1/* Tree SCC value numbering 2 Copyright (C) 2007-2015 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 */ 25bool expressions_equal_p (tree, tree); 26 27 28/* TOP of the VN lattice. */ 29extern 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 36typedef 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; 47typedef 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 51static inline size_t 52sizeof_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 63typedef 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; 73typedef 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 81typedef struct vn_reference_op_struct 82{ 83 ENUM_BITFIELD(tree_code) opcode : 16; 84 /* 1 for instrumented calls. */ 85 unsigned with_bounds : 1; 86 /* Constant offset this op adds or -1 if it is variable. */ 87 HOST_WIDE_INT off; 88 tree type; 89 tree op0; 90 tree op1; 91 tree op2; 92} vn_reference_op_s; 93typedef vn_reference_op_s *vn_reference_op_t; 94typedef const vn_reference_op_s *const_vn_reference_op_t; 95 96 97/* A reference operation in the hashtable is representation as 98 the vuse, representing the memory state at the time of 99 the operation, and a collection of operands that make up the 100 addressing calculation. If two vn_reference_t's have the same set 101 of operands, they access the same memory location. We also store 102 the resulting value number, and the hashcode. */ 103 104typedef struct vn_reference_s 105{ 106 /* Unique identifier that all expressions with the same value have. */ 107 unsigned int value_id; 108 hashval_t hashcode; 109 tree vuse; 110 alias_set_type set; 111 tree type; 112 vec<vn_reference_op_s> operands; 113 tree result; 114 tree result_vdef; 115} *vn_reference_t; 116typedef const struct vn_reference_s *const_vn_reference_t; 117 118typedef struct vn_constant_s 119{ 120 unsigned int value_id; 121 hashval_t hashcode; 122 tree constant; 123} *vn_constant_t; 124 125enum vn_kind { VN_NONE, VN_CONSTANT, VN_NARY, VN_REFERENCE, VN_PHI }; 126enum vn_kind vn_get_stmt_kind (gimple); 127 128/* Hash the type TYPE using bits that distinguishes it in the 129 types_compatible_p sense. */ 130 131static inline hashval_t 132vn_hash_type (tree type) 133{ 134 return (INTEGRAL_TYPE_P (type) 135 + (INTEGRAL_TYPE_P (type) 136 ? TYPE_PRECISION (type) + TYPE_UNSIGNED (type) : 0)); 137} 138 139/* Hash the constant CONSTANT with distinguishing type incompatible 140 constants in the types_compatible_p sense. */ 141 142static inline hashval_t 143vn_hash_constant_with_type (tree constant) 144{ 145 inchash::hash hstate; 146 inchash::add_expr (constant, hstate); 147 hstate.merge_hash (vn_hash_type (TREE_TYPE (constant))); 148 return hstate.end (); 149} 150 151/* Compare the constants C1 and C2 with distinguishing type incompatible 152 constants in the types_compatible_p sense. */ 153 154static inline bool 155vn_constant_eq_with_type (tree c1, tree c2) 156{ 157 return (expressions_equal_p (c1, c2) 158 && types_compatible_p (TREE_TYPE (c1), TREE_TYPE (c2))); 159} 160 161typedef struct vn_ssa_aux 162{ 163 /* Value number. This may be an SSA name or a constant. */ 164 tree valnum; 165 /* Representative expression, if not a direct constant. */ 166 tree expr; 167 168 /* Unique identifier that all expressions with the same value have. */ 169 unsigned int value_id; 170 171 /* SCC information. */ 172 unsigned int dfsnum; 173 unsigned int low; 174 unsigned visited : 1; 175 unsigned on_sccstack : 1; 176 177 /* Whether the representative expression contains constants. */ 178 unsigned has_constants : 1; 179 /* Whether the SSA_NAME has been value numbered already. This is 180 only saying whether visit_use has been called on it at least 181 once. It cannot be used to avoid visitation for SSA_NAME's 182 involved in non-singleton SCC's. */ 183 unsigned use_processed : 1; 184 185 /* Whether the SSA_NAME has no defining statement and thus an 186 insertion of such with EXPR as definition is required before 187 a use can be created of it. */ 188 unsigned needs_insertion : 1; 189} *vn_ssa_aux_t; 190 191typedef enum { VN_NOWALK, VN_WALK, VN_WALKREWRITE } vn_lookup_kind; 192 193/* Return the value numbering info for an SSA_NAME. */ 194extern vn_ssa_aux_t VN_INFO (tree); 195extern vn_ssa_aux_t VN_INFO_GET (tree); 196tree vn_get_expr_for (tree); 197bool run_scc_vn (vn_lookup_kind); 198void free_scc_vn (void); 199tree vn_nary_op_lookup (tree, vn_nary_op_t *); 200tree vn_nary_op_lookup_stmt (gimple, vn_nary_op_t *); 201tree vn_nary_op_lookup_pieces (unsigned int, enum tree_code, 202 tree, tree *, vn_nary_op_t *); 203vn_nary_op_t vn_nary_op_insert (tree, tree); 204vn_nary_op_t vn_nary_op_insert_stmt (gimple, tree); 205vn_nary_op_t vn_nary_op_insert_pieces (unsigned int, enum tree_code, 206 tree, tree *, tree, unsigned int); 207void vn_reference_fold_indirect (vec<vn_reference_op_s> *, 208 unsigned int *); 209bool ao_ref_init_from_vn_reference (ao_ref *, alias_set_type, tree, 210 vec<vn_reference_op_s> ); 211tree vn_reference_lookup_pieces (tree, alias_set_type, tree, 212 vec<vn_reference_op_s> , 213 vn_reference_t *, vn_lookup_kind); 214tree vn_reference_lookup (tree, tree, vn_lookup_kind, vn_reference_t *, bool); 215void vn_reference_lookup_call (gcall *, vn_reference_t *, vn_reference_t); 216vn_reference_t vn_reference_insert_pieces (tree, alias_set_type, tree, 217 vec<vn_reference_op_s> , 218 tree, unsigned int); 219 220bool vn_nary_op_eq (const_vn_nary_op_t const vno1, 221 const_vn_nary_op_t const vno2); 222bool vn_nary_may_trap (vn_nary_op_t); 223bool vn_reference_eq (const_vn_reference_t const, const_vn_reference_t const); 224unsigned int get_max_value_id (void); 225unsigned int get_next_value_id (void); 226unsigned int get_constant_value_id (tree); 227unsigned int get_or_alloc_constant_value_id (tree); 228bool value_id_constant_p (unsigned int); 229tree fully_constant_vn_reference_p (vn_reference_t); 230 231/* Valueize NAME if it is an SSA name, otherwise just return it. */ 232 233static inline tree 234vn_valueize (tree name) 235{ 236 if (TREE_CODE (name) == SSA_NAME) 237 { 238 tree tem = VN_INFO (name)->valnum; 239 return tem == VN_TOP ? name : tem; 240 } 241 return name; 242} 243 244#endif /* TREE_SSA_SCCVN_H */ 245