distribution.c (compute_alias_check_pairs): Don't do
	that here.
	* tree-vect-data-refs.c (vect_prune_runtime_alias_test_list): Likewise.

From-SVN: r278348

This patch adds support for scatter stores of partial vectors,
where the vector base or offset elements can be wider than the
elements being stored.

2019-11-16  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* config/aarch64/aarch64-sve.md
	(scatter_store<SVE_FULL_SD:mode><v_int_equiv>): Extend to...
	(scatter_store<SVE_24:mode><v_int_container>): ...this.
	(mask_scatter_store<SVE_FULL_S:mode><v_int_equiv>): Extend to...
	(mask_scatter_store<SVE_4:mode><v_int_equiv>): ...this.
	(mask_scatter_store<SVE_FULL_D:mode><v_int_equiv>): Extend to...
	(mask_scatter_store<SVE_2:mode><v_int_equiv>): ...this.
	(*mask_scatter_store<mode><v_int_container>_<su>xtw_unpacked): New
	pattern.
	(*mask_scatter_store<SVE_FULL_D:mode><v_int_equiv>_sxtw): Extend to...
	(*mask_scatter_store<SVE_2:mode><v_int_equiv>_sxtw): ...this.
	(*mask_scatter_store<SVE_FULL_D:mode><v_int_equiv>_uxtw): Extend to...
	(*mask_scatter_store<SVE_2:mode><v_int_equiv>_uxtw): ...this.

gcc/testsuite/
	* gcc.target/aarch64/sve/scatter_store_1.c (TEST_LOOP): Start at 0.
	(TEST_ALL): Add tests for 8-bit and 16-bit elements.
	* gcc.target/aarch64/sve/scatter_store_2.c: Update accordingly.
	* gcc.target/aarch64/sve/scatter_store_3.c (TEST_LOOP): Start at 0.
	(TEST_ALL): Add tests for 8-bit and 16-bit elements.
	* gcc.target/aarch64/sve/scatter_store_4.c: Update accordingly.
	* gcc.target/aarch64/sve/scatter_store_5.c (TEST_LOOP): Start at 0.
	(TEST_ALL): Add tests for 8-bit, 16-bit and 32-bit elements.
	* gcc.target/aarch64/sve/scatter_store_8.c: New test.
	* gcc.target/aarch64/sve/scatter_store_9.c: Likewise.

From-SVN: r278347

This patch pattern-matches a partial gather load followed by a sign or
zero extension into an extending gather load.  (The partial gather load
is already an extending load; we just don't rely on the upper bits of
the elements.)

2019-11-16  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* config/aarch64/iterators.md (SVE_2BHSI, SVE_2HSDI, SVE_4BHI)
	(SVE_4HSI): New mode iterators.
	(ANY_EXTEND2): New code iterator.
	* config/aarch64/aarch64-sve.md
	(@aarch64_gather_load_<ANY_EXTEND:optab><VNx4_WIDE:mode><VNx4_NARROW:mode>):
	Extend to...
	(@aarch64_gather_load_<ANY_EXTEND:optab><SVE_4HSI:mode><SVE_4BHI:mode>):
	...this, handling extension to partial modes as well as full modes.
	Describe the extension as a predicated rather than unpredicated
	extension.
	(@aarch64_gather_load_<ANY_EXTEND:optab><VNx2_WIDE:mode><VNx2_NARROW:mode>):
	Likewise extend to...
	(@aarch64_gather_load_<ANY_EXTEND:optab><SVE_2HSDI:mode><SVE_2BHSI:mode>):
	...this, making the same adjustments.
	(*aarch64_gather_load_<ANY_EXTEND:optab><VNx2_WIDE:mode><VNx2_NARROW:mode>_sxtw):
	Likewise extend to...
	(*aarch64_gather_load_<ANY_EXTEND:optab><SVE_2HSDI:mode><SVE_2BHSI:mode>_sxtw)
	...this, making the same adjustments.
	(*aarch64_gather_load_<ANY_EXTEND:optab><VNx2_WIDE:mode><VNx2_NARROW:mode>_uxtw):
	Likewise extend to...
	(*aarch64_gather_load_<ANY_EXTEND:optab><SVE_2HSDI:mode><SVE_2BHSI:mode>_uxtw)
	...this, making the same adjustments.
	(*aarch64_gather_load_<ANY_EXTEND:optab><SVE_2HSDI:mode><SVE_2BHSI:mode>_<ANY_EXTEND2:su>xtw_unpacked):
	New pattern.
	(*aarch64_ldff1_gather<mode>_sxtw): Canonicalize to a constant
	extension predicate.
	(@aarch64_ldff1_gather_<ANY_EXTEND:optab><VNx4_WIDE:mode><VNx4_NARROW:mode>)
	(@aarch64_ldff1_gather_<ANY_EXTEND:optab><VNx2_WIDE:mode><VNx2_NARROW:mode>)
	(*aarch64_ldff1_gather_<ANY_EXTEND:optab><VNx2_WIDE:mode><VNx2_NARROW:mode>_uxtw):
	Describe the extension as a predicated rather than unpredicated
	extension.
	(*aarch64_ldff1_gather_<ANY_EXTEND:optab><VNx2_WIDE:mode><VNx2_NARROW:mode>_sxtw):
	Likewise.  Canonicalize to a constant extension predicate.
	* config/aarch64/aarch64-sve-builtins-base.cc
	(svld1_gather_extend_impl::expand): Add an extra predicate for
	the extension.
	(svldff1_gather_extend_impl::expand): Likewise.

gcc/testsuite/
	* gcc.target/aarch64/sve/gather_load_extend_1.c: New test.
	* gcc.target/aarch64/sve/gather_load_extend_2.c: Likewise.
	* gcc.target/aarch64/sve/gather_load_extend_3.c: Likewise.
	* gcc.target/aarch64/sve/gather_load_extend_4.c: Likewise.
	* gcc.target/aarch64/sve/gather_load_extend_5.c: Likewise.
	* gcc.target/aarch64/sve/gather_load_extend_6.c: Likewise.
	* gcc.target/aarch64/sve/gather_load_extend_7.c: Likewise.
	* gcc.target/aarch64/sve/gather_load_extend_8.c: Likewise.
	* gcc.target/aarch64/sve/gather_load_extend_9.c: Likewise.
	* gcc.target/aarch64/sve/gather_load_extend_10.c: Likewise.
	* gcc.target/aarch64/sve/gather_load_extend_11.c: Likewise.
	* gcc.target/aarch64/sve/gather_load_extend_12.c: Likewise.

From-SVN: r278346

This patch adds support for gather loads of partial vectors,
where the vector base or offset elements can be wider than the
elements being loaded.

2019-11-16  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* config/aarch64/iterators.md (SVE_24, SVE_2, SVE_4): New mode
	iterators.
	* config/aarch64/aarch64-sve.md
	(gather_load<SVE_FULL_SD:mode><v_int_equiv>): Extend to...
	(gather_load<SVE_24:mode><v_int_container>): ...this.
	(mask_gather_load<SVE_FULL_S:mode><v_int_equiv>): Extend to...
	(mask_gather_load<SVE_4:mode><v_int_container>): ...this.
	(mask_gather_load<SVE_FULL_D:mode><v_int_equiv>): Extend to...
	(mask_gather_load<SVE_2:mode><v_int_container>): ...this.
	(*mask_gather_load<SVE_2:mode><v_int_container>_<su>xtw_unpacked):
	New pattern.
	(*mask_gather_load<SVE_FULL_D:mode><v_int_equiv>_sxtw): Extend to...
	(*mask_gather_load<SVE_2:mode><v_int_equiv>_sxtw): ...this.
	Allow the nominal extension predicate to be different from the
	load predicate.
	(*mask_gather_load<SVE_FULL_D:mode><v_int_equiv>_uxtw): Extend to...
	(*mask_gather_load<SVE_2:mode><v_int_equiv>_uxtw): ...this.

gcc/testsuite/
	* gcc.target/aarch64/sve/gather_load_1.c (TEST_LOOP): Start at 0.
	(TEST_ALL): Add tests for 8-bit and 16-bit elements.
	* gcc.target/aarch64/sve/gather_load_2.c: Update accordingly.
	* gcc.target/aarch64/sve/gather_load_3.c (TEST_LOOP): Start at 0.
	(TEST_ALL): Add tests for 8-bit and 16-bit elements.
	* gcc.target/aarch64/sve/gather_load_4.c: Update accordingly.
	* gcc.target/aarch64/sve/gather_load_5.c (TEST_LOOP): Start at 0.
	(TEST_ALL): Add tests for 8-bit, 16-bit and 32-bit elements.
	* gcc.target/aarch64/sve/gather_load_6.c: Add
	--param aarch64-sve-compare-costs=0.
	(TEST_LOOP): Start at 0.
	* gcc.target/aarch64/sve/gather_load_7.c: Add
	--param aarch64-sve-compare-costs=0.
	* gcc.target/aarch64/sve/gather_load_8.c: New test.
	* gcc.target/aarch64/sve/gather_load_9.c: Likewise.
	* gcc.target/aarch64/sve/mask_gather_load_6.c: Add
	--param aarch64-sve-compare-costs=0.

From-SVN: r278345

This patch adds support for "truncating" to a partial SVE vector from
either a full SVE vector or a wider partial vector.  This truncation is
actually a no-op and so should have zero cost in the vector cost model.

2019-11-16  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* config/aarch64/aarch64-sve.md
	(trunc<SVE_HSDI:mode><SVE_PARTIAL_I:mode>2): New pattern.
	* config/aarch64/aarch64.c (aarch64_integer_truncation_p): New
	function.
	(aarch64_sve_adjust_stmt_cost): Call it.

gcc/testsuite/
	* gcc.target/aarch64/sve/mask_struct_load_1.c: Add
	--param aarch64-sve-compare-costs=0.
	* gcc.target/aarch64/sve/mask_struct_load_2.c: Likewise.
	* gcc.target/aarch64/sve/mask_struct_load_3.c: Likewise.
	* gcc.target/aarch64/sve/mask_struct_load_4.c: Likewise.
	* gcc.target/aarch64/sve/mask_struct_load_5.c: Likewise.
	* gcc.target/aarch64/sve/pack_1.c: Likewise.
	* gcc.target/aarch64/sve/truncate_1.c: New test.

From-SVN: r278344

This patch pattern-matches a partial SVE load followed by a sign or zero
extension into an extending load.  (The partial load is already an
extending load; we just don't rely on the upper bits of the elements.)

Nothing yet uses the extra LDFF1 and LDNF1 combinations, but it seemed
more consistent to provide them, since I needed to update the pattern
to use a predicated extension anyway.

2019-11-16  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* config/aarch64/aarch64-sve.md
	(@aarch64_load_<ANY_EXTEND:optab><VNx8_WIDE:mode><VNx8_NARROW:mode>):
	(@aarch64_load_<ANY_EXTEND:optab><VNx4_WIDE:mode><VNx4_NARROW:mode>)
	(@aarch64_load_<ANY_EXTEND:optab><VNx2_WIDE:mode><VNx2_NARROW:mode>):
	Combine into...
	(@aarch64_load_<ANY_EXTEND:optab><SVE_HSDI:mode><SVE_PARTIAL_I:mode>):
	...this new pattern, handling extension to partial modes as well
	as full modes.  Describe the extension as a predicated rather than
	unpredicated extension.
	(@aarch64_ld<fn>f1_<ANY_EXTEND:optab><VNx8_WIDE:mode><VNx8_NARROW:mode>)
	(@aarch64_ld<fn>f1_<ANY_EXTEND:optab><VNx4_WIDE:mode><VNx4_NARROW:mode>)
	(@aarch64_ld<fn>f1_<ANY_EXTEND:optab><VNx2_WIDE:mode><VNx2_NARROW:mode>):
	Combine into...
	(@aarch64_ld<fn>f1_<ANY_EXTEND:optab><SVE_HSDI:mode><SVE_PARTIAL_I:mode>):
	...this new pattern, handling extension to partial modes as well
	as full modes.  Describe the extension as a predicated rather than
	unpredicated extension.
	* config/aarch64/aarch64-sve-builtins.cc
	(function_expander::use_contiguous_load_insn): Add an extra
	predicate for extending loads.
	* config/aarch64/aarch64.c (aarch64_extending_load_p): New function.
	(aarch64_sve_adjust_stmt_cost): Likewise.
	(aarch64_add_stmt_cost): Use aarch64_sve_adjust_stmt_cost to adjust
	the cost of SVE vector stmts.

gcc/testsuite/
	* gcc.target/aarch64/sve/load_extend_1.c: New test.
	* gcc.target/aarch64/sve/load_extend_2.c: Likewise.
	* gcc.target/aarch64/sve/load_extend_3.c: Likewise.
	* gcc.target/aarch64/sve/load_extend_4.c: Likewise.
	* gcc.target/aarch64/sve/load_extend_5.c: Likewise.
	* gcc.target/aarch64/sve/load_extend_6.c: Likewise.
	* gcc.target/aarch64/sve/load_extend_7.c: Likewise.
	* gcc.target/aarch64/sve/load_extend_8.c: Likewise.
	* gcc.target/aarch64/sve/load_extend_9.c: Likewise.
	* gcc.target/aarch64/sve/load_extend_10.c: Likewise.
	* gcc.target/aarch64/sve/reduc_4.c: Add
	--param aarch64-sve-compare-costs=0.

From-SVN: r278343

This patch adds support for extending from partial SVE modes
to both full vector modes and wider partial modes.

Some tests now need --param aarch64-sve-compare-costs=0 to force
the original full-vector code.

2019-11-16  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* config/aarch64/iterators.md (SVE_HSDI): New mode iterator.
	(narrower_mask): Handle VNx4HI, VNx2HI and VNx2SI.
	* config/aarch64/aarch64-sve.md
	(<ANY_EXTEND:optab><SVE_PARTIAL_I:mode><SVE_HSDI:mode>2): New pattern.
	(*<ANY_EXTEND:optab><SVE_PARTIAL_I:mode><SVE_HSDI:mode>2): Likewise.
	(@aarch64_pred_sxt<SVE_FULL_HSDI:mode><SVE_PARTIAL_I:mode>): Update
	comment.  Avoid new narrower_mask ambiguity.
	(@aarch64_cond_sxt<SVE_FULL_HSDI:mode><SVE_PARTIAL_I:mode>): Likewise.
	(*cond_uxt<mode>_2): Update comment.
	(*cond_uxt<mode>_any): Likewise.

gcc/testsuite/
	* gcc.target/aarch64/sve/cost_model_1.c: Expect the loop to be
	vectorized with bytes stored in 32-bit containers.
	* gcc.target/aarch64/sve/extend_1.c: New test.
	* gcc.target/aarch64/sve/extend_2.c: New test.
	* gcc.target/aarch64/sve/extend_3.c: New test.
	* gcc.target/aarch64/sve/extend_4.c: New test.
	* gcc.target/aarch64/sve/load_const_offset_3.c: Add
	--param aarch64-sve-compare-costs=0.
	* gcc.target/aarch64/sve/mask_struct_store_1.c: Likewise.
	* gcc.target/aarch64/sve/mask_struct_store_1_run.c: Likewise.
	* gcc.target/aarch64/sve/mask_struct_store_2.c: Likewise.
	* gcc.target/aarch64/sve/mask_struct_store_2_run.c: Likewise.
	* gcc.target/aarch64/sve/unpack_unsigned_1.c: Likewise.
	* gcc.target/aarch64/sve/unpack_unsigned_1_run.c: Likewise.

From-SVN: r278342

This patch adds the bare minimum needed to support autovectorisation of
partial SVE vectors, namely moves and integer addition.  Later patches
add more interesting cases.

2019-11-16  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* config/aarch64/aarch64-modes.def: Define partial SVE vector
	float modes.
	* config/aarch64/aarch64-protos.h (aarch64_sve_pred_mode): New
	function.
	* config/aarch64/aarch64.c (aarch64_classify_vector_mode): Handle the
	new vector float modes.
	(aarch64_sve_container_bits): New function.
	(aarch64_sve_pred_mode): Likewise.
	(aarch64_get_mask_mode): Use it.
	(aarch64_sve_element_int_mode): Handle structure modes and partial
	modes.
	(aarch64_sve_container_int_mode): New function.
	(aarch64_vectorize_related_mode): Return SVE modes when given
	SVE modes.  Handle partial modes, taking the preferred number
	of units from the size of the given mode.
	(aarch64_hard_regno_mode_ok): Allow partial modes to be stored
	in registers.
	(aarch64_expand_sve_ld1rq): Use the mode form of aarch64_sve_pred_mode.
	(aarch64_expand_sve_const_vector): Handle partial SVE vectors.
	(aarch64_split_sve_subreg_move): Use the mode form of
	aarch64_sve_pred_mode.
	(aarch64_secondary_reload): Handle partial modes in the same way
	as full big-endian vectors.
	(aarch64_vector_mode_supported_p): Allow partial SVE vectors.
	(aarch64_autovectorize_vector_modes): Try unpacked SVE vectors,
	merging with the Advanced SIMD modes.  If two modes have the
	same size, try the Advanced SIMD mode first.
	(aarch64_simd_valid_immediate): Use the container rather than
	the element mode for INDEX constants.
	(aarch64_simd_vector_alignment): Make the alignment of partial
	SVE vector modes the same as their minimum size.
	(aarch64_evpc_sel): Use the mode form of aarch64_sve_pred_mode.
	* config/aarch64/aarch64-sve.md (mov<SVE_FULL:mode>): Extend to...
	(mov<SVE_ALL:mode>): ...this.
	(movmisalign<SVE_FULL:mode>): Extend to...
	(movmisalign<SVE_ALL:mode>): ...this.
	(*aarch64_sve_mov<mode>_le): Rename to...
	(*aarch64_sve_mov<mode>_ldr_str): ...this.
	(*aarch64_sve_mov<SVE_FULL:mode>_be): Rename and extend to...
	(*aarch64_sve_mov<SVE_ALL:mode>_no_ldr_str): ...this.  Handle
	partial modes regardless of endianness.
	(aarch64_sve_reload_be): Rename to...
	(aarch64_sve_reload_mem): ...this and enable for little-endian.
	Use aarch64_sve_pred_mode to get the appropriate predicate mode.
	(@aarch64_pred_mov<SVE_FULL:mode>): Extend to...
	(@aarch64_pred_mov<SVE_ALL:mode>): ...this.
	(*aarch64_sve_mov<SVE_FULL:mode>_subreg_be): Extend to...
	(*aarch64_sve_mov<SVE_ALL:mode>_subreg_be): ...this.
	(@aarch64_sve_reinterpret<SVE_FULL:mode>): Extend to...
	(@aarch64_sve_reinterpret<SVE_ALL:mode>): ...this.
	(*aarch64_sve_reinterpret<SVE_FULL:mode>): Extend to...
	(*aarch64_sve_reinterpret<SVE_ALL:mode>): ...this.
	(maskload<SVE_FULL:mode><vpred>): Extend to...
	(maskload<SVE_ALL:mode><vpred>): ...this.
	(maskstore<SVE_FULL:mode><vpred>): Extend to...
	(maskstore<SVE_ALL:mode><vpred>): ...this.
	(vec_duplicate<SVE_FULL:mode>): Extend to...
	(vec_duplicate<SVE_ALL:mode>): ...this.
	(*vec_duplicate<SVE_FULL:mode>_reg): Extend to...
	(*vec_duplicate<SVE_ALL:mode>_reg): ...this.
	(sve_ld1r<SVE_FULL:mode>): Extend to...
	(sve_ld1r<SVE_ALL:mode>): ...this.
	(vec_series<SVE_FULL_I:mode>): Extend to...
	(vec_series<SVE_I:mode>): ...this.
	(*vec_series<SVE_FULL_I:mode>_plus): Extend to...
	(*vec_series<SVE_I:mode>_plus): ...this.
	(@aarch64_pred_sxt<SVE_FULL_HSDI:mode><SVE_PARTIAL_I:mode>): Avoid
	new VPRED ambiguity.
	(@aarch64_cond_sxt<SVE_FULL_HSDI:mode><SVE_PARTIAL_I:mode>): Likewise.
	(add<SVE_FULL_I:mode>3): Extend to...
	(add<SVE_I:mode>3): ...this.
	* config/aarch64/iterators.md (SVE_ALL, SVE_I): New mode iterators.
	(Vetype, Vesize, VEL, Vel, vwcore): Handle partial SVE vector modes.
	(VPRED, vpred): Likewise.
	(Vctype): New iterator.
	(vw): Remove SVE modes.

gcc/testsuite/
	* gcc.target/aarch64/sve/mixed_size_1.c: New test.
	* gcc.target/aarch64/sve/mixed_size_2.c: Likewise.
	* gcc.target/aarch64/sve/mixed_size_3.c: Likewise.
	* gcc.target/aarch64/sve/mixed_size_4.c: Likewise.
	* gcc.target/aarch64/sve/mixed_size_5.c: Likewise.

From-SVN: r278341

clastb_8.c was using scan-tree-dump-times to check for fully-masked
loops, which made it sensitive to the number of times we try to
vectorize.

2019-11-16  Richard Sandiford  <richard.sandiford@arm.com>

gcc/testsuite/
	* gcc.target/aarch64/sve/clastb_8.c: Use assembly tests to
	check for fully-masked loops.

From-SVN: r278340

Another renaming, this time to make way for partial/unpacked
float modes.

2019-11-16  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* config/aarch64/iterators.md (SVE_PARTIAL): Rename to...
	(SVE_PARTIAL_I): ...this.
	* config/aarch64/aarch64-sve.md: Apply the above renaming throughout.

From-SVN: r278339

An upcoming patch will make more use of partial/unpacked SVE vectors.
We then need a distinction between mode iterators that include partial
modes and those that only include "full" modes.  This patch prepares
for that by adding "FULL" to the names of iterators that only select
full modes.  There should be no change in behaviour.

2019-11-16  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* config/aarch64/iterators.md (SVE_ALL): Rename to...
	(SVE_FULL): ...this.
	(SVE_I): Rename to...
	(SVE_FULL_I): ...this.
	(SVE_F): Rename to...
	(SVE_FULL_F): ...this.
	(SVE_BHSI): Rename to...
	(SVE_FULL_BHSI): ...this.
	(SVE_HSD): Rename to...
	(SVE_FULL_HSD): ...this.
	(SVE_HSDI): Rename to...
	(SVE_FULL_HSDI): ...this.
	(SVE_HSF): Rename to...
	(SVE_FULL_HSF): ...this.
	(SVE_SD): Rename to...
	(SVE_FULL_SD): ...this.
	(SVE_SDI): Rename to...
	(SVE_FULL_SDI): ...this.
	(SVE_SDF): Rename to...
	(SVE_FULL_SDF): ...this.
	(SVE_S): Rename to...
	(SVE_FULL_S): ...this.
	(SVE_D): Rename to...
	(SVE_FULL_D): ...this.
	* config/aarch64/aarch64-sve.md: Apply the above renaming throughout.
	* config/aarch64/aarch64-sve2.md: Likewise.

From-SVN: r278338

This patch enables VECT_COMPARE_COSTS by default for SVE, both so
that we can compare SVE against Advanced SIMD and so that (with future
patches) we can compare multiple SVE vectorisation approaches against
each other.  It also adds a target-specific --param to control this.

2019-11-16  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* config/aarch64/aarch64.opt (--param=aarch64-sve-compare-costs):
	New option.
	* doc/invoke.texi: Document it.
	* config/aarch64/aarch64.c (aarch64_autovectorize_vector_modes):
	By default, return VECT_COMPARE_COSTS for SVE.

gcc/testsuite/
	* gcc.target/aarch64/sve/reduc_3.c: Split multi-vector cases out
	into...
	* gcc.target/aarch64/sve/reduc_3_costly.c: ...this new test,
	passing -fno-vect-cost-model for them.
	* gcc.target/aarch64/sve/slp_6.c: Add -fno-vect-cost-model.
	* gcc.target/aarch64/sve/slp_7.c,
	* gcc.target/aarch64/sve/slp_7_run.c: Split multi-vector cases out
	into...
	* gcc.target/aarch64/sve/slp_7_costly.c,
	* gcc.target/aarch64/sve/slp_7_costly_run.c: ...these new tests,
	passing -fno-vect-cost-model for them.
	* gcc.target/aarch64/sve/while_7.c: Add -fno-vect-cost-model.
	* gcc.target/aarch64/sve/while_9.c: Likewise.

From-SVN: r278337

This patch adds a mode in which the vectoriser tries each available
base vector mode and picks the one with the lowest cost.  The new
behaviour is selected by autovectorize_vector_modes.

The patch keeps the current behaviour of preferring a VF of
loop->simdlen over any larger or smaller VF, regardless of costs
or target preferences.

2019-11-16  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* target.h (VECT_COMPARE_COSTS): New constant.
	* target.def (autovectorize_vector_modes): Return a bitmask of flags.
	* doc/tm.texi: Regenerate.
	* targhooks.h (default_autovectorize_vector_modes): Update accordingly.
	* targhooks.c (default_autovectorize_vector_modes): Likewise.
	* config/aarch64/aarch64.c (aarch64_autovectorize_vector_modes):
	Likewise.
	* config/arc/arc.c (arc_autovectorize_vector_modes): Likewise.
	* config/arm/arm.c (arm_autovectorize_vector_modes): Likewise.
	* config/i386/i386.c (ix86_autovectorize_vector_modes): Likewise.
	* config/mips/mips.c (mips_autovectorize_vector_modes): Likewise.
	* tree-vectorizer.h (_loop_vec_info::vec_outside_cost)
	(_loop_vec_info::vec_inside_cost): New member variables.
	* tree-vect-loop.c (_loop_vec_info::_loop_vec_info): Initialize them.
	(vect_better_loop_vinfo_p, vect_joust_loop_vinfos): New functions.
	(vect_analyze_loop): When autovectorize_vector_modes returns
	VECT_COMPARE_COSTS, try vectorizing the loop with each available
	vector mode and picking the one with the lowest cost.
	(vect_estimate_min_profitable_iters): Record the computed costs
	in the loop_vec_info.

From-SVN: r278336

This patch makes can_duplicate_and_interleave_p cope with mixtures of
vector sizes, by using queries based on get_vectype_for_scalar_type
instead of directly querying GET_MODE_SIZE (vinfo->vector_mode).

int_mode_for_size is now the first check we do for a candidate mode,
so it seemed better to restrict it to MAX_FIXED_MODE_SIZE.  This avoids
unnecessary work and avoids trying to create scalar types that the
target might not support.

2019-11-16  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* tree-vectorizer.h (can_duplicate_and_interleave_p): Take an
	element type rather than an element mode.
	* tree-vect-slp.c (can_duplicate_and_interleave_p): Likewise.
	Use get_vectype_for_scalar_type to query the natural types
	for a given element type rather than basing everything on
	GET_MODE_SIZE (vinfo->vector_mode).  Limit int_mode_for_size
	query to MAX_FIXED_MODE_SIZE.
	(duplicate_and_interleave): Update call accordingly.
	* tree-vect-loop.c (vectorizable_reduction): Likewise.

From-SVN: r278335

The BB vectoriser picked vector types in the same way as the loop
vectoriser: it picked a vector mode/size for the region and then
based all the vector types off that choice.  This meant we could
end up trying to use vector types that had too many elements for
the group size.

The main part of this patch is therefore about passing the SLP
group size down to routines like get_vectype_for_scalar_type and
ensuring that each vector type in the SLP tree is chosen wrt the
group size.  That part in itself is pretty easy and mechanical.

The main warts are:

(1) We normally pick a STMT_VINFO_VECTYPE for data references at an
    early stage (vect_analyze_data_refs).  However, nothing in the
    BB vectoriser relied on this, or on the min_vf calculated from it.
    I couldn't see anything other than vect_recog_bool_pattern that
    tried to access the vector type before the SLP tree is built.

(2) It's possible for the same statement to be used in groups of
    different sizes.  Taking the group size into account meant that
    we could try to pick different vector types for the same statement.

    This problem should go away with the move to doing everything on
    SLP trees, where presumably we would attach the vector type to the
    SLP node rather than the stmt_vec_info.  Until then, the patch just
    uses a first-come, first-served approach.

(3) A similar problem exists for grouped data references, where
    different statements in the same dataref group could be used
    in SLP nodes that have different group sizes.  The patch copes
    with that by making sure that all vector types in a dataref
    group remain consistent.

The patch means that:

    void
    f (int *x, short *y)
    {
      x[0] += y[0];
      x[1] += y[1];
      x[2] += y[2];
      x[3] += y[3];
    }

now produces:

        ldr     q0, [x0]
        ldr     d1, [x1]
        saddw   v0.4s, v0.4s, v1.4h
        str     q0, [x0]
        ret

instead of:

        ldrsh   w2, [x1]
        ldrsh   w3, [x1, 2]
        fmov    s0, w2
        ldrsh   w2, [x1, 4]
        ldrsh   w1, [x1, 6]
        ins     v0.s[1], w3
        ldr     q1, [x0]
        ins     v0.s[2], w2
        ins     v0.s[3], w1
        add     v0.4s, v0.4s, v1.4s
        str     q0, [x0]
        ret

Unfortunately it also means we start to vectorise
gcc.target/i386/pr84101.c for -m32.  That seems like a target
cost issue though; see PR92265 for details.

2019-11-16  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* tree-vectorizer.h (vect_get_vector_types_for_stmt): Take an
	optional maximum nunits.
	(get_vectype_for_scalar_type): Likewise.  Also declare a form that
	takes an slp_tree.
	(get_mask_type_for_scalar_type): Take an optional slp_tree.
	(vect_get_mask_type_for_stmt): Likewise.
	* tree-vect-data-refs.c (vect_analyze_data_refs): Don't store
	the vector type in STMT_VINFO_VECTYPE for BB vectorization.
	* tree-vect-patterns.c (vect_recog_bool_pattern): Use
	vect_get_vector_types_for_stmt instead of STMT_VINFO_VECTYPE
	to get an assumed vector type for data references.
	* tree-vect-slp.c (vect_update_shared_vectype): New function.
	(vect_update_all_shared_vectypes): Likewise.
	(vect_build_slp_tree_1): Pass the group size to
	vect_get_vector_types_for_stmt.  Use vect_update_shared_vectype
	for BB vectorization.
	(vect_build_slp_tree_2): Call vect_update_all_shared_vectypes
	before building the vectof from scalars.
	(vect_analyze_slp_instance): Pass the group size to
	get_vectype_for_scalar_type.
	(vect_slp_analyze_node_operations_1): Don't recompute the vector
	types for BB vectorization here; just handle the case in which
	we deferred the choice for booleans.
	(vect_get_constant_vectors): Pass the slp_tree to
	get_vectype_for_scalar_type.
	* tree-vect-stmts.c (vect_prologue_cost_for_slp_op): Likewise.
	(vectorizable_call): Likewise.
	(vectorizable_simd_clone_call): Likewise.
	(vectorizable_conversion): Likewise.
	(vectorizable_shift): Likewise.
	(vectorizable_operation): Likewise.
	(vectorizable_comparison): Likewise.
	(vect_is_simple_cond): Take the slp_tree as argument and
	pass it to get_vectype_for_scalar_type.
	(vectorizable_condition): Update call accordingly.
	(get_vectype_for_scalar_type): Take a group_size argument.
	For BB vectorization, limit the the vector to that number
	of elements.  Also define an overload that takes an slp_tree.
	(get_mask_type_for_scalar_type): Add an slp_tree argument and
	pass it to get_vectype_for_scalar_type.
	(vect_get_vector_types_for_stmt): Add a group_size argument
	and pass it to get_vectype_for_scalar_type.  Don't use the
	cached vector type for BB vectorization if a group size is given.
	Handle data references in that case.
	(vect_get_mask_type_for_stmt): Take an slp_tree argument and
	pass it to get_mask_type_for_scalar_type.

gcc/testsuite/
	* gcc.dg/vect/bb-slp-4.c: Expect the block to be vectorized
	with -fno-vect-cost-model.
	* gcc.dg/vect/bb-slp-bool-1.c: New test.
	* gcc.target/aarch64/vect_mixed_sizes_14.c: Likewise.
	* gcc.target/i386/pr84101.c: XFAIL for -m32.

From-SVN: r278334

	* ipa-inline.h (do_estimate_edge_time): Add nonspec_time
	parameter.
	(estimate_edge_time): Use it.
	* ipa-inline-analysis.c (do_estimate_edge_time): Add
	ret_nonspec_time parameter.

From-SVN: r278333

2019-11-15  Edward Smith-Rowland  <3dw4rd@verizon.net>

	Implement the <tuple> part of C++20 p1032 Misc constexpr bits.
	* include/std/tuple (_Head_base, _Tuple_impl(allocator_arg_t,...)
	(_M_assign, tuple(allocator_arg_t,...), _Inherited, operator=, _M_swap)
	(swap, pair(piecewise_construct_t,): Constexpr.
	* (__uses_alloc0::_Sink::operator=, __uses_alloc_t): Constexpr.
	* testsuite/20_util/tuple/cons/constexpr_allocator_arg_t.cc: New test.
	* testsuite/20_util/tuple/constexpr_swap.cc : New test.
	* testsuite/20_util/uses_allocator/69293_neg.cc: Extra error for C++20.
	* testsuite/20_util/uses_allocator/cons_neg.cc: : Extra error for C++20.

From-SVN: r278331

From-SVN: r278328

	* include/std/stop_token: Reduce header dependencies by including
	internal headers.
	(stop_token::swap(stop_token&), swap(stop_token&, stop_token&)):
	Define.
	(operator!=(const stop_token&, const stop_token&)): Fix return value.
	(stop_token::_Stop_cb::_Stop_cb(Cb&&)): Use std::forward instead of
	(stop_token::_Stop_state_t) [_GLIBCXX_HAS_GTHREADS]: Use lock_guard
	instead of unique_lock.
	[!_GLIBCXX_HAS_GTHREADS]: Do not use mutex.
	(stop_token::stop_token(_Stop_state)): Change parameter to lvalue
	reference.
	(stop_source): Remove unnecessary using-declarations for names only
	used once.
	(swap(stop_source&, stop_source&)): Define.
	(stop_callback(const stop_token&, _Cb&&))
	(stop_callback(stop_token&&, _Cb&&)): Replace lambdas with a named
	function. Use std::forward instead of std::move. Run callbacks if a
	stop request has already been made.
	(stop_source::_M_execute()): Remove.
	(stop_source::_S_execute(_Stop_cb*)): Define.
	* include/std/version (__cpp_lib_jthread): Define conditionally.
	* testsuite/30_threads/stop_token/stop_callback.cc: New test.
	* testsuite/30_threads/stop_token/stop_source.cc: New test.
	* testsuite/30_threads/stop_token/stop_token.cc: Enable test for
	immediate execution of callback.

From-SVN: r278325

For each of the attributes currently included in C2x, it has a
constraint that the attribute shall appear at most once in each
attribute list (attribute-list being what appear between a single [[
and ]]).

This patch implements that check.  As the corresponding check in the
C++ front end (cp_parser_check_std_attribute) makes violations into
errors, I made them into errors, with the same wording, for C as well.

There is an existing check in the case of the fallthrough attribute,
with a warning rather than an error, in attribute_fallthrough_p.  That
is more general, as it also covers __attribute__ ((fallthrough)) and
the case of [[fallthrough]] [[fallthrough]] (multiple attribute-lists
in a single attribute-specifier-sequence), which is not a constraint
violation.  To avoid some [[fallthrough, fallthrough]] being diagnosed
twice, the check I added avoids adding duplicate attributes to the
list.

Bootstrapped with no regressions on x86_64-pc-linux-gnu.

gcc/c:
	* c-parser.c (c_parser_std_attribute_specifier): Diagnose
	duplicate standard attributes.

gcc/testsuite:
	* gcc.dg/c2x-attr-deprecated-4.c, gcc.dg/c2x-attr-fallthrough-4.c,
	gcc.dg/c2x-attr-maybe_unused-4.c: New tests.

From-SVN: r278324

/cp
2019-11-15  Paolo Carlini  <paolo.carlini@oracle.com>

	* typeck.c (cp_truthvalue_conversion): Add tsubst_flags_t parameter
	and use it in calls; also pass the location_t of the expression to
	cp_build_binary_op and c_common_truthvalue_conversion.
	* rtti.c (build_dynamic_cast_1): Adjust call.
	* cvt.c (ocp_convert): Likewise.
	* cp-gimplify.c (cp_fold): Likewise.
	* cp-tree.h (cp_truthvalue_conversion): Update declaration.

/testsuite
2019-11-15  Paolo Carlini  <paolo.carlini@oracle.com>

	* g++.dg/warn/Walways-true-1.C: Check locations too.
	* g++.dg/warn/Walways-true-2.C: Likewise.
	* g++.dg/warn/Walways-true-3.C: Likewise.
	* g++.dg/warn/Waddress-1.C: Check additional location.

From-SVN: r278320

From-SVN: r278318

2019-11-15  Edward Smith-Rowland  <3dw4rd@verizon.net>

	Implement the default_searcher part of C++20 p1032 Misc constexpr bits.
	* include/std/functional
	(default_searcher, default_searcher::operator()): Constexpr.
	* testsuite/20_util/function_objects/constexpr_searcher.cc: New.

From-SVN: r278317

    
    Patch by Maciej W. Rozycki.
    
    Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/207458

From-SVN: r278316

The change approved in Belfast did not actually rename the concept from
std::default_constructible to std::default_initializable, even though
that was intended. That is expected to be done soon as a separate issue,
so I'm implementing that now too.

	* include/bits/iterator_concepts.h (weakly_incrementable): Adjust.
	* include/std/concepts (default_constructible): Rename to
	default_initializable and require default-list-initialization and
	default-initialization to be valid (LWG 3149).
	(semiregular): Adjust to new name.
	* testsuite/std/concepts/concepts.lang/concept.defaultconstructible/
	1.cc: Rename directory to concept.defaultinitializable and adjust to
	new name.
	* testsuite/std/concepts/concepts.lang/concept.defaultinitializable/
	lwg3149.cc: New test.
	* testsuite/util/testsuite_iterators.h (test_range): Adjust.

From-SVN: r278314

	* src/c++17/fs_path.cc [_GLIBCXX_FILESYSTEM_IS_WINDOWS]
	(is_disk_designator): New helper function.
	(path::_Parser::root_path()): Use is_disk_designator.
	(path::lexically_relative(const path&)): Implement resolution of
	LWG 3070.
	* testsuite/27_io/filesystem/path/generation/relative.cc: Check with
	path components that look like a root-name.

From-SVN: r278313

Add the dynamic linker name and fix a type name to use the public name
instead of the glibc internal name.

gcc/ChangeLog:

2019-11-15  Szabolcs Nagy  <szabolcs.nagy@arm.com>

	* config/m68k/linux.h (MUSL_DYNAMIC_LINKER): Define.

libgcc/ChangeLog:

2019-11-15  Szabolcs Nagy  <szabolcs.nagy@arm.com>

	* config/m68k/linux-unwind.h (struct uw_ucontext): Use sigset_t instead
	of __sigset_t.

From-SVN: r278312

This patch adds support for the C2x [[maybe_unused]] attribute, using
the same handler as for GNU __attribute__ ((unused)).

As with other such attribute support, I think turning certain warnings
into pedwarns for usage in cases where that is a constraint violation
can be addressed later as a bug fix, as can the C2x constraint for
various standard attributes that they do not appear more than once
inside a single [[]].

However, the warnings that appear in c2x-attr-maybe_unused-1.c (that
the attribute is ignored on member declarations) need to remain as
warnings not pedwarns, since C2x does permit the attribute there.  (Or
they could be silenced, on the basis that GCC doesn't have warnings
for unused struct and union members so it's completely harmless that
it's ignoring an attribute that might do something useful with another
compiler that does have such warnings.)

Bootstrapped with no regressions on x86_64-pc-linux-gnu.

gcc/c:
	* c-decl.c (std_attribute_table): Add maybe_unused.

gcc/testsuite:
	* gcc.dg/c2x-attr-maybe_unused-1.c,
	gcc.dg/c2x-attr-maybe_unused-2.c,
	gcc.dg/c2x-attr-maybe_unused-3.c: New tests.

From-SVN: r278310

ChangeLog:

2019-11-15  Kelvin Nilsen  <kelvin@gcc.gnu.org>

	* MAINTAINERS: Change my email address as maintainer.

From-SVN: r278309

microblaze-linux-musl build fails without this.

(This is a rebase of an earlier patch posted on bugzilla.)

gcc/ChangeLog:

2019-11-15  Nick Clifton  <nickc@redhat.com>
	    Szabolcs Nagy  <szabolcs.nagy@arm.com>

	PR target/65649
	* config/microblaze/microblaze.c (print_operand): Print value as long.

Co-Authored-By: Szabolcs Nagy <szabolcs.nagy@arm.com>

From-SVN: r278308

	* ipa-inline.c (edge_badness, inline_small_functions): Revert
	accidental commit.

From-SVN: r278307

Allow the registers used for the frame pointer to be used for other purposes
if the frame pointer is not being used.

2019-11-15  Kwok Cheung Yeung  <kcy@codesourcery.com>

	gcc/
	* config/gcn/gcn.h (FIXED_REGISTERS): Unfix frame pointer.
	(CALL_USED_REGISTERS): Make frame pointer callee-saved.

From-SVN: r278306

Reduce the lower limits on the number of registers requested by non-leaf
kernels to help improve CU occupancy.

2019-11-15  Kwok Cheung Yeung  <kcy@codesourcery.com>

	gcc/
	* config/gcn/gcn.c (MAX_NORMAL_SGPR_COUNT, MAX_NORMAL_VGPR_COUNT): New.
	(gcn_conditional_register_usage): Use constants in place of hard-coded
	values.
	(gcn_hsa_declare_function_name): Set lower bound for number of
	SGPRs/VGPRs in non-leaf kernels to MAX_NORMAL_SGPR_COUNT and
	MAX_NORMAL_VGPR_COUNT.

From-SVN: r278305

2019-11-15  Martin Jambor  <mjambor@suse.cz>

	* ipa-utils.h (ipa_remove_useless_jump_functions): Remove stray
	declaration.

From-SVN: r278303

Restrict the number of SGPRs and VGPRs available to non-kernel functions
to improve compute-unit occupancy with multiple threads.

2019-11-15  Kwok Cheung Yeung  <kcy@codesourcery.com>

	gcc/
	* config/gcn/gcn.c (default_requested_args): New.
	(gcn_parse_amdgpu_hsa_kernel_attribute): Initialize requested args
	set with default_requested_args.
	(gcn_conditional_register_usage): Limit register usage of non-kernel
	functions.  Reassign fixed registers if a non-standard set of args is
	requested.
	* config/gcn/gcn.h (FIXED_REGISTERS): Fix registers according to ABI.

From-SVN: r278301