1/* Chains of recurrences. 2 Copyright (C) 2003-2020 Free Software Foundation, Inc. 3 Contributed by Sebastian Pop <pop@cri.ensmp.fr> 4 5This file is part of GCC. 6 7GCC is free software; you can redistribute it and/or modify it under 8the terms of the GNU General Public License as published by the Free 9Software Foundation; either version 3, or (at your option) any later 10version. 11 12GCC is distributed in the hope that it will be useful, but WITHOUT ANY 13WARRANTY; without even the implied warranty of MERCHANTABILITY or 14FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 15for more details. 16 17You should have received a copy of the GNU General Public License 18along with GCC; see the file COPYING3. If not see 19<http://www.gnu.org/licenses/>. */ 20 21#ifndef GCC_TREE_CHREC_H 22#define GCC_TREE_CHREC_H 23 24/* The following trees are unique elements. Thus the comparison of another 25 element to these elements should be done on the pointer to these trees, 26 and not on their value. 27 28 extern tree chrec_not_analyzed_yet; 29 extern tree chrec_dont_know; 30 extern tree chrec_known; 31 32 chrec_not_analyzed_yet is NULL_TREE and the others are defined 33 in global_trees[]. */ 34 35/* After having added an automatically generated element, please 36 include it in the following function. */ 37 38static inline bool 39automatically_generated_chrec_p (const_tree chrec) 40{ 41 return (chrec == chrec_dont_know 42 || chrec == chrec_known); 43} 44 45/* The tree nodes aka. CHRECs. */ 46 47static inline bool 48tree_is_chrec (const_tree expr) 49{ 50 if (TREE_CODE (expr) == POLYNOMIAL_CHREC 51 || automatically_generated_chrec_p (expr)) 52 return true; 53 else 54 return false; 55} 56 57 58enum ev_direction {EV_DIR_GROWS, EV_DIR_DECREASES, EV_DIR_UNKNOWN}; 59enum ev_direction scev_direction (const_tree); 60 61/* Chrec folding functions. */ 62extern tree chrec_fold_plus (tree, tree, tree); 63extern tree chrec_fold_minus (tree, tree, tree); 64extern tree chrec_fold_multiply (tree, tree, tree); 65extern tree chrec_convert (tree, tree, gimple *, bool = true, tree = NULL); 66extern tree chrec_convert_rhs (tree, tree, gimple *); 67extern tree chrec_convert_aggressive (tree, tree, bool *); 68 69/* Operations. */ 70extern tree chrec_apply (unsigned, tree, tree); 71extern tree chrec_apply_map (tree, vec<tree> ); 72extern tree chrec_replace_initial_condition (tree, tree); 73extern tree initial_condition (tree); 74extern tree initial_condition_in_loop_num (tree, unsigned); 75extern tree evolution_part_in_loop_num (tree, unsigned); 76extern tree hide_evolution_in_other_loops_than_loop (tree, unsigned); 77extern tree reset_evolution_in_loop (unsigned, tree, tree); 78extern tree chrec_merge (tree, tree); 79extern void for_each_scev_op (tree *, bool (*) (tree *, void *), void *); 80extern bool convert_affine_scev (class loop *, tree, tree *, tree *, gimple *, 81 bool, tree = NULL); 82 83/* Observers. */ 84extern bool eq_evolutions_p (const_tree, const_tree); 85extern bool is_multivariate_chrec (const_tree); 86extern bool chrec_contains_symbols (const_tree, class loop * = NULL); 87extern bool chrec_contains_symbols_defined_in_loop (const_tree, unsigned); 88extern bool chrec_contains_undetermined (const_tree); 89extern bool tree_contains_chrecs (const_tree, int *); 90extern bool evolution_function_is_affine_multivariate_p (const_tree, int); 91extern bool evolution_function_is_univariate_p (const_tree, int = 0); 92extern unsigned nb_vars_in_chrec (tree); 93extern bool evolution_function_is_invariant_p (tree, int); 94extern bool scev_is_linear_expression (tree); 95extern bool evolution_function_right_is_integer_cst (const_tree); 96 97/* Determines whether CHREC is equal to zero. */ 98 99static inline bool 100chrec_zerop (const_tree chrec) 101{ 102 if (chrec == NULL_TREE) 103 return false; 104 105 if (TREE_CODE (chrec) == INTEGER_CST) 106 return integer_zerop (chrec); 107 108 return false; 109} 110 111/* Determines whether CHREC is a loop invariant with respect to LOOP_NUM. 112 Set the result in RES and return true when the property can be computed. */ 113 114static inline bool 115no_evolution_in_loop_p (tree chrec, unsigned loop_num, bool *res) 116{ 117 tree scev; 118 119 if (chrec == chrec_not_analyzed_yet 120 || chrec == chrec_dont_know 121 || chrec_contains_symbols_defined_in_loop (chrec, loop_num)) 122 return false; 123 124 STRIP_NOPS (chrec); 125 scev = hide_evolution_in_other_loops_than_loop (chrec, loop_num); 126 *res = !tree_contains_chrecs (scev, NULL); 127 return true; 128} 129 130/* Build a polynomial chain of recurrence. */ 131 132static inline tree 133build_polynomial_chrec (unsigned loop_num, 134 tree left, 135 tree right) 136{ 137 bool val; 138 139 if (left == chrec_dont_know 140 || right == chrec_dont_know) 141 return chrec_dont_know; 142 143 if (!no_evolution_in_loop_p (left, loop_num, &val) 144 || !val) 145 return chrec_dont_know; 146 147 /* Types of left and right sides of a chrec should be compatible, but 148 pointer CHRECs are special in that the evolution is of ptroff type. */ 149 if (POINTER_TYPE_P (TREE_TYPE (left))) 150 gcc_checking_assert (ptrofftype_p (TREE_TYPE (right))); 151 else 152 { 153 /* Pointer types should occur only on the left hand side, i.e. in 154 the base of the chrec, and not in the step. */ 155 gcc_checking_assert (!POINTER_TYPE_P (TREE_TYPE (right)) 156 && types_compatible_p (TREE_TYPE (left), 157 TREE_TYPE (right))); 158 } 159 160 if (chrec_zerop (right)) 161 return left; 162 163 tree chrec = build2 (POLYNOMIAL_CHREC, TREE_TYPE (left), left, right); 164 CHREC_VARIABLE (chrec) = loop_num; 165 return chrec; 166} 167 168/* Determines whether the expression CHREC is a constant. */ 169 170static inline bool 171evolution_function_is_constant_p (const_tree chrec) 172{ 173 if (chrec == NULL_TREE) 174 return false; 175 176 return is_gimple_min_invariant (chrec); 177} 178 179/* Determine whether CHREC is an affine evolution function in LOOPNUM. */ 180 181static inline bool 182evolution_function_is_affine_in_loop (const_tree chrec, int loopnum) 183{ 184 if (chrec == NULL_TREE) 185 return false; 186 187 switch (TREE_CODE (chrec)) 188 { 189 case POLYNOMIAL_CHREC: 190 if (evolution_function_is_invariant_p (CHREC_LEFT (chrec), loopnum) 191 && evolution_function_is_invariant_p (CHREC_RIGHT (chrec), loopnum)) 192 return true; 193 else 194 return false; 195 196 default: 197 return false; 198 } 199} 200 201/* Determine whether CHREC is an affine evolution function or not. */ 202 203static inline bool 204evolution_function_is_affine_p (const_tree chrec) 205{ 206 return chrec 207 && TREE_CODE (chrec) == POLYNOMIAL_CHREC 208 && evolution_function_is_invariant_p (CHREC_RIGHT (chrec), 209 CHREC_VARIABLE (chrec)) 210 && (TREE_CODE (CHREC_RIGHT (chrec)) != POLYNOMIAL_CHREC 211 || evolution_function_is_affine_p (CHREC_RIGHT (chrec))); 212} 213 214/* Determines whether EXPR does not contains chrec expressions. */ 215 216static inline bool 217tree_does_not_contain_chrecs (const_tree expr) 218{ 219 return !tree_contains_chrecs (expr, NULL); 220} 221 222/* Returns the type of the chrec. */ 223 224static inline tree 225chrec_type (const_tree chrec) 226{ 227 if (automatically_generated_chrec_p (chrec)) 228 return NULL_TREE; 229 230 return TREE_TYPE (chrec); 231} 232 233static inline tree 234chrec_fold_op (enum tree_code code, tree type, tree op0, tree op1) 235{ 236 switch (code) 237 { 238 case PLUS_EXPR: 239 return chrec_fold_plus (type, op0, op1); 240 241 case MINUS_EXPR: 242 return chrec_fold_minus (type, op0, op1); 243 244 case MULT_EXPR: 245 return chrec_fold_multiply (type, op0, op1); 246 247 default: 248 gcc_unreachable (); 249 } 250 251} 252 253#endif /* GCC_TREE_CHREC_H */ 254