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 /* Determines whether CHREC is equal to zero.  */
  88
  89 static inline bool
  90 chrec_zerop (tree chrec)
  91 {
  92   if (chrec == NULL_TREE)
  93     return false;
  94
  95   if (TREE_CODE (chrec) == INTEGER_CST)
  96     return integer_zerop (chrec);
  97
  98   return false;
  99 }
 100
 101 /* Build a polynomial chain of recurrence.  */
 102
 103 static inline tree
 104 build_polynomial_chrec (unsigned loop_num,
 105                         tree left,
 106                         tree right)
 107 {
 108   if (left == chrec_dont_know
 109       || right == chrec_dont_know)
 110     return chrec_dont_know;
 111
 112   gcc_assert (TREE_TYPE (left) == TREE_TYPE (right));
 113
 114   if (chrec_zerop (right))
 115     return left;
 116
 117   return build3 (POLYNOMIAL_CHREC, TREE_TYPE (left),
 118                  build_int_cst (NULL_TREE, loop_num), left, right);
 119 }
 120
 121 /* Determines whether the expression CHREC is a constant.  */
 122
 123 static inline bool
 124 evolution_function_is_constant_p (tree chrec)
 125 {
 126   if (chrec == NULL_TREE)
 127     return false;
 128
 129   switch (TREE_CODE (chrec))
 130     {
 131     case INTEGER_CST:
 132     case REAL_CST:
 133       return true;
 134
 135     default:
 136       return false;
 137     }
 138 }
 139
 140 extern bool evolution_function_is_invariant_p (tree, int);
 141 /* Determine whether the given tree is an affine evolution function or not.  */
 142
 143 static inline bool
 144 evolution_function_is_affine_p (tree chrec)
 145 {
 146   if (chrec == NULL_TREE)
 147     return false;
 148
 149   switch (TREE_CODE (chrec))
 150     {
 151     case POLYNOMIAL_CHREC:
 152       if (evolution_function_is_invariant_p (CHREC_LEFT (chrec),
 153                                              CHREC_VARIABLE (chrec))
 154           && evolution_function_is_invariant_p (CHREC_RIGHT (chrec),
 155                                                 CHREC_VARIABLE (chrec)))
 156         return true;
 157       else
 158         return false;
 159
 160     default:
 161       return false;
 162     }
 163 }
 164
 165 /* Determine whether the given tree is an affine or constant evolution
 166    function.  */
 167
 168 static inline bool
 169 evolution_function_is_affine_or_constant_p (tree chrec)
 170 {
 171   return evolution_function_is_affine_p (chrec)
 172     || evolution_function_is_constant_p (chrec);
 173 }
 174
 175 /* Determines whether EXPR does not contains chrec expressions.  */
 176
 177 static inline bool
 178 tree_does_not_contain_chrecs (tree expr)
 179 {
 180   return !tree_contains_chrecs (expr, NULL);
 181 }
 182
 183 /* Determines whether CHREC is a loop invariant with respect to LOOP_NUM.
 184    Set the result in RES and return true when the property can be computed.  */
 185
 186 static inline bool
 187 no_evolution_in_loop_p (tree chrec, unsigned loop_num, bool *res)
 188 {
 189   tree scev;
 190
 191   if (chrec == chrec_not_analyzed_yet
 192       || chrec == chrec_dont_know
 193       || chrec_contains_symbols_defined_in_loop (chrec, loop_num))
 194     return false;
 195
 196   scev = hide_evolution_in_other_loops_than_loop (chrec, loop_num);
 197   *res = !tree_is_chrec (scev);
 198   return true;
 199 }
 200
 201 /* Returns the type of the chrec.  */
 202
 203 static inline tree
 204 chrec_type (tree chrec)
 205 {
 206   if (automatically_generated_chrec_p (chrec))
 207     return NULL_TREE;
 208
 209   return TREE_TYPE (chrec);
 210 }
 211
 212
 213 #endif  /* GCC_TREE_CHREC_H  */