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