gcc/gimple-ssa.h

   1 /* Header file for routines that straddle the border between GIMPLE and
   2    SSA in gimple.
   3    Copyright (C) 2009-2014 Free Software Foundation, Inc.
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 3, or (at your option)
  10 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 GCC_GIMPLE_SSA_H
  22 #define GCC_GIMPLE_SSA_H
  23
  24 #include "hash-map.h"
  25 #include "tree-hasher.h"
  26 #include "tree-ssa-operands.h"
  27
  28 /* This structure is used to map a gimple statement to a label,
  29    or list of labels to represent transaction restart.  */
  30
  31 struct GTY((for_user)) tm_restart_node {
  32   gimple stmt;
  33   tree label_or_list;
  34 };
  35
  36 /* Hasher for tm_restart_node.  */
  37
  38 struct tm_restart_hasher : ggc_hasher<tm_restart_node *>
  39 {
  40   static hashval_t hash (tm_restart_node *n) { return htab_hash_pointer (n); }
  41
  42   static bool
  43   equal (tm_restart_node *a, tm_restart_node *b)
  44   {
  45     return a == b;
  46   }
  47 };
  48
  49 struct ssa_name_hasher : ggc_hasher<tree>
  50 {
  51   /* Hash a tree in a uid_decl_map.  */
  52
  53   static hashval_t
  54   hash (tree item)
  55   {
  56     return item->ssa_name.var->decl_minimal.uid;
  57   }
  58
  59   /* Return true if the DECL_UID in both trees are equal.  */
  60
  61   static bool
  62   equal (tree a, tree b)
  63 {
  64   return (a->ssa_name.var->decl_minimal.uid == b->ssa_name.var->decl_minimal.uid);
  65 }
  66 };
  67
  68 /* Gimple dataflow datastructure. All publicly available fields shall have
  69    gimple_ accessor defined, all publicly modifiable fields should have
  70    gimple_set accessor.  */
  71 struct GTY(()) gimple_df {
  72   /* A vector of all the noreturn calls passed to modify_stmt.
  73      cleanup_control_flow uses it to detect cases where a mid-block
  74      indirect call has been turned into a noreturn call.  When this
  75      happens, all the instructions after the call are no longer
  76      reachable and must be deleted as dead.  */
  77   vec<gimple, va_gc> *modified_noreturn_calls;
  78
  79   /* Array of all SSA_NAMEs used in the function.  */
  80   vec<tree, va_gc> *ssa_names;
  81
  82   /* Artificial variable used for the virtual operand FUD chain.  */
  83   tree vop;
  84
  85   /* The PTA solution for the ESCAPED artificial variable.  */
  86   struct pt_solution escaped;
  87
  88   /* A map of decls to artificial ssa-names that point to the partition
  89      of the decl.  */
  90   hash_map<tree, tree> * GTY((skip(""))) decls_to_pointers;
  91
  92   /* Free list of SSA_NAMEs.  */
  93   vec<tree, va_gc> *free_ssanames;
  94
  95   /* Hashtable holding definition for symbol.  If this field is not NULL, it
  96      means that the first reference to this variable in the function is a
  97      USE or a VUSE.  In those cases, the SSA renamer creates an SSA name
  98      for this variable with an empty defining statement.  */
  99   hash_table<ssa_name_hasher> *default_defs;
 100
 101   /* True if there are any symbols that need to be renamed.  */
 102   unsigned int ssa_renaming_needed : 1;
 103
 104   /* True if all virtual operands need to be renamed.  */
 105   unsigned int rename_vops : 1;
 106
 107   /* True if the code is in ssa form.  */
 108   unsigned int in_ssa_p : 1;
 109
 110   /* True if IPA points-to information was computed for this function.  */
 111   unsigned int ipa_pta : 1;
 112
 113   struct ssa_operands ssa_operands;
 114
 115   /* Map gimple stmt to tree label (or list of labels) for transaction
 116      restart and abort.  */
 117   hash_table<tm_restart_hasher> *tm_restart;
 118 };
 119
 120
 121 /* Return true when gimple SSA form was built.
 122    gimple_in_ssa_p is queried by gimplifier in various early stages before SSA
 123    infrastructure is initialized.  Check for presence of the datastructures
 124    at first place.  */
 125 static inline bool
 126 gimple_in_ssa_p (const struct function *fun)
 127 {
 128   return fun && fun->gimple_df && fun->gimple_df->in_ssa_p;
 129 }
 130
 131 /* Artificial variable used for the virtual operand FUD chain.  */
 132 static inline tree
 133 gimple_vop (const struct function *fun)
 134 {
 135   gcc_checking_assert (fun && fun->gimple_df);
 136   return fun->gimple_df->vop;
 137 }
 138
 139 /* Return the set of VUSE operand for statement G.  */
 140
 141 static inline use_operand_p
 142 gimple_vuse_op (const_gimple g)
 143 {
 144   struct use_optype_d *ops;
 145   const gimple_statement_with_memory_ops *mem_ops_stmt =
 146      dyn_cast <const gimple_statement_with_memory_ops *> (g);
 147   if (!mem_ops_stmt)
 148     return NULL_USE_OPERAND_P;
 149   ops = mem_ops_stmt->use_ops;
 150   if (ops
 151       && USE_OP_PTR (ops)->use == &mem_ops_stmt->vuse)
 152     return USE_OP_PTR (ops);
 153   return NULL_USE_OPERAND_P;
 154 }
 155
 156 /* Return the set of VDEF operand for statement G.  */
 157
 158 static inline def_operand_p
 159 gimple_vdef_op (gimple g)
 160 {
 161   gimple_statement_with_memory_ops *mem_ops_stmt =
 162      dyn_cast <gimple_statement_with_memory_ops *> (g);
 163   if (!mem_ops_stmt)
 164     return NULL_DEF_OPERAND_P;
 165   if (mem_ops_stmt->vdef)
 166     return &mem_ops_stmt->vdef;
 167   return NULL_DEF_OPERAND_P;
 168 }
 169
 170 /* Mark statement S as modified, and update it.  */
 171
 172 static inline void
 173 update_stmt (gimple s)
 174 {
 175   if (gimple_has_ops (s))
 176     {
 177       gimple_set_modified (s, true);
 178       update_stmt_operands (cfun, s);
 179     }
 180 }
 181
 182 /* Update statement S if it has been optimized.  */
 183
 184 static inline void
 185 update_stmt_if_modified (gimple s)
 186 {
 187   if (gimple_modified_p (s))
 188     update_stmt_operands (cfun, s);
 189 }
 190
 191 /* Mark statement S as modified, and update it.  */
 192
 193 static inline void
 194 update_stmt_fn (struct function *fn, gimple s)
 195 {
 196   if (gimple_has_ops (s))
 197     {
 198       gimple_set_modified (s, true);
 199       update_stmt_operands (fn, s);
 200     }
 201 }
 202
 203
 204 #endif /* GCC_GIMPLE_SSA_H */