gcc/tree-chrec.h

   1 /* Chains of recurrences.
   2    Copyright (C) 2003, 2004 Free Software Foundation, Inc.
   3    Contributed by Sebastian Pop <s.pop@laposte.net>
   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, 59 Temple Place - Suite 330, Boston, MA
  20 02111-1307, 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);
  71 extern tree count_ev_in_wider_type (tree, tree);
  72 extern tree chrec_type (tree);
  73
  74 /* Operations.  */
  75 extern tree chrec_apply (unsigned, tree, tree);
  76 extern tree chrec_replace_initial_condition (tree, tree);
  77 extern tree initial_condition (tree);
  78 extern tree initial_condition_in_loop_num (tree, unsigned);
  79 extern tree evolution_part_in_loop_num (tree, unsigned);
  80 extern tree hide_evolution_in_other_loops_than_loop (tree, unsigned);
  81 extern tree reset_evolution_in_loop (unsigned, tree, tree);
  82 extern tree chrec_merge (tree, tree);
  83
  84 /* Observers.  */
  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);
  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   return build (POLYNOMIAL_CHREC, TREE_TYPE (left),
 109                 build_int_cst (NULL_TREE, loop_num), left, right);
 110 }
 111
 112 \f
 113
 114 /* Observers.  */
 115
 116 /* Determines whether CHREC is equal to zero.  */
 117
 118 static inline bool
 119 chrec_zerop (tree chrec)
 120 {
 121   if (chrec == NULL_TREE)
 122     return false;
 123
 124   if (TREE_CODE (chrec) == INTEGER_CST)
 125     return integer_zerop (chrec);
 126
 127   return false;
 128 }
 129
 130 /* Determines whether the expression CHREC is a constant.  */
 131
 132 static inline bool
 133 evolution_function_is_constant_p (tree chrec)
 134 {
 135   if (chrec == NULL_TREE)
 136     return false;
 137
 138   switch (TREE_CODE (chrec))
 139     {
 140     case INTEGER_CST:
 141     case REAL_CST:
 142       return true;
 143
 144     default:
 145       return false;
 146     }
 147 }
 148
 149 /* Determine whether the given tree is an affine evolution function or not.  */
 150
 151 static inline bool
 152 evolution_function_is_affine_p (tree chrec)
 153 {
 154   if (chrec == NULL_TREE)
 155     return false;
 156
 157   switch (TREE_CODE (chrec))
 158     {
 159     case POLYNOMIAL_CHREC:
 160       if (evolution_function_is_constant_p (CHREC_LEFT (chrec))
 161           && evolution_function_is_constant_p (CHREC_RIGHT (chrec)))
 162         return true;
 163       else
 164         return false;
 165
 166     default:
 167       return false;
 168     }
 169 }
 170
 171 /* Determine whether the given tree is an affine or constant evolution
 172    function.  */
 173
 174 static inline bool
 175 evolution_function_is_affine_or_constant_p (tree chrec)
 176 {
 177   return evolution_function_is_affine_p (chrec)
 178     || evolution_function_is_constant_p (chrec);
 179 }
 180
 181 /* Determines whether EXPR does not contains chrec expressions.  */
 182
 183 static inline bool
 184 tree_does_not_contain_chrecs (tree expr)
 185 {
 186   return !tree_contains_chrecs (expr);
 187 }
 188
 189 /* Determines whether CHREC is a loop invariant with respect to LOOP_NUM.
 190    Set the result in RES and return true when the property can be computed.  */
 191
 192 static inline bool
 193 no_evolution_in_loop_p (tree chrec, unsigned loop_num, bool *res)
 194 {
 195   tree scev;
 196
 197   if (chrec == chrec_not_analyzed_yet
 198       || chrec == chrec_dont_know
 199       || chrec_contains_symbols_defined_in_loop (chrec, loop_num))
 200     return false;
 201
 202   scev = hide_evolution_in_other_loops_than_loop (chrec, loop_num);
 203   *res = !tree_is_chrec (scev);
 204   return true;
 205 }
 206
 207 #endif  /* GCC_TREE_CHREC_H  */