gcc/tree-ssa-sccvn.h

   1 /* Tree SCC value numbering
   2    Copyright (C) 2007, 2008, 2009 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 /* TOP of the VN lattice.  */
  25 extern tree VN_TOP;
  26
  27 /* N-ary operations in the hashtable consist of length operands, an
  28    opcode, and a type.  Result is the value number of the operation,
  29    and hashcode is stored to avoid having to calculate it
  30    repeatedly.  */
  31
  32 typedef struct vn_nary_op_s
  33 {
  34   /* Unique identify that all expressions with the same value have. */
  35   unsigned int value_id;
  36   ENUM_BITFIELD(tree_code) opcode : 16;
  37   unsigned length : 16;
  38   hashval_t hashcode;
  39   tree result;
  40   tree type;
  41   tree op[4];
  42 } *vn_nary_op_t;
  43 typedef const struct vn_nary_op_s *const_vn_nary_op_t;
  44
  45 /* Phi nodes in the hashtable consist of their non-VN_TOP phi
  46    arguments, and the basic block the phi is in. Result is the value
  47    number of the operation, and hashcode is stored to avoid having to
  48    calculate it repeatedly.  Phi nodes not in the same block are never
  49    considered equivalent.  */
  50
  51 typedef struct vn_phi_s
  52 {
  53   /* Unique identifier that all expressions with the same value have. */
  54   unsigned int value_id;
  55   hashval_t hashcode;
  56   VEC (tree, heap) *phiargs;
  57   basic_block block;
  58   tree result;
  59 } *vn_phi_t;
  60 typedef const struct vn_phi_s *const_vn_phi_t;
  61
  62 /* Reference operands only exist in reference operations structures.
  63    They consist of an opcode, type, and some number of operands.  For
  64    a given opcode, some, all, or none of the operands may be used.
  65    The operands are there to store the information that makes up the
  66    portion of the addressing calculation that opcode performs.  */
  67
  68 typedef struct vn_reference_op_struct
  69 {
  70   enum tree_code opcode;
  71   tree type;
  72   tree op0;
  73   tree op1;
  74   tree op2;
  75 } vn_reference_op_s;
  76 typedef vn_reference_op_s *vn_reference_op_t;
  77 typedef const vn_reference_op_s *const_vn_reference_op_t;
  78
  79 DEF_VEC_O(vn_reference_op_s);
  80 DEF_VEC_ALLOC_O(vn_reference_op_s, heap);
  81
  82 /* A reference operation in the hashtable is representation as
  83    the vuse, representing the memory state at the time of
  84    the operation, and a collection of operands that make up the
  85    addressing calculation.  If two vn_reference_t's have the same set
  86    of operands, they access the same memory location. We also store
  87    the resulting value number, and the hashcode.  */
  88
  89 typedef struct vn_reference_s
  90 {
  91   /* Unique identifier that all expressions with the same value have. */
  92   unsigned int value_id;
  93   hashval_t hashcode;
  94   tree vuse;
  95   alias_set_type set;
  96   tree type;
  97   VEC (vn_reference_op_s, heap) *operands;
  98   tree result;
  99 } *vn_reference_t;
 100 typedef const struct vn_reference_s *const_vn_reference_t;
 101
 102 typedef struct vn_constant_s
 103 {
 104   unsigned int value_id;
 105   hashval_t hashcode;
 106   tree constant;
 107 } *vn_constant_t;
 108
 109 /* Hash the constant CONSTANT with distinguishing type incompatible
 110    constants in the types_compatible_p sense.  */
 111
 112 static inline hashval_t
 113 vn_hash_constant_with_type (tree constant)
 114 {
 115   tree type = TREE_TYPE (constant);
 116   return (iterative_hash_expr (constant, 0)
 117           + INTEGRAL_TYPE_P (type)
 118           + (INTEGRAL_TYPE_P (type)
 119              ? TYPE_PRECISION (type) + TYPE_UNSIGNED (type) : 0));
 120 }
 121
 122 /* Compare the constants C1 and C2 with distinguishing type incompatible
 123    constants in the types_compatible_p sense.  */
 124
 125 static inline bool
 126 vn_constant_eq_with_type (tree c1, tree c2)
 127 {
 128   return (expressions_equal_p (c1, c2)
 129           && types_compatible_p (TREE_TYPE (c1), TREE_TYPE (c2)));
 130 }
 131
 132 typedef struct vn_ssa_aux
 133 {
 134   /* Value number. This may be an SSA name or a constant.  */
 135   tree valnum;
 136   /* Representative expression, if not a direct constant. */
 137   tree expr;
 138
 139   /* Unique identifier that all expressions with the same value have. */
 140   unsigned int value_id;
 141
 142   /* SCC information.  */
 143   unsigned int dfsnum;
 144   unsigned int low;
 145   unsigned visited : 1;
 146   unsigned on_sccstack : 1;
 147
 148   /* Whether the representative expression contains constants.  */
 149   unsigned has_constants : 1;
 150   /* Whether the SSA_NAME has been value numbered already.  This is
 151      only saying whether visit_use has been called on it at least
 152      once.  It cannot be used to avoid visitation for SSA_NAME's
 153      involved in non-singleton SCC's.  */
 154   unsigned use_processed : 1;
 155
 156   /* Whether the SSA_NAME has no defining statement and thus an
 157      insertion of such with EXPR as definition is required before
 158      a use can be created of it.  */
 159   unsigned needs_insertion : 1;
 160 } *vn_ssa_aux_t;
 161
 162 /* Return the value numbering info for an SSA_NAME.  */
 163 extern vn_ssa_aux_t VN_INFO (tree);
 164 extern vn_ssa_aux_t VN_INFO_GET (tree);
 165 tree vn_get_expr_for (tree);
 166 bool run_scc_vn (bool);
 167 void free_scc_vn (void);
 168 tree vn_nary_op_lookup (tree, vn_nary_op_t *);
 169 tree vn_nary_op_lookup_stmt (gimple, vn_nary_op_t *);
 170 tree vn_nary_op_lookup_pieces (unsigned int, enum tree_code,
 171                                tree, tree, tree, tree, tree,
 172                                vn_nary_op_t *);
 173 vn_nary_op_t vn_nary_op_insert (tree, tree);
 174 vn_nary_op_t vn_nary_op_insert_stmt (gimple, tree);
 175 vn_nary_op_t vn_nary_op_insert_pieces (unsigned int, enum tree_code,
 176                                        tree, tree, tree, tree,
 177                                        tree, tree, unsigned int);
 178 void vn_reference_fold_indirect (VEC (vn_reference_op_s, heap) **,
 179                                  unsigned int *);
 180 void copy_reference_ops_from_ref (tree, VEC(vn_reference_op_s, heap) **);
 181 void copy_reference_ops_from_call (gimple, VEC(vn_reference_op_s, heap) **);
 182 bool ao_ref_init_from_vn_reference (ao_ref *, alias_set_type, tree,
 183                                     VEC (vn_reference_op_s, heap) *);
 184 tree vn_reference_lookup_pieces (tree, alias_set_type, tree,
 185                                  VEC (vn_reference_op_s, heap) *,
 186                                  vn_reference_t *, bool);
 187 tree vn_reference_lookup (tree, tree, bool, vn_reference_t *);
 188 vn_reference_t vn_reference_insert (tree, tree, tree);
 189 vn_reference_t vn_reference_insert_pieces (tree, alias_set_type, tree,
 190                                            VEC (vn_reference_op_s, heap) *,
 191                                            tree, unsigned int);
 192
 193 hashval_t vn_nary_op_compute_hash (const vn_nary_op_t);
 194 int vn_nary_op_eq (const void *, const void *);
 195 bool vn_nary_may_trap (vn_nary_op_t);
 196 hashval_t vn_reference_compute_hash (const vn_reference_t);
 197 int vn_reference_eq (const void *, const void *);
 198 unsigned int get_max_value_id (void);
 199 unsigned int get_next_value_id (void);
 200 unsigned int get_constant_value_id (tree);
 201 unsigned int get_or_alloc_constant_value_id (tree);
 202 bool value_id_constant_p (unsigned int);
 203 #endif /* TREE_SSA_SCCVN_H  */