1 /* Tree SCC value numbering
2 Copyright (C) 2007-2018 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 /* Dependence info, used for [TARGET_]MEM_REF only. */
88 unsigned short clique;
89 unsigned short base;
90 /* 1 for instrumented calls. */
91 unsigned with_bounds : 1;
92 unsigned reverse : 1;
93 /* For storing TYPE_ALIGN for array ref element size computation. */
94 unsigned align : 6;
95 /* Constant offset this op adds or -1 if it is variable. */
96 poly_int64_pod off;
97 tree type;
98 tree op0;
99 tree op1;
100 tree op2;
101 } vn_reference_op_s;
102 typedef vn_reference_op_s *vn_reference_op_t;
103 typedef const vn_reference_op_s *const_vn_reference_op_t;
104
105 inline unsigned
vn_ref_op_align_unit(vn_reference_op_t op)106 vn_ref_op_align_unit (vn_reference_op_t op)
107 {
108 return op->align ? ((unsigned)1 << (op->align - 1)) / BITS_PER_UNIT : 0;
109 }
110
111 /* A reference operation in the hashtable is representation as
112 the vuse, representing the memory state at the time of
113 the operation, and a collection of operands that make up the
114 addressing calculation. If two vn_reference_t's have the same set
115 of operands, they access the same memory location. We also store
116 the resulting value number, and the hashcode. */
117
118 typedef struct vn_reference_s
119 {
120 /* Unique identifier that all expressions with the same value have. */
121 unsigned int value_id;
122 hashval_t hashcode;
123 tree vuse;
124 alias_set_type set;
125 tree type;
126 vec<vn_reference_op_s> operands;
127 tree result;
128 tree result_vdef;
129 } *vn_reference_t;
130 typedef const struct vn_reference_s *const_vn_reference_t;
131
132 typedef struct vn_constant_s
133 {
134 unsigned int value_id;
135 hashval_t hashcode;
136 tree constant;
137 } *vn_constant_t;
138
139 enum vn_kind { VN_NONE, VN_CONSTANT, VN_NARY, VN_REFERENCE, VN_PHI };
140 enum vn_kind vn_get_stmt_kind (gimple *);
141
142 /* Hash the type TYPE using bits that distinguishes it in the
143 types_compatible_p sense. */
144
145 static inline hashval_t
vn_hash_type(tree type)146 vn_hash_type (tree type)
147 {
148 return (INTEGRAL_TYPE_P (type)
149 + (INTEGRAL_TYPE_P (type)
150 ? TYPE_PRECISION (type) + TYPE_UNSIGNED (type) : 0));
151 }
152
153 /* Hash the constant CONSTANT with distinguishing type incompatible
154 constants in the types_compatible_p sense. */
155
156 static inline hashval_t
vn_hash_constant_with_type(tree constant)157 vn_hash_constant_with_type (tree constant)
158 {
159 inchash::hash hstate;
160 inchash::add_expr (constant, hstate);
161 hstate.merge_hash (vn_hash_type (TREE_TYPE (constant)));
162 return hstate.end ();
163 }
164
165 /* Compare the constants C1 and C2 with distinguishing type incompatible
166 constants in the types_compatible_p sense. */
167
168 static inline bool
vn_constant_eq_with_type(tree c1,tree c2)169 vn_constant_eq_with_type (tree c1, tree c2)
170 {
171 return (expressions_equal_p (c1, c2)
172 && types_compatible_p (TREE_TYPE (c1), TREE_TYPE (c2)));
173 }
174
175 typedef struct vn_ssa_aux
176 {
177 /* Value number. This may be an SSA name or a constant. */
178 tree valnum;
179 /* Statements to insert if needs_insertion is true. */
180 gimple_seq expr;
181
182 /* Saved SSA name info. */
183 tree_ssa_name::ssa_name_info_type info;
184
185 /* Unique identifier that all expressions with the same value have. */
186 unsigned int value_id;
187
188 /* SCC information. */
189 unsigned int dfsnum;
190 unsigned int low;
191 unsigned visited : 1;
192 unsigned on_sccstack : 1;
193
194 /* Whether the SSA_NAME has been value numbered already. This is
195 only saying whether visit_use has been called on it at least
196 once. It cannot be used to avoid visitation for SSA_NAME's
197 involved in non-singleton SCC's. */
198 unsigned use_processed : 1;
199
200 /* Whether the SSA_NAME has no defining statement and thus an
201 insertion of such with EXPR as definition is required before
202 a use can be created of it. */
203 unsigned needs_insertion : 1;
204
205 /* Whether range-info is anti-range. */
206 unsigned range_info_anti_range_p : 1;
207 } *vn_ssa_aux_t;
208
209 enum vn_lookup_kind { VN_NOWALK, VN_WALK, VN_WALKREWRITE };
210
211 /* Return the value numbering info for an SSA_NAME. */
212 bool has_VN_INFO (tree);
213 extern vn_ssa_aux_t VN_INFO (tree);
214 extern vn_ssa_aux_t VN_INFO_GET (tree);
215 tree vn_get_expr_for (tree);
216 void run_scc_vn (vn_lookup_kind);
217 unsigned int vn_eliminate (bitmap);
218 void free_scc_vn (void);
219 void scc_vn_restore_ssa_info (void);
220 tree vn_nary_op_lookup (tree, vn_nary_op_t *);
221 tree vn_nary_op_lookup_stmt (gimple *, vn_nary_op_t *);
222 tree vn_nary_op_lookup_pieces (unsigned int, enum tree_code,
223 tree, tree *, vn_nary_op_t *);
224 vn_nary_op_t vn_nary_op_insert (tree, tree);
225 vn_nary_op_t vn_nary_op_insert_pieces (unsigned int, enum tree_code,
226 tree, tree *, tree, unsigned int);
227 bool ao_ref_init_from_vn_reference (ao_ref *, alias_set_type, tree,
228 vec<vn_reference_op_s> );
229 vec<vn_reference_op_s> vn_reference_operands_for_lookup (tree);
230 tree vn_reference_lookup_pieces (tree, alias_set_type, tree,
231 vec<vn_reference_op_s> ,
232 vn_reference_t *, vn_lookup_kind);
233 tree vn_reference_lookup (tree, tree, vn_lookup_kind, vn_reference_t *, bool);
234 void vn_reference_lookup_call (gcall *, vn_reference_t *, vn_reference_t);
235 vn_reference_t vn_reference_insert_pieces (tree, alias_set_type, tree,
236 vec<vn_reference_op_s> ,
237 tree, unsigned int);
238
239 bool vn_nary_op_eq (const_vn_nary_op_t const vno1,
240 const_vn_nary_op_t const vno2);
241 bool vn_nary_may_trap (vn_nary_op_t);
242 bool vn_reference_may_trap (vn_reference_t);
243 bool vn_reference_eq (const_vn_reference_t const, const_vn_reference_t const);
244 unsigned int get_max_value_id (void);
245 unsigned int get_next_value_id (void);
246 unsigned int get_constant_value_id (tree);
247 unsigned int get_or_alloc_constant_value_id (tree);
248 bool value_id_constant_p (unsigned int);
249 tree fully_constant_vn_reference_p (vn_reference_t);
250 tree vn_nary_simplify (vn_nary_op_t);
251
252 /* Valueize NAME if it is an SSA name, otherwise just return it. */
253
254 static inline tree
vn_valueize(tree name)255 vn_valueize (tree name)
256 {
257 if (TREE_CODE (name) == SSA_NAME)
258 {
259 tree tem = VN_INFO (name)->valnum;
260 return tem == VN_TOP ? name : tem;
261 }
262 return name;
263 }
264
265 /* Get at the original range info for NAME. */
266
267 inline range_info_def *
VN_INFO_RANGE_INFO(tree name)268 VN_INFO_RANGE_INFO (tree name)
269 {
270 return (VN_INFO (name)->info.range_info
271 ? VN_INFO (name)->info.range_info
272 : SSA_NAME_RANGE_INFO (name));
273 }
274
275 /* Whether the original range info of NAME is an anti-range. */
276
277 inline bool
VN_INFO_ANTI_RANGE_P(tree name)278 VN_INFO_ANTI_RANGE_P (tree name)
279 {
280 return (VN_INFO (name)->info.range_info
281 ? VN_INFO (name)->range_info_anti_range_p
282 : SSA_NAME_ANTI_RANGE_P (name));
283 }
284
285 /* Get at the original range info kind for NAME. */
286
287 inline value_range_type
VN_INFO_RANGE_TYPE(tree name)288 VN_INFO_RANGE_TYPE (tree name)
289 {
290 return VN_INFO_ANTI_RANGE_P (name) ? VR_ANTI_RANGE : VR_RANGE;
291 }
292
293 /* Get at the original pointer info for NAME. */
294
295 inline ptr_info_def *
VN_INFO_PTR_INFO(tree name)296 VN_INFO_PTR_INFO (tree name)
297 {
298 return (VN_INFO (name)->info.ptr_info
299 ? VN_INFO (name)->info.ptr_info
300 : SSA_NAME_PTR_INFO (name));
301 }
302
303 #endif /* TREE_SSA_SCCVN_H */
304