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
  39 /* Range of values that can be associated with an SSA_NAME after VRP
  40    has executed.  */
  41 class GTY((for_user)) value_range_base
  42 {
  43 public:
  44   value_range_base ();
  45   value_range_base (value_range_kind, tree, tree);
  46
  47   enum value_range_kind kind () const;
  48   tree min () const;
  49   tree max () const;
  50
  51   /* Types of value ranges.  */
  52   bool symbolic_p () const;
  53   bool constant_p () const;
  54   bool undefined_p () const;
  55   bool varying_p () const;
  56   void set_varying ();
  57   void set_undefined ();
  58
  59   void union_ (const value_range_base *);
  60
  61   bool ignore_equivs_equal_p (const value_range_base &) const;
  62
  63   /* Misc methods.  */
  64   tree type () const;
  65   bool may_contain_p (tree) const;
  66   void set_and_canonicalize (enum value_range_kind, tree, tree);
  67   bool zero_p () const;
  68   bool singleton_p (tree *result = NULL) const;
  69
  70   void dump (FILE *) const;
  71   void dump () const;
  72
  73 protected:
  74   void set (value_range_kind, tree, tree);
  75   void check ();
  76
  77   enum value_range_kind m_kind;
  78
  79   tree m_min;
  80   tree m_max;
  81
  82   friend void gt_ggc_mx_value_range_base (void *);
  83   friend void gt_pch_p_16value_range_base (void *, void *,
  84                                            gt_pointer_operator, void *);
  85   friend void gt_pch_nx_value_range_base (void *);
  86   friend void gt_ggc_mx (value_range_base &);
  87   friend void gt_ggc_mx (value_range_base *&);
  88   friend void gt_pch_nx (value_range_base &);
  89   friend void gt_pch_nx (value_range_base *, gt_pointer_operator, void *);
  90 };
  91
  92 /* Note value_range cannot currently be used with GC memory, only
  93    value_range_base is fully set up for this.  */
  94 class GTY((user)) value_range : public value_range_base
  95 {
  96  public:
  97   value_range ();
  98   value_range (const value_range_base &);
  99   value_range (value_range_kind, tree, tree, bitmap = NULL);
 100   void update (value_range_kind, tree, tree);
 101   bool operator== (const value_range &) const;
 102   bool operator!= (const value_range &) const;
 103   void intersect (const value_range *);
 104   void union_ (const value_range *);
 105
 106   /* Types of value ranges.  */
 107   void set_undefined ();
 108   void set_varying ();
 109
 110   /* Equivalence bitmap methods.  */
 111   bitmap equiv () const;
 112   void equiv_clear ();
 113   void equiv_add (const_tree, const value_range *, bitmap_obstack * = NULL);
 114
 115   /* Misc methods.  */
 116   void deep_copy (const value_range *);
 117   void set_and_canonicalize (enum value_range_kind, tree, tree, bitmap);
 118   void dump (FILE *) const;
 119   void dump () const;
 120
 121  private:
 122   void set (value_range_kind, tree, tree, bitmap);
 123   void set_equiv (bitmap);
 124   void check ();
 125   bool equal_p (const value_range &, bool ignore_equivs) const;
 126   void intersect_helper (value_range *, const value_range *);
 127   void union_helper (value_range *, const value_range *);
 128
 129   /* Set of SSA names whose value ranges are equivalent to this one.
 130      This set is only valid when TYPE is VR_RANGE or VR_ANTI_RANGE.  */
 131   bitmap m_equiv;
 132 };
 133
 134 inline
 135 value_range_base::value_range_base ()
 136 {
 137   m_kind = VR_UNDEFINED;
 138   m_min = m_max = NULL;
 139 }
 140
 141 inline
 142 value_range::value_range ()
 143   : value_range_base ()
 144 {
 145   m_equiv = NULL;
 146 }
 147
 148 /* Return the kind of this range.  */
 149
 150 inline value_range_kind
 151 value_range_base::kind () const
 152 {
 153   return m_kind;
 154 }
 155
 156 inline bitmap
 157 value_range::equiv () const
 158 {
 159   return m_equiv;
 160 }
 161
 162 /* Return the lower bound.  */
 163
 164 inline tree
 165 value_range_base::min () const
 166 {
 167   return m_min;
 168 }
 169
 170 /* Return the upper bound.  */
 171
 172 inline tree
 173 value_range_base::max () const
 174 {
 175   return m_max;
 176 }
 177
 178 /* Return TRUE if range spans the entire possible domain.  */
 179
 180 inline bool
 181 value_range_base::varying_p () const
 182 {
 183   return m_kind == VR_VARYING;
 184 }
 185
 186 /* Return TRUE if range is undefined (essentially the empty set).  */
 187
 188 inline bool
 189 value_range_base::undefined_p () const
 190 {
 191   return m_kind == VR_UNDEFINED;
 192 }
 193
 194 /* Return TRUE if range is the constant zero.  */
 195
 196 inline bool
 197 value_range_base::zero_p () const
 198 {
 199   return (m_kind == VR_RANGE
 200           && integer_zerop (m_min)
 201           && integer_zerop (m_max));
 202 }
 203
 204 extern void dump_value_range (FILE *, const value_range *);
 205 extern void dump_value_range (FILE *, const value_range_base *);
 206
 207 struct assert_info
 208 {
 209   /* Predicate code for the ASSERT_EXPR.  Must be COMPARISON_CLASS_P.  */
 210   enum tree_code comp_code;
 211
 212   /* Name to register the assert for.  */
 213   tree name;
 214
 215   /* Value being compared against.  */
 216   tree val;
 217
 218   /* Expression to compare.  */
 219   tree expr;
 220 };
 221
 222 extern void register_edge_assert_for (tree, edge, enum tree_code,
 223                                       tree, tree, vec<assert_info> &);
 224 extern bool stmt_interesting_for_vrp (gimple *);
 225 extern bool range_includes_zero_p (const value_range_base *);
 226 extern bool infer_value_range (gimple *, tree, tree_code *, tree *);
 227
 228 extern void set_value_range_to_nonnull (value_range *, tree);
 229 extern void set_value_range_to_null (value_range *, tree);
 230 extern void set_value_range (value_range *, enum value_range_kind, tree,
 231                              tree, bitmap);
 232 extern void set_value_range_to_value (value_range *, tree, bitmap);
 233
 234 extern bool vrp_bitmap_equal_p (const_bitmap, const_bitmap);
 235
 236 extern tree value_range_constant_singleton (const value_range_base *);
 237 extern bool range_int_cst_p (const value_range_base *);
 238 extern bool range_int_cst_singleton_p (const value_range_base *);
 239
 240 extern int compare_values (tree, tree);
 241 extern int compare_values_warnv (tree, tree, bool *);
 242 extern int operand_less_p (tree, tree);
 243 extern bool vrp_val_is_min (const_tree);
 244 extern bool vrp_val_is_max (const_tree);
 245 extern int value_inside_range (tree, tree, tree);
 246
 247 extern tree vrp_val_min (const_tree);
 248 extern tree vrp_val_max (const_tree);
 249
 250 extern void extract_range_from_unary_expr (value_range *vr,
 251                                            enum tree_code code,
 252                                            tree type,
 253                                            const value_range *vr0_,
 254                                            tree op0_type);
 255 extern void extract_range_from_binary_expr_1 (value_range *, enum tree_code,
 256                                               tree, const value_range *,
 257                                               const value_range *);
 258
 259 extern bool vrp_operand_equal_p (const_tree, const_tree);
 260 extern enum value_range_kind intersect_range_with_nonzero_bits
 261   (enum value_range_kind, wide_int *, wide_int *, const wide_int &, signop);
 262 extern bool vrp_set_zero_nonzero_bits (const tree, const value_range_base *,
 263                                        wide_int *, wide_int *);
 264
 265 extern bool find_case_label_range (gswitch *, tree, tree, size_t *, size_t *);
 266 extern bool find_case_label_index (gswitch *, size_t, tree, size_t *);
 267 extern bool overflow_comparison_p (tree_code, tree, tree, bool, tree *);
 268 extern tree get_single_symbol (tree, bool *, tree *);
 269 extern void maybe_set_nonzero_bits (edge, tree);
 270 extern value_range_kind determine_value_range (tree, wide_int *, wide_int *);
 271
 272 #endif /* GCC_TREE_VRP_H */