gcc/tree-chrec.h

   1 /* Chains of recurrences.
   2    Copyright (C) 2003, 2004, 2005, 2006, 2007 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 3, 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 COPYING3.  If not see
  19 <http://www.gnu.org/licenses/>.  */
  20
  21 #ifndef GCC_TREE_CHREC_H
  22 #define GCC_TREE_CHREC_H
  23
  24 /* Accessors for the chains of recurrences.  */
  25 #define CHREC_VAR(NODE)           TREE_OPERAND (NODE, 0)
  26 #define CHREC_LEFT(NODE)          TREE_OPERAND (NODE, 1)
  27 #define CHREC_RIGHT(NODE)         TREE_OPERAND (NODE, 2)
  28 #define CHREC_VARIABLE(NODE)      TREE_INT_CST_LOW (CHREC_VAR (NODE))
  29
  30 \f
  31
  32 /* The following trees are unique elements.  Thus the comparison of another
  33    element to these elements should be done on the pointer to these trees,
  34    and not on their value.  */
  35
  36 extern tree chrec_not_analyzed_yet;
  37 extern GTY(()) tree chrec_dont_know;
  38 extern GTY(()) tree chrec_known;
  39
  40 /* After having added an automatically generated element, please
  41    include it in the following function.  */
  42
  43 static inline bool
  44 automatically_generated_chrec_p (tree chrec)
  45 {
  46   return (chrec == chrec_not_analyzed_yet
  47           || chrec == chrec_dont_know
  48           || chrec == chrec_known);
  49 }
  50
  51 /* The tree nodes aka. CHRECs.  */
  52
  53 static inline bool
  54 tree_is_chrec (tree expr)
  55 {
  56   if (TREE_CODE (expr) == POLYNOMIAL_CHREC
  57       || automatically_generated_chrec_p (expr))
  58     return true;
  59   else
  60     return false;
  61 }
  62
  63 \f
  64
  65 /* Chrec folding functions.  */
  66 extern tree chrec_fold_plus (tree, tree, tree);
  67 extern tree chrec_fold_minus (tree, tree, tree);
  68 extern tree chrec_fold_multiply (tree, tree, tree);
  69 extern tree chrec_convert (tree, tree, tree);
  70 extern tree chrec_convert_aggressive (tree, tree);
  71
  72 /* Operations.  */
  73 extern tree chrec_apply (unsigned, tree, tree);
  74 extern tree chrec_replace_initial_condition (tree, tree);
  75 extern tree initial_condition (tree);
  76 extern tree initial_condition_in_loop_num (tree, unsigned);
  77 extern tree evolution_part_in_loop_num (tree, unsigned);
  78 extern tree hide_evolution_in_other_loops_than_loop (tree, unsigned);
  79 extern tree reset_evolution_in_loop (unsigned, tree, tree);
  80 extern tree chrec_merge (tree, tree);
  81
  82 /* Observers.  */
  83 extern bool eq_evolutions_p (tree, tree);
  84 extern bool is_multivariate_chrec (tree);
  85 extern bool chrec_is_positive (tree, bool *);
  86 extern bool chrec_contains_symbols (tree);
  87 extern bool chrec_contains_symbols_defined_in_loop (tree, unsigned);
  88 extern bool chrec_contains_undetermined (tree);
  89 extern bool tree_contains_chrecs (tree, int *);
  90 extern bool evolution_function_is_affine_multivariate_p (tree);
  91 extern bool evolution_function_is_univariate_p (tree);
  92 extern unsigned nb_vars_in_chrec (tree);
  93
  94 \f
  95
  96 /* Build a polynomial chain of recurrence.  */
  97
  98 static inline tree
  99 build_polynomial_chrec (unsigned loop_num,
 100                         tree left,
 101                         tree right)
 102 {
 103   if (left == chrec_dont_know
 104       || right == chrec_dont_know)
 105     return chrec_dont_know;
 106
 107   gcc_assert (TREE_TYPE (left) == TREE_TYPE (right));
 108
 109   return build3 (POLYNOMIAL_CHREC, TREE_TYPE (left),
 110                  build_int_cst (NULL_TREE, loop_num), left, right);
 111 }
 112
 113 \f
 114
 115 /* Observers.  */
 116
 117 /* Determines whether CHREC is equal to zero.  */
 118
 119 static inline bool
 120 chrec_zerop (tree chrec)
 121 {
 122   if (chrec == NULL_TREE)
 123     return false;
 124
 125   if (TREE_CODE (chrec) == INTEGER_CST)
 126     return integer_zerop (chrec);
 127
 128   return false;
 129 }
 130
 131 /* Determines whether the expression CHREC is a constant.  */
 132
 133 static inline bool
 134 evolution_function_is_constant_p (tree chrec)
 135 {
 136   if (chrec == NULL_TREE)
 137     return false;
 138
 139   switch (TREE_CODE (chrec))
 140     {
 141     case INTEGER_CST:
 142     case REAL_CST:
 143       return true;
 144
 145     default:
 146       return false;
 147     }
 148 }
 149
 150 extern bool evolution_function_is_invariant_p (tree, int);
 151 /* Determine whether the given tree is an affine evolution function or not.  */
 152
 153 static inline bool
 154 evolution_function_is_affine_p (tree chrec)
 155 {
 156   if (chrec == NULL_TREE)
 157     return false;
 158
 159   switch (TREE_CODE (chrec))
 160     {
 161     case POLYNOMIAL_CHREC:
 162       if (evolution_function_is_invariant_p (CHREC_LEFT (chrec),
 163                                              CHREC_VARIABLE (chrec))
 164           && evolution_function_is_invariant_p (CHREC_RIGHT (chrec),
 165                                                 CHREC_VARIABLE (chrec)))
 166         return true;
 167       else
 168         return false;
 169
 170     default:
 171       return false;
 172     }
 173 }
 174
 175 /* Determine whether the given tree is an affine or constant evolution
 176    function.  */
 177
 178 static inline bool
 179 evolution_function_is_affine_or_constant_p (tree chrec)
 180 {
 181   return evolution_function_is_affine_p (chrec)
 182     || evolution_function_is_constant_p (chrec);
 183 }
 184
 185 /* Determines whether EXPR does not contains chrec expressions.  */
 186
 187 static inline bool
 188 tree_does_not_contain_chrecs (tree expr)
 189 {
 190   return !tree_contains_chrecs (expr, NULL);
 191 }
 192
 193 /* Determines whether CHREC is a loop invariant with respect to LOOP_NUM.
 194    Set the result in RES and return true when the property can be computed.  */
 195
 196 static inline bool
 197 no_evolution_in_loop_p (tree chrec, unsigned loop_num, bool *res)
 198 {
 199   tree scev;
 200
 201   if (chrec == chrec_not_analyzed_yet
 202       || chrec == chrec_dont_know
 203       || chrec_contains_symbols_defined_in_loop (chrec, loop_num))
 204     return false;
 205
 206   scev = hide_evolution_in_other_loops_than_loop (chrec, loop_num);
 207   *res = !tree_is_chrec (scev);
 208   return true;
 209 }
 210
 211 /* Returns the type of the chrec.  */
 212
 213 static inline tree
 214 chrec_type (tree chrec)
 215 {
 216   if (automatically_generated_chrec_p (chrec))
 217     return NULL_TREE;
 218
 219   return TREE_TYPE (chrec);
 220 }
 221
 222
 223 #endif  /* GCC_TREE_CHREC_H  */