poly_int: TYPE_VECTOR_SUBPARTS

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

1 files changed, 60 insertions, 17 deletions

diff --git a/gcc/tree.h b/gcc/tree.h
index 418075d..60c4411 100644
--- a/gcc/tree.h
+++ b/gcc/tree.h
@@ -2035,15 +2035,6 @@ extern machine_mode vector_type_mode (const_tree);
    If set in a INTEGER_TYPE, indicates a character type.  */
 #define TYPE_STRING_FLAG(NODE) (TYPE_CHECK (NODE)->type_common.string_flag)
 
-/* For a VECTOR_TYPE, this is the number of sub-parts of the vector.  */
-#define TYPE_VECTOR_SUBPARTS(VECTOR_TYPE) \
-  (HOST_WIDE_INT_1U \
-   << VECTOR_TYPE_CHECK (VECTOR_TYPE)->type_common.precision)
-
-/* Set precision to n when we have 2^n sub-parts of the vector.  */
-#define SET_TYPE_VECTOR_SUBPARTS(VECTOR_TYPE, X) \
-  (VECTOR_TYPE_CHECK (VECTOR_TYPE)->type_common.precision = exact_log2 (X))
-
 /* Nonzero in a VECTOR_TYPE if the frontends should not emit warnings
    about missing conversions to other vector types of the same size.  */
 #define TYPE_VECTOR_OPAQUE(NODE) \
@@ -3677,6 +3668,64 @@ id_equal (const char *str, const_tree id)
   return !strcmp (str, IDENTIFIER_POINTER (id));
 }
 
+/* Return the number of elements in the VECTOR_TYPE given by NODE.  */
+
+inline poly_uint64
+TYPE_VECTOR_SUBPARTS (const_tree node)
+{
+  STATIC_ASSERT (NUM_POLY_INT_COEFFS <= 2);
+  unsigned int precision = VECTOR_TYPE_CHECK (node)->type_common.precision;
+  if (NUM_POLY_INT_COEFFS == 2)
+    {
+      poly_uint64 res = 0;
+      res.coeffs[0] = 1 << (precision & 0xff);
+      if (precision & 0x100)
+	res.coeffs[1] = 1 << (precision & 0xff);
+      return res;
+    }
+  else
+    return 1 << precision;
+}
+
+/* Set the number of elements in VECTOR_TYPE NODE to SUBPARTS, which must
+   satisfy valid_vector_subparts_p.  */
+
+inline void
+SET_TYPE_VECTOR_SUBPARTS (tree node, poly_uint64 subparts)
+{
+  STATIC_ASSERT (NUM_POLY_INT_COEFFS <= 2);
+  unsigned HOST_WIDE_INT coeff0 = subparts.coeffs[0];
+  int index = exact_log2 (coeff0);
+  gcc_assert (index >= 0);
+  if (NUM_POLY_INT_COEFFS == 2)
+    {
+      unsigned HOST_WIDE_INT coeff1 = subparts.coeffs[1];
+      gcc_assert (coeff1 == 0 || coeff1 == coeff0);
+      VECTOR_TYPE_CHECK (node)->type_common.precision
+	= index + (coeff1 != 0 ? 0x100 : 0);
+    }
+  else
+    VECTOR_TYPE_CHECK (node)->type_common.precision = index;
+}
+
+/* Return true if we can construct vector types with the given number
+   of subparts.  */
+
+static inline bool
+valid_vector_subparts_p (poly_uint64 subparts)
+{
+  unsigned HOST_WIDE_INT coeff0 = subparts.coeffs[0];
+  if (!pow2p_hwi (coeff0))
+    return false;
+  if (NUM_POLY_INT_COEFFS == 2)
+    {
+      unsigned HOST_WIDE_INT coeff1 = subparts.coeffs[1];
+      if (coeff1 != 0 && coeff1 != coeff0)
+	return false;
+    }
+  return true;
+}
+
 #define error_mark_node			global_trees[TI_ERROR_MARK]
 
 #define intQI_type_node			global_trees[TI_INTQI_TYPE]
@@ -4121,16 +4170,10 @@ extern tree build_pointer_type (tree);
 extern tree build_reference_type_for_mode (tree, machine_mode, bool);
 extern tree build_reference_type (tree);
 extern tree build_vector_type_for_mode (tree, machine_mode);
-extern tree build_vector_type (tree innertype, int nunits);
-/* Temporary.  */
-inline tree
-build_vector_type (tree innertype, poly_uint64 nunits)
-{
-  return build_vector_type (innertype, (int) nunits.to_constant ());
-}
+extern tree build_vector_type (tree, poly_int64);
 extern tree build_truth_vector_type (poly_uint64, poly_uint64);
 extern tree build_same_sized_truth_vector_type (tree vectype);
-extern tree build_opaque_vector_type (tree innertype, int nunits);
+extern tree build_opaque_vector_type (tree, poly_int64);
 extern tree build_index_type (tree);
 extern tree build_array_type (tree, tree, bool = false);
 extern tree build_nonshared_array_type (tree, tree);