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