gcc/tree-ssa-sccvn.h

   1 /* Tree SCC value numbering
   2    Copyright (C) 2007-2017 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   /* Dependence info, used for [TARGET_]MEM_REF only.  */
  85   unsigned short clique;
  86   unsigned short base;
  87   /* 1 for instrumented calls.  */
  88   unsigned with_bounds : 1;
  89   unsigned reverse : 1;
  90   /* For storing TYPE_ALIGN for array ref element size computation.  */
  91   unsigned align : 6;
  92   /* Constant offset this op adds or -1 if it is variable.  */
  93   HOST_WIDE_INT off;
  94   tree type;
  95   tree op0;
  96   tree op1;
  97   tree op2;
  98 } vn_reference_op_s;
  99 typedef vn_reference_op_s *vn_reference_op_t;
 100 typedef const vn_reference_op_s *const_vn_reference_op_t;
 101
 102 inline unsigned
 103 vn_ref_op_align_unit (vn_reference_op_t op)
 104 {
 105   return op->align ? ((unsigned)1 << (op->align - 1)) / BITS_PER_UNIT : 0;
 106 }
 107
 108 /* A reference operation in the hashtable is representation as
 109    the vuse, representing the memory state at the time of
 110    the operation, and a collection of operands that make up the
 111    addressing calculation.  If two vn_reference_t's have the same set
 112    of operands, they access the same memory location. We also store
 113    the resulting value number, and the hashcode.  */
 114
 115 typedef struct vn_reference_s
 116 {
 117   /* Unique identifier that all expressions with the same value have. */
 118   unsigned int value_id;
 119   hashval_t hashcode;
 120   tree vuse;
 121   alias_set_type set;
 122   tree type;
 123   vec<vn_reference_op_s> operands;
 124   tree result;
 125   tree result_vdef;
 126 } *vn_reference_t;
 127 typedef const struct vn_reference_s *const_vn_reference_t;
 128
 129 typedef struct vn_constant_s
 130 {
 131   unsigned int value_id;
 132   hashval_t hashcode;
 133   tree constant;
 134 } *vn_constant_t;
 135
 136 enum vn_kind { VN_NONE, VN_CONSTANT, VN_NARY, VN_REFERENCE, VN_PHI };
 137 enum vn_kind vn_get_stmt_kind (gimple *);
 138
 139 /* Hash the type TYPE using bits that distinguishes it in the
 140    types_compatible_p sense.  */
 141
 142 static inline hashval_t
 143 vn_hash_type (tree type)
 144 {
 145   return (INTEGRAL_TYPE_P (type)
 146           + (INTEGRAL_TYPE_P (type)
 147              ? TYPE_PRECISION (type) + TYPE_UNSIGNED (type) : 0));
 148 }
 149
 150 /* Hash the constant CONSTANT with distinguishing type incompatible
 151    constants in the types_compatible_p sense.  */
 152
 153 static inline hashval_t
 154 vn_hash_constant_with_type (tree constant)
 155 {
 156   inchash::hash hstate;
 157   inchash::add_expr (constant, hstate);
 158   hstate.merge_hash (vn_hash_type (TREE_TYPE (constant)));
 159   return hstate.end ();
 160 }
 161
 162 /* Compare the constants C1 and C2 with distinguishing type incompatible
 163    constants in the types_compatible_p sense.  */
 164
 165 static inline bool
 166 vn_constant_eq_with_type (tree c1, tree c2)
 167 {
 168   return (expressions_equal_p (c1, c2)
 169           && types_compatible_p (TREE_TYPE (c1), TREE_TYPE (c2)));
 170 }
 171
 172 typedef struct vn_ssa_aux
 173 {
 174   /* Value number. This may be an SSA name or a constant.  */
 175   tree valnum;
 176   /* Statements to insert if needs_insertion is true.  */
 177   gimple_seq expr;
 178
 179   /* Saved SSA name info.  */
 180   tree_ssa_name::ssa_name_info_type info;
 181
 182   /* Unique identifier that all expressions with the same value have. */
 183   unsigned int value_id;
 184
 185   /* SCC information.  */
 186   unsigned int dfsnum;
 187   unsigned int low;
 188   unsigned visited : 1;
 189   unsigned on_sccstack : 1;
 190
 191   /* Whether the SSA_NAME has been value numbered already.  This is
 192      only saying whether visit_use has been called on it at least
 193      once.  It cannot be used to avoid visitation for SSA_NAME's
 194      involved in non-singleton SCC's.  */
 195   unsigned use_processed : 1;
 196
 197   /* Whether the SSA_NAME has no defining statement and thus an
 198      insertion of such with EXPR as definition is required before
 199      a use can be created of it.  */
 200   unsigned needs_insertion : 1;
 201
 202   /* Whether range-info is anti-range.  */
 203   unsigned range_info_anti_range_p : 1;
 204 } *vn_ssa_aux_t;
 205
 206 enum vn_lookup_kind { VN_NOWALK, VN_WALK, VN_WALKREWRITE };
 207
 208 /* Return the value numbering info for an SSA_NAME.  */
 209 extern vn_ssa_aux_t VN_INFO (tree);
 210 extern vn_ssa_aux_t VN_INFO_GET (tree);
 211 tree vn_get_expr_for (tree);
 212 bool run_scc_vn (vn_lookup_kind);
 213 void free_scc_vn (void);
 214 void scc_vn_restore_ssa_info (void);
 215 tree vn_nary_op_lookup (tree, vn_nary_op_t *);
 216 tree vn_nary_op_lookup_stmt (gimple *, vn_nary_op_t *);
 217 tree vn_nary_op_lookup_pieces (unsigned int, enum tree_code,
 218                                tree, tree *, vn_nary_op_t *);
 219 vn_nary_op_t vn_nary_op_insert (tree, tree);
 220 vn_nary_op_t vn_nary_op_insert_pieces (unsigned int, enum tree_code,
 221                                        tree, tree *, tree, unsigned int);
 222 bool ao_ref_init_from_vn_reference (ao_ref *, alias_set_type, tree,
 223                                     vec<vn_reference_op_s> );
 224 vec<vn_reference_op_s> vn_reference_operands_for_lookup (tree);
 225 tree vn_reference_lookup_pieces (tree, alias_set_type, tree,
 226                                  vec<vn_reference_op_s> ,
 227                                  vn_reference_t *, vn_lookup_kind);
 228 tree vn_reference_lookup (tree, tree, vn_lookup_kind, vn_reference_t *, bool);
 229 void vn_reference_lookup_call (gcall *, vn_reference_t *, vn_reference_t);
 230 vn_reference_t vn_reference_insert_pieces (tree, alias_set_type, tree,
 231                                            vec<vn_reference_op_s> ,
 232                                            tree, unsigned int);
 233
 234 bool vn_nary_op_eq (const_vn_nary_op_t const vno1,
 235                     const_vn_nary_op_t const vno2);
 236 bool vn_nary_may_trap (vn_nary_op_t);
 237 bool vn_reference_eq (const_vn_reference_t const, const_vn_reference_t const);
 238 unsigned int get_max_value_id (void);
 239 unsigned int get_next_value_id (void);
 240 unsigned int get_constant_value_id (tree);
 241 unsigned int get_or_alloc_constant_value_id (tree);
 242 bool value_id_constant_p (unsigned int);
 243 tree fully_constant_vn_reference_p (vn_reference_t);
 244 tree vn_nary_simplify (vn_nary_op_t);
 245
 246 /* Valueize NAME if it is an SSA name, otherwise just return it.  */
 247
 248 static inline tree
 249 vn_valueize (tree name)
 250 {
 251   if (TREE_CODE (name) == SSA_NAME)
 252     {
 253       tree tem = VN_INFO (name)->valnum;
 254       return tem == VN_TOP ? name : tem;
 255     }
 256   return name;
 257 }
 258
 259 /* Get at the original range info for NAME.  */
 260
 261 inline range_info_def *
 262 VN_INFO_RANGE_INFO (tree name)
 263 {
 264   return (VN_INFO (name)->info.range_info
 265           ? VN_INFO (name)->info.range_info
 266           : SSA_NAME_RANGE_INFO (name));
 267 }
 268
 269 /* Whether the original range info of NAME is an anti-range.  */
 270
 271 inline bool
 272 VN_INFO_ANTI_RANGE_P (tree name)
 273 {
 274   return (VN_INFO (name)->info.range_info
 275           ? VN_INFO (name)->range_info_anti_range_p
 276           : SSA_NAME_ANTI_RANGE_P (name));
 277 }
 278
 279 /* Get at the original range info kind for NAME.  */
 280
 281 inline value_range_type
 282 VN_INFO_RANGE_TYPE (tree name)
 283 {
 284   return VN_INFO_ANTI_RANGE_P (name) ? VR_ANTI_RANGE : VR_RANGE;
 285 }
 286
 287 /* Get at the original pointer info for NAME.  */
 288
 289 inline ptr_info_def *
 290 VN_INFO_PTR_INFO (tree name)
 291 {
 292   return (VN_INFO (name)->info.ptr_info
 293           ? VN_INFO (name)->info.ptr_info
 294           : SSA_NAME_PTR_INFO (name));
 295 }
 296
 297 #endif /* TREE_SSA_SCCVN_H  */