GCC Middle and Back End API Reference
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1/* Tree SCC value numbering
2 Copyright (C) 2007-2024 Free Software Foundation, Inc.
3 Contributed by Daniel Berlin <dberlin@dberlin.org>
5 This file is part of GCC.
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.
12 GCC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 GNU General Public License for more details.
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/>. */
21#ifndef TREE_SSA_SCCVN_H
22#define TREE_SSA_SCCVN_H
24/* In tree-ssa-sccvn.cc */
25bool expressions_equal_p (tree, tree, bool = true);
28/* TOP of the VN lattice. */
29extern tree VN_TOP;
31/* A predicated value. */
32struct vn_pval
35 /* The value of the expression this is attached to is RESULT in
36 case the expression is computed dominated by one of the blocks
37 in valid_dominated_by_p. */
39 unsigned n;
43/* N-ary operations in the hashtable consist of length operands, an
44 opcode, and a type. Result is the value number of the operation,
45 and hashcode is stored to avoid having to calculate it
46 repeatedly. */
48typedef struct vn_nary_op_s
52 /* Unique identify that all expressions with the same value have. */
53 unsigned int value_id;
54 ENUM_BITFIELD(tree_code) opcode : 16;
55 unsigned length : 16;
56 hashval_t hashcode;
57 unsigned predicated_values : 1;
58 union {
59 /* If ! predicated_values this is the value of the expression. */
61 /* If predicated_values this is a list of values of the expression. */
63 } u;
65 tree op[1];
67typedef const struct vn_nary_op_s *const_vn_nary_op_t;
69/* Return the size of a vn_nary_op_t with LENGTH operands. */
71inline size_t
74 return sizeof (struct vn_nary_op_s) + sizeof (tree) * length - sizeof (tree);
77/* Phi nodes in the hashtable consist of their non-VN_TOP phi
78 arguments, and the basic block the phi is in. Result is the value
79 number of the operation, and hashcode is stored to avoid having to
80 calculate it repeatedly. Phi nodes not in the same block are never
81 considered equivalent. */
83typedef struct vn_phi_s
86 /* Unique identifier that all expressions with the same value have. */
87 unsigned int value_id;
88 hashval_t hashcode;
90 /* Controlling condition lhs/rhs. */
95 /* The number of args is determined by EDGE_COUT (block->preds). */
98typedef const struct vn_phi_s *const_vn_phi_t;
100/* Reference operands only exist in reference operations structures.
101 They consist of an opcode, type, and some number of operands. For
102 a given opcode, some, all, or none of the operands may be used.
103 The operands are there to store the information that makes up the
104 portion of the addressing calculation that opcode performs. */
108 ENUM_BITFIELD(tree_code) opcode : 16;
109 /* Dependence info, used for [TARGET_]MEM_REF only. For internal
110 function calls clique is also used for the internal function code. */
111 unsigned short clique;
112 unsigned short base;
113 unsigned reverse : 1;
114 /* For storing TYPE_ALIGN for array ref element size computation. */
115 unsigned align : 6;
116 /* Constant offset this op adds or -1 if it is variable. */
126inline unsigned
129 return op->align ? ((unsigned)1 << (op->align - 1)) / BITS_PER_UNIT : 0;
132/* A reference operation in the hashtable is representation as
133 the vuse, representing the memory state at the time of
134 the operation, and a collection of operands that make up the
135 addressing calculation. If two vn_reference_t's have the same set
136 of operands, they access the same memory location. We also store
137 the resulting value number, and the hashcode. */
158typedef struct vn_constant_s
160 unsigned int value_id;
161 hashval_t hashcode;
168/* Hash the type TYPE using bits that distinguishes it in the
169 types_compatible_p sense. */
171inline hashval_t
174 return (INTEGRAL_TYPE_P (type)
179/* Hash the constant CONSTANT with distinguishing type incompatible
180 constants in the types_compatible_p sense. */
182inline hashval_t
185 inchash::hash hstate;
186 inchash::add_expr (constant, hstate);
187 hstate.merge_hash (vn_hash_type (TREE_TYPE (constant)));
188 return hstate.end ();
191/* Compare the constants C1 and C2 with distinguishing type incompatible
192 constants in the types_compatible_p sense. */
194inline bool
197 return (expressions_equal_p (c1, c2)
198 && types_compatible_p (TREE_TYPE (c1), TREE_TYPE (c2)));
201/* Instead of having a local availability lattice for each basic-block
202 and availability at X defined as union of the local availabilities
203 at X and its dominators we're turning this upside down and track
204 availability per value given values are usually made available at very
205 few points.
206 So we have a chain of LOCATION, LEADER entries where LOCATION is
207 specifying the basic-block LEADER is made available for VALUE.
208 We prepend to this chain in RPO order thus for iteration we can simply
209 remove the last entries.
210 LOCATION is the basic-block index and LEADER is its SSA name version. */
214 /* The basic-block LEADER is made available. */
216 /* The LEADER for the value we are chained on. */
218 /* The previous value we pushed a avail record to. */
222typedef struct vn_ssa_aux
224 /* SSA name this vn_ssa_aux is associated with in the lattice. */
226 /* Value number. This may be an SSA name or a constant. */
228 /* Statements to insert if needs_insertion is true. */
231 /* AVAIL entries, last in RPO order is first. This is only tracked
232 for SSA names also serving as values (NAME == VALNUM). */
235 /* Unique identifier that all expressions with the same value have. */
236 unsigned int value_id;
238 /* Whether the SSA_NAME has been processed at least once. */
239 unsigned visited : 1;
241 /* Whether the SSA_NAME has no defining statement and thus an
242 insertion of such with EXPR as definition is required before
243 a use can be created of it. */
244 unsigned needs_insertion : 1;
249/* Return the value numbering info for an SSA_NAME. */
250bool has_VN_INFO (tree);
251extern vn_ssa_aux_t VN_INFO (tree);
254vn_nary_op_t alloc_vn_nary_op_noinit (unsigned int, struct obstack *);
255unsigned int vn_nary_length_from_stmt (gimple *);
257hashval_t vn_nary_op_compute_hash (const vn_nary_op_t);
259tree vn_nary_op_lookup_pieces (unsigned int, enum tree_code,
260 tree, tree *, vn_nary_op_t *);
262 tree, tree *, tree, unsigned int);
270 tree * = NULL, tree = NULL_TREE, bool = false);
275 tree, unsigned int);
278bool vn_nary_op_eq (const_vn_nary_op_t const vno1,
279 const_vn_nary_op_t const vno2);
284unsigned int get_max_value_id (void);
285unsigned int get_max_constant_value_id (void);
286unsigned int get_next_value_id (void);
287unsigned int get_next_constant_value_id (void);
288unsigned int get_constant_value_id (tree);
291/* Return true if V is a value id for a constant. */
292inline bool
293value_id_constant_p (unsigned int v)
295 return (int)v < 0;
301unsigned do_rpo_vn (function *, edge, bitmap,
302 /* iterate */ bool = false,
303 /* eliminate */ bool = true,
304 /* skip_entry_phis */ bool = false,
307/* Private interface for PRE. */
310void free_rpo_vn (void);
312/* Valueize NAME if it is an SSA name, otherwise just return it. This hook
313 is initialized by run_scc_vn. */
314extern tree (*vn_valueize) (tree);
316/* Context that valueization should operate on. */
320#endif /* TREE_SSA_SCCVN_H */
Definition tree-ssa-alias.h:77
Definition inchash.h:38
void merge_hash(hashval_t other)
Definition inchash.h:106
hashval_t end()
Definition inchash.h:49
class edge_def * edge
Definition coretypes.h:343
class bitmap_head * bitmap
Definition coretypes.h:51
union tree_node * tree
Definition coretypes.h:97
int alias_set_type
Definition coretypes.h:340
static struct obstack obstack
Definition gcc.cc:357
Definition genmatch.cc:347
bool types_compatible_p(tree type1, tree type2)
Definition gimple-expr.h:64
void add_expr(const_tree t, inchash::hash &hstate, unsigned int flags)
Definition fold-const.cc:4248
Definition basic-block.h:117
Definition function.h:249
Definition gimple.h:904
Definition gimple.h:353
Definition gimple.h:225
Definition gengtype.h:252
Definition vec.h:450
Definition tree-ssa-sccvn.h:212
int location
Definition tree-ssa-sccvn.h:215
int leader
Definition tree-ssa-sccvn.h:217
vn_avail * next
Definition tree-ssa-sccvn.h:213
struct vn_ssa_aux * next_undo
Definition tree-ssa-sccvn.h:219
Definition tree-ssa-sccvn.h:159
tree constant
Definition tree-ssa-sccvn.h:162
hashval_t hashcode
Definition tree-ssa-sccvn.h:161
unsigned int value_id
Definition tree-ssa-sccvn.h:160
Definition tree-ssa-sccvn.h:49
union vn_nary_op_s::@77 u
unsigned int value_id
Definition tree-ssa-sccvn.h:53
hashval_t hashcode
Definition tree-ssa-sccvn.h:56
tree type
Definition tree-ssa-sccvn.h:64
unsigned predicated_values
Definition tree-ssa-sccvn.h:57
unsigned length
Definition tree-ssa-sccvn.h:55
tree result
Definition tree-ssa-sccvn.h:60
vn_pval * values
Definition tree-ssa-sccvn.h:62
enum tree_code opcode
Definition tree-ssa-sccvn.h:54
vn_nary_op_s * next
Definition tree-ssa-sccvn.h:50
tree op[1]
Definition tree-ssa-sccvn.h:65
vn_nary_op_s * unwind_to
Definition tree-ssa-sccvn.h:51
Definition tree-ssa-sccvn.h:84
vn_phi_s * next
Definition tree-ssa-sccvn.h:85
tree phiargs[1]
Definition tree-ssa-sccvn.h:96
tree type
Definition tree-ssa-sccvn.h:93
hashval_t hashcode
Definition tree-ssa-sccvn.h:88
tree cclhs
Definition tree-ssa-sccvn.h:91
tree ccrhs
Definition tree-ssa-sccvn.h:92
tree result
Definition tree-ssa-sccvn.h:94
basic_block block
Definition tree-ssa-sccvn.h:89
unsigned int value_id
Definition tree-ssa-sccvn.h:87
Definition tree-ssa-sccvn.h:33
vn_pval * next
Definition tree-ssa-sccvn.h:34
unsigned n
Definition tree-ssa-sccvn.h:39
tree result
Definition tree-ssa-sccvn.h:38
int valid_dominated_by_p[1]
Definition tree-ssa-sccvn.h:40
Definition tree-ssa-sccvn.h:107
enum tree_code opcode
Definition tree-ssa-sccvn.h:108
tree op1
Definition tree-ssa-sccvn.h:120
tree op2
Definition tree-ssa-sccvn.h:121
unsigned reverse
Definition tree-ssa-sccvn.h:113
tree type
Definition tree-ssa-sccvn.h:118
unsigned short clique
Definition tree-ssa-sccvn.h:111
tree op0
Definition tree-ssa-sccvn.h:119
poly_int64 off
Definition tree-ssa-sccvn.h:117
unsigned short base
Definition tree-ssa-sccvn.h:112
unsigned align
Definition tree-ssa-sccvn.h:115
Definition tree-ssa-sccvn.h:140
vec< vn_reference_op_s > operands
Definition tree-ssa-sccvn.h:152
tree result_vdef
Definition tree-ssa-sccvn.h:154
unsigned int value_id
Definition tree-ssa-sccvn.h:143
poly_int64 max_size
Definition tree-ssa-sccvn.h:149
vn_reference_s * next
Definition tree-ssa-sccvn.h:141
unsigned punned
Definition tree-ssa-sccvn.h:151
tree result
Definition tree-ssa-sccvn.h:153
alias_set_type base_set
Definition tree-ssa-sccvn.h:147
alias_set_type set
Definition tree-ssa-sccvn.h:146
hashval_t hashcode
Definition tree-ssa-sccvn.h:144
poly_int64 offset
Definition tree-ssa-sccvn.h:148
tree vuse
Definition tree-ssa-sccvn.h:145
tree type
Definition tree-ssa-sccvn.h:150
Definition tree-ssa-sccvn.h:223
tree name
Definition tree-ssa-sccvn.h:225
unsigned needs_insertion
Definition tree-ssa-sccvn.h:244
vn_avail * avail
Definition tree-ssa-sccvn.h:233
unsigned int value_id
Definition tree-ssa-sccvn.h:236
tree valnum
Definition tree-ssa-sccvn.h:227
unsigned visited
Definition tree-ssa-sccvn.h:239
gimple_seq expr
Definition tree-ssa-sccvn.h:229
#define NULL
Definition system.h:50
unsigned do_rpo_vn(function *, edge, bitmap, bool=false, bool=true, bool=false, vn_lookup_kind=VN_WALKREWRITE)
Definition tree-ssa-sccvn.cc:8785
basic_block vn_context_bb
Definition tree-ssa-sccvn.cc:2664
tree vn_nary_simplify(vn_nary_op_t)
Definition tree-ssa-sccvn.cc:2593
unsigned int get_or_alloc_constant_value_id(tree)
Definition tree-ssa-sccvn.cc:666
bool vn_reference_may_trap(vn_reference_t)
Definition tree-ssa-sccvn.cc:6620
struct vn_reference_s * vn_reference_t
void run_rpo_vn(vn_lookup_kind)
Definition tree-ssa-sccvn.cc:7643
vn_reference_t vn_reference_insert_pieces(tree, alias_set_type, alias_set_type, poly_int64, poly_int64, tree, vec< vn_reference_op_s >, tree, unsigned int)
Definition tree-ssa-sccvn.cc:4240
struct vn_phi_s * vn_phi_t
bool vn_constant_eq_with_type(tree c1, tree c2)
Definition tree-ssa-sccvn.h:195
void print_vn_reference_ops(FILE *, const vec< vn_reference_op_s >)
Definition tree-ssa-sccvn.cc:265
tree vn_nary_op_lookup_pieces(unsigned int, enum tree_code, tree, tree *, vn_nary_op_t *)
Definition tree-ssa-sccvn.cc:4450
unsigned int get_max_value_id(void)
Definition tree-ssa-sccvn.cc:6505
unsigned int get_max_constant_value_id(void)
Definition tree-ssa-sccvn.cc:6513
bool vn_nary_may_trap(vn_nary_op_t)
Definition tree-ssa-sccvn.cc:6577
tree vn_reference_lookup_pieces(tree, alias_set_type, alias_set_type, tree, vec< vn_reference_op_s >, vn_reference_t *, vn_lookup_kind)
Definition tree-ssa-sccvn.cc:3888
void vn_reference_lookup_call(gcall *, vn_reference_t *, vn_reference_t)
Definition tree-ssa-sccvn.cc:4113
vn_nary_op_t alloc_vn_nary_op_noinit(unsigned int, struct obstack *)
Definition tree-ssa-sccvn.cc:4477
unsigned eliminate_with_rpo_vn(bitmap)
Definition tree-ssa-sccvn.cc:7625
hashval_t vn_nary_op_compute_hash(const vn_nary_op_t)
Definition tree-ssa-sccvn.cc:4284
const struct vn_reference_s * const_vn_reference_t
Definition tree-ssa-sccvn.h:156
tree vn_get_expr_for(tree)
struct vn_nary_op_s * vn_nary_op_t
Definition tree-ssa-sccvn.h:247
Definition tree-ssa-sccvn.h:247
Definition tree-ssa-sccvn.h:247
Definition tree-ssa-sccvn.h:247
bool has_VN_INFO(tree)
Definition tree-ssa-sccvn.cc:447
Definition tree-ssa-sccvn.h:165
Definition tree-ssa-sccvn.h:165
Definition tree-ssa-sccvn.h:165
Definition tree-ssa-sccvn.h:165
Definition tree-ssa-sccvn.h:165
Definition tree-ssa-sccvn.h:165
vn_reference_op_s * vn_reference_op_t
Definition tree-ssa-sccvn.h:123
tree vn_nary_op_lookup_stmt(gimple *, vn_nary_op_t *)
Definition tree-ssa-sccvn.cc:4465
vec< vn_reference_op_s > vn_reference_operands_for_lookup(tree)
Definition tree-ssa-sccvn.cc:3876
bool value_id_constant_p(unsigned int v)
Definition tree-ssa-sccvn.h:293
unsigned int vn_nary_length_from_stmt(gimple *)
Definition tree-ssa-sccvn.cc:4357
bool vn_nary_op_eq(const_vn_nary_op_t const vno1, const_vn_nary_op_t const vno2)
Definition tree-ssa-sccvn.cc:4313
struct vn_ssa_aux * vn_ssa_aux_t
vn_ssa_aux_t VN_INFO(tree)
Definition tree-ssa-sccvn.cc:453
vn_nary_op_t vn_nary_op_insert_pieces(unsigned int, enum tree_code, tree, tree *, tree, unsigned int)
Definition tree-ssa-sccvn.cc:4639
unsigned vn_ref_op_align_unit(vn_reference_op_t op)
Definition tree-ssa-sccvn.h:127
const struct vn_nary_op_s * const_vn_nary_op_t
Definition tree-ssa-sccvn.h:67
tree(* vn_valueize)(tree)
Definition tree-ssa-sccvn.cc:372
const vn_reference_op_s * const_vn_reference_op_t
Definition tree-ssa-sccvn.h:124
enum vn_kind vn_get_stmt_kind(gimple *)
Definition tree-ssa-sccvn.cc:590
unsigned int get_next_value_id(void)
Definition tree-ssa-sccvn.cc:6521
unsigned int get_next_constant_value_id(void)
Definition tree-ssa-sccvn.cc:6530
hashval_t vn_hash_type(tree type)
Definition tree-ssa-sccvn.h:172
hashval_t vn_hash_constant_with_type(tree constant)
Definition tree-ssa-sccvn.h:183
bool expressions_equal_p(tree, tree, bool=true)
Definition tree-ssa-sccvn.cc:6542
struct vn_reference_op_struct vn_reference_op_s
void scc_vn_restore_ssa_info(void)
const struct vn_phi_s * const_vn_phi_t
Definition tree-ssa-sccvn.h:98
tree fully_constant_vn_reference_p(vn_reference_t)
Definition tree-ssa-sccvn.cc:1509
size_t sizeof_vn_nary_op(unsigned int length)
Definition tree-ssa-sccvn.h:72
unsigned int get_constant_value_id(tree)
Definition tree-ssa-sccvn.cc:649
bool ao_ref_init_from_vn_reference(ao_ref *, alias_set_type, alias_set_type, tree, const vec< vn_reference_op_s > &)
Definition tree-ssa-sccvn.cc:1100
void init_vn_nary_op_from_stmt(vn_nary_op_t, gassign *)
Definition tree-ssa-sccvn.cc:4380
void free_rpo_vn(void)
Definition tree-ssa-sccvn.cc:7698
tree vn_reference_lookup(tree, tree, vn_lookup_kind, vn_reference_t *, bool, tree *=NULL, tree=NULL_TREE, bool=false)
Definition tree-ssa-sccvn.cc:3987
bool vn_reference_eq(const_vn_reference_t const, const_vn_reference_t const)
Definition tree-ssa-sccvn.cc:765
struct vn_constant_s * vn_constant_t
tree VN_TOP
Definition tree-ssa-sccvn.cc:393
Definition tree.h:2253
Definition tree.h:949
Definition tree.h:512
Definition tree.h:613
#define NULL_TREE
Definition tree.h:317