poly_int: tree constants

This patch adds a tree representation for poly_ints.  Unlike the
rtx version, the coefficients are INTEGER_CSTs rather than plain
integers, so that we can easily access them as poly_widest_ints
and poly_offset_ints.

The patch also adjusts some places that previously
relied on "constant" meaning "INTEGER_CST".  It also makes
sure that the TYPE_SIZE agrees with the TYPE_SIZE_UNIT for
vector booleans, given the existing:

	/* Several boolean vector elements may fit in a single unit.  */
	if (VECTOR_BOOLEAN_TYPE_P (type)
	    && type->type_common.mode != BLKmode)
	  TYPE_SIZE_UNIT (type)
	    = size_int (GET_MODE_SIZE (type->type_common.mode));
	else
	  TYPE_SIZE_UNIT (type) = int_const_binop (MULT_EXPR,
						   TYPE_SIZE_UNIT (innertype),
						   size_int (nunits));

2017-12-20  Richard Sandiford  <richard.sandiford@linaro.org>
	    Alan Hayward  <alan.hayward@arm.com>
	    David Sherwood  <david.sherwood@arm.com>

gcc/
	* doc/generic.texi (POLY_INT_CST): Document.
	* tree.def (POLY_INT_CST): New tree code.
	* treestruct.def (TS_POLY_INT_CST): New tree layout.
	* tree-core.h (tree_poly_int_cst): New struct.
	(tree_node): Add a poly_int_cst field.
	* tree.h (POLY_INT_CST_P, POLY_INT_CST_COEFF): New macros.
	(wide_int_to_tree, force_fit_type): Take a poly_wide_int_ref
	instead of a wide_int_ref.
	(build_int_cst, build_int_cst_type): Take a poly_int64 instead
	of a HOST_WIDE_INT.
	(build_int_cstu, build_array_type_nelts): Take a poly_uint64
	instead of an unsigned HOST_WIDE_INT.
	(build_poly_int_cst, tree_fits_poly_int64_p, tree_fits_poly_uint64_p)
	(ptrdiff_tree_p): Declare.
	(tree_to_poly_int64, tree_to_poly_uint64): Likewise.  Provide
	extern inline implementations if the target doesn't use POLY_INT_CST.
	(poly_int_tree_p): New function.
	(wi::unextended_tree): New class.
	(wi::int_traits <unextended_tree>): New override.
	(wi::extended_tree): Add a default constructor.
	(wi::extended_tree::get_tree): New function.
	(wi::widest_extended_tree, wi::offset_extended_tree): New typedefs.
	(wi::tree_to_widest_ref, wi::tree_to_offset_ref): Use them.
	(wi::tree_to_poly_widest_ref, wi::tree_to_poly_offset_ref)
	(wi::tree_to_poly_wide_ref): New typedefs.
	(wi::ints_for): Provide overloads for extended_tree and
	unextended_tree.
	(poly_int_cst_value, wi::to_poly_widest, wi::to_poly_offset)
	(wi::to_wide): New functions.
	(wi::fits_to_boolean_p, wi::fits_to_tree_p): Handle poly_ints.
	* tree.c (poly_int_cst_hasher): New struct.
	(poly_int_cst_hash_table): New variable.
	(tree_node_structure_for_code, tree_code_size, simple_cst_equal)
	(valid_constant_size_p, add_expr, drop_tree_overflow): Handle
	POLY_INT_CST.
	(initialize_tree_contains_struct): Handle TS_POLY_INT_CST.
	(init_ttree): Initialize poly_int_cst_hash_table.
	(build_int_cst, build_int_cst_type, build_invariant_address): Take
	a poly_int64 instead of a HOST_WIDE_INT.
	(build_int_cstu, build_array_type_nelts): Take a poly_uint64
	instead of an unsigned HOST_WIDE_INT.
	(wide_int_to_tree): Rename to...
	(wide_int_to_tree_1): ...this.
	(build_new_poly_int_cst, build_poly_int_cst): New functions.
	(force_fit_type): Take a poly_wide_int_ref instead of a wide_int_ref.
	(wide_int_to_tree): New function that takes a poly_wide_int_ref.
	(ptrdiff_tree_p, tree_to_poly_int64, tree_to_poly_uint64)
	(tree_fits_poly_int64_p, tree_fits_poly_uint64_p): New functions.
	* lto-streamer-out.c (DFS::DFS_write_tree_body, hash_tree): Handle
	TS_POLY_INT_CST.
	* tree-streamer-in.c (lto_input_ts_poly_tree_pointers): Likewise.
	(streamer_read_tree_body): Likewise.
	* tree-streamer-out.c (write_ts_poly_tree_pointers): Likewise.
	(streamer_write_tree_body): Likewise.
	* tree-streamer.c (streamer_check_handled_ts_structures): Likewise.
	* asan.c (asan_protect_global): Require the size to be an INTEGER_CST.
	* cfgexpand.c (expand_debug_expr): Handle POLY_INT_CST.
	* expr.c (expand_expr_real_1, const_vector_from_tree): Likewise.
	* gimple-expr.h (is_gimple_constant): Likewise.
	* gimplify.c (maybe_with_size_expr): Likewise.
	* print-tree.c (print_node): Likewise.
	* tree-data-ref.c (data_ref_compare_tree): Likewise.
	* tree-pretty-print.c (dump_generic_node): Likewise.
	* tree-ssa-address.c (addr_for_mem_ref): Likewise.
	* tree-vect-data-refs.c (dr_group_sort_cmp): Likewise.
	* tree-vrp.c (compare_values_warnv): Likewise.
	* tree-ssa-loop-ivopts.c (determine_base_object, constant_multiple_of)
	(get_loop_invariant_expr, add_candidate_1, get_computation_aff_1)
	(force_expr_to_var_cost): Likewise.
	* tree-ssa-loop.c (for_each_index): Likewise.
	* fold-const.h (build_invariant_address, size_int_kind): Take a
	poly_int64 instead of a HOST_WIDE_INT.
	* fold-const.c (fold_negate_expr_1, const_binop, const_unop)
	(fold_convert_const, multiple_of_p, fold_negate_const): Handle
	POLY_INT_CST.
	(size_binop_loc): Likewise.  Allow int_const_binop_1 to fail.
	(int_const_binop_2): New function, split out from...
	(int_const_binop_1): ...here.  Handle POLY_INT_CST.
	(size_int_kind): Take a poly_int64 instead of a HOST_WIDE_INT.
	* expmed.c (make_tree): Handle CONST_POLY_INT_P.
	* gimple-ssa-strength-reduction.c (slsr_process_add)
	(slsr_process_mul): Check for INTEGER_CSTs before using them
	as candidates.
	* stor-layout.c (bits_from_bytes): New function.
	(bit_from_pos): Use it.
	(layout_type): Likewise.  For vectors, multiply the TYPE_SIZE_UNIT
	by BITS_PER_UNIT to get the TYPE_SIZE.
	* tree-cfg.c (verify_expr, verify_types_in_gimple_reference): Allow
	MEM_REF and TARGET_MEM_REF offsets to be a POLY_INT_CST.

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

From-SVN: r255863

1 files changed, 225 insertions, 17 deletions

diff --git a/gcc/tree.h b/gcc/tree.h
index ae40e903e4c..a7b8c2f400c 100644
--- a/gcc/tree.h
+++ b/gcc/tree.h
@@ -991,6 +991,15 @@ extern void omp_clause_range_check_failed (const_tree, const char *, int,
 #define TREE_INT_CST_LOW(NODE) \
   ((unsigned HOST_WIDE_INT) TREE_INT_CST_ELT (NODE, 0))
 
+/* Return true if NODE is a POLY_INT_CST.  This is only ever true on
+   targets with variable-sized modes.  */
+#define POLY_INT_CST_P(NODE) \
+  (NUM_POLY_INT_COEFFS > 1 && TREE_CODE (NODE) == POLY_INT_CST)
+
+/* In a POLY_INT_CST node.  */
+#define POLY_INT_CST_COEFF(NODE, I) \
+  (POLY_INT_CST_CHECK (NODE)->poly_int_cst.coeffs[I])
+
 #define TREE_REAL_CST_PTR(NODE) (REAL_CST_CHECK (NODE)->real_cst.real_cst_ptr)
 #define TREE_REAL_CST(NODE) (*TREE_REAL_CST_PTR (NODE))
 
@@ -4040,15 +4049,15 @@ build5_loc (location_t loc, enum tree_code code, tree type, tree arg0,
 
 extern tree double_int_to_tree (tree, double_int);
 
-extern tree wide_int_to_tree (tree type, const wide_int_ref &cst);
-extern tree force_fit_type (tree, const wide_int_ref &, int, bool);
+extern tree wide_int_to_tree (tree type, const poly_wide_int_ref &cst);
+extern tree force_fit_type (tree, const poly_wide_int_ref &, int, bool);
 
 /* Create an INT_CST node with a CST value zero extended.  */
 
 /* static inline */
-extern tree build_int_cst (tree, HOST_WIDE_INT);
-extern tree build_int_cstu (tree type, unsigned HOST_WIDE_INT cst);
-extern tree build_int_cst_type (tree, HOST_WIDE_INT);
+extern tree build_int_cst (tree, poly_int64);
+extern tree build_int_cstu (tree type, poly_uint64);
+extern tree build_int_cst_type (tree, poly_int64);
 extern tree make_vector (unsigned, unsigned CXX_MEM_STAT_INFO);
 extern tree build_vector_from_ctor (tree, vec<constructor_elt, va_gc> *);
 extern tree build_vector_from_val (tree, tree);
@@ -4068,6 +4077,7 @@ extern tree build_minus_one_cst (tree);
 extern tree build_all_ones_cst (tree);
 extern tree build_zero_cst (tree);
 extern tree build_string (int, const char *);
+extern tree build_poly_int_cst (tree, const poly_wide_int_ref &);
 extern tree build_tree_list (tree, tree CXX_MEM_STAT_INFO);
 extern tree build_tree_list_vec (const vec<tree, va_gc> * CXX_MEM_STAT_INFO);
 extern tree build_decl (location_t, enum tree_code,
@@ -4117,7 +4127,7 @@ extern tree build_opaque_vector_type (tree innertype, int nunits);
 extern tree build_index_type (tree);
 extern tree build_array_type (tree, tree, bool = false);
 extern tree build_nonshared_array_type (tree, tree);
-extern tree build_array_type_nelts (tree, unsigned HOST_WIDE_INT);
+extern tree build_array_type_nelts (tree, poly_uint64);
 extern tree build_function_type (tree, tree);
 extern tree build_function_type_list (tree, ...);
 extern tree build_varargs_function_type_list (tree, ...);
@@ -4141,12 +4151,14 @@ extern tree chain_index (int, tree);
 
 extern int tree_int_cst_equal (const_tree, const_tree);
 
-extern bool tree_fits_shwi_p (const_tree)
-  ATTRIBUTE_PURE;
-extern bool tree_fits_uhwi_p (const_tree)
-  ATTRIBUTE_PURE;
+extern bool tree_fits_shwi_p (const_tree) ATTRIBUTE_PURE;
+extern bool tree_fits_poly_int64_p (const_tree) ATTRIBUTE_PURE;
+extern bool tree_fits_uhwi_p (const_tree) ATTRIBUTE_PURE;
+extern bool tree_fits_poly_uint64_p (const_tree) ATTRIBUTE_PURE;
 extern HOST_WIDE_INT tree_to_shwi (const_tree);
+extern poly_int64 tree_to_poly_int64 (const_tree);
 extern unsigned HOST_WIDE_INT tree_to_uhwi (const_tree);
+extern poly_uint64 tree_to_poly_uint64 (const_tree);
 #if !defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 4003)
 extern inline __attribute__ ((__gnu_inline__)) HOST_WIDE_INT
 tree_to_shwi (const_tree t)
@@ -4161,6 +4173,21 @@ tree_to_uhwi (const_tree t)
   gcc_assert (tree_fits_uhwi_p (t));
   return TREE_INT_CST_LOW (t);
 }
+#if NUM_POLY_INT_COEFFS == 1
+extern inline __attribute__ ((__gnu_inline__)) poly_int64
+tree_to_poly_int64 (const_tree t)
+{
+  gcc_assert (tree_fits_poly_int64_p (t));
+  return TREE_INT_CST_LOW (t);
+}
+
+extern inline __attribute__ ((__gnu_inline__)) poly_uint64
+tree_to_poly_uint64 (const_tree t)
+{
+  gcc_assert (tree_fits_poly_uint64_p (t));
+  return TREE_INT_CST_LOW (t);
+}
+#endif
 #endif
 extern int tree_int_cst_sgn (const_tree);
 extern int tree_int_cst_sign_bit (const_tree);
@@ -4169,6 +4196,33 @@ extern tree strip_array_types (tree);
 extern tree excess_precision_type (tree);
 extern bool valid_constant_size_p (const_tree);
 
+/* Return true if T holds a value that can be represented as a poly_int64
+   without loss of precision.  Store the value in *VALUE if so.  */
+
+inline bool
+poly_int_tree_p (const_tree t, poly_int64_pod *value)
+{
+  if (tree_fits_poly_int64_p (t))
+    {
+      *value = tree_to_poly_int64 (t);
+      return true;
+    }
+  return false;
+}
+
+/* Return true if T holds a value that can be represented as a poly_uint64
+   without loss of precision.  Store the value in *VALUE if so.  */
+
+inline bool
+poly_int_tree_p (const_tree t, poly_uint64_pod *value)
+{
+  if (tree_fits_poly_uint64_p (t))
+    {
+      *value = tree_to_poly_uint64 (t);
+      return true;
+    }
+  return false;
+}
 
 /* From expmed.c.  Since rtl.h is included after tree.h, we can't
    put the prototype here.  Rtl.h does declare the prototype if
@@ -4722,8 +4776,17 @@ complete_or_array_type_p (const_tree type)
 	     && COMPLETE_TYPE_P (TREE_TYPE (type)));
 }
 
+/* Return true if the value of T could be represented as a poly_widest_int.  */
+
+inline bool
+poly_int_tree_p (const_tree t)
+{
+  return (TREE_CODE (t) == INTEGER_CST || POLY_INT_CST_P (t));
+}
+
 extern tree strip_float_extensions (tree);
 extern int really_constant_p (const_tree);
+extern bool ptrdiff_tree_p (const_tree, poly_int64_pod *);
 extern bool decl_address_invariant_p (const_tree);
 extern bool decl_address_ip_invariant_p (const_tree);
 extern bool int_fits_type_p (const_tree, const_tree);
@@ -5159,6 +5222,29 @@ extern bool anon_aggrname_p (const_tree);
 /* The tree and const_tree overload templates.   */
 namespace wi
 {
+  class unextended_tree
+  {
+  private:
+    const_tree m_t;
+
+  public:
+    unextended_tree () {}
+    unextended_tree (const_tree t) : m_t (t) {}
+
+    unsigned int get_precision () const;
+    const HOST_WIDE_INT *get_val () const;
+    unsigned int get_len () const;
+    const_tree get_tree () const { return m_t; }
+  };
+
+  template <>
+  struct int_traits <unextended_tree>
+  {
+    static const enum precision_type precision_type = VAR_PRECISION;
+    static const bool host_dependent_precision = false;
+    static const bool is_sign_extended = false;
+  };
+
   template <int N>
   class extended_tree
   {
@@ -5166,11 +5252,13 @@ namespace wi
     const_tree m_t;
 
   public:
+    extended_tree () {}
     extended_tree (const_tree);
 
     unsigned int get_precision () const;
     const HOST_WIDE_INT *get_val () const;
     unsigned int get_len () const;
+    const_tree get_tree () const { return m_t; }
   };
 
   template <int N>
@@ -5182,10 +5270,11 @@ namespace wi
     static const unsigned int precision = N;
   };
 
-  typedef const generic_wide_int <extended_tree <WIDE_INT_MAX_PRECISION> >
-    tree_to_widest_ref;
-  typedef const generic_wide_int <extended_tree <ADDR_MAX_PRECISION> >
-    tree_to_offset_ref;
+  typedef extended_tree <WIDE_INT_MAX_PRECISION> widest_extended_tree;
+  typedef extended_tree <ADDR_MAX_PRECISION> offset_extended_tree;
+
+  typedef const generic_wide_int <widest_extended_tree> tree_to_widest_ref;
+  typedef const generic_wide_int <offset_extended_tree> tree_to_offset_ref;
   typedef const generic_wide_int<wide_int_ref_storage<false, false> >
     tree_to_wide_ref;
 
@@ -5193,6 +5282,34 @@ namespace wi
   tree_to_offset_ref to_offset (const_tree);
   tree_to_wide_ref to_wide (const_tree);
   wide_int to_wide (const_tree, unsigned int);
+
+  typedef const poly_int <NUM_POLY_INT_COEFFS,
+			  generic_wide_int <widest_extended_tree> >
+    tree_to_poly_widest_ref;
+  typedef const poly_int <NUM_POLY_INT_COEFFS,
+			  generic_wide_int <offset_extended_tree> >
+    tree_to_poly_offset_ref;
+  typedef const poly_int <NUM_POLY_INT_COEFFS,
+			  generic_wide_int <unextended_tree> >
+    tree_to_poly_wide_ref;
+
+  tree_to_poly_widest_ref to_poly_widest (const_tree);
+  tree_to_poly_offset_ref to_poly_offset (const_tree);
+  tree_to_poly_wide_ref to_poly_wide (const_tree);
+
+  template <int N>
+  struct ints_for <generic_wide_int <extended_tree <N> >, CONST_PRECISION>
+  {
+    typedef generic_wide_int <extended_tree <N> > extended;
+    static extended zero (const extended &);
+  };
+
+  template <>
+  struct ints_for <generic_wide_int <unextended_tree>, VAR_PRECISION>
+  {
+    typedef generic_wide_int <unextended_tree> unextended;
+    static unextended zero (const unextended &);
+  };
 }
 
 /* Refer to INTEGER_CST T as though it were a widest_int.
@@ -5337,6 +5454,95 @@ wi::extended_tree <N>::get_len () const
     gcc_unreachable ();
 }
 
+inline unsigned int
+wi::unextended_tree::get_precision () const
+{
+  return TYPE_PRECISION (TREE_TYPE (m_t));
+}
+
+inline const HOST_WIDE_INT *
+wi::unextended_tree::get_val () const
+{
+  return &TREE_INT_CST_ELT (m_t, 0);
+}
+
+inline unsigned int
+wi::unextended_tree::get_len () const
+{
+  return TREE_INT_CST_NUNITS (m_t);
+}
+
+/* Return the value of a POLY_INT_CST in its native precision.  */
+
+inline wi::tree_to_poly_wide_ref
+poly_int_cst_value (const_tree x)
+{
+  poly_int <NUM_POLY_INT_COEFFS, generic_wide_int <wi::unextended_tree> > res;
+  for (unsigned int i = 0; i < NUM_POLY_INT_COEFFS; ++i)
+    res.coeffs[i] = POLY_INT_CST_COEFF (x, i);
+  return res;
+}
+
+/* Access INTEGER_CST or POLY_INT_CST tree T as if it were a
+   poly_widest_int.  See wi::to_widest for more details.  */
+
+inline wi::tree_to_poly_widest_ref
+wi::to_poly_widest (const_tree t)
+{
+  if (POLY_INT_CST_P (t))
+    {
+      poly_int <NUM_POLY_INT_COEFFS,
+		generic_wide_int <widest_extended_tree> > res;
+      for (unsigned int i = 0; i < NUM_POLY_INT_COEFFS; ++i)
+	res.coeffs[i] = POLY_INT_CST_COEFF (t, i);
+      return res;
+    }
+  return t;
+}
+
+/* Access INTEGER_CST or POLY_INT_CST tree T as if it were a
+   poly_offset_int.  See wi::to_offset for more details.  */
+
+inline wi::tree_to_poly_offset_ref
+wi::to_poly_offset (const_tree t)
+{
+  if (POLY_INT_CST_P (t))
+    {
+      poly_int <NUM_POLY_INT_COEFFS,
+		generic_wide_int <offset_extended_tree> > res;
+      for (unsigned int i = 0; i < NUM_POLY_INT_COEFFS; ++i)
+	res.coeffs[i] = POLY_INT_CST_COEFF (t, i);
+      return res;
+    }
+  return t;
+}
+
+/* Access INTEGER_CST or POLY_INT_CST tree T as if it were a
+   poly_wide_int.  See wi::to_wide for more details.  */
+
+inline wi::tree_to_poly_wide_ref
+wi::to_poly_wide (const_tree t)
+{
+  if (POLY_INT_CST_P (t))
+    return poly_int_cst_value (t);
+  return t;
+}
+
+template <int N>
+inline generic_wide_int <wi::extended_tree <N> >
+wi::ints_for <generic_wide_int <wi::extended_tree <N> >,
+	      wi::CONST_PRECISION>::zero (const extended &x)
+{
+  return build_zero_cst (TREE_TYPE (x.get_tree ()));
+}
+
+inline generic_wide_int <wi::unextended_tree>
+wi::ints_for <generic_wide_int <wi::unextended_tree>,
+	      wi::VAR_PRECISION>::zero (const unextended &x)
+{
+  return build_zero_cst (TREE_TYPE (x.get_tree ()));
+}
+
 namespace wi
 {
   template <typename T>
@@ -5354,7 +5560,9 @@ template <typename T>
 bool
 wi::fits_to_boolean_p (const T &x, const_tree type)
 {
-  return eq_p (x, 0) || eq_p (x, TYPE_UNSIGNED (type) ? 1 : -1);
+  typedef typename poly_int_traits<T>::int_type int_type;
+  return (known_eq (x, int_type (0))
+	  || known_eq (x, int_type (TYPE_UNSIGNED (type) ? 1 : -1)));
 }
 
 template <typename T>
@@ -5367,9 +5575,9 @@ wi::fits_to_tree_p (const T &x, const_tree type)
     return fits_to_boolean_p (x, type);
 
   if (TYPE_UNSIGNED (type))
-    return eq_p (x, zext (x, TYPE_PRECISION (type)));
+    return known_eq (x, zext (x, TYPE_PRECISION (type)));
   else
-    return eq_p (x, sext (x, TYPE_PRECISION (type)));
+    return known_eq (x, sext (x, TYPE_PRECISION (type)));
 }
 
 /* Produce the smallest number that is represented in TYPE.  The precision