1 /* Chains of recurrences. 2 Copyright (C) 2003-2013 Free Software Foundation, Inc. 3 Contributed by Sebastian Pop <pop@cri.ensmp.fr> 4 5 This file is part of GCC. 6 7 GCC is free software; you can redistribute it and/or modify it under 8 the terms of the GNU General Public License as published by the Free 9 Software Foundation; either version 3, or (at your option) any later 10 version. 11 12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY 13 WARRANTY; without even the implied warranty of MERCHANTABILITY or 14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 15 for more details. 16 17 You should have received a copy of the GNU General Public License 18 along 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 GTY(()) tree chrec_dont_know; 30 extern GTY(()) tree chrec_known; 31 32 /* After having added an automatically generated element, please 33 include it in the following function. */ 34 35 static inline bool 36 automatically_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 44 static inline bool 45 tree_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 55 56 /* Chrec folding functions. */ 57 extern tree chrec_fold_plus (tree, tree, tree); 58 extern tree chrec_fold_minus (tree, tree, tree); 59 extern tree chrec_fold_multiply (tree, tree, tree); 60 extern tree chrec_convert (tree, tree, gimple); 61 extern tree chrec_convert_rhs (tree, tree, gimple); 62 extern tree chrec_convert_aggressive (tree, tree); 63 64 /* Operations. */ 65 extern tree chrec_apply (unsigned, tree, tree); 66 extern tree chrec_apply_map (tree, vec<tree> ); 67 extern tree chrec_replace_initial_condition (tree, tree); 68 extern tree initial_condition (tree); 69 extern tree initial_condition_in_loop_num (tree, unsigned); 70 extern tree evolution_part_in_loop_num (tree, unsigned); 71 extern tree hide_evolution_in_other_loops_than_loop (tree, unsigned); 72 extern tree reset_evolution_in_loop (unsigned, tree, tree); 73 extern tree chrec_merge (tree, tree); 74 extern void for_each_scev_op (tree *, bool (*) (tree *, void *), void *); 75 76 /* Observers. */ 77 extern bool eq_evolutions_p (const_tree, const_tree); 78 extern bool is_multivariate_chrec (const_tree); 79 extern bool chrec_contains_symbols (const_tree); 80 extern bool chrec_contains_symbols_defined_in_loop (const_tree, unsigned); 81 extern bool chrec_contains_undetermined (const_tree); 82 extern bool tree_contains_chrecs (const_tree, int *); 83 extern bool evolution_function_is_affine_multivariate_p (const_tree, int); 84 extern bool evolution_function_is_univariate_p (const_tree); 85 extern unsigned nb_vars_in_chrec (tree); 86 extern bool evolution_function_is_invariant_p (tree, int); 87 extern bool scev_is_linear_expression (tree); 88 extern bool evolution_function_right_is_integer_cst (const_tree); 89 90 /* Determines whether CHREC is equal to zero. */ 91 92 static inline bool 93 chrec_zerop (const_tree chrec) 94 { 95 if (chrec == NULL_TREE) 96 return false; 97 98 if (TREE_CODE (chrec) == INTEGER_CST) 99 return integer_zerop (chrec); 100 101 return false; 102 } 103 104 /* Determines whether CHREC is a loop invariant with respect to LOOP_NUM. 105 Set the result in RES and return true when the property can be computed. */ 106 107 static inline bool 108 no_evolution_in_loop_p (tree chrec, unsigned loop_num, bool *res) 109 { 110 tree scev; 111 112 if (chrec == chrec_not_analyzed_yet 113 || chrec == chrec_dont_know 114 || chrec_contains_symbols_defined_in_loop (chrec, loop_num)) 115 return false; 116 117 STRIP_NOPS (chrec); 118 scev = hide_evolution_in_other_loops_than_loop (chrec, loop_num); 119 *res = !tree_contains_chrecs (scev, NULL); 120 return true; 121 } 122 123 /* Build a polynomial chain of recurrence. */ 124 125 static inline tree 126 build_polynomial_chrec (unsigned loop_num, 127 tree left, 128 tree right) 129 { 130 bool val; 131 132 if (left == chrec_dont_know 133 || right == chrec_dont_know) 134 return chrec_dont_know; 135 136 if (!no_evolution_in_loop_p (left, loop_num, &val) 137 || !val) 138 return chrec_dont_know; 139 140 /* Pointer types should occur only on the left hand side, i.e. in 141 the base of the chrec, and not in the step. */ 142 gcc_assert (!POINTER_TYPE_P (TREE_TYPE (right))); 143 144 /* Types of left and right sides of a chrec should be compatible. */ 145 if (POINTER_TYPE_P (TREE_TYPE (left))) 146 gcc_assert (ptrofftype_p (TREE_TYPE (right))); 147 else 148 gcc_assert (TREE_TYPE (left) == TREE_TYPE (right)); 149 150 if (chrec_zerop (right)) 151 return left; 152 153 return build3 (POLYNOMIAL_CHREC, TREE_TYPE (left), 154 build_int_cst (NULL_TREE, loop_num), left, right); 155 } 156 157 /* Determines whether the expression CHREC is a constant. */ 158 159 static inline bool 160 evolution_function_is_constant_p (const_tree chrec) 161 { 162 if (chrec == NULL_TREE) 163 return false; 164 165 switch (TREE_CODE (chrec)) 166 { 167 case INTEGER_CST: 168 case REAL_CST: 169 return true; 170 171 default: 172 return false; 173 } 174 } 175 176 /* Determine whether CHREC is an affine evolution function in LOOPNUM. */ 177 178 static inline bool 179 evolution_function_is_affine_in_loop (const_tree chrec, int loopnum) 180 { 181 if (chrec == NULL_TREE) 182 return false; 183 184 switch (TREE_CODE (chrec)) 185 { 186 case POLYNOMIAL_CHREC: 187 if (evolution_function_is_invariant_p (CHREC_LEFT (chrec), loopnum) 188 && evolution_function_is_invariant_p (CHREC_RIGHT (chrec), loopnum)) 189 return true; 190 else 191 return false; 192 193 default: 194 return false; 195 } 196 } 197 198 /* Determine whether CHREC is an affine evolution function or not. */ 199 200 static inline bool 201 evolution_function_is_affine_p (const_tree chrec) 202 { 203 return chrec 204 && TREE_CODE (chrec) == POLYNOMIAL_CHREC 205 && evolution_function_is_invariant_p (CHREC_RIGHT (chrec), 206 CHREC_VARIABLE (chrec)) 207 && (TREE_CODE (CHREC_RIGHT (chrec)) != POLYNOMIAL_CHREC 208 || evolution_function_is_affine_p (CHREC_RIGHT (chrec))); 209 } 210 211 /* Determines whether EXPR does not contains chrec expressions. */ 212 213 static inline bool 214 tree_does_not_contain_chrecs (const_tree expr) 215 { 216 return !tree_contains_chrecs (expr, NULL); 217 } 218 219 /* Returns the type of the chrec. */ 220 221 static inline tree 222 chrec_type (const_tree chrec) 223 { 224 if (automatically_generated_chrec_p (chrec)) 225 return NULL_TREE; 226 227 return TREE_TYPE (chrec); 228 } 229 230 static inline tree 231 chrec_fold_op (enum tree_code code, tree type, tree op0, tree op1) 232 { 233 switch (code) 234 { 235 case PLUS_EXPR: 236 return chrec_fold_plus (type, op0, op1); 237 238 case MINUS_EXPR: 239 return chrec_fold_minus (type, op0, op1); 240 241 case MULT_EXPR: 242 return chrec_fold_multiply (type, op0, op1); 243 244 default: 245 gcc_unreachable (); 246 } 247 248 } 249 250 #endif /* GCC_TREE_CHREC_H */ 251