gcc/tree-vrp.h

   1 /* Support routines for Value Range Propagation (VRP).
   2    Copyright (C) 2016-2018 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 3, or (at your option)
   9 any later version.
  10
  11 GCC is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef GCC_TREE_VRP_H
  21 #define GCC_TREE_VRP_H
  22
  23 /* Types of value ranges.  */
  24 enum value_range_kind
  25 {
  26   /* Empty range.  */
  27   VR_UNDEFINED,
  28   /* Range spans the entire domain.  */
  29   VR_VARYING,
  30   /* Range is [MIN, MAX].  */
  31   VR_RANGE,
  32   /* Range is ~[MIN, MAX].  */
  33   VR_ANTI_RANGE,
  34   /* Range is a nice guy.  */
  35   VR_LAST
  36 };
  37
  38 /* Range of values that can be associated with an SSA_NAME after VRP
  39    has executed.  */
  40 class GTY((for_user)) value_range
  41 {
  42  public:
  43   value_range ();
  44   value_range (value_range_kind, tree, tree, bitmap = NULL);
  45   void update (value_range_kind, tree, tree);
  46   bool operator== (const value_range &) const;
  47   bool operator!= (const value_range &) const;
  48   void intersect (const value_range *);
  49   void union_ (const value_range *);
  50
  51   /* Types of value ranges.  */
  52   bool undefined_p () const;
  53   bool varying_p () const;
  54   bool symbolic_p () const;
  55   bool constant_p () const;
  56   void set_undefined ();
  57   void set_varying ();
  58
  59   /* Equivalence bitmap methods.  */
  60   bitmap equiv () const;
  61   void equiv_clear ();
  62   void equiv_add (const_tree, const value_range *, bitmap_obstack * = NULL);
  63
  64   /* Misc methods.  */
  65   tree type () const;
  66   bool null_p () const;
  67   bool may_contain_p (tree) const;
  68   bool singleton_p (tree *result = NULL) const;
  69   void deep_copy (const value_range *);
  70   bool ignore_equivs_equal_p (const value_range &) const;
  71   void set_and_canonicalize (enum value_range_kind, tree, tree, bitmap);
  72   void dump (FILE *) const;
  73   void dump () const;
  74
  75   enum value_range_kind kind () const;
  76   tree min () const;
  77   tree max () const;
  78
  79  private:
  80   void set (value_range_kind, tree, tree, bitmap);
  81   void check ();
  82   bool equal_p (const value_range &, bool ignore_equivs) const;
  83   void intersect_helper (value_range *, const value_range *);
  84   void union_helper (value_range *, const value_range *);
  85
  86   enum value_range_kind m_kind;
  87  public:
  88   /* These should be private, but GTY is a piece of crap.  */
  89   tree m_min;
  90   tree m_max;
  91   /* Set of SSA names whose value ranges are equivalent to this one.
  92      This set is only valid when TYPE is VR_RANGE or VR_ANTI_RANGE.  */
  93   bitmap m_equiv;
  94 };
  95
  96 inline
  97 value_range::value_range ()
  98 {
  99   m_kind = VR_UNDEFINED;
 100   m_min = m_max = NULL;
 101   m_equiv = NULL;
 102 }
 103
 104 /* Return the kind of this range.  */
 105
 106 inline value_range_kind
 107 value_range::kind () const
 108 {
 109   return m_kind;
 110 }
 111
 112 inline bitmap
 113 value_range::equiv () const
 114 {
 115   return m_equiv;
 116 }
 117
 118 /* Return the lower bound.  */
 119
 120 inline tree
 121 value_range::min () const
 122 {
 123   return m_min;
 124 }
 125
 126 /* Return the upper bound.  */
 127
 128 inline tree
 129 value_range::max () const
 130 {
 131   return m_max;
 132 }
 133
 134 /* Return TRUE if range spans the entire possible domain.  */
 135
 136 inline bool
 137 value_range::varying_p () const
 138 {
 139   return m_kind == VR_VARYING;
 140 }
 141
 142 /* Return TRUE if range is undefined (essentially the empty set).  */
 143
 144 inline bool
 145 value_range::undefined_p () const
 146 {
 147   return m_kind == VR_UNDEFINED;
 148 }
 149
 150 /* Return TRUE if range is the constant zero.  */
 151
 152 inline bool
 153 value_range::null_p () const
 154 {
 155   return (m_kind == VR_RANGE
 156           && integer_zerop (m_min)
 157           && integer_zerop (m_max));
 158 }
 159
 160 extern void dump_value_range (FILE *, const value_range *);
 161 extern void extract_range_from_unary_expr (value_range *vr,
 162                                            enum tree_code code,
 163                                            tree type,
 164                                            const value_range *vr0_,
 165                                            tree op0_type);
 166
 167 extern bool vrp_operand_equal_p (const_tree, const_tree);
 168 extern enum value_range_kind intersect_range_with_nonzero_bits
 169   (enum value_range_kind, wide_int *, wide_int *, const wide_int &, signop);
 170
 171 struct assert_info
 172 {
 173   /* Predicate code for the ASSERT_EXPR.  Must be COMPARISON_CLASS_P.  */
 174   enum tree_code comp_code;
 175
 176   /* Name to register the assert for.  */
 177   tree name;
 178
 179   /* Value being compared against.  */
 180   tree val;
 181
 182   /* Expression to compare.  */
 183   tree expr;
 184 };
 185
 186 extern void register_edge_assert_for (tree, edge, enum tree_code,
 187                                       tree, tree, vec<assert_info> &);
 188 extern bool stmt_interesting_for_vrp (gimple *);
 189 extern void set_value_range_to_varying (value_range *);
 190 extern bool range_includes_zero_p (const value_range *);
 191 extern bool infer_value_range (gimple *, tree, tree_code *, tree *);
 192
 193 extern void set_value_range_to_nonnull (value_range *, tree);
 194 extern void set_value_range (value_range *, enum value_range_kind, tree,
 195                              tree, bitmap);
 196 extern bool vrp_bitmap_equal_p (const_bitmap, const_bitmap);
 197 extern tree value_range_constant_singleton (const value_range *);
 198 extern int compare_values (tree, tree);
 199 extern int compare_values_warnv (tree, tree, bool *);
 200 extern bool vrp_val_is_min (const_tree);
 201 extern bool vrp_val_is_max (const_tree);
 202 extern void set_value_range_to_value (value_range *, tree, bitmap);
 203 extern void extract_range_from_binary_expr_1 (value_range *, enum tree_code,
 204                                               tree, const value_range *,
 205                                               const value_range *);
 206 extern tree vrp_val_min (const_tree);
 207 extern tree vrp_val_max (const_tree);
 208 extern void set_value_range_to_null (value_range *, tree);
 209 extern bool range_int_cst_p (const value_range *);
 210 extern int operand_less_p (tree, tree);
 211 extern bool find_case_label_range (gswitch *, tree, tree, size_t *, size_t *);
 212 extern bool find_case_label_index (gswitch *, size_t, tree, size_t *);
 213 extern bool vrp_set_zero_nonzero_bits (const tree, const value_range *,
 214                                        wide_int *, wide_int *);
 215 extern bool overflow_comparison_p (tree_code, tree, tree, bool, tree *);
 216 extern bool range_int_cst_singleton_p (const value_range *);
 217 extern int value_inside_range (tree, tree, tree);
 218 extern tree get_single_symbol (tree, bool *, tree *);
 219 extern void maybe_set_nonzero_bits (edge, tree);
 220 extern value_range_kind determine_value_range (tree, wide_int *, wide_int *);
 221 #endif /* GCC_TREE_VRP_H */