1 /* Infrastructure for tracking user variable locations and values
2 throughout compilation.
3 Copyright (C) 2010-2023 Free Software Foundation, Inc.
4 Contributed by Alexandre Oliva <aoliva@redhat.com>.
5
6 This file is part of GCC.
7
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
11 version.
12
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
21
22 #ifndef GCC_VALTRACK_H
23 #define GCC_VALTRACK_H
24
25 /* Debug uses of dead regs. */
26
27 /* Entry that maps a dead pseudo (REG) used in a debug insns that dies
28 at different blocks to the debug temp (DTEMP) it was replaced
29 with. */
30
31 struct dead_debug_global_entry
32 {
33 rtx reg;
34 rtx dtemp;
35 };
36
37 /* Descriptor for hash_table to hash by dead_debug_global_entry's REG
38 and map to DTEMP. */
39
40 struct dead_debug_hash_descr : free_ptr_hash <dead_debug_global_entry>
41 {
42 /* Hash on the pseudo number. */
43 static inline hashval_t hash (const dead_debug_global_entry *my);
44 /* Entries are identical if they refer to the same pseudo. */
45 static inline bool equal (const dead_debug_global_entry *my,
46 const dead_debug_global_entry *other);
47 };
48
49 /* Hash on the pseudo number. */
50 inline hashval_t
51 dead_debug_hash_descr::hash (const dead_debug_global_entry *my)
52 {
53 return REGNO (my->reg);
54 }
55
56 /* Entries are identical if they refer to the same pseudo. */
57 inline bool
58 dead_debug_hash_descr::equal (const dead_debug_global_entry *my,
59 const dead_debug_global_entry *other)
60 {
61 return my->reg == other->reg;
62 }
63
64 /* Maintain a global table of pseudos used in debug insns after their
65 deaths in other blocks, and debug temps their deathpoint values are
66 to be bound to. */
67
68 struct dead_debug_global
69 {
70 /* This hash table that maps pseudos to debug temps. */
71 hash_table<dead_debug_hash_descr> *htab;
72 /* For each entry in htab, the bit corresponding to its REGNO will
73 be set. */
74 bitmap used;
75 };
76
77 /* Node of a linked list of uses of dead REGs in debug insns. */
78
79 struct dead_debug_use
80 {
81 df_ref use;
82 struct dead_debug_use *next;
83 };
84
85 /* Linked list of the above, with a bitmap of the REGs in the
86 list. */
87
88 struct dead_debug_local
89 {
90 /* The first dead_debug_use entry in the list. */
91 struct dead_debug_use *head;
92 /* A pointer to the global tracking data structure. */
93 struct dead_debug_global *global;
94 /* A bitmap that has bits set for each REG used in the
95 dead_debug_use list, and for each entry in the global hash
96 table. */
97 bitmap used;
98 /* A bitmap that has bits set for each INSN that is to be
99 rescanned. */
100 bitmap to_rescan;
101 };
102
103 /* This type controls the behavior of dead_debug_insert_temp WRT
104 UREGNO and INSN. */
105
106 enum debug_temp_where
107 {
108 /* Bind a newly-created debug temporary to a REG for UREGNO, and
109 insert the debug insn before INSN. REG is expected to die at
110 INSN. */
111 DEBUG_TEMP_BEFORE_WITH_REG = -1,
112 /* Bind a newly-created debug temporary to the value INSN stores
113 in REG, and insert the debug insn before INSN. */
114 DEBUG_TEMP_BEFORE_WITH_VALUE = 0,
115 /* Bind a newly-created debug temporary to a REG for UREGNO, and
116 insert the debug insn after INSN. REG is expected to be set at
117 INSN. */
118 DEBUG_TEMP_AFTER_WITH_REG = 1,
119 /* Like DEBUG_TEMP_AFTER_WITH_REG, but force addition of a debug
120 temporary even if there is just a single debug use. This is used
121 on regs that are becoming REG_DEAD on INSN and so uses of the
122 reg later on are invalid. */
123 DEBUG_TEMP_AFTER_WITH_REG_FORCE = 2
124 };
125
126 extern void dead_debug_global_init (struct dead_debug_global *, bitmap);
127 extern void dead_debug_global_finish (struct dead_debug_global *, bitmap);
128 extern void dead_debug_local_init (struct dead_debug_local *, bitmap,
129 struct dead_debug_global *);
130 extern void dead_debug_local_finish (struct dead_debug_local *, bitmap);
131 extern void dead_debug_add (struct dead_debug_local *, df_ref, unsigned int);
132 extern int dead_debug_insert_temp (struct dead_debug_local *,
133 unsigned int uregno, rtx_insn *insn,
134 enum debug_temp_where);
135
136 extern void propagate_for_debug (rtx_insn *, rtx_insn *, rtx, rtx, basic_block);
137
138
139 #endif /* GCC_VALTRACK_H */