1 /* Chains of recurrences. 2 Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 3 Free Software Foundation, Inc. 4 Contributed by Sebastian Pop <pop@cri.ensmp.fr> 5 6 This file is part of GCC. 7 8 GCC is free software; you can redistribute it and/or modify it under 9 the terms of the GNU General Public License as published by the Free 10 Software Foundation; either version 3, or (at your option) any later 11 version. 12 13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY 14 WARRANTY; without even the implied warranty of MERCHANTABILITY or 15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 16 for more details. 17 18 You should have received a copy of the GNU General Public License 19 along 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 29 extern tree chrec_not_analyzed_yet; 30 extern GTY(()) tree chrec_dont_know; 31 extern GTY(()) tree chrec_known; 32 33 /* After having added an automatically generated element, please 34 include it in the following function. */ 35 36 static inline bool 37 automatically_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 45 static inline bool 46 tree_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. */ 58 extern tree chrec_fold_plus (tree, tree, tree); 59 extern tree chrec_fold_minus (tree, tree, tree); 60 extern tree chrec_fold_multiply (tree, tree, tree); 61 extern tree chrec_convert (tree, tree, gimple); 62 extern tree chrec_convert_rhs (tree, tree, gimple); 63 extern tree chrec_convert_aggressive (tree, tree); 64 65 /* Operations. */ 66 extern tree chrec_apply (unsigned, tree, tree); 67 extern tree chrec_apply_map (tree, VEC (tree, heap) *); 68 extern tree chrec_replace_initial_condition (tree, tree); 69 extern tree initial_condition (tree); 70 extern tree initial_condition_in_loop_num (tree, unsigned); 71 extern tree evolution_part_in_loop_num (tree, unsigned); 72 extern tree hide_evolution_in_other_loops_than_loop (tree, unsigned); 73 extern tree reset_evolution_in_loop (unsigned, tree, tree); 74 extern tree chrec_merge (tree, tree); 75 extern void for_each_scev_op (tree *, bool (*) (tree *, void *), void *); 76 77 /* Observers. */ 78 extern bool eq_evolutions_p (const_tree, const_tree); 79 extern bool is_multivariate_chrec (const_tree); 80 extern bool chrec_contains_symbols (const_tree); 81 extern bool chrec_contains_symbols_defined_in_loop (const_tree, unsigned); 82 extern bool chrec_contains_undetermined (const_tree); 83 extern bool tree_contains_chrecs (const_tree, int *); 84 extern bool evolution_function_is_affine_multivariate_p (const_tree, int); 85 extern bool evolution_function_is_univariate_p (const_tree); 86 extern unsigned nb_vars_in_chrec (tree); 87 extern bool evolution_function_is_invariant_p (tree, int); 88 extern bool scev_is_linear_expression (tree); 89 extern bool evolution_function_right_is_integer_cst (const_tree); 90 91 /* Determines whether CHREC is equal to zero. */ 92 93 static inline bool 94 chrec_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. */ 107 108 static inline bool 109 no_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. */ 125 126 static inline tree 127 build_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 (ptrofftype_p (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. */ 159 160 static inline bool 161 evolution_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. */ 178 179 static inline bool 180 evolution_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. */ 200 201 static inline bool 202 evolution_function_is_affine_p (const_tree chrec) 203 { 204 return chrec 205 && TREE_CODE (chrec) == POLYNOMIAL_CHREC 206 && evolution_function_is_invariant_p (CHREC_RIGHT (chrec), 207 CHREC_VARIABLE (chrec)) 208 && (TREE_CODE (CHREC_RIGHT (chrec)) != POLYNOMIAL_CHREC 209 || evolution_function_is_affine_p (CHREC_RIGHT (chrec))); 210 } 211 212 /* Determines whether EXPR does not contains chrec expressions. */ 213 214 static inline bool 215 tree_does_not_contain_chrecs (const_tree expr) 216 { 217 return !tree_contains_chrecs (expr, NULL); 218 } 219 220 /* Returns the type of the chrec. */ 221 222 static inline tree 223 chrec_type (const_tree chrec) 224 { 225 if (automatically_generated_chrec_p (chrec)) 226 return NULL_TREE; 227 228 return TREE_TYPE (chrec); 229 } 230 231 static inline tree 232 chrec_fold_op (enum tree_code code, tree type, tree op0, tree op1) 233 { 234 switch (code) 235 { 236 case PLUS_EXPR: 237 return chrec_fold_plus (type, op0, op1); 238 239 case MINUS_EXPR: 240 return chrec_fold_minus (type, op0, op1); 241 242 case MULT_EXPR: 243 return chrec_fold_multiply (type, op0, op1); 244 245 default: 246 gcc_unreachable (); 247 } 248 249 } 250 251 #endif /* GCC_TREE_CHREC_H */ 252