1 /* Tree SCC value numbering 2 Copyright (C) 2007-2013 Free Software Foundation, Inc. 3 Contributed by Daniel Berlin <dberlin (at) 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 tree type; 71 tree result; 72 } *vn_phi_t; 73 typedef const struct vn_phi_s *const_vn_phi_t; 74 75 /* Reference operands only exist in reference operations structures. 76 They consist of an opcode, type, and some number of operands. For 77 a given opcode, some, all, or none of the operands may be used. 78 The operands are there to store the information that makes up the 79 portion of the addressing calculation that opcode performs. */ 80 81 typedef struct vn_reference_op_struct 82 { 83 enum tree_code opcode; 84 /* Constant offset this op adds or -1 if it is variable. */ 85 HOST_WIDE_INT off; 86 tree type; 87 tree op0; 88 tree op1; 89 tree op2; 90 } vn_reference_op_s; 91 typedef vn_reference_op_s *vn_reference_op_t; 92 typedef const vn_reference_op_s *const_vn_reference_op_t; 93 94 95 /* A reference operation in the hashtable is representation as 96 the vuse, representing the memory state at the time of 97 the operation, and a collection of operands that make up the 98 addressing calculation. If two vn_reference_t's have the same set 99 of operands, they access the same memory location. We also store 100 the resulting value number, and the hashcode. */ 101 102 typedef struct vn_reference_s 103 { 104 /* Unique identifier that all expressions with the same value have. */ 105 unsigned int value_id; 106 hashval_t hashcode; 107 tree vuse; 108 alias_set_type set; 109 tree type; 110 vec<vn_reference_op_s> operands; 111 tree result; 112 tree result_vdef; 113 } *vn_reference_t; 114 typedef const struct vn_reference_s *const_vn_reference_t; 115 116 typedef struct vn_constant_s 117 { 118 unsigned int value_id; 119 hashval_t hashcode; 120 tree constant; 121 } *vn_constant_t; 122 123 enum vn_kind { VN_NONE, VN_CONSTANT, VN_NARY, VN_REFERENCE, VN_PHI }; 124 enum vn_kind vn_get_stmt_kind (gimple); 125 126 /* Hash the type TYPE using bits that distinguishes it in the 127 types_compatible_p sense. */ 128 129 static inline hashval_t 130 vn_hash_type (tree type) 131 { 132 return (INTEGRAL_TYPE_P (type) 133 + (INTEGRAL_TYPE_P (type) 134 ? TYPE_PRECISION (type) + TYPE_UNSIGNED (type) : 0)); 135 } 136 137 /* Hash the constant CONSTANT with distinguishing type incompatible 138 constants in the types_compatible_p sense. */ 139 140 static inline hashval_t 141 vn_hash_constant_with_type (tree constant) 142 { 143 return (iterative_hash_expr (constant, 0) 144 + vn_hash_type (TREE_TYPE (constant))); 145 } 146 147 /* Compare the constants C1 and C2 with distinguishing type incompatible 148 constants in the types_compatible_p sense. */ 149 150 static inline bool 151 vn_constant_eq_with_type (tree c1, tree c2) 152 { 153 return (expressions_equal_p (c1, c2) 154 && types_compatible_p (TREE_TYPE (c1), TREE_TYPE (c2))); 155 } 156 157 typedef struct vn_ssa_aux 158 { 159 /* Value number. This may be an SSA name or a constant. */ 160 tree valnum; 161 /* Representative expression, if not a direct constant. */ 162 tree expr; 163 164 /* Unique identifier that all expressions with the same value have. */ 165 unsigned int value_id; 166 167 /* SCC information. */ 168 unsigned int dfsnum; 169 unsigned int low; 170 unsigned visited : 1; 171 unsigned on_sccstack : 1; 172 173 /* Whether the representative expression contains constants. */ 174 unsigned has_constants : 1; 175 /* Whether the SSA_NAME has been value numbered already. This is 176 only saying whether visit_use has been called on it at least 177 once. It cannot be used to avoid visitation for SSA_NAME's 178 involved in non-singleton SCC's. */ 179 unsigned use_processed : 1; 180 181 /* Whether the SSA_NAME has no defining statement and thus an 182 insertion of such with EXPR as definition is required before 183 a use can be created of it. */ 184 unsigned needs_insertion : 1; 185 } *vn_ssa_aux_t; 186 187 typedef enum { VN_NOWALK, VN_WALK, VN_WALKREWRITE } vn_lookup_kind; 188 189 /* Return the value numbering info for an SSA_NAME. */ 190 extern vn_ssa_aux_t VN_INFO (tree); 191 extern vn_ssa_aux_t VN_INFO_GET (tree); 192 tree vn_get_expr_for (tree); 193 bool run_scc_vn (vn_lookup_kind); 194 void free_scc_vn (void); 195 tree vn_nary_op_lookup (tree, vn_nary_op_t *); 196 tree vn_nary_op_lookup_stmt (gimple, vn_nary_op_t *); 197 tree vn_nary_op_lookup_pieces (unsigned int, enum tree_code, 198 tree, tree *, vn_nary_op_t *); 199 vn_nary_op_t vn_nary_op_insert (tree, tree); 200 vn_nary_op_t vn_nary_op_insert_stmt (gimple, tree); 201 vn_nary_op_t vn_nary_op_insert_pieces (unsigned int, enum tree_code, 202 tree, tree *, tree, unsigned int); 203 void vn_reference_fold_indirect (vec<vn_reference_op_s> *, 204 unsigned int *); 205 void copy_reference_ops_from_ref (tree, vec<vn_reference_op_s> *); 206 void copy_reference_ops_from_call (gimple, vec<vn_reference_op_s> *); 207 bool ao_ref_init_from_vn_reference (ao_ref *, alias_set_type, tree, 208 vec<vn_reference_op_s> ); 209 tree vn_reference_lookup_pieces (tree, alias_set_type, tree, 210 vec<vn_reference_op_s> , 211 vn_reference_t *, vn_lookup_kind); 212 tree vn_reference_lookup (tree, tree, vn_lookup_kind, vn_reference_t *); 213 vn_reference_t vn_reference_insert (tree, tree, tree, tree); 214 vn_reference_t vn_reference_insert_pieces (tree, alias_set_type, tree, 215 vec<vn_reference_op_s> , 216 tree, unsigned int); 217 218 hashval_t vn_nary_op_compute_hash (const vn_nary_op_t); 219 int vn_nary_op_eq (const void *, const void *); 220 bool vn_nary_may_trap (vn_nary_op_t); 221 hashval_t vn_reference_compute_hash (const vn_reference_t); 222 int vn_reference_eq (const void *, const void *); 223 unsigned int get_max_value_id (void); 224 unsigned int get_next_value_id (void); 225 unsigned int get_constant_value_id (tree); 226 unsigned int get_or_alloc_constant_value_id (tree); 227 bool value_id_constant_p (unsigned int); 228 tree fully_constant_vn_reference_p (vn_reference_t); 229 230 /* Valueize NAME if it is an SSA name, otherwise just return it. */ 231 232 static inline tree 233 vn_valueize (tree name) 234 { 235 if (TREE_CODE (name) == SSA_NAME) 236 { 237 tree tem = VN_INFO (name)->valnum; 238 return tem == VN_TOP ? name : tem; 239 } 240 return name; 241 } 242 243 #endif /* TREE_SSA_SCCVN_H */ 244
