gcc/tree-ssa-sccvn.h

   1 /* Tree SCC value numbering
   2    Copyright (C) 2007-2018 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   /* Controlling condition lhs/rhs.  */
  71   tree cclhs;
  72   tree ccrhs;
  73   tree type;
  74   tree result;
  75 } *vn_phi_t;
  76 typedef const struct vn_phi_s *const_vn_phi_t;
  77
  78 /* Reference operands only exist in reference operations structures.
  79    They consist of an opcode, type, and some number of operands.  For
  80    a given opcode, some, all, or none of the operands may be used.
  81    The operands are there to store the information that makes up the
  82    portion of the addressing calculation that opcode performs.  */
  83
  84 typedef struct vn_reference_op_struct
  85 {
  86   ENUM_BITFIELD(tree_code) opcode : 16;
  87   /* Dependence info, used for [TARGET_]MEM_REF only.  */
  88   unsigned short clique;
  89   unsigned short base;
  90   unsigned reverse : 1;
  91   /* For storing TYPE_ALIGN for array ref element size computation.  */
  92   unsigned align : 6;
  93   /* Constant offset this op adds or -1 if it is variable.  */
  94   poly_int64_pod off;
  95   tree type;
  96   tree op0;
  97   tree op1;
  98   tree op2;
  99 } vn_reference_op_s;
 100 typedef vn_reference_op_s *vn_reference_op_t;
 101 typedef const vn_reference_op_s *const_vn_reference_op_t;
 102
 103 inline unsigned
 104 vn_ref_op_align_unit (vn_reference_op_t op)
 105 {
 106   return op->align ? ((unsigned)1 << (op->align - 1)) / BITS_PER_UNIT : 0;
 107 }
 108
 109 /* A reference operation in the hashtable is representation as
 110    the vuse, representing the memory state at the time of
 111    the operation, and a collection of operands that make up the
 112    addressing calculation.  If two vn_reference_t's have the same set
 113    of operands, they access the same memory location. We also store
 114    the resulting value number, and the hashcode.  */
 115
 116 typedef struct vn_reference_s
 117 {
 118   /* Unique identifier that all expressions with the same value have. */
 119   unsigned int value_id;
 120   hashval_t hashcode;
 121   tree vuse;
 122   alias_set_type set;
 123   tree type;
 124   vec<vn_reference_op_s> operands;
 125   tree result;
 126   tree result_vdef;
 127 } *vn_reference_t;
 128 typedef const struct vn_reference_s *const_vn_reference_t;
 129
 130 typedef struct vn_constant_s
 131 {
 132   unsigned int value_id;
 133   hashval_t hashcode;
 134   tree constant;
 135 } *vn_constant_t;
 136
 137 enum vn_kind { VN_NONE, VN_CONSTANT, VN_NARY, VN_REFERENCE, VN_PHI };
 138 enum vn_kind vn_get_stmt_kind (gimple *);
 139
 140 /* Hash the type TYPE using bits that distinguishes it in the
 141    types_compatible_p sense.  */
 142
 143 static inline hashval_t
 144 vn_hash_type (tree type)
 145 {
 146   return (INTEGRAL_TYPE_P (type)
 147           + (INTEGRAL_TYPE_P (type)
 148              ? TYPE_PRECISION (type) + TYPE_UNSIGNED (type) : 0));
 149 }
 150
 151 /* Hash the constant CONSTANT with distinguishing type incompatible
 152    constants in the types_compatible_p sense.  */
 153
 154 static inline hashval_t
 155 vn_hash_constant_with_type (tree constant)
 156 {
 157   inchash::hash hstate;
 158   inchash::add_expr (constant, hstate);
 159   hstate.merge_hash (vn_hash_type (TREE_TYPE (constant)));
 160   return hstate.end ();
 161 }
 162
 163 /* Compare the constants C1 and C2 with distinguishing type incompatible
 164    constants in the types_compatible_p sense.  */
 165
 166 static inline bool
 167 vn_constant_eq_with_type (tree c1, tree c2)
 168 {
 169   return (expressions_equal_p (c1, c2)
 170           && types_compatible_p (TREE_TYPE (c1), TREE_TYPE (c2)));
 171 }
 172
 173 typedef struct vn_ssa_aux
 174 {
 175   /* Value number. This may be an SSA name or a constant.  */
 176   tree valnum;
 177   /* Statements to insert if needs_insertion is true.  */
 178   gimple_seq expr;
 179
 180   /* Saved SSA name info.  */
 181   tree_ssa_name::ssa_name_info_type info;
 182
 183   /* Unique identifier that all expressions with the same value have. */
 184   unsigned int value_id;
 185
 186   /* SCC information.  */
 187   unsigned int dfsnum;
 188   unsigned int low;
 189   unsigned visited : 1;
 190   unsigned on_sccstack : 1;
 191
 192   /* Whether the SSA_NAME has been value numbered already.  This is
 193      only saying whether visit_use has been called on it at least
 194      once.  It cannot be used to avoid visitation for SSA_NAME's
 195      involved in non-singleton SCC's.  */
 196   unsigned use_processed : 1;
 197
 198   /* Whether the SSA_NAME has no defining statement and thus an
 199      insertion of such with EXPR as definition is required before
 200      a use can be created of it.  */
 201   unsigned needs_insertion : 1;
 202
 203   /* Whether range-info is anti-range.  */
 204   unsigned range_info_anti_range_p : 1;
 205 } *vn_ssa_aux_t;
 206
 207 enum vn_lookup_kind { VN_NOWALK, VN_WALK, VN_WALKREWRITE };
 208
 209 /* Return the value numbering info for an SSA_NAME.  */
 210 bool has_VN_INFO (tree);
 211 extern vn_ssa_aux_t VN_INFO (tree);
 212 extern vn_ssa_aux_t VN_INFO_GET (tree);
 213 tree vn_get_expr_for (tree);
 214 void run_scc_vn (vn_lookup_kind);
 215 unsigned int vn_eliminate (bitmap);
 216 void free_scc_vn (void);
 217 void scc_vn_restore_ssa_info (void);
 218 tree vn_nary_op_lookup (tree, vn_nary_op_t *);
 219 tree vn_nary_op_lookup_stmt (gimple *, vn_nary_op_t *);
 220 tree vn_nary_op_lookup_pieces (unsigned int, enum tree_code,
 221                                tree, tree *, vn_nary_op_t *);
 222 vn_nary_op_t vn_nary_op_insert (tree, tree);
 223 vn_nary_op_t vn_nary_op_insert_pieces (unsigned int, enum tree_code,
 224                                        tree, tree *, tree, unsigned int);
 225 bool ao_ref_init_from_vn_reference (ao_ref *, alias_set_type, tree,
 226                                     vec<vn_reference_op_s> );
 227 vec<vn_reference_op_s> vn_reference_operands_for_lookup (tree);
 228 tree vn_reference_lookup_pieces (tree, alias_set_type, tree,
 229                                  vec<vn_reference_op_s> ,
 230                                  vn_reference_t *, vn_lookup_kind);
 231 tree vn_reference_lookup (tree, tree, vn_lookup_kind, vn_reference_t *, bool);
 232 void vn_reference_lookup_call (gcall *, vn_reference_t *, vn_reference_t);
 233 vn_reference_t vn_reference_insert_pieces (tree, alias_set_type, tree,
 234                                            vec<vn_reference_op_s> ,
 235                                            tree, unsigned int);
 236
 237 bool vn_nary_op_eq (const_vn_nary_op_t const vno1,
 238                     const_vn_nary_op_t const vno2);
 239 bool vn_nary_may_trap (vn_nary_op_t);
 240 bool vn_reference_eq (const_vn_reference_t const, const_vn_reference_t const);
 241 unsigned int get_max_value_id (void);
 242 unsigned int get_next_value_id (void);
 243 unsigned int get_constant_value_id (tree);
 244 unsigned int get_or_alloc_constant_value_id (tree);
 245 bool value_id_constant_p (unsigned int);
 246 tree fully_constant_vn_reference_p (vn_reference_t);
 247 tree vn_nary_simplify (vn_nary_op_t);
 248
 249 /* Valueize NAME if it is an SSA name, otherwise just return it.  */
 250
 251 static inline tree
 252 vn_valueize (tree name)
 253 {
 254   if (TREE_CODE (name) == SSA_NAME)
 255     {
 256       tree tem = VN_INFO (name)->valnum;
 257       return tem == VN_TOP ? name : tem;
 258     }
 259   return name;
 260 }
 261
 262 /* Get at the original range info for NAME.  */
 263
 264 inline range_info_def *
 265 VN_INFO_RANGE_INFO (tree name)
 266 {
 267   return (VN_INFO (name)->info.range_info
 268           ? VN_INFO (name)->info.range_info
 269           : SSA_NAME_RANGE_INFO (name));
 270 }
 271
 272 /* Whether the original range info of NAME is an anti-range.  */
 273
 274 inline bool
 275 VN_INFO_ANTI_RANGE_P (tree name)
 276 {
 277   return (VN_INFO (name)->info.range_info
 278           ? VN_INFO (name)->range_info_anti_range_p
 279           : SSA_NAME_ANTI_RANGE_P (name));
 280 }
 281
 282 /* Get at the original range info kind for NAME.  */
 283
 284 inline value_range_type
 285 VN_INFO_RANGE_TYPE (tree name)
 286 {
 287   return VN_INFO_ANTI_RANGE_P (name) ? VR_ANTI_RANGE : VR_RANGE;
 288 }
 289
 290 /* Get at the original pointer info for NAME.  */
 291
 292 inline ptr_info_def *
 293 VN_INFO_PTR_INFO (tree name)
 294 {
 295   return (VN_INFO (name)->info.ptr_info
 296           ? VN_INFO (name)->info.ptr_info
 297           : SSA_NAME_PTR_INFO (name));
 298 }
 299
 300 #endif /* TREE_SSA_SCCVN_H  */