1 /* Tree SCC value numbering
2 Copyright (C) 2007-2016 Free Software Foundation, Inc.
3 Contributed by Daniel Berlin <dberlin@dberlin.org>
4
5 This file is part of GCC.
6
7 GCC is free software; you can redistribute it and/or modify
8 under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
11
12 GCC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
20
21 #ifndef TREE_SSA_SCCVN_H
22 #define TREE_SSA_SCCVN_H
23
24 /* In tree-ssa-sccvn.c */
25 bool expressions_equal_p (tree, tree);
26
27
28 /* TOP of the VN lattice. */
29 extern tree VN_TOP;
30
31 /* N-ary operations in the hashtable consist of length operands, an
32 opcode, and a type. Result is the value number of the operation,
33 and hashcode is stored to avoid having to calculate it
34 repeatedly. */
35
36 typedef struct vn_nary_op_s
37 {
38 /* Unique identify that all expressions with the same value have. */
39 unsigned int value_id;
40 ENUM_BITFIELD(tree_code) opcode : 16;
41 unsigned length : 16;
42 hashval_t hashcode;
43 tree result;
44 tree type;
45 tree op[1];
46 } *vn_nary_op_t;
47 typedef const struct vn_nary_op_s *const_vn_nary_op_t;
48
49 /* Return the size of a vn_nary_op_t with LENGTH operands. */
50
51 static inline size_t
sizeof_vn_nary_op(unsigned int length)52 sizeof_vn_nary_op (unsigned int length)
53 {
54 return sizeof (struct vn_nary_op_s) + sizeof (tree) * length - sizeof (tree);
55 }
56
57 /* Phi nodes in the hashtable consist of their non-VN_TOP phi
58 arguments, and the basic block the phi is in. Result is the value
59 number of the operation, and hashcode is stored to avoid having to
60 calculate it repeatedly. Phi nodes not in the same block are never
61 considered equivalent. */
62
63 typedef struct vn_phi_s
64 {
65 /* Unique identifier that all expressions with the same value have. */
66 unsigned int value_id;
67 hashval_t hashcode;
68 vec<tree> phiargs;
69 basic_block block;
70 /* Controlling condition lhs/rhs. */
71 tree cclhs;
72 tree ccrhs;
73 tree type;
74 tree result;
75 } *vn_phi_t;
76 typedef const struct vn_phi_s *const_vn_phi_t;
77
78 /* Reference operands only exist in reference operations structures.
79 They consist of an opcode, type, and some number of operands. For
80 a given opcode, some, all, or none of the operands may be used.
81 The operands are there to store the information that makes up the
82 portion of the addressing calculation that opcode performs. */
83
84 typedef struct vn_reference_op_struct
85 {
86 ENUM_BITFIELD(tree_code) opcode : 16;
87 /* 1 for instrumented calls. */
88 unsigned with_bounds : 1;
89 /* Dependence info, used for [TARGET_]MEM_REF only. */
90 unsigned short clique;
91 unsigned short base;
92 /* Constant offset this op adds or -1 if it is variable. */
93 HOST_WIDE_INT off;
94 tree type;
95 tree op0;
96 tree op1;
97 tree op2;
98 bool reverse;
99 } vn_reference_op_s;
100 typedef vn_reference_op_s *vn_reference_op_t;
101 typedef const vn_reference_op_s *const_vn_reference_op_t;
102
103
104 /* A reference operation in the hashtable is representation as
105 the vuse, representing the memory state at the time of
106 the operation, and a collection of operands that make up the
107 addressing calculation. If two vn_reference_t's have the same set
108 of operands, they access the same memory location. We also store
109 the resulting value number, and the hashcode. */
110
111 typedef struct vn_reference_s
112 {
113 /* Unique identifier that all expressions with the same value have. */
114 unsigned int value_id;
115 hashval_t hashcode;
116 tree vuse;
117 alias_set_type set;
118 tree type;
119 vec<vn_reference_op_s> operands;
120 tree result;
121 tree result_vdef;
122 } *vn_reference_t;
123 typedef const struct vn_reference_s *const_vn_reference_t;
124
125 typedef struct vn_constant_s
126 {
127 unsigned int value_id;
128 hashval_t hashcode;
129 tree constant;
130 } *vn_constant_t;
131
132 enum vn_kind { VN_NONE, VN_CONSTANT, VN_NARY, VN_REFERENCE, VN_PHI };
133 enum vn_kind vn_get_stmt_kind (gimple *);
134
135 /* Hash the type TYPE using bits that distinguishes it in the
136 types_compatible_p sense. */
137
138 static inline hashval_t
vn_hash_type(tree type)139 vn_hash_type (tree type)
140 {
141 return (INTEGRAL_TYPE_P (type)
142 + (INTEGRAL_TYPE_P (type)
143 ? TYPE_PRECISION (type) + TYPE_UNSIGNED (type) : 0));
144 }
145
146 /* Hash the constant CONSTANT with distinguishing type incompatible
147 constants in the types_compatible_p sense. */
148
149 static inline hashval_t
vn_hash_constant_with_type(tree constant)150 vn_hash_constant_with_type (tree constant)
151 {
152 inchash::hash hstate;
153 inchash::add_expr (constant, hstate);
154 hstate.merge_hash (vn_hash_type (TREE_TYPE (constant)));
155 return hstate.end ();
156 }
157
158 /* Compare the constants C1 and C2 with distinguishing type incompatible
159 constants in the types_compatible_p sense. */
160
161 static inline bool
vn_constant_eq_with_type(tree c1,tree c2)162 vn_constant_eq_with_type (tree c1, tree c2)
163 {
164 return (expressions_equal_p (c1, c2)
165 && types_compatible_p (TREE_TYPE (c1), TREE_TYPE (c2)));
166 }
167
168 typedef struct vn_ssa_aux
169 {
170 /* Value number. This may be an SSA name or a constant. */
171 tree valnum;
172 /* Statements to insert if needs_insertion is true. */
173 gimple_seq expr;
174
175 /* Saved SSA name info. */
176 tree_ssa_name::ssa_name_info_type info;
177
178 /* Unique identifier that all expressions with the same value have. */
179 unsigned int value_id;
180
181 /* SCC information. */
182 unsigned int dfsnum;
183 unsigned int low;
184 unsigned visited : 1;
185 unsigned on_sccstack : 1;
186
187 /* Whether the SSA_NAME has been value numbered already. This is
188 only saying whether visit_use has been called on it at least
189 once. It cannot be used to avoid visitation for SSA_NAME's
190 involved in non-singleton SCC's. */
191 unsigned use_processed : 1;
192
193 /* Whether the SSA_NAME has no defining statement and thus an
194 insertion of such with EXPR as definition is required before
195 a use can be created of it. */
196 unsigned needs_insertion : 1;
197
198 /* Whether range-info is anti-range. */
199 unsigned range_info_anti_range_p : 1;
200 } *vn_ssa_aux_t;
201
202 enum vn_lookup_kind { VN_NOWALK, VN_WALK, VN_WALKREWRITE };
203
204 /* Return the value numbering info for an SSA_NAME. */
205 extern vn_ssa_aux_t VN_INFO (tree);
206 extern vn_ssa_aux_t VN_INFO_GET (tree);
207 tree vn_get_expr_for (tree);
208 bool run_scc_vn (vn_lookup_kind);
209 void free_scc_vn (void);
210 void scc_vn_restore_ssa_info (void);
211 tree vn_nary_op_lookup (tree, vn_nary_op_t *);
212 tree vn_nary_op_lookup_stmt (gimple *, vn_nary_op_t *);
213 tree vn_nary_op_lookup_pieces (unsigned int, enum tree_code,
214 tree, tree *, vn_nary_op_t *);
215 vn_nary_op_t vn_nary_op_insert (tree, tree);
216 vn_nary_op_t vn_nary_op_insert_pieces (unsigned int, enum tree_code,
217 tree, tree *, tree, unsigned int);
218 bool ao_ref_init_from_vn_reference (ao_ref *, alias_set_type, tree,
219 vec<vn_reference_op_s> );
220 tree vn_reference_lookup_pieces (tree, alias_set_type, tree,
221 vec<vn_reference_op_s> ,
222 vn_reference_t *, vn_lookup_kind);
223 tree vn_reference_lookup (tree, tree, vn_lookup_kind, vn_reference_t *, bool);
224 void vn_reference_lookup_call (gcall *, vn_reference_t *, vn_reference_t);
225 vn_reference_t vn_reference_insert_pieces (tree, alias_set_type, tree,
226 vec<vn_reference_op_s> ,
227 tree, unsigned int);
228
229 bool vn_nary_op_eq (const_vn_nary_op_t const vno1,
230 const_vn_nary_op_t const vno2);
231 bool vn_nary_may_trap (vn_nary_op_t);
232 bool vn_reference_eq (const_vn_reference_t const, const_vn_reference_t const);
233 unsigned int get_max_value_id (void);
234 unsigned int get_next_value_id (void);
235 unsigned int get_constant_value_id (tree);
236 unsigned int get_or_alloc_constant_value_id (tree);
237 bool value_id_constant_p (unsigned int);
238 tree fully_constant_vn_reference_p (vn_reference_t);
239
240 /* Valueize NAME if it is an SSA name, otherwise just return it. */
241
242 static inline tree
vn_valueize(tree name)243 vn_valueize (tree name)
244 {
245 if (TREE_CODE (name) == SSA_NAME)
246 {
247 tree tem = VN_INFO (name)->valnum;
248 return tem == VN_TOP ? name : tem;
249 }
250 return name;
251 }
252
253 /* Get at the original range info for NAME. */
254
255 inline range_info_def *
VN_INFO_RANGE_INFO(tree name)256 VN_INFO_RANGE_INFO (tree name)
257 {
258 return (VN_INFO (name)->info.range_info
259 ? VN_INFO (name)->info.range_info
260 : SSA_NAME_RANGE_INFO (name));
261 }
262
263 /* Whether the original range info of NAME is an anti-range. */
264
265 inline bool
VN_INFO_ANTI_RANGE_P(tree name)266 VN_INFO_ANTI_RANGE_P (tree name)
267 {
268 return (VN_INFO (name)->info.range_info
269 ? VN_INFO (name)->range_info_anti_range_p
270 : SSA_NAME_ANTI_RANGE_P (name));
271 }
272
273 /* Get at the original range info kind for NAME. */
274
275 inline value_range_type
VN_INFO_RANGE_TYPE(tree name)276 VN_INFO_RANGE_TYPE (tree name)
277 {
278 return VN_INFO_ANTI_RANGE_P (name) ? VR_ANTI_RANGE : VR_RANGE;
279 }
280
281 /* Get at the original pointer info for NAME. */
282
283 inline ptr_info_def *
VN_INFO_PTR_INFO(tree name)284 VN_INFO_PTR_INFO (tree name)
285 {
286 return (VN_INFO (name)->info.ptr_info
287 ? VN_INFO (name)->info.ptr_info
288 : SSA_NAME_PTR_INFO (name));
289 }
290
291 #endif /* TREE_SSA_SCCVN_H */
292