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_dont_know
  40           || chrec == chrec_known);
  41 }
  42
  43 /* The tree nodes aka. CHRECs.  */
  44
  45 static inline bool
  46 tree_is_chrec (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 \f
  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, tree);
  62 extern tree chrec_convert_aggressive (tree, tree);
  63
  64 /* Operations.  */
  65 extern tree chrec_apply (unsigned, tree, tree);
  66 extern tree chrec_replace_initial_condition (tree, tree);
  67 extern tree initial_condition (tree);
  68 extern tree initial_condition_in_loop_num (tree, unsigned);
  69 extern tree evolution_part_in_loop_num (tree, unsigned);
  70 extern tree hide_evolution_in_other_loops_than_loop (tree, unsigned);
  71 extern tree reset_evolution_in_loop (unsigned, tree, tree);
  72 extern tree chrec_merge (tree, tree);
  73
  74 /* Observers.  */
  75 extern bool eq_evolutions_p (tree, tree);
  76 extern bool is_multivariate_chrec (tree);
  77 extern bool chrec_is_positive (tree, bool *);
  78 extern bool chrec_contains_symbols (tree);
  79 extern bool chrec_contains_symbols_defined_in_loop (tree, unsigned);
  80 extern bool chrec_contains_undetermined (tree);
  81 extern bool tree_contains_chrecs (tree, int *);
  82 extern bool evolution_function_is_affine_multivariate_p (tree, int);
  83 extern bool evolution_function_is_univariate_p (tree);
  84 extern unsigned nb_vars_in_chrec (tree);
  85
  86 /* Determines whether CHREC is equal to zero.  */
  87
  88 static inline bool
  89 chrec_zerop (tree chrec)
  90 {
  91   if (chrec == NULL_TREE)
  92     return false;
  93
  94   if (TREE_CODE (chrec) == INTEGER_CST)
  95     return integer_zerop (chrec);
  96
  97   return false;
  98 }
  99
 100 /* Build a polynomial chain of recurrence.  */
 101
 102 static inline tree
 103 build_polynomial_chrec (unsigned loop_num,
 104                         tree left,
 105                         tree right)
 106 {
 107   if (left == chrec_dont_know
 108       || right == chrec_dont_know)
 109     return chrec_dont_know;
 110
 111   gcc_assert (TREE_TYPE (left) == TREE_TYPE (right));
 112
 113   if (chrec_zerop (right))
 114     return left;
 115
 116   return build3 (POLYNOMIAL_CHREC, TREE_TYPE (left),
 117                  build_int_cst (NULL_TREE, loop_num), left, right);
 118 }
 119
 120 /* Determines whether the expression CHREC is a constant.  */
 121
 122 static inline bool
 123 evolution_function_is_constant_p (tree chrec)
 124 {
 125   if (chrec == NULL_TREE)
 126     return false;
 127
 128   switch (TREE_CODE (chrec))
 129     {
 130     case INTEGER_CST:
 131     case REAL_CST:
 132       return true;
 133
 134     default:
 135       return false;
 136     }
 137 }
 138
 139 extern bool evolution_function_is_invariant_p (tree, int);
 140 /* Determine whether the given tree is an affine evolution function or not.  */
 141
 142 static inline bool
 143 evolution_function_is_affine_p (tree chrec)
 144 {
 145   if (chrec == NULL_TREE)
 146     return false;
 147
 148   switch (TREE_CODE (chrec))
 149     {
 150     case POLYNOMIAL_CHREC:
 151       if (evolution_function_is_invariant_p (CHREC_LEFT (chrec),
 152                                              CHREC_VARIABLE (chrec))
 153           && evolution_function_is_invariant_p (CHREC_RIGHT (chrec),
 154                                                 CHREC_VARIABLE (chrec)))
 155         return true;
 156       else
 157         return false;
 158
 159     default:
 160       return false;
 161     }
 162 }
 163
 164 /* Determine whether the given tree is an affine or constant evolution
 165    function.  */
 166
 167 static inline bool
 168 evolution_function_is_affine_or_constant_p (tree chrec)
 169 {
 170   return evolution_function_is_affine_p (chrec)
 171     || evolution_function_is_constant_p (chrec);
 172 }
 173
 174 /* Determines whether EXPR does not contains chrec expressions.  */
 175
 176 static inline bool
 177 tree_does_not_contain_chrecs (tree expr)
 178 {
 179   return !tree_contains_chrecs (expr, NULL);
 180 }
 181
 182 /* Determines whether CHREC is a loop invariant with respect to LOOP_NUM.
 183    Set the result in RES and return true when the property can be computed.  */
 184
 185 static inline bool
 186 no_evolution_in_loop_p (tree chrec, unsigned loop_num, bool *res)
 187 {
 188   tree scev;
 189
 190   if (chrec == chrec_not_analyzed_yet
 191       || chrec == chrec_dont_know
 192       || chrec_contains_symbols_defined_in_loop (chrec, loop_num))
 193     return false;
 194
 195   scev = hide_evolution_in_other_loops_than_loop (chrec, loop_num);
 196   *res = !tree_is_chrec (scev);
 197   return true;
 198 }
 199
 200 /* Returns the type of the chrec.  */
 201
 202 static inline tree
 203 chrec_type (tree chrec)
 204 {
 205   if (automatically_generated_chrec_p (chrec))
 206     return NULL_TREE;
 207
 208   return TREE_TYPE (chrec);
 209 }
 210
 211
 212 #endif  /* GCC_TREE_CHREC_H  */