1 /* Support routines for value ranges.
2 Copyright (C) 2019-2020 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_VALUE_RANGE_H
21 #define GCC_VALUE_RANGE_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 // Range of values that can be associated with an SSA_NAME.
39
class(for_user)40 class GTY((for_user)) value_range
41 {
42 public:
43 value_range ();
44 value_range (tree, tree, value_range_kind = VR_RANGE);
45 value_range (tree type, const wide_int &, const wide_int &,
46 value_range_kind = VR_RANGE);
47 value_range (tree type);
48
49 void set (tree, tree, value_range_kind = VR_RANGE);
50 void set (tree);
51 void set_nonzero (tree);
52 void set_zero (tree);
53
54 enum value_range_kind kind () const;
55 tree min () const;
56 tree max () const;
57
58 /* Types of value ranges. */
59 bool symbolic_p () const;
60 bool constant_p () const;
61 bool undefined_p () const;
62 bool varying_p () const;
63 void set_varying (tree type);
64 void set_undefined ();
65
66 void union_ (const value_range *);
67 void intersect (const value_range *);
68 void union_ (const value_range &);
69 void intersect (const value_range &);
70
71 bool operator== (const value_range &) const;
72 bool operator!= (const value_range &) const /* = delete */;
73 bool equal_p (const value_range &) const;
74
75 /* Misc methods. */
76 tree type () const;
77 bool may_contain_p (tree) const;
78 bool zero_p () const;
79 bool nonzero_p () const;
80 bool singleton_p (tree *result = NULL) const;
81 void dump (FILE *) const;
82 void dump () const;
83
84 static bool supports_type_p (tree);
85 void normalize_symbolics ();
86 void normalize_addresses ();
87
88 static const unsigned int m_max_pairs = 2;
89 bool contains_p (tree) const;
90 unsigned num_pairs () const;
91 wide_int lower_bound (unsigned = 0) const;
92 wide_int upper_bound (unsigned) const;
93 wide_int upper_bound () const;
94 void invert ();
95
96 protected:
97 void check ();
98 static value_range union_helper (const value_range *, const value_range *);
99 static value_range intersect_helper (const value_range *,
100 const value_range *);
101
102 friend void gt_ggc_mx_value_range (void *);
103 friend void gt_pch_p_11value_range (void *, void *,
104 gt_pointer_operator, void *);
105 friend void gt_pch_nx_value_range (void *);
106 friend void gt_ggc_mx (value_range &);
107 friend void gt_ggc_mx (value_range *&);
108 friend void gt_pch_nx (value_range &);
109 friend void gt_pch_nx (value_range *, gt_pointer_operator, void *);
110
111 enum value_range_kind m_kind;
112 tree m_min;
113 tree m_max;
114
115 private:
116 int value_inside_range (tree) const;
117 };
118
119 extern bool range_has_numeric_bounds_p (const value_range *);
120 extern bool ranges_from_anti_range (const value_range *,
121 value_range *, value_range *);
122 extern void dump_value_range (FILE *, const value_range *);
123 extern bool vrp_val_is_min (const_tree);
124 extern bool vrp_val_is_max (const_tree);
125 extern tree vrp_val_min (const_tree);
126 extern tree vrp_val_max (const_tree);
127 extern bool vrp_operand_equal_p (const_tree, const_tree);
128
129 inline
value_range()130 value_range::value_range ()
131 {
132 m_kind = VR_UNDEFINED;
133 m_min = m_max = NULL;
134 }
135
136 inline value_range_kind
kind()137 value_range::kind () const
138 {
139 return m_kind;
140 }
141
142 inline tree
type()143 value_range::type () const
144 {
145 return TREE_TYPE (min ());
146 }
147
148 inline tree
min()149 value_range::min () const
150 {
151 return m_min;
152 }
153
154 inline tree
max()155 value_range::max () const
156 {
157 return m_max;
158 }
159
160 inline bool
varying_p()161 value_range::varying_p () const
162 {
163 return m_kind == VR_VARYING;
164 }
165
166 inline bool
undefined_p()167 value_range::undefined_p () const
168 {
169 return m_kind == VR_UNDEFINED;
170 }
171
172 inline bool
zero_p()173 value_range::zero_p () const
174 {
175 return (m_kind == VR_RANGE
176 && integer_zerop (m_min)
177 && integer_zerop (m_max));
178 }
179
180 inline bool
nonzero_p()181 value_range::nonzero_p () const
182 {
183 if (m_kind == VR_ANTI_RANGE
184 && !TYPE_UNSIGNED (type ())
185 && integer_zerop (m_min)
186 && integer_zerop (m_max))
187 return true;
188
189 return (m_kind == VR_RANGE
190 && TYPE_UNSIGNED (type ())
191 && integer_onep (m_min)
192 && vrp_val_is_max (m_max));
193 }
194
195 inline bool
supports_type_p(tree type)196 value_range::supports_type_p (tree type)
197 {
198 if (type && (INTEGRAL_TYPE_P (type) || POINTER_TYPE_P (type)))
199 return type;
200 return false;
201 }
202
203 inline bool
range_includes_zero_p(const value_range * vr)204 range_includes_zero_p (const value_range *vr)
205 {
206 if (vr->undefined_p ())
207 return false;
208
209 if (vr->varying_p ())
210 return true;
211
212 return vr->may_contain_p (build_zero_cst (vr->type ()));
213 }
214
215 #endif // GCC_VALUE_RANGE_H
216