1 /* Support routines for Value Range Propagation (VRP). 2 Copyright (C) 2016-2021 Free Software Foundation, Inc. 3 4 This file is part of GCC. 5 6 GCC is free software; you can redistribute it and/or modify 7 it under the terms of the GNU General Public License as published by 8 the Free Software Foundation; either version 3, or (at your option) 9 any later version. 10 11 GCC is distributed in the hope that it will be useful, 12 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 GNU General Public License for more details. 15 16 You should have received a copy of the GNU General Public License 17 along with GCC; see the file COPYING3. If not see 18 <http://www.gnu.org/licenses/>. */ 19 20 #ifndef GCC_VR_VALUES_H 21 #define GCC_VR_VALUES_H 22 23 #include "value-range-equiv.h" 24 #include "value-query.h" 25 26 // Abstract class to return a range for a given SSA. 27 28 // Class to simplify a statement using range information. 29 30 class simplify_using_ranges 31 { 32 public: 33 simplify_using_ranges (class range_query *query = NULL); 34 ~simplify_using_ranges (); set_range_query(class range_query * q)35 void set_range_query (class range_query *q) { query = q; } 36 37 bool simplify (gimple_stmt_iterator *); 38 39 // ?? These should be cleaned, merged, and made private. 40 tree vrp_evaluate_conditional (tree_code, tree, tree, gimple *); 41 void vrp_visit_cond_stmt (gcond *, edge *); 42 tree vrp_evaluate_conditional_warnv_with_ops (gimple *stmt, enum tree_code, 43 tree, tree, bool, 44 bool *, bool *); 45 46 private: 47 bool simplify_truth_ops_using_ranges (gimple_stmt_iterator *, gimple *); 48 bool simplify_div_or_mod_using_ranges (gimple_stmt_iterator *, gimple *); 49 bool simplify_abs_using_ranges (gimple_stmt_iterator *, gimple *); 50 bool simplify_bit_ops_using_ranges (gimple_stmt_iterator *, gimple *); 51 bool simplify_min_or_max_using_ranges (gimple_stmt_iterator *, gimple *); 52 bool simplify_cond_using_ranges_1 (gcond *); 53 bool fold_cond (gcond *); 54 bool simplify_switch_using_ranges (gswitch *); 55 bool simplify_float_conversion_using_ranges (gimple_stmt_iterator *, 56 gimple *); 57 bool simplify_internal_call_using_ranges (gimple_stmt_iterator *, gimple *); 58 59 bool two_valued_val_range_p (tree, tree *, tree *); 60 bool op_with_boolean_value_range_p (tree); 61 tree compare_name_with_value (enum tree_code, tree, tree, bool *, bool); 62 tree compare_names (enum tree_code, tree, tree, bool *); 63 const value_range_equiv *get_vr_for_comparison (int, value_range_equiv *); 64 tree vrp_evaluate_conditional_warnv_with_ops_using_ranges (enum tree_code, 65 tree, tree, 66 bool *); 67 void cleanup_edges_and_switches (void); 68 69 /* Vectors of edges that need removing and switch statements that 70 need updating. It is expected that a pass using the simplification 71 routines will, at the end of the pass, clean up the edges and 72 switch statements. The class dtor will try to detect cases 73 that do not follow that expectation. */ 74 struct switch_update { 75 gswitch *stmt; 76 tree vec; 77 }; 78 79 vec<edge> to_remove_edges; 80 vec<switch_update> to_update_switch_stmts; 81 class range_query *query; 82 }; 83 84 /* The VR_VALUES class holds the current view of range information 85 for all the SSA_NAMEs in the IL. 86 87 It can be used to hold context sensitive range information during 88 a dominator walk or it may be used to hold range information in the 89 standard VRP pass as ranges are propagated through the lattice to a 90 steady state. 91 92 This information is independent of the range information that gets 93 attached to SSA_NAMEs. A pass such as VRP may choose to transfer 94 the global information it produces into global range information that 95 gets attached to an SSA_NAME. It's unclear how useful that global 96 information will be in a world where we can compute context sensitive 97 range information fast or perform on-demand queries. */ 98 class vr_values : public range_query 99 { 100 public: 101 vr_values (void); 102 ~vr_values (void); 103 104 virtual bool range_of_expr (irange &r, tree expr, gimple *stmt) OVERRIDE; 105 virtual tree value_of_expr (tree, gimple * = NULL) OVERRIDE; 106 virtual tree value_on_edge (edge, tree) OVERRIDE; 107 virtual tree value_of_stmt (gimple *, tree = NULL_TREE) OVERRIDE; 108 virtual const value_range_equiv *get_value_range (const_tree, 109 gimple * = NULL) OVERRIDE; 110 void set_vr_value (tree, value_range_equiv *); 111 value_range_equiv *swap_vr_value (tree, value_range_equiv *); 112 113 void set_def_to_varying (const_tree); 114 void set_defs_to_varying (gimple *); 115 bool update_value_range (const_tree, value_range_equiv *); 116 tree op_with_constant_singleton_value_range (tree); 117 void adjust_range_with_scev (value_range_equiv *, class loop *, 118 gimple *, tree); 119 void dump_all_value_ranges (FILE *); 120 121 void extract_range_for_var_from_comparison_expr (tree, enum tree_code, 122 tree, tree, 123 value_range_equiv *); 124 void extract_range_from_phi_node (gphi *, value_range_equiv *); 125 void extract_range_basic (value_range_equiv *, gimple *); 126 void extract_range_from_stmt (gimple *, edge *, tree *, value_range_equiv *); 127 128 /* Indicate that propagation through the lattice is complete. */ set_lattice_propagation_complete(void)129 void set_lattice_propagation_complete (void) { values_propagated = true; } 130 131 /* Allocate a new value_range object. */ allocate_value_range_equiv(void)132 value_range_equiv *allocate_value_range_equiv (void) 133 { return range_query::allocate_value_range_equiv (); } free_value_range(value_range_equiv * vr)134 void free_value_range (value_range_equiv *vr) 135 { free_value_range_equiv (vr); } 136 137 private: 138 value_range_equiv *get_lattice_entry (const_tree); 139 bool vrp_stmt_computes_nonzero (gimple *); 140 void extract_range_from_assignment (value_range_equiv *, gassign *); 141 void extract_range_from_assert (value_range_equiv *, tree); 142 void extract_range_from_ssa_name (value_range_equiv *, tree); 143 void extract_range_from_binary_expr (value_range_equiv *, enum tree_code, 144 tree, tree, tree); 145 void extract_range_from_unary_expr (value_range_equiv *, enum tree_code, 146 tree, tree); 147 void extract_range_from_cond_expr (value_range_equiv *, gassign *); 148 void extract_range_from_comparison (value_range_equiv *, gimple *); 149 void vrp_visit_assignment_or_call (gimple*, tree *, value_range_equiv *); 150 void vrp_visit_switch_stmt (gswitch *, edge *); 151 bool extract_range_from_ubsan_builtin (value_range_equiv *, gimple *); 152 153 /* This probably belongs in the lattice rather than in here. */ 154 bool values_propagated; 155 156 /* Allocations for equivalences all come from this obstack. */ 157 bitmap_obstack vrp_equiv_obstack; 158 159 /* Value range array. After propagation, VR_VALUE[I] holds the range 160 of values that SSA name N_I may take. */ 161 unsigned int num_vr_values; 162 value_range_equiv **vr_value; 163 164 /* For a PHI node which sets SSA name N_I, VR_COUNTS[I] holds the 165 number of executable edges we saw the last time we visited the 166 node. */ 167 int *vr_phi_edge_counts; 168 simplify_using_ranges simplifier; 169 }; 170 171 extern tree get_output_for_vrp (gimple *); 172 173 extern bool range_fits_type_p (const value_range *vr, 174 unsigned dest_precision, signop dest_sgn); 175 extern bool bounds_of_var_in_loop (tree *min, tree *max, range_query *, 176 class loop *loop, gimple *stmt, tree var); 177 178 #endif /* GCC_VR_VALUES_H */ 179