1/* Chains of recurrences. 2 Copyright (C) 2003, 2004, 2005, 2006 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 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); 72 73/* Operations. */ 74extern tree chrec_apply (unsigned, tree, tree); 75extern tree chrec_replace_initial_condition (tree, tree); 76extern tree initial_condition (tree); 77extern tree initial_condition_in_loop_num (tree, unsigned); 78extern tree evolution_part_in_loop_num (tree, unsigned); 79extern tree hide_evolution_in_other_loops_than_loop (tree, unsigned); 80extern tree reset_evolution_in_loop (unsigned, tree, tree); 81extern tree chrec_merge (tree, tree); 82 83/* Observers. */ 84extern bool eq_evolutions_p (tree, tree); 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 gcc_assert (TREE_TYPE (left) == TREE_TYPE (right)); 109 110 return build3 (POLYNOMIAL_CHREC, TREE_TYPE (left), 111 build_int_cst (NULL_TREE, loop_num), left, right); 112} 113 114 115 116/* Observers. */ 117 118/* Determines whether CHREC is equal to zero. */ 119 120static inline bool 121chrec_zerop (tree chrec) 122{ 123 if (chrec == NULL_TREE) 124 return false; 125 126 if (TREE_CODE (chrec) == INTEGER_CST) 127 return integer_zerop (chrec); 128 129 return false; 130} 131 132/* Determines whether the expression CHREC is a constant. */ 133 134static inline bool 135evolution_function_is_constant_p (tree chrec) 136{ 137 if (chrec == NULL_TREE) 138 return false; 139 140 switch (TREE_CODE (chrec)) 141 { 142 case INTEGER_CST: 143 case REAL_CST: 144 return true; 145 146 default: 147 return false; 148 } 149} 150 151extern bool evolution_function_is_invariant_p (tree, int); 152/* Determine whether the given tree is an affine evolution function or not. */ 153 154static inline bool 155evolution_function_is_affine_p (tree chrec) 156{ 157 if (chrec == NULL_TREE) 158 return false; 159 160 switch (TREE_CODE (chrec)) 161 { 162 case POLYNOMIAL_CHREC: 163 if (evolution_function_is_invariant_p (CHREC_LEFT (chrec), 164 CHREC_VARIABLE (chrec)) 165 && evolution_function_is_invariant_p (CHREC_RIGHT (chrec), 166 CHREC_VARIABLE (chrec))) 167 return true; 168 else 169 return false; 170 171 default: 172 return false; 173 } 174} 175 176/* Determine whether the given tree is an affine or constant evolution 177 function. */ 178 179static inline bool 180evolution_function_is_affine_or_constant_p (tree chrec) 181{ 182 return evolution_function_is_affine_p (chrec) 183 || evolution_function_is_constant_p (chrec); 184} 185 186/* Determines whether EXPR does not contains chrec expressions. */ 187 188static inline bool 189tree_does_not_contain_chrecs (tree expr) 190{ 191 return !tree_contains_chrecs (expr, NULL); 192} 193 194/* Determines whether CHREC is a loop invariant with respect to LOOP_NUM. 195 Set the result in RES and return true when the property can be computed. */ 196 197static inline bool 198no_evolution_in_loop_p (tree chrec, unsigned loop_num, bool *res) 199{ 200 tree scev; 201 202 if (chrec == chrec_not_analyzed_yet 203 || chrec == chrec_dont_know 204 || chrec_contains_symbols_defined_in_loop (chrec, loop_num)) 205 return false; 206 207 scev = hide_evolution_in_other_loops_than_loop (chrec, loop_num); 208 *res = !tree_is_chrec (scev); 209 return true; 210} 211 212/* Returns the type of the chrec. */ 213 214static inline tree 215chrec_type (tree chrec) 216{ 217 if (automatically_generated_chrec_p (chrec)) 218 return NULL_TREE; 219 220 return TREE_TYPE (chrec); 221} 222 223 224#endif /* GCC_TREE_CHREC_H */ 225