gcc/tree-ssa-sccvn.h

   1 /* Tree SCC value numbering
   2    Copyright (C) 2007, 2008, 2009, 2010 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   /* Constant offset this op adds or -1 if it is variable.  */
  76   HOST_WIDE_INT off;
  77   tree type;
  78   tree op0;
  79   tree op1;
  80   tree op2;
  81 } vn_reference_op_s;
  82 typedef vn_reference_op_s *vn_reference_op_t;
  83 typedef const vn_reference_op_s *const_vn_reference_op_t;
  84
  85 DEF_VEC_O(vn_reference_op_s);
  86 DEF_VEC_ALLOC_O(vn_reference_op_s, heap);
  87
  88 /* A reference operation in the hashtable is representation as
  89    the vuse, representing the memory state at the time of
  90    the operation, and a collection of operands that make up the
  91    addressing calculation.  If two vn_reference_t's have the same set
  92    of operands, they access the same memory location. We also store
  93    the resulting value number, and the hashcode.  */
  94
  95 typedef struct vn_reference_s
  96 {
  97   /* Unique identifier that all expressions with the same value have. */
  98   unsigned int value_id;
  99   hashval_t hashcode;
 100   tree vuse;
 101   alias_set_type set;
 102   tree type;
 103   VEC (vn_reference_op_s, heap) *operands;
 104   tree result;
 105 } *vn_reference_t;
 106 typedef const struct vn_reference_s *const_vn_reference_t;
 107
 108 typedef struct vn_constant_s
 109 {
 110   unsigned int value_id;
 111   hashval_t hashcode;
 112   tree constant;
 113 } *vn_constant_t;
 114
 115 /* Hash the constant CONSTANT with distinguishing type incompatible
 116    constants in the types_compatible_p sense.  */
 117
 118 static inline hashval_t
 119 vn_hash_constant_with_type (tree constant)
 120 {
 121   tree type = TREE_TYPE (constant);
 122   return (iterative_hash_expr (constant, 0)
 123           + INTEGRAL_TYPE_P (type)
 124           + (INTEGRAL_TYPE_P (type)
 125              ? TYPE_PRECISION (type) + TYPE_UNSIGNED (type) : 0));
 126 }
 127
 128 /* Compare the constants C1 and C2 with distinguishing type incompatible
 129    constants in the types_compatible_p sense.  */
 130
 131 static inline bool
 132 vn_constant_eq_with_type (tree c1, tree c2)
 133 {
 134   return (expressions_equal_p (c1, c2)
 135           && types_compatible_p (TREE_TYPE (c1), TREE_TYPE (c2)));
 136 }
 137
 138 typedef struct vn_ssa_aux
 139 {
 140   /* Value number. This may be an SSA name or a constant.  */
 141   tree valnum;
 142   /* Representative expression, if not a direct constant. */
 143   tree expr;
 144
 145   /* Unique identifier that all expressions with the same value have. */
 146   unsigned int value_id;
 147
 148   /* SCC information.  */
 149   unsigned int dfsnum;
 150   unsigned int low;
 151   unsigned visited : 1;
 152   unsigned on_sccstack : 1;
 153
 154   /* Whether the representative expression contains constants.  */
 155   unsigned has_constants : 1;
 156   /* Whether the SSA_NAME has been value numbered already.  This is
 157      only saying whether visit_use has been called on it at least
 158      once.  It cannot be used to avoid visitation for SSA_NAME's
 159      involved in non-singleton SCC's.  */
 160   unsigned use_processed : 1;
 161
 162   /* Whether the SSA_NAME has no defining statement and thus an
 163      insertion of such with EXPR as definition is required before
 164      a use can be created of it.  */
 165   unsigned needs_insertion : 1;
 166 } *vn_ssa_aux_t;
 167
 168 typedef enum { VN_NOWALK, VN_WALK, VN_WALKREWRITE } vn_lookup_kind;
 169
 170 /* Return the value numbering info for an SSA_NAME.  */
 171 extern vn_ssa_aux_t VN_INFO (tree);
 172 extern vn_ssa_aux_t VN_INFO_GET (tree);
 173 tree vn_get_expr_for (tree);
 174 bool run_scc_vn (vn_lookup_kind);
 175 void free_scc_vn (void);
 176 tree vn_nary_op_lookup (tree, vn_nary_op_t *);
 177 tree vn_nary_op_lookup_stmt (gimple, vn_nary_op_t *);
 178 tree vn_nary_op_lookup_pieces (unsigned int, enum tree_code,
 179                                tree, tree, tree, tree, tree,
 180                                vn_nary_op_t *);
 181 vn_nary_op_t vn_nary_op_insert (tree, tree);
 182 vn_nary_op_t vn_nary_op_insert_stmt (gimple, tree);
 183 vn_nary_op_t vn_nary_op_insert_pieces (unsigned int, enum tree_code,
 184                                        tree, tree, tree, tree,
 185                                        tree, tree, unsigned int);
 186 void vn_reference_fold_indirect (VEC (vn_reference_op_s, heap) **,
 187                                  unsigned int *);
 188 void copy_reference_ops_from_ref (tree, VEC(vn_reference_op_s, heap) **);
 189 void copy_reference_ops_from_call (gimple, VEC(vn_reference_op_s, heap) **);
 190 bool ao_ref_init_from_vn_reference (ao_ref *, alias_set_type, tree,
 191                                     VEC (vn_reference_op_s, heap) *);
 192 tree vn_reference_lookup_pieces (tree, alias_set_type, tree,
 193                                  VEC (vn_reference_op_s, heap) *,
 194                                  vn_reference_t *, vn_lookup_kind);
 195 tree vn_reference_lookup (tree, tree, vn_lookup_kind, vn_reference_t *);
 196 vn_reference_t vn_reference_insert (tree, tree, tree);
 197 vn_reference_t vn_reference_insert_pieces (tree, alias_set_type, tree,
 198                                            VEC (vn_reference_op_s, heap) *,
 199                                            tree, unsigned int);
 200
 201 hashval_t vn_nary_op_compute_hash (const vn_nary_op_t);
 202 int vn_nary_op_eq (const void *, const void *);
 203 bool vn_nary_may_trap (vn_nary_op_t);
 204 hashval_t vn_reference_compute_hash (const vn_reference_t);
 205 int vn_reference_eq (const void *, const void *);
 206 unsigned int get_max_value_id (void);
 207 unsigned int get_next_value_id (void);
 208 unsigned int get_constant_value_id (tree);
 209 unsigned int get_or_alloc_constant_value_id (tree);
 210 bool value_id_constant_p (unsigned int);
 211 tree fully_constant_vn_reference_p (vn_reference_t);
 212 #endif /* TREE_SSA_SCCVN_H  */