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 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
  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   return build (POLYNOMIAL_CHREC, TREE_TYPE (left),
 108                 build_int_cst (NULL_TREE, loop_num), left, right);
 109 }
 110
 111 \f
 112
 113 /* Observers.  */
 114
 115 /* Determines whether CHREC is equal to zero.  */
 116
 117 static inline bool
 118 chrec_zerop (tree chrec)
 119 {
 120   if (chrec == NULL_TREE)
 121     return false;
 122
 123   if (TREE_CODE (chrec) == INTEGER_CST)
 124     return integer_zerop (chrec);
 125
 126   return false;
 127 }
 128
 129 /* Determines whether the expression CHREC is a constant.  */
 130
 131 static inline bool
 132 evolution_function_is_constant_p (tree chrec)
 133 {
 134   if (chrec == NULL_TREE)
 135     return false;
 136
 137   switch (TREE_CODE (chrec))
 138     {
 139     case INTEGER_CST:
 140     case REAL_CST:
 141       return true;
 142
 143     default:
 144       return false;
 145     }
 146 }
 147
 148 /* Determine whether the given tree is an affine evolution function or not.  */
 149
 150 static inline bool
 151 evolution_function_is_affine_p (tree chrec)
 152 {
 153   if (chrec == NULL_TREE)
 154     return false;
 155
 156   switch (TREE_CODE (chrec))
 157     {
 158     case POLYNOMIAL_CHREC:
 159       if (evolution_function_is_constant_p (CHREC_LEFT (chrec))
 160           && evolution_function_is_constant_p (CHREC_RIGHT (chrec)))
 161         return true;
 162       else
 163         return false;
 164
 165     default:
 166       return false;
 167     }
 168 }
 169
 170 /* Determine whether the given tree is an affine or constant evolution
 171    function.  */
 172
 173 static inline bool
 174 evolution_function_is_affine_or_constant_p (tree chrec)
 175 {
 176   return evolution_function_is_affine_p (chrec)
 177     || evolution_function_is_constant_p (chrec);
 178 }
 179
 180 /* Determines whether EXPR does not contains chrec expressions.  */
 181
 182 static inline bool
 183 tree_does_not_contain_chrecs (tree expr)
 184 {
 185   return !tree_contains_chrecs (expr);
 186 }
 187
 188 /* Determines whether CHREC is a loop invariant with respect to LOOP_NUM.
 189    Set the result in RES and return true when the property can be computed.  */
 190
 191 static inline bool
 192 no_evolution_in_loop_p (tree chrec, unsigned loop_num, bool *res)
 193 {
 194   tree scev;
 195
 196   if (chrec == chrec_not_analyzed_yet
 197       || chrec == chrec_dont_know
 198       || chrec_contains_symbols_defined_in_loop (chrec, loop_num))
 199     return false;
 200
 201   scev = hide_evolution_in_other_loops_than_loop (chrec, loop_num);
 202   *res = !tree_is_chrec (scev);
 203   return true;
 204 }
 205
 206 #endif  /* GCC_TREE_CHREC_H  */