gcc/tree-affine.h

   1 /* Operations with affine combinations of trees.
   2    Copyright (C) 2005-2014 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 #include "wide-int.h"
  24
  25 #define MAX_AFF_ELTS 8
  26
  27 /* Element of an affine combination.  */
  28
  29 struct aff_comb_elt
  30 {
  31   /* The value of the element.  */
  32   tree val;
  33
  34   /* Its coefficient in the combination.  */
  35   widest_int coef;
  36 };
  37
  38 struct aff_tree
  39 {
  40   /* Type of the result of the combination.  */
  41   tree type;
  42
  43   /* Constant offset.  */
  44   widest_int offset;
  45
  46   /* Number of elements of the combination.  */
  47   unsigned n;
  48
  49   /* Elements and their coefficients.  Type of elements may be different from
  50      TYPE, but their sizes must be the same (STRIP_NOPS is applied to the
  51      elements).
  52
  53      The coefficients are always sign extended from the precision of TYPE
  54      (regardless of signedness of TYPE).  */
  55   struct aff_comb_elt elts[MAX_AFF_ELTS];
  56
  57   /* Remainder of the expression.  Usually NULL, used only if there are more
  58      than MAX_AFF_ELTS elements.  Type of REST will be either sizetype for
  59      TYPE of POINTER_TYPEs or TYPE.  */
  60   tree rest;
  61 };
  62
  63 widest_int wide_int_ext_for_comb (const widest_int &, aff_tree *);
  64 void aff_combination_const (aff_tree *, tree, const widest_int &);
  65 void aff_combination_elt (aff_tree *, tree, tree);
  66 void aff_combination_scale (aff_tree *, const widest_int &);
  67 void aff_combination_mult (aff_tree *, aff_tree *, aff_tree *);
  68 void aff_combination_add (aff_tree *, aff_tree *);
  69 void aff_combination_add_elt (aff_tree *, tree, const widest_int &);
  70 void aff_combination_remove_elt (aff_tree *, unsigned);
  71 void aff_combination_convert (aff_tree *, tree);
  72 void tree_to_aff_combination (tree, tree, aff_tree *);
  73 tree aff_combination_to_tree (aff_tree *);
  74 void unshare_aff_combination (aff_tree *);
  75 bool aff_combination_constant_multiple_p (aff_tree *, aff_tree *, widest_int *);
  76 void aff_combination_expand (aff_tree *, struct pointer_map_t **);
  77 void tree_to_aff_combination_expand (tree, tree, aff_tree *,
  78                                      struct pointer_map_t **);
  79 tree get_inner_reference_aff (tree, aff_tree *, widest_int *);
  80 void free_affine_expand_cache (struct pointer_map_t **);
  81 bool aff_comb_cannot_overlap_p (aff_tree *, const widest_int &,
  82                                 const widest_int &);
  83
  84 /* Debugging functions.  */
  85 void debug_aff (aff_tree *);
  86
  87 /* Return true if AFF is actually ZERO.  */
  88 static inline bool
  89 aff_combination_zero_p (aff_tree *aff)
  90 {
  91   if (!aff)
  92     return true;
  93
  94   if (aff->n == 0 && aff->offset == 0)
  95     return true;
  96
  97   return false;
  98 }