gcc/tree-ssa-sccvn.h

   1 /* Tree SCC value numbering
   2    Copyright (C) 2007 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 a
  83    collection of vuses, 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.  The vuses are
  88    always stored in order sorted by ssa name version.  */
  89
  90 typedef struct vn_reference_s
  91 {
  92   /* Unique identifier that all expressions with the same value have. */
  93   unsigned int value_id;
  94   hashval_t hashcode;
  95   VEC (tree, gc) *vuses;
  96   VEC (vn_reference_op_s, heap) *operands;
  97   tree result;
  98 } *vn_reference_t;
  99 typedef const struct vn_reference_s *const_vn_reference_t;
 100
 101 typedef struct vn_constant_s
 102 {
 103   unsigned int value_id;
 104   hashval_t hashcode;
 105   tree constant;
 106 } *vn_constant_t;
 107
 108 /* Hash the constant CONSTANT with distinguishing type incompatible
 109    constants in the types_compatible_p sense.  */
 110
 111 static inline hashval_t
 112 vn_hash_constant_with_type (tree constant)
 113 {
 114   tree type = TREE_TYPE (constant);
 115   return (iterative_hash_expr (constant, 0)
 116           + INTEGRAL_TYPE_P (type)
 117           + (INTEGRAL_TYPE_P (type)
 118              ? TYPE_PRECISION (type) + TYPE_UNSIGNED (type) : 0));
 119 }
 120
 121 /* Compare the constants C1 and C2 with distinguishing type incompatible
 122    constants in the types_compatible_p sense.  */
 123
 124 static inline bool
 125 vn_constant_eq_with_type (tree c1, tree c2)
 126 {
 127   return (expressions_equal_p (c1, c2)
 128           && types_compatible_p (TREE_TYPE (c1), TREE_TYPE (c2)));
 129 }
 130
 131 typedef struct vn_ssa_aux
 132 {
 133   /* Value number. This may be an SSA name or a constant.  */
 134   tree valnum;
 135   /* Representative expression, if not a direct constant. */
 136   tree expr;
 137
 138   /* Unique identifier that all expressions with the same value have. */
 139   unsigned int value_id;
 140
 141   /* SCC information.  */
 142   unsigned int dfsnum;
 143   unsigned int low;
 144   unsigned visited : 1;
 145   unsigned on_sccstack : 1;
 146
 147   /* Whether the representative expression contains constants.  */
 148   unsigned has_constants : 1;
 149   /* Whether the SSA_NAME has been value numbered already.  This is
 150      only saying whether visit_use has been called on it at least
 151      once.  It cannot be used to avoid visitation for SSA_NAME's
 152      involved in non-singleton SCC's.  */
 153   unsigned use_processed : 1;
 154
 155   /* Whether the SSA_NAME has no defining statement and thus an
 156      insertion of such with EXPR as definition is required before
 157      a use can be created of it.  */
 158   unsigned needs_insertion : 1;
 159 } *vn_ssa_aux_t;
 160
 161 /* Return the value numbering info for an SSA_NAME.  */
 162 extern vn_ssa_aux_t VN_INFO (tree);
 163 extern vn_ssa_aux_t VN_INFO_GET (tree);
 164 tree vn_get_expr_for (tree);
 165 bool run_scc_vn (bool);
 166 void free_scc_vn (void);
 167 tree vn_nary_op_lookup (tree, vn_nary_op_t *);
 168 tree vn_nary_op_lookup_stmt (gimple, vn_nary_op_t *);
 169 tree vn_nary_op_lookup_pieces (unsigned int, enum tree_code,
 170                                tree, tree, tree, tree, tree,
 171                                vn_nary_op_t *);
 172 vn_nary_op_t vn_nary_op_insert (tree, tree);
 173 vn_nary_op_t vn_nary_op_insert_stmt (gimple, tree);
 174 vn_nary_op_t vn_nary_op_insert_pieces (unsigned int, enum tree_code,
 175                                        tree, tree, tree, tree,
 176                                        tree, tree, unsigned int);
 177 void copy_reference_ops_from_ref (tree, VEC(vn_reference_op_s, heap) **);
 178 void copy_reference_ops_from_call (gimple, VEC(vn_reference_op_s, heap) **);
 179 tree vn_reference_lookup_pieces (VEC (tree, gc) *,
 180                                  VEC (vn_reference_op_s, heap) *,
 181                                  vn_reference_t *, bool);
 182 tree vn_reference_lookup (tree, VEC (tree, gc) *, bool, vn_reference_t *);
 183 vn_reference_t vn_reference_insert (tree, tree, VEC (tree, gc) *);
 184 vn_reference_t vn_reference_insert_pieces (VEC (tree, gc) *,
 185                                            VEC (vn_reference_op_s, heap) *,
 186                                            tree, unsigned int);
 187 tree vn_phi_lookup (gimple);
 188
 189 hashval_t vn_nary_op_compute_hash (const vn_nary_op_t);
 190 int vn_nary_op_eq (const void *, const void *);
 191 hashval_t vn_reference_compute_hash (const vn_reference_t);
 192 int vn_reference_eq (const void *, const void *);
 193 unsigned int get_max_value_id (void);
 194 unsigned int get_next_value_id (void);
 195 unsigned int get_constant_value_id (tree);
 196 unsigned int get_or_alloc_constant_value_id (tree);
 197 bool value_id_constant_p (unsigned int);
 198 VEC (tree, gc) *shared_vuses_from_stmt (gimple);
 199 VEC (tree, gc) *copy_vuses_from_stmt (gimple);
 200 #endif /* TREE_SSA_SCCVN_H  */