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. */
class(for_user)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. */
class(user)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
value_range_base()156 value_range_base::value_range_base ()
157 {
158 m_kind = VR_UNDEFINED;
159 m_min = m_max = NULL;
160 }
161
162 inline
value_range()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
kind()172 value_range_base::kind () const
173 {
174 return m_kind;
175 }
176
177 inline bitmap
equiv()178 value_range::equiv () const
179 {
180 return m_equiv;
181 }
182
183 /* Return the lower bound. */
184
185 inline tree
min()186 value_range_base::min () const
187 {
188 return m_min;
189 }
190
191 /* Return the upper bound. */
192
193 inline tree
max()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
varying_p()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
undefined_p()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
zero_p()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_p (const value_range_base *, HOST_WIDE_INT);
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 /* Return TRUE if *VR includes the value zero. */
289
290 inline bool
range_includes_zero_p(const value_range_base * vr)291 range_includes_zero_p (const value_range_base *vr)
292 {
293 return range_includes_p (vr, 0);
294 }
295
296 #endif /* GCC_TREE_VRP_H */
297