gcc/tree-ssa-sccvn.h

   1 /* Tree SCC value numbering
   2    Copyright (C) 2007-2016 Free Software Foundation, Inc.
   3    Contributed by Daniel Berlin <dberlin@dberlin.org>
   4
   5    This file is part of GCC.
   6
   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.
  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 TREE_SSA_SCCVN_H
  22 #define TREE_SSA_SCCVN_H
  23
  24 /* In tree-ssa-sccvn.c  */
  25 bool expressions_equal_p (tree, tree);
  26
  27
  28 /* TOP of the VN lattice.  */
  29 extern tree VN_TOP;
  30
  31 /* N-ary operations in the hashtable consist of length operands, an
  32    opcode, and a type.  Result is the value number of the operation,
  33    and hashcode is stored to avoid having to calculate it
  34    repeatedly.  */
  35
  36 typedef struct vn_nary_op_s
  37 {
  38   /* Unique identify that all expressions with the same value have. */
  39   unsigned int value_id;
  40   ENUM_BITFIELD(tree_code) opcode : 16;
  41   unsigned length : 16;
  42   hashval_t hashcode;
  43   tree result;
  44   tree type;
  45   tree op[1];
  46 } *vn_nary_op_t;
  47 typedef const struct vn_nary_op_s *const_vn_nary_op_t;
  48
  49 /* Return the size of a vn_nary_op_t with LENGTH operands.  */
  50
  51 static inline size_t
  52 sizeof_vn_nary_op (unsigned int length)
  53 {
  54   return sizeof (struct vn_nary_op_s) + sizeof (tree) * length - sizeof (tree);
  55 }
  56
  57 /* Phi nodes in the hashtable consist of their non-VN_TOP phi
  58    arguments, and the basic block the phi is in. Result is the value
  59    number of the operation, and hashcode is stored to avoid having to
  60    calculate it repeatedly.  Phi nodes not in the same block are never
  61    considered equivalent.  */
  62
  63 typedef struct vn_phi_s
  64 {
  65   /* Unique identifier that all expressions with the same value have. */
  66   unsigned int value_id;
  67   hashval_t hashcode;
  68   vec<tree> phiargs;
  69   basic_block block;
  70   tree type;
  71   tree result;
  72 } *vn_phi_t;
  73 typedef const struct vn_phi_s *const_vn_phi_t;
  74
  75 /* Reference operands only exist in reference operations structures.
  76    They consist of an opcode, type, and some number of operands.  For
  77    a given opcode, some, all, or none of the operands may be used.
  78    The operands are there to store the information that makes up the
  79    portion of the addressing calculation that opcode performs.  */
  80
  81 typedef struct vn_reference_op_struct
  82 {
  83   ENUM_BITFIELD(tree_code) opcode : 16;
  84   /* 1 for instrumented calls.  */
  85   unsigned with_bounds : 1;
  86   /* Dependence info, used for [TARGET_]MEM_REF only.  */
  87   unsigned short clique;
  88   unsigned short base;
  89   /* Constant offset this op adds or -1 if it is variable.  */
  90   HOST_WIDE_INT off;
  91   tree type;
  92   tree op0;
  93   tree op1;
  94   tree op2;
  95   bool reverse;
  96 } vn_reference_op_s;
  97 typedef vn_reference_op_s *vn_reference_op_t;
  98 typedef const vn_reference_op_s *const_vn_reference_op_t;
  99
 100
 101 /* A reference operation in the hashtable is representation as
 102    the vuse, representing the memory state at the time of
 103    the operation, and a collection of operands that make up the
 104    addressing calculation.  If two vn_reference_t's have the same set
 105    of operands, they access the same memory location. We also store
 106    the resulting value number, and the hashcode.  */
 107
 108 typedef struct vn_reference_s
 109 {
 110   /* Unique identifier that all expressions with the same value have. */
 111   unsigned int value_id;
 112   hashval_t hashcode;
 113   tree vuse;
 114   alias_set_type set;
 115   tree type;
 116   vec<vn_reference_op_s> operands;
 117   tree result;
 118   tree result_vdef;
 119 } *vn_reference_t;
 120 typedef const struct vn_reference_s *const_vn_reference_t;
 121
 122 typedef struct vn_constant_s
 123 {
 124   unsigned int value_id;
 125   hashval_t hashcode;
 126   tree constant;
 127 } *vn_constant_t;
 128
 129 enum vn_kind { VN_NONE, VN_CONSTANT, VN_NARY, VN_REFERENCE, VN_PHI };
 130 enum vn_kind vn_get_stmt_kind (gimple *);
 131
 132 /* Hash the type TYPE using bits that distinguishes it in the
 133    types_compatible_p sense.  */
 134
 135 static inline hashval_t
 136 vn_hash_type (tree type)
 137 {
 138   return (INTEGRAL_TYPE_P (type)
 139           + (INTEGRAL_TYPE_P (type)
 140              ? TYPE_PRECISION (type) + TYPE_UNSIGNED (type) : 0));
 141 }
 142
 143 /* Hash the constant CONSTANT with distinguishing type incompatible
 144    constants in the types_compatible_p sense.  */
 145
 146 static inline hashval_t
 147 vn_hash_constant_with_type (tree constant)
 148 {
 149   inchash::hash hstate;
 150   inchash::add_expr (constant, hstate);
 151   hstate.merge_hash (vn_hash_type (TREE_TYPE (constant)));
 152   return hstate.end ();
 153 }
 154
 155 /* Compare the constants C1 and C2 with distinguishing type incompatible
 156    constants in the types_compatible_p sense.  */
 157
 158 static inline bool
 159 vn_constant_eq_with_type (tree c1, tree c2)
 160 {
 161   return (expressions_equal_p (c1, c2)
 162           && types_compatible_p (TREE_TYPE (c1), TREE_TYPE (c2)));
 163 }
 164
 165 typedef struct vn_ssa_aux
 166 {
 167   /* Value number. This may be an SSA name or a constant.  */
 168   tree valnum;
 169   /* Statements to insert if needs_insertion is true.  */
 170   gimple_seq expr;
 171
 172   /* Saved SSA name info.  */
 173   tree_ssa_name::ssa_name_info_type info;
 174
 175   /* Unique identifier that all expressions with the same value have. */
 176   unsigned int value_id;
 177
 178   /* SCC information.  */
 179   unsigned int dfsnum;
 180   unsigned int low;
 181   unsigned visited : 1;
 182   unsigned on_sccstack : 1;
 183
 184   /* Whether the SSA_NAME has been value numbered already.  This is
 185      only saying whether visit_use has been called on it at least
 186      once.  It cannot be used to avoid visitation for SSA_NAME's
 187      involved in non-singleton SCC's.  */
 188   unsigned use_processed : 1;
 189
 190   /* Whether the SSA_NAME has no defining statement and thus an
 191      insertion of such with EXPR as definition is required before
 192      a use can be created of it.  */
 193   unsigned needs_insertion : 1;
 194
 195   /* Whether range-info is anti-range.  */
 196   unsigned range_info_anti_range_p : 1;
 197 } *vn_ssa_aux_t;
 198
 199 enum vn_lookup_kind { VN_NOWALK, VN_WALK, VN_WALKREWRITE };
 200
 201 /* Return the value numbering info for an SSA_NAME.  */
 202 extern vn_ssa_aux_t VN_INFO (tree);
 203 extern vn_ssa_aux_t VN_INFO_GET (tree);
 204 tree vn_get_expr_for (tree);
 205 bool run_scc_vn (vn_lookup_kind);
 206 void free_scc_vn (void);
 207 tree vn_nary_op_lookup (tree, vn_nary_op_t *);
 208 tree vn_nary_op_lookup_stmt (gimple *, vn_nary_op_t *);
 209 tree vn_nary_op_lookup_pieces (unsigned int, enum tree_code,
 210                                tree, tree *, vn_nary_op_t *);
 211 vn_nary_op_t vn_nary_op_insert (tree, tree);
 212 vn_nary_op_t vn_nary_op_insert_pieces (unsigned int, enum tree_code,
 213                                        tree, tree *, tree, unsigned int);
 214 bool ao_ref_init_from_vn_reference (ao_ref *, alias_set_type, tree,
 215                                     vec<vn_reference_op_s> );
 216 tree vn_reference_lookup_pieces (tree, alias_set_type, tree,
 217                                  vec<vn_reference_op_s> ,
 218                                  vn_reference_t *, vn_lookup_kind);
 219 tree vn_reference_lookup (tree, tree, vn_lookup_kind, vn_reference_t *, bool);
 220 void vn_reference_lookup_call (gcall *, vn_reference_t *, vn_reference_t);
 221 vn_reference_t vn_reference_insert_pieces (tree, alias_set_type, tree,
 222                                            vec<vn_reference_op_s> ,
 223                                            tree, unsigned int);
 224
 225 bool vn_nary_op_eq (const_vn_nary_op_t const vno1,
 226                     const_vn_nary_op_t const vno2);
 227 bool vn_nary_may_trap (vn_nary_op_t);
 228 bool vn_reference_eq (const_vn_reference_t const, const_vn_reference_t const);
 229 unsigned int get_max_value_id (void);
 230 unsigned int get_next_value_id (void);
 231 unsigned int get_constant_value_id (tree);
 232 unsigned int get_or_alloc_constant_value_id (tree);
 233 bool value_id_constant_p (unsigned int);
 234 tree fully_constant_vn_reference_p (vn_reference_t);
 235
 236 /* Valueize NAME if it is an SSA name, otherwise just return it.  */
 237
 238 static inline tree
 239 vn_valueize (tree name)
 240 {
 241   if (TREE_CODE (name) == SSA_NAME)
 242     {
 243       tree tem = VN_INFO (name)->valnum;
 244       return tem == VN_TOP ? name : tem;
 245     }
 246   return name;
 247 }
 248
 249 /* Get at the original range info for NAME.  */
 250
 251 inline range_info_def *
 252 VN_INFO_RANGE_INFO (tree name)
 253 {
 254   return (VN_INFO (name)->info.range_info
 255           ? VN_INFO (name)->info.range_info
 256           : SSA_NAME_RANGE_INFO (name));
 257 }
 258
 259 /* Whether the original range info of NAME is an anti-range.  */
 260
 261 inline bool
 262 VN_INFO_ANTI_RANGE_P (tree name)
 263 {
 264   return (VN_INFO (name)->info.range_info
 265           ? VN_INFO (name)->range_info_anti_range_p
 266           : SSA_NAME_ANTI_RANGE_P (name));
 267 }
 268
 269 /* Get at the original range info kind for NAME.  */
 270
 271 inline value_range_type
 272 VN_INFO_RANGE_TYPE (tree name)
 273 {
 274   return VN_INFO_ANTI_RANGE_P (name) ? VR_ANTI_RANGE : VR_RANGE;
 275 }
 276
 277 /* Get at the original pointer info for NAME.  */
 278
 279 inline ptr_info_def *
 280 VN_INFO_PTR_INFO (tree name)
 281 {
 282   return (VN_INFO (name)->info.ptr_info
 283           ? VN_INFO (name)->info.ptr_info
 284           : SSA_NAME_PTR_INFO (name));
 285 }
 286
 287 #endif /* TREE_SSA_SCCVN_H  */