1/* Chains of recurrences. 2 Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009 3 Free Software Foundation, Inc. 4 Contributed by Sebastian Pop <pop@cri.ensmp.fr> 5 6This file is part of GCC. 7 8GCC is free software; you can redistribute it and/or modify it under 9the terms of the GNU General Public License as published by the Free 10Software Foundation; either version 3, or (at your option) any later 11version. 12 13GCC is distributed in the hope that it will be useful, but WITHOUT ANY 14WARRANTY; without even the implied warranty of MERCHANTABILITY or 15FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 16for more details. 17 18You should have received a copy of the GNU General Public License 19along with GCC; see the file COPYING3. If not see 20<http://www.gnu.org/licenses/>. */ 21 22#ifndef GCC_TREE_CHREC_H 23#define GCC_TREE_CHREC_H 24 25/* The following trees are unique elements. Thus the comparison of another 26 element to these elements should be done on the pointer to these trees, 27 and not on their value. */ 28 29extern tree chrec_not_analyzed_yet; 30extern GTY(()) tree chrec_dont_know; 31extern GTY(()) tree chrec_known; 32 33/* After having added an automatically generated element, please 34 include it in the following function. */ 35 36static inline bool 37automatically_generated_chrec_p (const_tree chrec) 38{ 39 return (chrec == chrec_dont_know 40 || chrec == chrec_known); 41} 42 43/* The tree nodes aka. CHRECs. */ 44 45static inline bool 46tree_is_chrec (const_tree expr) 47{ 48 if (TREE_CODE (expr) == POLYNOMIAL_CHREC 49 || automatically_generated_chrec_p (expr)) 50 return true; 51 else 52 return false; 53} 54 55 56 57/* Chrec folding functions. */ 58extern tree chrec_fold_plus (tree, tree, tree); 59extern tree chrec_fold_minus (tree, tree, tree); 60extern tree chrec_fold_multiply (tree, tree, tree); 61extern tree chrec_convert (tree, tree, gimple); 62extern tree chrec_convert_rhs (tree, tree, gimple); 63extern tree chrec_convert_aggressive (tree, tree); 64 65/* Operations. */ 66extern tree chrec_apply (unsigned, tree, tree); 67extern tree chrec_replace_initial_condition (tree, tree); 68extern tree initial_condition (tree); 69extern tree initial_condition_in_loop_num (tree, unsigned); 70extern tree evolution_part_in_loop_num (tree, unsigned); 71extern tree hide_evolution_in_other_loops_than_loop (tree, unsigned); 72extern tree reset_evolution_in_loop (unsigned, tree, tree); 73extern tree chrec_merge (tree, tree); 74extern void for_each_scev_op (tree *, bool (*) (tree *, void *), void *); 75 76/* Observers. */ 77extern bool eq_evolutions_p (const_tree, const_tree); 78extern bool is_multivariate_chrec (const_tree); 79extern bool chrec_is_positive (tree, bool *); 80extern bool chrec_contains_symbols (const_tree); 81extern bool chrec_contains_symbols_defined_in_loop (const_tree, unsigned); 82extern bool chrec_contains_undetermined (const_tree); 83extern bool tree_contains_chrecs (const_tree, int *); 84extern bool evolution_function_is_affine_multivariate_p (const_tree, int); 85extern bool evolution_function_is_univariate_p (const_tree); 86extern unsigned nb_vars_in_chrec (tree); 87extern bool evolution_function_is_invariant_p (tree, int); 88extern bool scev_is_linear_expression (tree); 89extern bool evolution_function_right_is_integer_cst (const_tree); 90 91/* Determines whether CHREC is equal to zero. */ 92 93static inline bool 94chrec_zerop (const_tree chrec) 95{ 96 if (chrec == NULL_TREE) 97 return false; 98 99 if (TREE_CODE (chrec) == INTEGER_CST) 100 return integer_zerop (chrec); 101 102 return false; 103} 104 105/* Determines whether CHREC is a loop invariant with respect to LOOP_NUM. 106 Set the result in RES and return true when the property can be computed. */ 107 108static inline bool 109no_evolution_in_loop_p (tree chrec, unsigned loop_num, bool *res) 110{ 111 tree scev; 112 113 if (chrec == chrec_not_analyzed_yet 114 || chrec == chrec_dont_know 115 || chrec_contains_symbols_defined_in_loop (chrec, loop_num)) 116 return false; 117 118 STRIP_NOPS (chrec); 119 scev = hide_evolution_in_other_loops_than_loop (chrec, loop_num); 120 *res = !tree_is_chrec (scev); 121 return true; 122} 123 124/* Build a polynomial chain of recurrence. */ 125 126static inline tree 127build_polynomial_chrec (unsigned loop_num, 128 tree left, 129 tree right) 130{ 131 bool val; 132 133 if (left == chrec_dont_know 134 || right == chrec_dont_know) 135 return chrec_dont_know; 136 137 if (!no_evolution_in_loop_p (left, loop_num, &val) 138 || !val) 139 return chrec_dont_know; 140 141 /* Pointer types should occur only on the left hand side, i.e. in 142 the base of the chrec, and not in the step. */ 143 gcc_assert (!POINTER_TYPE_P (TREE_TYPE (right))); 144 145 /* Types of left and right sides of a chrec should be compatible. */ 146 if (POINTER_TYPE_P (TREE_TYPE (left))) 147 gcc_assert (sizetype == TREE_TYPE (right)); 148 else 149 gcc_assert (TREE_TYPE (left) == TREE_TYPE (right)); 150 151 if (chrec_zerop (right)) 152 return left; 153 154 return build3 (POLYNOMIAL_CHREC, TREE_TYPE (left), 155 build_int_cst (NULL_TREE, loop_num), left, right); 156} 157 158/* Determines whether the expression CHREC is a constant. */ 159 160static inline bool 161evolution_function_is_constant_p (const_tree chrec) 162{ 163 if (chrec == NULL_TREE) 164 return false; 165 166 switch (TREE_CODE (chrec)) 167 { 168 case INTEGER_CST: 169 case REAL_CST: 170 return true; 171 172 default: 173 return false; 174 } 175} 176 177/* Determine whether CHREC is an affine evolution function in LOOPNUM. */ 178 179static inline bool 180evolution_function_is_affine_in_loop (const_tree chrec, int loopnum) 181{ 182 if (chrec == NULL_TREE) 183 return false; 184 185 switch (TREE_CODE (chrec)) 186 { 187 case POLYNOMIAL_CHREC: 188 if (evolution_function_is_invariant_p (CHREC_LEFT (chrec), loopnum) 189 && evolution_function_is_invariant_p (CHREC_RIGHT (chrec), loopnum)) 190 return true; 191 else 192 return false; 193 194 default: 195 return false; 196 } 197} 198 199/* Determine whether CHREC is an affine evolution function or not. */ 200 201static inline bool 202evolution_function_is_affine_p (const_tree chrec) 203{ 204 if (chrec == NULL_TREE) 205 return false; 206 207 switch (TREE_CODE (chrec)) 208 { 209 case POLYNOMIAL_CHREC: 210 if (evolution_function_is_invariant_p (CHREC_LEFT (chrec), 211 CHREC_VARIABLE (chrec)) 212 && evolution_function_is_invariant_p (CHREC_RIGHT (chrec), 213 CHREC_VARIABLE (chrec))) 214 return true; 215 else 216 return false; 217 218 default: 219 return false; 220 } 221} 222 223/* Determines whether EXPR does not contains chrec expressions. */ 224 225static inline bool 226tree_does_not_contain_chrecs (const_tree expr) 227{ 228 return !tree_contains_chrecs (expr, NULL); 229} 230 231/* Returns the type of the chrec. */ 232 233static inline tree 234chrec_type (const_tree chrec) 235{ 236 if (automatically_generated_chrec_p (chrec)) 237 return NULL_TREE; 238 239 return TREE_TYPE (chrec); 240} 241 242static inline tree 243chrec_fold_op (enum tree_code code, tree type, tree op0, tree op1) 244{ 245 switch (code) 246 { 247 case PLUS_EXPR: 248 return chrec_fold_plus (type, op0, op1); 249 250 case MINUS_EXPR: 251 return chrec_fold_minus (type, op0, op1); 252 253 case MULT_EXPR: 254 return chrec_fold_multiply (type, op0, op1); 255 256 default: 257 gcc_unreachable (); 258 } 259 260} 261 262#endif /* GCC_TREE_CHREC_H */ 263