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   /* 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   /* 1 for instrumented calls.  */
  91   unsigned with_bounds : 1;
  92   unsigned reverse : 1;
  93   /* For storing TYPE_ALIGN for array ref element size computation.  */
  94   unsigned align : 6;
  95   /* Constant offset this op adds or -1 if it is variable.  */
  96   HOST_WIDE_INT off;
  97   tree type;
  98   tree op0;
  99   tree op1;
 100   tree op2;
 101 } vn_reference_op_s;
 102 typedef vn_reference_op_s *vn_reference_op_t;
 103 typedef const vn_reference_op_s *const_vn_reference_op_t;
 104
 105 inline unsigned
 106 vn_ref_op_align_unit (vn_reference_op_t op)
 107 {
 108   return op->align ? ((unsigned)1 << (op->align - 1)) / BITS_PER_UNIT : 0;
 109 }
 110
 111 /* A reference operation in the hashtable is representation as
 112    the vuse, representing the memory state at the time of
 113    the operation, and a collection of operands that make up the
 114    addressing calculation.  If two vn_reference_t's have the same set
 115    of operands, they access the same memory location. We also store
 116    the resulting value number, and the hashcode.  */
 117
 118 typedef struct vn_reference_s
 119 {
 120   /* Unique identifier that all expressions with the same value have. */
 121   unsigned int value_id;
 122   hashval_t hashcode;
 123   tree vuse;
 124   alias_set_type set;
 125   tree type;
 126   vec<vn_reference_op_s> operands;
 127   tree result;
 128   tree result_vdef;
 129 } *vn_reference_t;
 130 typedef const struct vn_reference_s *const_vn_reference_t;
 131
 132 typedef struct vn_constant_s
 133 {
 134   unsigned int value_id;
 135   hashval_t hashcode;
 136   tree constant;
 137 } *vn_constant_t;
 138
 139 enum vn_kind { VN_NONE, VN_CONSTANT, VN_NARY, VN_REFERENCE, VN_PHI };
 140 enum vn_kind vn_get_stmt_kind (gimple *);
 141
 142 /* Hash the type TYPE using bits that distinguishes it in the
 143    types_compatible_p sense.  */
 144
 145 static inline hashval_t
 146 vn_hash_type (tree type)
 147 {
 148   return (INTEGRAL_TYPE_P (type)
 149           + (INTEGRAL_TYPE_P (type)
 150              ? TYPE_PRECISION (type) + TYPE_UNSIGNED (type) : 0));
 151 }
 152
 153 /* Hash the constant CONSTANT with distinguishing type incompatible
 154    constants in the types_compatible_p sense.  */
 155
 156 static inline hashval_t
 157 vn_hash_constant_with_type (tree constant)
 158 {
 159   inchash::hash hstate;
 160   inchash::add_expr (constant, hstate);
 161   hstate.merge_hash (vn_hash_type (TREE_TYPE (constant)));
 162   return hstate.end ();
 163 }
 164
 165 /* Compare the constants C1 and C2 with distinguishing type incompatible
 166    constants in the types_compatible_p sense.  */
 167
 168 static inline bool
 169 vn_constant_eq_with_type (tree c1, tree c2)
 170 {
 171   return (expressions_equal_p (c1, c2)
 172           && types_compatible_p (TREE_TYPE (c1), TREE_TYPE (c2)));
 173 }
 174
 175 typedef struct vn_ssa_aux
 176 {
 177   /* Value number. This may be an SSA name or a constant.  */
 178   tree valnum;
 179   /* Statements to insert if needs_insertion is true.  */
 180   gimple_seq expr;
 181
 182   /* Saved SSA name info.  */
 183   tree_ssa_name::ssa_name_info_type info;
 184
 185   /* Unique identifier that all expressions with the same value have. */
 186   unsigned int value_id;
 187
 188   /* SCC information.  */
 189   unsigned int dfsnum;
 190   unsigned int low;
 191   unsigned visited : 1;
 192   unsigned on_sccstack : 1;
 193
 194   /* Whether the SSA_NAME has been value numbered already.  This is
 195      only saying whether visit_use has been called on it at least
 196      once.  It cannot be used to avoid visitation for SSA_NAME's
 197      involved in non-singleton SCC's.  */
 198   unsigned use_processed : 1;
 199
 200   /* Whether the SSA_NAME has no defining statement and thus an
 201      insertion of such with EXPR as definition is required before
 202      a use can be created of it.  */
 203   unsigned needs_insertion : 1;
 204
 205   /* Whether range-info is anti-range.  */
 206   unsigned range_info_anti_range_p : 1;
 207 } *vn_ssa_aux_t;
 208
 209 enum vn_lookup_kind { VN_NOWALK, VN_WALK, VN_WALKREWRITE };
 210
 211 /* Return the value numbering info for an SSA_NAME.  */
 212 bool has_VN_INFO (tree);
 213 extern vn_ssa_aux_t VN_INFO (tree);
 214 extern vn_ssa_aux_t VN_INFO_GET (tree);
 215 tree vn_get_expr_for (tree);
 216 void run_scc_vn (vn_lookup_kind);
 217 unsigned int vn_eliminate (bitmap);
 218 void free_scc_vn (void);
 219 void scc_vn_restore_ssa_info (void);
 220 tree vn_nary_op_lookup (tree, vn_nary_op_t *);
 221 tree vn_nary_op_lookup_stmt (gimple *, vn_nary_op_t *);
 222 tree vn_nary_op_lookup_pieces (unsigned int, enum tree_code,
 223                                tree, tree *, vn_nary_op_t *);
 224 vn_nary_op_t vn_nary_op_insert (tree, tree);
 225 vn_nary_op_t vn_nary_op_insert_pieces (unsigned int, enum tree_code,
 226                                        tree, tree *, tree, unsigned int);
 227 bool ao_ref_init_from_vn_reference (ao_ref *, alias_set_type, tree,
 228                                     vec<vn_reference_op_s> );
 229 vec<vn_reference_op_s> vn_reference_operands_for_lookup (tree);
 230 tree vn_reference_lookup_pieces (tree, alias_set_type, tree,
 231                                  vec<vn_reference_op_s> ,
 232                                  vn_reference_t *, vn_lookup_kind);
 233 tree vn_reference_lookup (tree, tree, vn_lookup_kind, vn_reference_t *, bool);
 234 void vn_reference_lookup_call (gcall *, vn_reference_t *, vn_reference_t);
 235 vn_reference_t vn_reference_insert_pieces (tree, alias_set_type, tree,
 236                                            vec<vn_reference_op_s> ,
 237                                            tree, unsigned int);
 238
 239 bool vn_nary_op_eq (const_vn_nary_op_t const vno1,
 240                     const_vn_nary_op_t const vno2);
 241 bool vn_nary_may_trap (vn_nary_op_t);
 242 bool vn_reference_eq (const_vn_reference_t const, const_vn_reference_t const);
 243 unsigned int get_max_value_id (void);
 244 unsigned int get_next_value_id (void);
 245 unsigned int get_constant_value_id (tree);
 246 unsigned int get_or_alloc_constant_value_id (tree);
 247 bool value_id_constant_p (unsigned int);
 248 tree fully_constant_vn_reference_p (vn_reference_t);
 249 tree vn_nary_simplify (vn_nary_op_t);
 250
 251 /* Valueize NAME if it is an SSA name, otherwise just return it.  */
 252
 253 static inline tree
 254 vn_valueize (tree name)
 255 {
 256   if (TREE_CODE (name) == SSA_NAME)
 257     {
 258       tree tem = VN_INFO (name)->valnum;
 259       return tem == VN_TOP ? name : tem;
 260     }
 261   return name;
 262 }
 263
 264 /* Get at the original range info for NAME.  */
 265
 266 inline range_info_def *
 267 VN_INFO_RANGE_INFO (tree name)
 268 {
 269   return (VN_INFO (name)->info.range_info
 270           ? VN_INFO (name)->info.range_info
 271           : SSA_NAME_RANGE_INFO (name));
 272 }
 273
 274 /* Whether the original range info of NAME is an anti-range.  */
 275
 276 inline bool
 277 VN_INFO_ANTI_RANGE_P (tree name)
 278 {
 279   return (VN_INFO (name)->info.range_info
 280           ? VN_INFO (name)->range_info_anti_range_p
 281           : SSA_NAME_ANTI_RANGE_P (name));
 282 }
 283
 284 /* Get at the original range info kind for NAME.  */
 285
 286 inline value_range_type
 287 VN_INFO_RANGE_TYPE (tree name)
 288 {
 289   return VN_INFO_ANTI_RANGE_P (name) ? VR_ANTI_RANGE : VR_RANGE;
 290 }
 291
 292 /* Get at the original pointer info for NAME.  */
 293
 294 inline ptr_info_def *
 295 VN_INFO_PTR_INFO (tree name)
 296 {
 297   return (VN_INFO (name)->info.ptr_info
 298           ? VN_INFO (name)->info.ptr_info
 299           : SSA_NAME_PTR_INFO (name));
 300 }
 301
 302 #endif /* TREE_SSA_SCCVN_H  */