gcc/tree-chrec.h

   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
   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 2, 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 COPYING.  If not, write to the Free
  19 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
  20 02110-1301, USA.  */
  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 (tree chrec)
  38 {
  39   return (chrec == chrec_not_analyzed_yet
  40           || chrec == chrec_dont_know
  41           || chrec == chrec_known);
  42 }
  43
  44 /* The tree nodes aka. CHRECs.  */
  45
  46 static inline bool
  47 tree_is_chrec (tree expr)
  48 {
  49   if (TREE_CODE (expr) == POLYNOMIAL_CHREC
  50       || automatically_generated_chrec_p (expr))
  51     return true;
  52   else
  53     return false;
  54 }
  55
  56 \f
  57
  58 /* Chrec folding functions.  */
  59 extern tree chrec_fold_plus (tree, tree, tree);
  60 extern tree chrec_fold_minus (tree, tree, tree);
  61 extern tree chrec_fold_multiply (tree, tree, tree);
  62 extern tree chrec_convert (tree, tree, tree);
  63 extern tree chrec_convert_aggressive (tree, tree);
  64
  65 /* Operations.  */
  66 extern tree chrec_apply (unsigned, tree, 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
  75 /* Observers.  */
  76 extern bool eq_evolutions_p (tree, tree);
  77 extern bool is_multivariate_chrec (tree);
  78 extern bool chrec_is_positive (tree, bool *);
  79 extern bool chrec_contains_symbols (tree);
  80 extern bool chrec_contains_symbols_defined_in_loop (tree, unsigned);
  81 extern bool chrec_contains_undetermined (tree);
  82 extern bool tree_contains_chrecs (tree, int *);
  83 extern bool evolution_function_is_affine_multivariate_p (tree);
  84 extern bool evolution_function_is_univariate_p (tree);
  85 extern unsigned nb_vars_in_chrec (tree);
  86
  87 \f
  88
  89 /* Build a polynomial chain of recurrence.  */
  90
  91 static inline tree
  92 build_polynomial_chrec (unsigned loop_num,
  93                         tree left,
  94                         tree right)
  95 {
  96   if (left == chrec_dont_know
  97       || right == chrec_dont_know)
  98     return chrec_dont_know;
  99
 100   gcc_assert (TREE_TYPE (left) == TREE_TYPE (right));
 101
 102   return build3 (POLYNOMIAL_CHREC, TREE_TYPE (left),
 103                  build_int_cst (NULL_TREE, loop_num), left, right);
 104 }
 105
 106 \f
 107
 108 /* Observers.  */
 109
 110 /* Determines whether CHREC is equal to zero.  */
 111
 112 static inline bool
 113 chrec_zerop (tree chrec)
 114 {
 115   if (chrec == NULL_TREE)
 116     return false;
 117
 118   if (TREE_CODE (chrec) == INTEGER_CST)
 119     return integer_zerop (chrec);
 120
 121   return false;
 122 }
 123
 124 /* Determines whether the expression CHREC is a constant.  */
 125
 126 static inline bool
 127 evolution_function_is_constant_p (tree chrec)
 128 {
 129   if (chrec == NULL_TREE)
 130     return false;
 131
 132   switch (TREE_CODE (chrec))
 133     {
 134     case INTEGER_CST:
 135     case REAL_CST:
 136       return true;
 137
 138     default:
 139       return false;
 140     }
 141 }
 142
 143 extern bool evolution_function_is_invariant_p (tree, int);
 144 /* Determine whether the given tree is an affine evolution function or not.  */
 145
 146 static inline bool
 147 evolution_function_is_affine_p (tree chrec)
 148 {
 149   if (chrec == NULL_TREE)
 150     return false;
 151
 152   switch (TREE_CODE (chrec))
 153     {
 154     case POLYNOMIAL_CHREC:
 155       if (evolution_function_is_invariant_p (CHREC_LEFT (chrec),
 156                                              CHREC_VARIABLE (chrec))
 157           && evolution_function_is_invariant_p (CHREC_RIGHT (chrec),
 158                                                 CHREC_VARIABLE (chrec)))
 159         return true;
 160       else
 161         return false;
 162
 163     default:
 164       return false;
 165     }
 166 }
 167
 168 /* Determine whether the given tree is an affine or constant evolution
 169    function.  */
 170
 171 static inline bool
 172 evolution_function_is_affine_or_constant_p (tree chrec)
 173 {
 174   return evolution_function_is_affine_p (chrec)
 175     || evolution_function_is_constant_p (chrec);
 176 }
 177
 178 /* Determines whether EXPR does not contains chrec expressions.  */
 179
 180 static inline bool
 181 tree_does_not_contain_chrecs (tree expr)
 182 {
 183   return !tree_contains_chrecs (expr, NULL);
 184 }
 185
 186 /* Determines whether CHREC is a loop invariant with respect to LOOP_NUM.
 187    Set the result in RES and return true when the property can be computed.  */
 188
 189 static inline bool
 190 no_evolution_in_loop_p (tree chrec, unsigned loop_num, bool *res)
 191 {
 192   tree scev;
 193
 194   if (chrec == chrec_not_analyzed_yet
 195       || chrec == chrec_dont_know
 196       || chrec_contains_symbols_defined_in_loop (chrec, loop_num))
 197     return false;
 198
 199   scev = hide_evolution_in_other_loops_than_loop (chrec, loop_num);
 200   *res = !tree_is_chrec (scev);
 201   return true;
 202 }
 203
 204 /* Returns the type of the chrec.  */
 205
 206 static inline tree
 207 chrec_type (tree chrec)
 208 {
 209   if (automatically_generated_chrec_p (chrec))
 210     return NULL_TREE;
 211
 212   return TREE_TYPE (chrec);
 213 }
 214
 215
 216 #endif  /* GCC_TREE_CHREC_H  */