gcc/valtrack.h

   1 /* Infrastructure for tracking user variable locations and values
   2    throughout compilation.
   3    Copyright (C) 2010-2021 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 */