1 /* Tree SCC value numbering 2 Copyright (C) 2007, 2008, 2009 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 /* TOP of the VN lattice. */ 25 extern tree VN_TOP; 26 27 /* N-ary operations in the hashtable consist of length operands, an 28 opcode, and a type. Result is the value number of the operation, 29 and hashcode is stored to avoid having to calculate it 30 repeatedly. */ 31 32 typedef struct vn_nary_op_s 33 { 34 /* Unique identify that all expressions with the same value have. */ 35 unsigned int value_id; 36 ENUM_BITFIELD(tree_code) opcode : 16; 37 unsigned length : 16; 38 hashval_t hashcode; 39 tree result; 40 tree type; 41 tree op[4]; 42 } *vn_nary_op_t; 43 typedef const struct vn_nary_op_s *const_vn_nary_op_t; 44 45 /* Phi nodes in the hashtable consist of their non-VN_TOP phi 46 arguments, and the basic block the phi is in. Result is the value 47 number of the operation, and hashcode is stored to avoid having to 48 calculate it repeatedly. Phi nodes not in the same block are never 49 considered equivalent. */ 50 51 typedef struct vn_phi_s 52 { 53 /* Unique identifier that all expressions with the same value have. */ 54 unsigned int value_id; 55 hashval_t hashcode; 56 VEC (tree, heap) *phiargs; 57 basic_block block; 58 tree result; 59 } *vn_phi_t; 60 typedef const struct vn_phi_s *const_vn_phi_t; 61 62 /* Reference operands only exist in reference operations structures. 63 They consist of an opcode, type, and some number of operands. For 64 a given opcode, some, all, or none of the operands may be used. 65 The operands are there to store the information that makes up the 66 portion of the addressing calculation that opcode performs. */ 67 68 typedef struct vn_reference_op_struct 69 { 70 enum tree_code opcode; 71 tree type; 72 tree op0; 73 tree op1; 74 tree op2; 75 } vn_reference_op_s; 76 typedef vn_reference_op_s *vn_reference_op_t; 77 typedef const vn_reference_op_s *const_vn_reference_op_t; 78 79 DEF_VEC_O(vn_reference_op_s); 80 DEF_VEC_ALLOC_O(vn_reference_op_s, heap); 81 82 /* A reference operation in the hashtable is representation as a 83 collection of vuses, representing the memory state at the time of 84 the operation, and a collection of operands that make up the 85 addressing calculation. If two vn_reference_t's have the same set 86 of operands, they access the same memory location. We also store 87 the resulting value number, and the hashcode. The vuses are 88 always stored in order sorted by ssa name version. */ 89 90 typedef struct vn_reference_s 91 { 92 /* Unique identifier that all expressions with the same value have. */ 93 unsigned int value_id; 94 hashval_t hashcode; 95 VEC (tree, gc) *vuses; 96 VEC (vn_reference_op_s, heap) *operands; 97 tree result; 98 } *vn_reference_t; 99 typedef const struct vn_reference_s *const_vn_reference_t; 100 101 typedef struct vn_constant_s 102 { 103 unsigned int value_id; 104 hashval_t hashcode; 105 tree constant; 106 } *vn_constant_t; 107 108 /* Hash the constant CONSTANT with distinguishing type incompatible 109 constants in the types_compatible_p sense. */ 110 111 static inline hashval_t 112 vn_hash_constant_with_type (tree constant) 113 { 114 tree type = TREE_TYPE (constant); 115 return (iterative_hash_expr (constant, 0) 116 + INTEGRAL_TYPE_P (type) 117 + (INTEGRAL_TYPE_P (type) 118 ? TYPE_PRECISION (type) + TYPE_UNSIGNED (type) : 0)); 119 } 120 121 /* Compare the constants C1 and C2 with distinguishing type incompatible 122 constants in the types_compatible_p sense. */ 123 124 static inline bool 125 vn_constant_eq_with_type (tree c1, tree c2) 126 { 127 return (expressions_equal_p (c1, c2) 128 && types_compatible_p (TREE_TYPE (c1), TREE_TYPE (c2))); 129 } 130 131 typedef struct vn_ssa_aux 132 { 133 /* Value number. This may be an SSA name or a constant. */ 134 tree valnum; 135 /* Representative expression, if not a direct constant. */ 136 tree expr; 137 138 /* Unique identifier that all expressions with the same value have. */ 139 unsigned int value_id; 140 141 /* SCC information. */ 142 unsigned int dfsnum; 143 unsigned int low; 144 unsigned visited : 1; 145 unsigned on_sccstack : 1; 146 147 /* Whether the representative expression contains constants. */ 148 unsigned has_constants : 1; 149 /* Whether the SSA_NAME has been value numbered already. This is 150 only saying whether visit_use has been called on it at least 151 once. It cannot be used to avoid visitation for SSA_NAME's 152 involved in non-singleton SCC's. */ 153 unsigned use_processed : 1; 154 155 /* Whether the SSA_NAME has no defining statement and thus an 156 insertion of such with EXPR as definition is required before 157 a use can be created of it. */ 158 unsigned needs_insertion : 1; 159 } *vn_ssa_aux_t; 160 161 /* Return the value numbering info for an SSA_NAME. */ 162 extern vn_ssa_aux_t VN_INFO (tree); 163 extern vn_ssa_aux_t VN_INFO_GET (tree); 164 tree vn_get_expr_for (tree); 165 bool run_scc_vn (bool); 166 void free_scc_vn (void); 167 tree vn_nary_op_lookup (tree, vn_nary_op_t *); 168 tree vn_nary_op_lookup_stmt (gimple, vn_nary_op_t *); 169 tree vn_nary_op_lookup_pieces (unsigned int, enum tree_code, 170 tree, tree, tree, tree, tree, 171 vn_nary_op_t *); 172 vn_nary_op_t vn_nary_op_insert (tree, tree); 173 vn_nary_op_t vn_nary_op_insert_stmt (gimple, tree); 174 vn_nary_op_t vn_nary_op_insert_pieces (unsigned int, enum tree_code, 175 tree, tree, tree, tree, 176 tree, tree, unsigned int); 177 void copy_reference_ops_from_ref (tree, VEC(vn_reference_op_s, heap) **); 178 void copy_reference_ops_from_call (gimple, VEC(vn_reference_op_s, heap) **); 179 tree vn_reference_lookup_pieces (VEC (tree, gc) *, 180 VEC (vn_reference_op_s, heap) *, 181 vn_reference_t *, bool); 182 tree vn_reference_lookup (tree, VEC (tree, gc) *, bool, vn_reference_t *); 183 vn_reference_t vn_reference_insert (tree, tree, VEC (tree, gc) *); 184 vn_reference_t vn_reference_insert_pieces (VEC (tree, gc) *, 185 VEC (vn_reference_op_s, heap) *, 186 tree, unsigned int); 187 188 hashval_t vn_nary_op_compute_hash (const vn_nary_op_t); 189 int vn_nary_op_eq (const void *, const void *); 190 bool vn_nary_may_trap (vn_nary_op_t); 191 hashval_t vn_reference_compute_hash (const vn_reference_t); 192 int vn_reference_eq (const void *, const void *); 193 unsigned int get_max_value_id (void); 194 unsigned int get_next_value_id (void); 195 unsigned int get_constant_value_id (tree); 196 unsigned int get_or_alloc_constant_value_id (tree); 197 bool value_id_constant_p (unsigned int); 198 VEC (tree, gc) *shared_vuses_from_stmt (gimple); 199 #endif /* TREE_SSA_SCCVN_H */ 200
