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[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 - 1); 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, heap) *phiargs; 69 basic_block block; 70 tree result; 71 } *vn_phi_t; 72 typedef const struct vn_phi_s *const_vn_phi_t; 73 74 /* Reference operands only exist in reference operations structures. 75 They consist of an opcode, type, and some number of operands. For 76 a given opcode, some, all, or none of the operands may be used. 77 The operands are there to store the information that makes up the 78 portion of the addressing calculation that opcode performs. */ 79 80 typedef struct vn_reference_op_struct 81 { 82 enum tree_code opcode; 83 /* Constant offset this op adds or -1 if it is variable. */ 84 HOST_WIDE_INT off; 85 tree type; 86 tree op0; 87 tree op1; 88 tree op2; 89 } vn_reference_op_s; 90 typedef vn_reference_op_s *vn_reference_op_t; 91 typedef const vn_reference_op_s *const_vn_reference_op_t; 92 93 DEF_VEC_O(vn_reference_op_s); 94 DEF_VEC_ALLOC_O(vn_reference_op_s, heap); 95 96 /* A reference operation in the hashtable is representation as 97 the vuse, representing the memory state at the time of 98 the operation, and a collection of operands that make up the 99 addressing calculation. If two vn_reference_t's have the same set 100 of operands, they access the same memory location. We also store 101 the resulting value number, and the hashcode. */ 102 103 typedef struct vn_reference_s 104 { 105 /* Unique identifier that all expressions with the same value have. */ 106 unsigned int value_id; 107 hashval_t hashcode; 108 tree vuse; 109 alias_set_type set; 110 tree type; 111 VEC (vn_reference_op_s, heap) *operands; 112 tree result; 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 /* Hash the constant CONSTANT with distinguishing type incompatible 124 constants in the types_compatible_p sense. */ 125 126 static inline hashval_t 127 vn_hash_constant_with_type (tree constant) 128 { 129 tree type = TREE_TYPE (constant); 130 return (iterative_hash_expr (constant, 0) 131 + INTEGRAL_TYPE_P (type) 132 + (INTEGRAL_TYPE_P (type) 133 ? TYPE_PRECISION (type) + TYPE_UNSIGNED (type) : 0)); 134 } 135 136 /* Compare the constants C1 and C2 with distinguishing type incompatible 137 constants in the types_compatible_p sense. */ 138 139 static inline bool 140 vn_constant_eq_with_type (tree c1, tree c2) 141 { 142 return (expressions_equal_p (c1, c2) 143 && types_compatible_p (TREE_TYPE (c1), TREE_TYPE (c2))); 144 } 145 146 typedef struct vn_ssa_aux 147 { 148 /* Value number. This may be an SSA name or a constant. */ 149 tree valnum; 150 /* Representative expression, if not a direct constant. */ 151 tree expr; 152 153 /* Unique identifier that all expressions with the same value have. */ 154 unsigned int value_id; 155 156 /* SCC information. */ 157 unsigned int dfsnum; 158 unsigned int low; 159 unsigned visited : 1; 160 unsigned on_sccstack : 1; 161 162 /* Whether the representative expression contains constants. */ 163 unsigned has_constants : 1; 164 /* Whether the SSA_NAME has been value numbered already. This is 165 only saying whether visit_use has been called on it at least 166 once. It cannot be used to avoid visitation for SSA_NAME's 167 involved in non-singleton SCC's. */ 168 unsigned use_processed : 1; 169 170 /* Whether the SSA_NAME has no defining statement and thus an 171 insertion of such with EXPR as definition is required before 172 a use can be created of it. */ 173 unsigned needs_insertion : 1; 174 } *vn_ssa_aux_t; 175 176 typedef enum { VN_NOWALK, VN_WALK, VN_WALKREWRITE } vn_lookup_kind; 177 178 /* Return the value numbering info for an SSA_NAME. */ 179 extern vn_ssa_aux_t VN_INFO (tree); 180 extern vn_ssa_aux_t VN_INFO_GET (tree); 181 tree vn_get_expr_for (tree); 182 bool run_scc_vn (vn_lookup_kind); 183 void free_scc_vn (void); 184 tree vn_nary_op_lookup (tree, vn_nary_op_t *); 185 tree vn_nary_op_lookup_stmt (gimple, vn_nary_op_t *); 186 tree vn_nary_op_lookup_pieces (unsigned int, enum tree_code, 187 tree, tree *, vn_nary_op_t *); 188 vn_nary_op_t vn_nary_op_insert (tree, tree); 189 vn_nary_op_t vn_nary_op_insert_stmt (gimple, tree); 190 vn_nary_op_t vn_nary_op_insert_pieces (unsigned int, enum tree_code, 191 tree, tree *, tree, unsigned int); 192 void vn_reference_fold_indirect (VEC (vn_reference_op_s, heap) **, 193 unsigned int *); 194 void copy_reference_ops_from_ref (tree, VEC(vn_reference_op_s, heap) **); 195 void copy_reference_ops_from_call (gimple, VEC(vn_reference_op_s, heap) **); 196 bool ao_ref_init_from_vn_reference (ao_ref *, alias_set_type, tree, 197 VEC (vn_reference_op_s, heap) *); 198 tree vn_reference_lookup_pieces (tree, alias_set_type, tree, 199 VEC (vn_reference_op_s, heap) *, 200 vn_reference_t *, vn_lookup_kind); 201 tree vn_reference_lookup (tree, tree, vn_lookup_kind, vn_reference_t *); 202 vn_reference_t vn_reference_insert (tree, tree, tree); 203 vn_reference_t vn_reference_insert_pieces (tree, alias_set_type, tree, 204 VEC (vn_reference_op_s, heap) *, 205 tree, unsigned int); 206 207 hashval_t vn_nary_op_compute_hash (const vn_nary_op_t); 208 int vn_nary_op_eq (const void *, const void *); 209 bool vn_nary_may_trap (vn_nary_op_t); 210 hashval_t vn_reference_compute_hash (const vn_reference_t); 211 int vn_reference_eq (const void *, const void *); 212 unsigned int get_max_value_id (void); 213 unsigned int get_next_value_id (void); 214 unsigned int get_constant_value_id (tree); 215 unsigned int get_or_alloc_constant_value_id (tree); 216 bool value_id_constant_p (unsigned int); 217 tree fully_constant_vn_reference_p (vn_reference_t); 218 219 /* Valueize NAME if it is an SSA name, otherwise just return it. */ 220 221 static inline tree 222 vn_valueize (tree name) 223 { 224 if (TREE_CODE (name) == SSA_NAME) 225 { 226 tree tem = VN_INFO (name)->valnum; 227 return tem == VN_TOP ? name : tem; 228 } 229 return name; 230 } 231 232 #endif /* TREE_SSA_SCCVN_H */ 233