1/* Chains of recurrences. 2 Copyright (C) 2003, 2004, 2005 Free Software Foundation, Inc. 3 Contributed by Sebastian Pop <s.pop@laposte.net> 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 2, 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 COPYING. If not, write to the Free 19Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 2002110-1301, USA. */ 21 22#ifndef GCC_TREE_CHREC_H 23#define GCC_TREE_CHREC_H 24 25/* Accessors for the chains of recurrences. */ 26#define CHREC_VAR(NODE) TREE_OPERAND (NODE, 0) 27#define CHREC_LEFT(NODE) TREE_OPERAND (NODE, 1) 28#define CHREC_RIGHT(NODE) TREE_OPERAND (NODE, 2) 29#define CHREC_VARIABLE(NODE) TREE_INT_CST_LOW (CHREC_VAR (NODE)) 30 31 32 33/* The following trees are unique elements. Thus the comparison of another 34 element to these elements should be done on the pointer to these trees, 35 and not on their value. */ 36 37extern tree chrec_not_analyzed_yet; 38extern GTY(()) tree chrec_dont_know; 39extern GTY(()) tree chrec_known; 40 41/* After having added an automatically generated element, please 42 include it in the following function. */ 43 44static inline bool 45automatically_generated_chrec_p (tree chrec) 46{ 47 return (chrec == chrec_not_analyzed_yet 48 || chrec == chrec_dont_know 49 || chrec == chrec_known); 50} 51 52/* The tree nodes aka. CHRECs. */ 53 54static inline bool 55tree_is_chrec (tree expr) 56{ 57 if (TREE_CODE (expr) == POLYNOMIAL_CHREC 58 || automatically_generated_chrec_p (expr)) 59 return true; 60 else 61 return false; 62} 63 64 65 66/* Chrec folding functions. */ 67extern tree chrec_fold_plus (tree, tree, tree); 68extern tree chrec_fold_minus (tree, tree, tree); 69extern tree chrec_fold_multiply (tree, tree, tree); 70extern tree chrec_convert (tree, tree, tree); 71extern tree chrec_convert_aggressive (tree, tree); 72extern tree chrec_type (tree); 73 74/* Operations. */ 75extern tree chrec_apply (unsigned, tree, tree); 76extern tree chrec_replace_initial_condition (tree, tree); 77extern tree initial_condition (tree); 78extern tree initial_condition_in_loop_num (tree, unsigned); 79extern tree evolution_part_in_loop_num (tree, unsigned); 80extern tree hide_evolution_in_other_loops_than_loop (tree, unsigned); 81extern tree reset_evolution_in_loop (unsigned, tree, tree); 82extern tree chrec_merge (tree, tree); 83 84/* Observers. */ 85extern bool is_multivariate_chrec (tree); 86extern bool chrec_is_positive (tree, bool *); 87extern bool chrec_contains_symbols (tree); 88extern bool chrec_contains_symbols_defined_in_loop (tree, unsigned); 89extern bool chrec_contains_undetermined (tree); 90extern bool tree_contains_chrecs (tree, int *); 91extern bool evolution_function_is_affine_multivariate_p (tree); 92extern bool evolution_function_is_univariate_p (tree); 93extern unsigned nb_vars_in_chrec (tree); 94 95 96 97/* Build a polynomial chain of recurrence. */ 98 99static inline tree 100build_polynomial_chrec (unsigned loop_num, 101 tree left, 102 tree right) 103{ 104 if (left == chrec_dont_know 105 || right == chrec_dont_know) 106 return chrec_dont_know; 107 108 return build (POLYNOMIAL_CHREC, TREE_TYPE (left), 109 build_int_cst (NULL_TREE, loop_num), left, right); 110} 111 112 113 114/* Observers. */ 115 116/* Determines whether CHREC is equal to zero. */ 117 118static inline bool 119chrec_zerop (tree chrec) 120{ 121 if (chrec == NULL_TREE) 122 return false; 123 124 if (TREE_CODE (chrec) == INTEGER_CST) 125 return integer_zerop (chrec); 126 127 return false; 128} 129 130/* Determines whether the expression CHREC is a constant. */ 131 132static inline bool 133evolution_function_is_constant_p (tree chrec) 134{ 135 if (chrec == NULL_TREE) 136 return false; 137 138 switch (TREE_CODE (chrec)) 139 { 140 case INTEGER_CST: 141 case REAL_CST: 142 return true; 143 144 default: 145 return false; 146 } 147} 148 149extern bool evolution_function_is_invariant_p (tree, int); 150/* Determine whether the given tree is an affine evolution function or not. */ 151 152static inline bool 153evolution_function_is_affine_p (tree chrec) 154{ 155 if (chrec == NULL_TREE) 156 return false; 157 158 switch (TREE_CODE (chrec)) 159 { 160 case POLYNOMIAL_CHREC: 161 if (evolution_function_is_invariant_p (CHREC_LEFT (chrec), 162 CHREC_VARIABLE (chrec)) 163 && evolution_function_is_invariant_p (CHREC_RIGHT (chrec), 164 CHREC_VARIABLE (chrec))) 165 return true; 166 else 167 return false; 168 169 default: 170 return false; 171 } 172} 173 174/* Determine whether the given tree is an affine or constant evolution 175 function. */ 176 177static inline bool 178evolution_function_is_affine_or_constant_p (tree chrec) 179{ 180 return evolution_function_is_affine_p (chrec) 181 || evolution_function_is_constant_p (chrec); 182} 183 184/* Determines whether EXPR does not contains chrec expressions. */ 185 186static inline bool 187tree_does_not_contain_chrecs (tree expr) 188{ 189 return !tree_contains_chrecs (expr, NULL); 190} 191 192/* Determines whether CHREC is a loop invariant with respect to LOOP_NUM. 193 Set the result in RES and return true when the property can be computed. */ 194 195static inline bool 196no_evolution_in_loop_p (tree chrec, unsigned loop_num, bool *res) 197{ 198 tree scev; 199 200 if (chrec == chrec_not_analyzed_yet 201 || chrec == chrec_dont_know 202 || chrec_contains_symbols_defined_in_loop (chrec, loop_num)) 203 return false; 204 205 scev = hide_evolution_in_other_loops_than_loop (chrec, loop_num); 206 *res = !tree_is_chrec (scev); 207 return true; 208} 209 210#endif /* GCC_TREE_CHREC_H */ 211