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 /* 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 \f
  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
  37 extern tree chrec_not_analyzed_yet;
  38 extern GTY(()) tree chrec_dont_know;
  39 extern GTY(()) tree chrec_known;
  40
  41 /* After having added an automatically generated element, please
  42    include it in the following function.  */
  43
  44 static inline bool
  45 automatically_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
  54 static inline bool
  55 tree_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 \f
  65
  66 /* Chrec folding functions.  */
  67 extern tree chrec_fold_plus (tree, tree, tree);
  68 extern tree chrec_fold_minus (tree, tree, tree);
  69 extern tree chrec_fold_multiply (tree, tree, tree);
  70 extern tree chrec_convert (tree, tree, tree);
  71 extern tree chrec_convert_aggressive (tree, tree);
  72
  73 /* Operations.  */
  74 extern tree chrec_apply (unsigned, tree, tree);
  75 extern tree chrec_replace_initial_condition (tree, tree);
  76 extern tree initial_condition (tree);
  77 extern tree initial_condition_in_loop_num (tree, unsigned);
  78 extern tree evolution_part_in_loop_num (tree, unsigned);
  79 extern tree hide_evolution_in_other_loops_than_loop (tree, unsigned);
  80 extern tree reset_evolution_in_loop (unsigned, tree, tree);
  81 extern tree chrec_merge (tree, tree);
  82
  83 /* Observers.  */
  84 extern bool eq_evolutions_p (tree, tree);
  85 extern bool is_multivariate_chrec (tree);
  86 extern bool chrec_is_positive (tree, bool *);
  87 extern bool chrec_contains_symbols (tree);
  88 extern bool chrec_contains_symbols_defined_in_loop (tree, unsigned);
  89 extern bool chrec_contains_undetermined (tree);
  90 extern bool tree_contains_chrecs (tree, int *);
  91 extern bool evolution_function_is_affine_multivariate_p (tree);
  92 extern bool evolution_function_is_univariate_p (tree);
  93 extern unsigned nb_vars_in_chrec (tree);
  94
  95 \f
  96
  97 /* Build a polynomial chain of recurrence.  */
  98
  99 static inline tree
 100 build_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 \f
 115
 116 /* Observers.  */
 117
 118 /* Determines whether CHREC is equal to zero.  */
 119
 120 static inline bool
 121 chrec_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
 134 static inline bool
 135 evolution_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
 151 extern bool evolution_function_is_invariant_p (tree, int);
 152 /* Determine whether the given tree is an affine evolution function or not.  */
 153
 154 static inline bool
 155 evolution_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
 179 static inline bool
 180 evolution_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
 188 static inline bool
 189 tree_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
 197 static inline bool
 198 no_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
 214 static inline tree
 215 chrec_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  */