gcc/cselib.h

   1 /* Common subexpression elimination for GNU compiler.
   2    Copyright (C) 1987-2015 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify it under
   7 the terms of the GNU General Public License as published by the Free
   8 Software Foundation; either version 3, or (at your option) any later
   9 version.
  10
  11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef GCC_CSELIB_H
  21 #define GCC_CSELIB_H
  22
  23 /* Describe a value.  */
  24 struct cselib_val
  25 {
  26   /* The hash value.  */
  27   unsigned int hash;
  28
  29   /* A unique id assigned to values.  */
  30   int uid;
  31
  32   /* A VALUE rtx that points back to this structure.  */
  33   rtx val_rtx;
  34
  35   /* All rtl expressions that hold this value at the current time during a
  36      scan.  */
  37   struct elt_loc_list *locs;
  38
  39   /* If this value is used as an address, points to a list of values that
  40      use it as an address in a MEM.  */
  41   struct elt_list *addr_list;
  42
  43   struct cselib_val *next_containing_mem;
  44
  45   /* Pool allocation new operator.  */
  46   inline void *operator new (size_t)
  47   {
  48     return pool.allocate ();
  49   }
  50
  51   /* Delete operator utilizing pool allocation.  */
  52   inline void operator delete (void *ptr)
  53   {
  54     pool.remove ((cselib_val *) ptr);
  55   }
  56
  57   /* Memory allocation pool.  */
  58   static pool_allocator<cselib_val> pool;
  59 };
  60
  61 /* A list of rtl expressions that hold the same value.  */
  62 struct elt_loc_list {
  63   /* Next element in the list.  */
  64   struct elt_loc_list *next;
  65   /* An rtl expression that holds the value.  */
  66   rtx loc;
  67   /* The insn that made the equivalence.  */
  68   rtx_insn *setting_insn;
  69
  70   /* Pool allocation new operator.  */
  71   inline void *operator new (size_t)
  72   {
  73     return pool.allocate ();
  74   }
  75
  76   /* Delete operator utilizing pool allocation.  */
  77   inline void operator delete (void *ptr)
  78   {
  79     pool.remove ((elt_loc_list *) ptr);
  80   }
  81
  82   /* Memory allocation pool.  */
  83   static pool_allocator<elt_loc_list> pool;
  84 };
  85
  86 /* Describe a single set that is part of an insn.  */
  87 struct cselib_set
  88 {
  89   rtx src;
  90   rtx dest;
  91   cselib_val *src_elt;
  92   cselib_val *dest_addr_elt;
  93 };
  94
  95 enum cselib_record_what
  96 {
  97   CSELIB_RECORD_MEMORY = 1,
  98   CSELIB_PRESERVE_CONSTANTS = 2
  99 };
 100
 101 extern void (*cselib_discard_hook) (cselib_val *);
 102 extern void (*cselib_record_sets_hook) (rtx_insn *insn, struct cselib_set *sets,
 103                                         int n_sets);
 104
 105 extern cselib_val *cselib_lookup (rtx, machine_mode,
 106                                   int, machine_mode);
 107 extern cselib_val *cselib_lookup_from_insn (rtx, machine_mode,
 108                                             int, machine_mode, rtx_insn *);
 109 extern void cselib_init (int);
 110 extern void cselib_clear_table (void);
 111 extern void cselib_finish (void);
 112 extern void cselib_process_insn (rtx_insn *);
 113 extern bool fp_setter_insn (rtx_insn *);
 114 extern machine_mode cselib_reg_set_mode (const_rtx);
 115 extern int rtx_equal_for_cselib_p (rtx, rtx);
 116 extern int references_value_p (const_rtx, int);
 117 extern rtx cselib_expand_value_rtx (rtx, bitmap, int);
 118 typedef rtx (*cselib_expand_callback)(rtx, bitmap, int, void *);
 119 extern rtx cselib_expand_value_rtx_cb (rtx, bitmap, int,
 120                                        cselib_expand_callback, void *);
 121 extern bool cselib_dummy_expand_value_rtx_cb (rtx, bitmap, int,
 122                                               cselib_expand_callback, void *);
 123 extern rtx cselib_subst_to_values (rtx, machine_mode);
 124 extern rtx cselib_subst_to_values_from_insn (rtx, machine_mode, rtx_insn *);
 125 extern void cselib_invalidate_rtx (rtx);
 126
 127 extern void cselib_reset_table (unsigned int);
 128 extern unsigned int cselib_get_next_uid (void);
 129 extern void cselib_preserve_value (cselib_val *);
 130 extern bool cselib_preserved_value_p (cselib_val *);
 131 extern void cselib_preserve_only_values (void);
 132 extern void cselib_preserve_cfa_base_value (cselib_val *, unsigned int);
 133 extern void cselib_add_permanent_equiv (cselib_val *, rtx, rtx_insn *);
 134 extern bool cselib_have_permanent_equivalences (void);
 135 extern void cselib_set_value_sp_based (cselib_val *);
 136 extern bool cselib_sp_based_value_p (cselib_val *);
 137
 138 extern void dump_cselib_table (FILE *);
 139
 140 /* Return the canonical value for VAL, following the equivalence chain
 141    towards the earliest (== lowest uid) equivalent value.  */
 142
 143 static inline cselib_val *
 144 canonical_cselib_val (cselib_val *val)
 145 {
 146   cselib_val *canon;
 147
 148   if (!val->locs || val->locs->next
 149       || !val->locs->loc || GET_CODE (val->locs->loc) != VALUE
 150       || val->uid < CSELIB_VAL_PTR (val->locs->loc)->uid)
 151     return val;
 152
 153   canon = CSELIB_VAL_PTR (val->locs->loc);
 154   gcc_checking_assert (canonical_cselib_val (canon) == canon);
 155   return canon;
 156 }
 157
 158 #endif /* GCC_CSELIB_H */