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 update_initial_condition_to_origin (tree);
  78 extern tree initial_condition (tree);
  79 extern tree initial_condition_in_loop_num (tree, unsigned);
  80 extern tree evolution_part_in_loop_num (tree, unsigned);
  81 extern tree hide_evolution_in_other_loops_than_loop (tree, unsigned);
  82 extern tree reset_evolution_in_loop (unsigned, tree, tree);
  83 extern tree chrec_merge (tree, tree);
  84
  85 /* Observers.  */
  86 extern bool is_multivariate_chrec (tree);
  87 extern bool chrec_is_positive (tree, bool *);
  88 extern bool chrec_contains_symbols (tree);
  89 extern bool chrec_contains_symbols_defined_in_loop (tree, unsigned);
  90 extern bool chrec_contains_undetermined (tree);
  91 extern bool tree_contains_chrecs (tree);
  92 extern bool evolution_function_is_affine_multivariate_p (tree);
  93 extern bool evolution_function_is_univariate_p (tree);
  94 extern unsigned nb_vars_in_chrec (tree);
  95
  96 \f
  97
  98 /* Build a polynomial chain of recurrence.  */
  99
 100 static inline tree
 101 build_polynomial_chrec (unsigned loop_num,
 102                         tree left,
 103                         tree right)
 104 {
 105   if (left == chrec_dont_know
 106       || right == chrec_dont_know)
 107     return chrec_dont_know;
 108
 109   return build (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 /* Determine whether the given tree is an affine evolution function or not.  */
 151
 152 static inline bool
 153 evolution_function_is_affine_p (tree chrec)
 154 {
 155   if (chrec == NULL_TREE)
 156     return false;
 157
 158   switch (TREE_CODE (chrec))
 159     {
 160     case POLYNOMIAL_CHREC:
 161       if (evolution_function_is_constant_p (CHREC_LEFT (chrec))
 162           && evolution_function_is_constant_p (CHREC_RIGHT (chrec)))
 163         return true;
 164       else
 165         return false;
 166
 167     default:
 168       return false;
 169     }
 170 }
 171
 172 /* Determine whether the given tree is an affine or constant evolution
 173    function.  */
 174
 175 static inline bool
 176 evolution_function_is_affine_or_constant_p (tree chrec)
 177 {
 178   return evolution_function_is_affine_p (chrec)
 179     || evolution_function_is_constant_p (chrec);
 180 }
 181
 182 /* Determines whether EXPR does not contains chrec expressions.  */
 183
 184 static inline bool
 185 tree_does_not_contain_chrecs (tree expr)
 186 {
 187   return !tree_contains_chrecs (expr);
 188 }
 189
 190 /* Determines whether CHREC is a loop invariant with respect to LOOP_NUM.
 191    Set the result in RES and return true when the property can be computed.  */
 192
 193 static inline bool
 194 no_evolution_in_loop_p (tree chrec, unsigned loop_num, bool *res)
 195 {
 196   tree scev;
 197
 198   if (chrec == chrec_not_analyzed_yet
 199       || chrec == chrec_dont_know
 200       || chrec_contains_symbols_defined_in_loop (chrec, loop_num))
 201     return false;
 202
 203   scev = hide_evolution_in_other_loops_than_loop (chrec, loop_num);
 204   *res = !tree_is_chrec (scev);
 205   return true;
 206 }
 207
 208 #endif  /* GCC_TREE_CHREC_H  */