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   void set (value_range_kind, tree, tree);
  48   void set (tree);
  49   void set_nonnull (tree);
  50   void set_null (tree);
  51
  52   enum value_range_kind kind () const;
  53   tree min () const;
  54   tree max () const;
  55
  56   /* Types of value ranges.  */
  57   bool symbolic_p () const;
  58   bool constant_p () const;
  59   bool undefined_p () const;
  60   bool varying_p () const;
  61   void set_varying ();
  62   void set_undefined ();
  63
  64   void union_ (const value_range_base *);
  65
  66   bool ignore_equivs_equal_p (const value_range_base &) const;
  67
  68   /* Misc methods.  */
  69   tree type () const;
  70   bool may_contain_p (tree) const;
  71   void set_and_canonicalize (enum value_range_kind, tree, tree);
  72   bool zero_p () const;
  73   bool singleton_p (tree *result = NULL) const;
  74   void dump (FILE *) const;
  75
  76 protected:
  77   void check ();
  78   static value_range_base union_helper (const value_range_base *,
  79                                         const value_range_base *);
  80
  81   enum value_range_kind m_kind;
  82
  83   tree m_min;
  84   tree m_max;
  85
  86   friend void gt_ggc_mx_value_range_base (void *);
  87   friend void gt_pch_p_16value_range_base (void *, void *,
  88                                            gt_pointer_operator, void *);
  89   friend void gt_pch_nx_value_range_base (void *);
  90   friend void gt_ggc_mx (value_range_base &);
  91   friend void gt_ggc_mx (value_range_base *&);
  92   friend void gt_pch_nx (value_range_base &);
  93   friend void gt_pch_nx (value_range_base *, gt_pointer_operator, void *);
  94 };
  95
  96 /* Note value_range cannot currently be used with GC memory, only
  97    value_range_base is fully set up for this.  */
  98 class GTY((user)) value_range : public value_range_base
  99 {
 100  public:
 101   value_range ();
 102   value_range (const value_range_base &);
 103   /* Deep-copies equiv bitmap argument.  */
 104   value_range (value_range_kind, tree, tree, bitmap = NULL);
 105
 106   /* Shallow-copies equiv bitmap.  */
 107   value_range (const value_range &) /* = delete */;
 108   /* Shallow-copies equiv bitmap.  */
 109   value_range& operator=(const value_range&) /* = delete */;
 110
 111   /* Move equiv bitmap from source range.  */
 112   void move (value_range *);
 113
 114   /* Leaves equiv bitmap alone.  */
 115   void update (value_range_kind, tree, tree);
 116   /* Deep-copies equiv bitmap argument.  */
 117   void set (value_range_kind, tree, tree, bitmap = NULL);
 118   void set (tree);
 119   void set_nonnull (tree);
 120   void set_null (tree);
 121
 122   bool operator== (const value_range &) const;
 123   bool operator!= (const value_range &) const;
 124   void intersect (const value_range *);
 125   void union_ (const value_range *);
 126
 127   /* Types of value ranges.  */
 128   void set_undefined ();
 129   void set_varying ();
 130
 131   /* Equivalence bitmap methods.  */
 132   bitmap equiv () const;
 133   void equiv_clear ();
 134   void equiv_add (const_tree, const value_range *, bitmap_obstack * = NULL);
 135
 136   /* Misc methods.  */
 137   void deep_copy (const value_range *);
 138   void set_and_canonicalize (enum value_range_kind, tree, tree, bitmap = NULL);
 139   void dump (FILE *) const;
 140
 141  private:
 142   /* Deep-copies bitmap argument.  */
 143   void set_equiv (bitmap);
 144   void check ();
 145   bool equal_p (const value_range &, bool ignore_equivs) const;
 146   void intersect_helper (value_range *, const value_range *);
 147
 148   /* Set of SSA names whose value ranges are equivalent to this one.
 149      This set is only valid when TYPE is VR_RANGE or VR_ANTI_RANGE.  */
 150   bitmap m_equiv;
 151 };
 152
 153 inline
 154 value_range_base::value_range_base ()
 155 {
 156   m_kind = VR_UNDEFINED;
 157   m_min = m_max = NULL;
 158 }
 159
 160 inline
 161 value_range::value_range ()
 162   : value_range_base ()
 163 {
 164   m_equiv = NULL;
 165 }
 166
 167 /* Return the kind of this range.  */
 168
 169 inline value_range_kind
 170 value_range_base::kind () const
 171 {
 172   return m_kind;
 173 }
 174
 175 inline bitmap
 176 value_range::equiv () const
 177 {
 178   return m_equiv;
 179 }
 180
 181 /* Return the lower bound.  */
 182
 183 inline tree
 184 value_range_base::min () const
 185 {
 186   return m_min;
 187 }
 188
 189 /* Return the upper bound.  */
 190
 191 inline tree
 192 value_range_base::max () const
 193 {
 194   return m_max;
 195 }
 196
 197 /* Return TRUE if range spans the entire possible domain.  */
 198
 199 inline bool
 200 value_range_base::varying_p () const
 201 {
 202   return m_kind == VR_VARYING;
 203 }
 204
 205 /* Return TRUE if range is undefined (essentially the empty set).  */
 206
 207 inline bool
 208 value_range_base::undefined_p () const
 209 {
 210   return m_kind == VR_UNDEFINED;
 211 }
 212
 213 /* Return TRUE if range is the constant zero.  */
 214
 215 inline bool
 216 value_range_base::zero_p () const
 217 {
 218   return (m_kind == VR_RANGE
 219           && integer_zerop (m_min)
 220           && integer_zerop (m_max));
 221 }
 222
 223 extern void dump_value_range (FILE *, const value_range *);
 224 extern void dump_value_range (FILE *, const value_range_base *);
 225
 226 struct assert_info
 227 {
 228   /* Predicate code for the ASSERT_EXPR.  Must be COMPARISON_CLASS_P.  */
 229   enum tree_code comp_code;
 230
 231   /* Name to register the assert for.  */
 232   tree name;
 233
 234   /* Value being compared against.  */
 235   tree val;
 236
 237   /* Expression to compare.  */
 238   tree expr;
 239 };
 240
 241 extern void register_edge_assert_for (tree, edge, enum tree_code,
 242                                       tree, tree, vec<assert_info> &);
 243 extern bool stmt_interesting_for_vrp (gimple *);
 244 extern bool range_includes_zero_p (const value_range_base *);
 245 extern bool infer_value_range (gimple *, tree, tree_code *, tree *);
 246
 247 extern bool vrp_bitmap_equal_p (const_bitmap, const_bitmap);
 248
 249 extern tree value_range_constant_singleton (const value_range_base *);
 250 extern bool range_int_cst_p (const value_range_base *);
 251 extern bool range_int_cst_singleton_p (const value_range_base *);
 252
 253 extern int compare_values (tree, tree);
 254 extern int compare_values_warnv (tree, tree, bool *);
 255 extern int operand_less_p (tree, tree);
 256 extern bool vrp_val_is_min (const_tree);
 257 extern bool vrp_val_is_max (const_tree);
 258 extern int value_inside_range (tree, tree, tree);
 259
 260 extern tree vrp_val_min (const_tree);
 261 extern tree vrp_val_max (const_tree);
 262
 263 extern void extract_range_from_unary_expr (value_range_base *vr,
 264                                            enum tree_code code,
 265                                            tree type,
 266                                            const value_range_base *vr0_,
 267                                            tree op0_type);
 268 extern void extract_range_from_binary_expr (value_range_base *,
 269                                             enum tree_code,
 270                                             tree, const value_range_base *,
 271                                             const value_range_base *);
 272
 273 extern bool vrp_operand_equal_p (const_tree, const_tree);
 274 extern enum value_range_kind intersect_range_with_nonzero_bits
 275   (enum value_range_kind, wide_int *, wide_int *, const wide_int &, signop);
 276 extern bool vrp_set_zero_nonzero_bits (const tree, const value_range_base *,
 277                                        wide_int *, wide_int *);
 278
 279 extern bool find_case_label_range (gswitch *, tree, tree, size_t *, size_t *);
 280 extern bool find_case_label_index (gswitch *, size_t, tree, size_t *);
 281 extern bool overflow_comparison_p (tree_code, tree, tree, bool, tree *);
 282 extern tree get_single_symbol (tree, bool *, tree *);
 283 extern void maybe_set_nonzero_bits (edge, tree);
 284 extern value_range_kind determine_value_range (tree, wide_int *, wide_int *);
 285
 286 #endif /* GCC_TREE_VRP_H */