gcc/tree-affine.h

   1 /* Operations with affine combinations of trees.
   2    Copyright (C) 2005-2017 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify it
   7 under the terms of the GNU General Public License as published by the
   8 Free Software Foundation; either version 3, or (at your option) any
   9 later version.
  10
  11 GCC is distributed in the hope that it will be useful, but WITHOUT
  12 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.  */
  19
  20 /* Affine combination of trees.  We keep track of at most MAX_AFF_ELTS elements
  21    to make things simpler; this is sufficient in most cases.  */
  22
  23 #ifndef GCC_TREE_AFFINE_H
  24 #define GCC_TREE_AFFINE_H
  25
  26
  27 #define MAX_AFF_ELTS 8
  28
  29 /* Element of an affine combination.  */
  30
  31 struct aff_comb_elt
  32 {
  33   /* The value of the element.  */
  34   tree val;
  35
  36   /* Its coefficient in the combination.  */
  37   widest_int coef;
  38 };
  39
  40 struct aff_tree
  41 {
  42   /* Type of the result of the combination.  */
  43   tree type;
  44
  45   /* Constant offset.  */
  46   widest_int offset;
  47
  48   /* Number of elements of the combination.  */
  49   unsigned n;
  50
  51   /* Elements and their coefficients.  Type of elements may be different from
  52      TYPE, but their sizes must be the same (STRIP_NOPS is applied to the
  53      elements).
  54
  55      The coefficients are always sign extended from the precision of TYPE
  56      (regardless of signedness of TYPE).  */
  57   struct aff_comb_elt elts[MAX_AFF_ELTS];
  58
  59   /* Remainder of the expression.  Usually NULL, used only if there are more
  60      than MAX_AFF_ELTS elements.  Type of REST will be either sizetype for
  61      TYPE of POINTER_TYPEs or TYPE.  */
  62   tree rest;
  63 };
  64
  65 struct name_expansion;
  66
  67 widest_int wide_int_ext_for_comb (const widest_int &, aff_tree *);
  68 void aff_combination_const (aff_tree *, tree, const widest_int &);
  69 void aff_combination_elt (aff_tree *, tree, tree);
  70 void aff_combination_scale (aff_tree *, const widest_int &);
  71 void aff_combination_mult (aff_tree *, aff_tree *, aff_tree *);
  72 void aff_combination_add (aff_tree *, aff_tree *);
  73 void aff_combination_add_elt (aff_tree *, tree, const widest_int &);
  74 void aff_combination_remove_elt (aff_tree *, unsigned);
  75 void aff_combination_convert (aff_tree *, tree);
  76 void tree_to_aff_combination (tree, tree, aff_tree *);
  77 tree aff_combination_to_tree (aff_tree *);
  78 void unshare_aff_combination (aff_tree *);
  79 bool aff_combination_constant_multiple_p (aff_tree *, aff_tree *, widest_int *);
  80 void aff_combination_expand (aff_tree *, hash_map<tree, name_expansion *> **);
  81 void tree_to_aff_combination_expand (tree, tree, aff_tree *,
  82                                      hash_map<tree, name_expansion *> **);
  83 tree get_inner_reference_aff (tree, aff_tree *, widest_int *);
  84 void free_affine_expand_cache (hash_map<tree, name_expansion *> **);
  85 bool aff_comb_cannot_overlap_p (aff_tree *, const widest_int &,
  86                                 const widest_int &);
  87
  88 /* Debugging functions.  */
  89 void debug_aff (aff_tree *);
  90
  91 /* Return true if AFF is actually ZERO.  */
  92 static inline bool
  93 aff_combination_zero_p (aff_tree *aff)
  94 {
  95   if (!aff)
  96     return true;
  97
  98   if (aff->n == 0 && aff->offset == 0)
  99     return true;
 100
 101   return false;
 102 }
 103
 104 #endif /* GCC_TREE_AFFINE_H */