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