gcc/tree-vrp.h

   1 /* Support routines for Value Range Propagation (VRP).
   2    Copyright (C) 2016-2019 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_nonzero (tree);
  50   void set_zero (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 (tree type);
  62   void set_undefined ();
  63
  64   void union_ (const value_range_base *);
  65   void intersect (const value_range_base *);
  66
  67   bool operator== (const value_range_base &) const /* = delete */;
  68   bool operator!= (const value_range_base &) const /* = delete */;
  69   bool equal_p (const value_range_base &) const;
  70
  71   /* Misc methods.  */
  72   tree type () const;
  73   bool may_contain_p (tree) const;
  74   bool zero_p () const;
  75   bool nonzero_p () const;
  76   bool singleton_p (tree *result = NULL) const;
  77   void dump (FILE *) const;
  78   void dump () const;
  79
  80   static bool supports_type_p (tree);
  81   value_range_base normalize_symbolics () const;
  82
  83 protected:
  84   void check ();
  85   static value_range_base union_helper (const value_range_base *,
  86                                         const value_range_base *);
  87   static value_range_base intersect_helper (const value_range_base *,
  88                                             const value_range_base *);
  89
  90   enum value_range_kind m_kind;
  91
  92   tree m_min;
  93   tree m_max;
  94
  95   friend void gt_ggc_mx_value_range_base (void *);
  96   friend void gt_pch_p_16value_range_base (void *, void *,
  97                                            gt_pointer_operator, void *);
  98   friend void gt_pch_nx_value_range_base (void *);
  99   friend void gt_ggc_mx (value_range_base &);
 100   friend void gt_ggc_mx (value_range_base *&);
 101   friend void gt_pch_nx (value_range_base &);
 102   friend void gt_pch_nx (value_range_base *, gt_pointer_operator, void *);
 103
 104 private:
 105   int value_inside_range (tree) const;
 106 };
 107
 108 /* Note value_range cannot currently be used with GC memory, only
 109    value_range_base is fully set up for this.  */
 110 class GTY((user)) value_range : public value_range_base
 111 {
 112  public:
 113   value_range ();
 114   value_range (const value_range_base &);
 115   /* Deep-copies equiv bitmap argument.  */
 116   value_range (value_range_kind, tree, tree, bitmap = NULL);
 117
 118   /* Shallow-copies equiv bitmap.  */
 119   value_range (const value_range &) /* = delete */;
 120   /* Shallow-copies equiv bitmap.  */
 121   value_range& operator=(const value_range&) /* = delete */;
 122
 123   /* Move equiv bitmap from source range.  */
 124   void move (value_range *);
 125
 126   /* Leaves equiv bitmap alone.  */
 127   void update (value_range_kind, tree, tree);
 128   /* Deep-copies equiv bitmap argument.  */
 129   void set (value_range_kind, tree, tree, bitmap = NULL);
 130   void set (tree);
 131
 132   bool operator== (const value_range &) const /* = delete */;
 133   bool operator!= (const value_range &) const /* = delete */;
 134   void intersect (const value_range *);
 135   void union_ (const value_range *);
 136   bool equal_p (const value_range &, bool ignore_equivs) const;
 137
 138   /* Types of value ranges.  */
 139   void set_undefined ();
 140   void set_varying (tree);
 141
 142   /* Equivalence bitmap methods.  */
 143   bitmap equiv () const;
 144   void equiv_clear ();
 145   void equiv_add (const_tree, const value_range *, bitmap_obstack * = NULL);
 146
 147   /* Misc methods.  */
 148   void deep_copy (const value_range *);
 149   void dump (FILE *) const;
 150   void dump () const;
 151
 152  private:
 153   /* Deep-copies bitmap argument.  */
 154   void set_equiv (bitmap);
 155   void check ();
 156
 157   /* Set of SSA names whose value ranges are equivalent to this one.
 158      This set is only valid when TYPE is VR_RANGE or VR_ANTI_RANGE.  */
 159   bitmap m_equiv;
 160 };
 161
 162 inline
 163 value_range_base::value_range_base ()
 164 {
 165   m_kind = VR_UNDEFINED;
 166   m_min = m_max = NULL;
 167 }
 168
 169 inline
 170 value_range::value_range ()
 171   : value_range_base ()
 172 {
 173   m_equiv = NULL;
 174 }
 175
 176 /* Return the kind of this range.  */
 177
 178 inline value_range_kind
 179 value_range_base::kind () const
 180 {
 181   return m_kind;
 182 }
 183
 184 inline bitmap
 185 value_range::equiv () const
 186 {
 187   return m_equiv;
 188 }
 189
 190 /* Return the lower bound.  */
 191
 192 inline tree
 193 value_range_base::min () const
 194 {
 195   return m_min;
 196 }
 197
 198 /* Return the upper bound.  */
 199
 200 inline tree
 201 value_range_base::max () const
 202 {
 203   return m_max;
 204 }
 205
 206 /* Return TRUE if range spans the entire possible domain.  */
 207
 208 inline bool
 209 value_range_base::varying_p () const
 210 {
 211   return m_kind == VR_VARYING;
 212 }
 213
 214 /* Return TRUE if range is undefined (essentially the empty set).  */
 215
 216 inline bool
 217 value_range_base::undefined_p () const
 218 {
 219   return m_kind == VR_UNDEFINED;
 220 }
 221
 222 /* Return TRUE if range is the constant zero.  */
 223
 224 inline bool
 225 value_range_base::zero_p () const
 226 {
 227   return (m_kind == VR_RANGE
 228           && integer_zerop (m_min)
 229           && integer_zerop (m_max));
 230 }
 231
 232 /* Return TRUE if range is nonzero.  */
 233
 234 inline bool
 235 value_range_base::nonzero_p () const
 236 {
 237   return (m_kind == VR_ANTI_RANGE
 238           && integer_zerop (m_min)
 239           && integer_zerop (m_max));
 240 }
 241
 242 extern void dump_value_range (FILE *, const value_range *);
 243 extern void dump_value_range (FILE *, const value_range_base *);
 244
 245 struct assert_info
 246 {
 247   /* Predicate code for the ASSERT_EXPR.  Must be COMPARISON_CLASS_P.  */
 248   enum tree_code comp_code;
 249
 250   /* Name to register the assert for.  */
 251   tree name;
 252
 253   /* Value being compared against.  */
 254   tree val;
 255
 256   /* Expression to compare.  */
 257   tree expr;
 258 };
 259
 260 // Return true if TYPE is a valid type for value_range to operate on.
 261 // Otherwise return FALSE.
 262
 263 inline bool
 264 value_range_base::supports_type_p (tree type)
 265 {
 266   if (type && (INTEGRAL_TYPE_P (type) || POINTER_TYPE_P (type)))
 267     return type;
 268   return NULL;
 269 }
 270
 271 extern void register_edge_assert_for (tree, edge, enum tree_code,
 272                                       tree, tree, vec<assert_info> &);
 273 extern bool stmt_interesting_for_vrp (gimple *);
 274 extern bool infer_value_range (gimple *, tree, tree_code *, tree *);
 275
 276 extern bool vrp_bitmap_equal_p (const_bitmap, const_bitmap);
 277
 278 extern bool range_int_cst_p (const value_range_base *);
 279 extern bool range_int_cst_singleton_p (const value_range_base *);
 280
 281 extern int compare_values (tree, tree);
 282 extern int compare_values_warnv (tree, tree, bool *);
 283 extern int operand_less_p (tree, tree);
 284 extern bool vrp_val_is_min (const_tree);
 285 extern bool vrp_val_is_max (const_tree);
 286
 287 extern tree vrp_val_min (const_tree, bool handle_pointers = false);
 288 extern tree vrp_val_max (const_tree, bool handle_pointers = false);
 289
 290 extern void extract_range_from_unary_expr (value_range_base *vr,
 291                                            enum tree_code code,
 292                                            tree type,
 293                                            const value_range_base *vr0_,
 294                                            tree op0_type);
 295 extern void extract_range_from_binary_expr (value_range_base *,
 296                                             enum tree_code,
 297                                             tree, const value_range_base *,
 298                                             const value_range_base *);
 299
 300 extern bool vrp_operand_equal_p (const_tree, const_tree);
 301 extern enum value_range_kind intersect_range_with_nonzero_bits
 302   (enum value_range_kind, wide_int *, wide_int *, const wide_int &, signop);
 303 extern bool vrp_set_zero_nonzero_bits (const tree, const value_range_base *,
 304                                        wide_int *, wide_int *);
 305
 306 extern bool find_case_label_range (gswitch *, tree, tree, size_t *, size_t *);
 307 extern bool find_case_label_index (gswitch *, size_t, tree, size_t *);
 308 extern bool overflow_comparison_p (tree_code, tree, tree, bool, tree *);
 309 extern tree get_single_symbol (tree, bool *, tree *);
 310 extern void maybe_set_nonzero_bits (edge, tree);
 311 extern value_range_kind determine_value_range (tree, wide_int *, wide_int *);
 312
 313 /* Return TRUE if *VR includes the value zero.  */
 314
 315 inline bool
 316 range_includes_zero_p (const value_range_base *vr)
 317 {
 318   if (vr->undefined_p ())
 319     return false;
 320
 321   if (vr->varying_p ())
 322     return true;
 323
 324   return vr->may_contain_p (build_zero_cst (vr->type ()));
 325 }
 326
 327 #endif /* GCC_TREE_VRP_H */