1/* Chains of recurrences. 2 Copyright (C) 2003-2015 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 28extern tree chrec_not_analyzed_yet; 29extern GTY(()) tree chrec_dont_know; 30extern GTY(()) tree chrec_known; 31 32/* After having added an automatically generated element, please 33 include it in the following function. */ 34 35static inline bool 36automatically_generated_chrec_p (const_tree chrec) 37{ 38 return (chrec == chrec_dont_know 39 || chrec == chrec_known); 40} 41 42/* The tree nodes aka. CHRECs. */ 43 44static inline bool 45tree_is_chrec (const_tree expr) 46{ 47 if (TREE_CODE (expr) == POLYNOMIAL_CHREC 48 || automatically_generated_chrec_p (expr)) 49 return true; 50 else 51 return false; 52} 53 54 55enum ev_direction {EV_DIR_GROWS, EV_DIR_DECREASES, EV_DIR_UNKNOWN}; 56enum ev_direction scev_direction (const_tree); 57 58/* Chrec folding functions. */ 59extern tree chrec_fold_plus (tree, tree, tree); 60extern tree chrec_fold_minus (tree, tree, tree); 61extern tree chrec_fold_multiply (tree, tree, tree); 62extern tree chrec_convert (tree, tree, gimple); 63extern tree chrec_convert_rhs (tree, tree, gimple); 64extern tree chrec_convert_aggressive (tree, tree); 65 66/* Operations. */ 67extern tree chrec_apply (unsigned, tree, tree); 68extern tree chrec_apply_map (tree, vec<tree> ); 69extern tree chrec_replace_initial_condition (tree, tree); 70extern tree initial_condition (tree); 71extern tree initial_condition_in_loop_num (tree, unsigned); 72extern tree evolution_part_in_loop_num (tree, unsigned); 73extern tree hide_evolution_in_other_loops_than_loop (tree, unsigned); 74extern tree reset_evolution_in_loop (unsigned, tree, tree); 75extern tree chrec_merge (tree, tree); 76extern void for_each_scev_op (tree *, bool (*) (tree *, void *), void *); 77extern bool convert_affine_scev (struct loop *, tree, tree *, tree *, gimple, 78 bool); 79 80/* Observers. */ 81extern bool eq_evolutions_p (const_tree, const_tree); 82extern bool is_multivariate_chrec (const_tree); 83extern bool chrec_contains_symbols (const_tree); 84extern bool chrec_contains_symbols_defined_in_loop (const_tree, unsigned); 85extern bool chrec_contains_undetermined (const_tree); 86extern bool tree_contains_chrecs (const_tree, int *); 87extern bool evolution_function_is_affine_multivariate_p (const_tree, int); 88extern bool evolution_function_is_univariate_p (const_tree); 89extern unsigned nb_vars_in_chrec (tree); 90extern bool evolution_function_is_invariant_p (tree, int); 91extern bool scev_is_linear_expression (tree); 92extern bool evolution_function_right_is_integer_cst (const_tree); 93 94/* Determines whether CHREC is equal to zero. */ 95 96static inline bool 97chrec_zerop (const_tree chrec) 98{ 99 if (chrec == NULL_TREE) 100 return false; 101 102 if (TREE_CODE (chrec) == INTEGER_CST) 103 return integer_zerop (chrec); 104 105 return false; 106} 107 108/* Determines whether CHREC is a loop invariant with respect to LOOP_NUM. 109 Set the result in RES and return true when the property can be computed. */ 110 111static inline bool 112no_evolution_in_loop_p (tree chrec, unsigned loop_num, bool *res) 113{ 114 tree scev; 115 116 if (chrec == chrec_not_analyzed_yet 117 || chrec == chrec_dont_know 118 || chrec_contains_symbols_defined_in_loop (chrec, loop_num)) 119 return false; 120 121 STRIP_NOPS (chrec); 122 scev = hide_evolution_in_other_loops_than_loop (chrec, loop_num); 123 *res = !tree_contains_chrecs (scev, NULL); 124 return true; 125} 126 127/* Build a polynomial chain of recurrence. */ 128 129static inline tree 130build_polynomial_chrec (unsigned loop_num, 131 tree left, 132 tree right) 133{ 134 bool val; 135 136 if (left == chrec_dont_know 137 || right == chrec_dont_know) 138 return chrec_dont_know; 139 140 if (!no_evolution_in_loop_p (left, loop_num, &val) 141 || !val) 142 return chrec_dont_know; 143 144 /* Types of left and right sides of a chrec should be compatible, but 145 pointer CHRECs are special in that the evolution is of ptroff type. */ 146 if (POINTER_TYPE_P (TREE_TYPE (left))) 147 gcc_checking_assert (ptrofftype_p (TREE_TYPE (right))); 148 else 149 { 150 /* Pointer types should occur only on the left hand side, i.e. in 151 the base of the chrec, and not in the step. */ 152 gcc_checking_assert (!POINTER_TYPE_P (TREE_TYPE (right)) 153 && types_compatible_p (TREE_TYPE (left), 154 TREE_TYPE (right))); 155 } 156 157 if (chrec_zerop (right)) 158 return left; 159 160 return build3 (POLYNOMIAL_CHREC, TREE_TYPE (left), 161 build_int_cst (NULL_TREE, loop_num), left, right); 162} 163 164/* Determines whether the expression CHREC is a constant. */ 165 166static inline bool 167evolution_function_is_constant_p (const_tree chrec) 168{ 169 if (chrec == NULL_TREE) 170 return false; 171 172 switch (TREE_CODE (chrec)) 173 { 174 case INTEGER_CST: 175 case REAL_CST: 176 return true; 177 178 default: 179 return false; 180 } 181} 182 183/* Determine whether CHREC is an affine evolution function in LOOPNUM. */ 184 185static inline bool 186evolution_function_is_affine_in_loop (const_tree chrec, int loopnum) 187{ 188 if (chrec == NULL_TREE) 189 return false; 190 191 switch (TREE_CODE (chrec)) 192 { 193 case POLYNOMIAL_CHREC: 194 if (evolution_function_is_invariant_p (CHREC_LEFT (chrec), loopnum) 195 && evolution_function_is_invariant_p (CHREC_RIGHT (chrec), loopnum)) 196 return true; 197 else 198 return false; 199 200 default: 201 return false; 202 } 203} 204 205/* Determine whether CHREC is an affine evolution function or not. */ 206 207static inline bool 208evolution_function_is_affine_p (const_tree chrec) 209{ 210 return chrec 211 && TREE_CODE (chrec) == POLYNOMIAL_CHREC 212 && evolution_function_is_invariant_p (CHREC_RIGHT (chrec), 213 CHREC_VARIABLE (chrec)) 214 && (TREE_CODE (CHREC_RIGHT (chrec)) != POLYNOMIAL_CHREC 215 || evolution_function_is_affine_p (CHREC_RIGHT (chrec))); 216} 217 218/* Determines whether EXPR does not contains chrec expressions. */ 219 220static inline bool 221tree_does_not_contain_chrecs (const_tree expr) 222{ 223 return !tree_contains_chrecs (expr, NULL); 224} 225 226/* Returns the type of the chrec. */ 227 228static inline tree 229chrec_type (const_tree chrec) 230{ 231 if (automatically_generated_chrec_p (chrec)) 232 return NULL_TREE; 233 234 return TREE_TYPE (chrec); 235} 236 237static inline tree 238chrec_fold_op (enum tree_code code, tree type, tree op0, tree op1) 239{ 240 switch (code) 241 { 242 case PLUS_EXPR: 243 return chrec_fold_plus (type, op0, op1); 244 245 case MINUS_EXPR: 246 return chrec_fold_minus (type, op0, op1); 247 248 case MULT_EXPR: 249 return chrec_fold_multiply (type, op0, op1); 250 251 default: 252 gcc_unreachable (); 253 } 254 255} 256 257#endif /* GCC_TREE_CHREC_H */ 258