1 /* Support routines for Value Range Propagation (VRP). 2 Copyright (C) 2016-2022 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 (range_query *query = NULL, 34 int not_executable_flag = 0); 35 ~simplify_using_ranges (); 36 void set_range_query (class range_query *q, int not_executable_flag = 0) 37 { query = q; m_not_executable_flag = not_executable_flag; } 38 39 bool simplify (gimple_stmt_iterator *); 40 41 // ?? These should be cleaned, merged, and made private. 42 tree vrp_evaluate_conditional (tree_code, tree, tree, gimple *); 43 void vrp_visit_cond_stmt (gcond *, edge *); 44 tree vrp_evaluate_conditional_warnv_with_ops (gimple *stmt, enum tree_code, 45 tree, tree, bool, 46 bool *, bool *); 47 bool simplify_casted_cond (gcond *); 48 49 private: 50 bool simplify_truth_ops_using_ranges (gimple_stmt_iterator *, gimple *); 51 bool simplify_div_or_mod_using_ranges (gimple_stmt_iterator *, gimple *); 52 bool simplify_abs_using_ranges (gimple_stmt_iterator *, gimple *); 53 bool simplify_bit_ops_using_ranges (gimple_stmt_iterator *, gimple *); 54 bool simplify_min_or_max_using_ranges (gimple_stmt_iterator *, gimple *); 55 bool simplify_cond_using_ranges_1 (gcond *); 56 bool fold_cond (gcond *); 57 bool simplify_switch_using_ranges (gswitch *); 58 bool simplify_float_conversion_using_ranges (gimple_stmt_iterator *, 59 gimple *); 60 bool simplify_internal_call_using_ranges (gimple_stmt_iterator *, gimple *); 61 62 bool two_valued_val_range_p (tree, tree *, tree *, gimple *); 63 bool op_with_boolean_value_range_p (tree, gimple *); 64 tree compare_name_with_value (enum tree_code, tree, tree, bool *, bool, 65 gimple *); 66 tree compare_names (enum tree_code, tree, tree, bool *, gimple *s); 67 const value_range_equiv *get_vr_for_comparison (int, value_range_equiv *, 68 gimple *s); 69 tree vrp_evaluate_conditional_warnv_with_ops_using_ranges (enum tree_code, 70 tree, tree, 71 bool *, gimple *s); 72 void set_and_propagate_unexecutable (edge e); 73 void cleanup_edges_and_switches (void); 74 75 /* Vectors of edges that need removing and switch statements that 76 need updating. It is expected that a pass using the simplification 77 routines will, at the end of the pass, clean up the edges and 78 switch statements. The class dtor will try to detect cases 79 that do not follow that expectation. */ 80 struct switch_update { 81 gswitch *stmt; 82 tree vec; 83 }; 84 85 vec<edge> to_remove_edges; 86 vec<switch_update> to_update_switch_stmts; 87 class range_query *query; 88 int m_not_executable_flag; // Non zero if not_executable flag exists. 89 vec<edge> m_flag_set_edges; // List of edges with flag to be cleared. 90 }; 91 92 /* The VR_VALUES class holds the current view of range information 93 for all the SSA_NAMEs in the IL. 94 95 It can be used to hold context sensitive range information during 96 a dominator walk or it may be used to hold range information in the 97 standard VRP pass as ranges are propagated through the lattice to a 98 steady state. 99 100 This information is independent of the range information that gets 101 attached to SSA_NAMEs. A pass such as VRP may choose to transfer 102 the global information it produces into global range information that 103 gets attached to an SSA_NAME. It's unclear how useful that global 104 information will be in a world where we can compute context sensitive 105 range information fast or perform on-demand queries. */ 106 class vr_values : public range_query 107 { 108 public: 109 vr_values (void); 110 ~vr_values (void); 111 112 virtual bool range_of_expr (irange &r, tree expr, gimple *stmt) OVERRIDE; 113 virtual tree value_of_expr (tree, gimple * = NULL) OVERRIDE; 114 virtual tree value_on_edge (edge, tree) OVERRIDE; 115 virtual tree value_of_stmt (gimple *, tree = NULL_TREE) OVERRIDE; 116 virtual const value_range_equiv *get_value_range (const_tree, 117 gimple * = NULL) OVERRIDE; 118 void set_vr_value (tree, value_range_equiv *); 119 value_range_equiv *swap_vr_value (tree, value_range_equiv *); 120 121 void set_def_to_varying (const_tree); 122 void set_defs_to_varying (gimple *); 123 bool update_value_range (const_tree, value_range_equiv *); 124 tree op_with_constant_singleton_value_range (tree); 125 void adjust_range_with_scev (value_range_equiv *, class loop *, 126 gimple *, tree); 127 virtual void dump (FILE *) OVERRIDE; 128 129 void extract_range_for_var_from_comparison_expr (tree, enum tree_code, 130 tree, tree, 131 value_range_equiv *); 132 void extract_range_from_phi_node (gphi *, value_range_equiv *); 133 void extract_range_basic (value_range_equiv *, gimple *); 134 void extract_range_from_stmt (gimple *, edge *, tree *, value_range_equiv *); 135 136 /* Indicate that propagation through the lattice is complete. */ set_lattice_propagation_complete(void)137 void set_lattice_propagation_complete (void) { values_propagated = true; } 138 139 /* Allocate a new value_range object. */ allocate_value_range_equiv(void)140 value_range_equiv *allocate_value_range_equiv (void) 141 { return range_query::allocate_value_range_equiv (); } free_value_range(value_range_equiv * vr)142 void free_value_range (value_range_equiv *vr) 143 { free_value_range_equiv (vr); } 144 145 private: 146 value_range_equiv *get_lattice_entry (const_tree); 147 bool vrp_stmt_computes_nonzero (gimple *); 148 void extract_range_from_assignment (value_range_equiv *, gassign *); 149 void extract_range_from_assert (value_range_equiv *, tree); 150 void extract_range_from_ssa_name (value_range_equiv *, tree); 151 void extract_range_from_binary_expr (value_range_equiv *, enum tree_code, 152 tree, tree, tree); 153 void extract_range_from_unary_expr (value_range_equiv *, enum tree_code, 154 tree, tree); 155 void extract_range_from_cond_expr (value_range_equiv *, gassign *); 156 void extract_range_from_comparison (value_range_equiv *, gimple *); 157 void vrp_visit_assignment_or_call (gimple*, tree *, value_range_equiv *); 158 void vrp_visit_switch_stmt (gswitch *, edge *); 159 bool extract_range_from_ubsan_builtin (value_range_equiv *, gimple *); 160 161 /* This probably belongs in the lattice rather than in here. */ 162 bool values_propagated; 163 164 /* Allocations for equivalences all come from this obstack. */ 165 bitmap_obstack vrp_equiv_obstack; 166 167 /* Value range array. After propagation, VR_VALUE[I] holds the range 168 of values that SSA name N_I may take. */ 169 unsigned int num_vr_values; 170 value_range_equiv **vr_value; 171 172 /* For a PHI node which sets SSA name N_I, VR_COUNTS[I] holds the 173 number of executable edges we saw the last time we visited the 174 node. */ 175 int *vr_phi_edge_counts; 176 simplify_using_ranges simplifier; 177 }; 178 179 extern tree get_output_for_vrp (gimple *); 180 181 extern bool range_fits_type_p (const value_range *vr, 182 unsigned dest_precision, signop dest_sgn); 183 extern bool bounds_of_var_in_loop (tree *min, tree *max, range_query *, 184 class loop *loop, gimple *stmt, tree var); 185 186 #endif /* GCC_VR_VALUES_H */ 187