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