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 #ifndef GCC_TREE_AFFINE_H
  24 #define GCC_TREE_AFFINE_H
  25
  26 #include "hash-map.h"
  27 #include "wide-int.h"
  28
  29 #define MAX_AFF_ELTS 8
  30
  31 /* Element of an affine combination.  */
  32
  33 struct aff_comb_elt
  34 {
  35   /* The value of the element.  */
  36   tree val;
  37
  38   /* Its coefficient in the combination.  */
  39   widest_int coef;
  40 };
  41
  42 struct aff_tree
  43 {
  44   /* Type of the result of the combination.  */
  45   tree type;
  46
  47   /* Constant offset.  */
  48   widest_int offset;
  49
  50   /* Number of elements of the combination.  */
  51   unsigned n;
  52
  53   /* Elements and their coefficients.  Type of elements may be different from
  54      TYPE, but their sizes must be the same (STRIP_NOPS is applied to the
  55      elements).
  56
  57      The coefficients are always sign extended from the precision of TYPE
  58      (regardless of signedness of TYPE).  */
  59   struct aff_comb_elt elts[MAX_AFF_ELTS];
  60
  61   /* Remainder of the expression.  Usually NULL, used only if there are more
  62      than MAX_AFF_ELTS elements.  Type of REST will be either sizetype for
  63      TYPE of POINTER_TYPEs or TYPE.  */
  64   tree rest;
  65 };
  66
  67 struct name_expansion;
  68
  69 widest_int wide_int_ext_for_comb (const widest_int &, aff_tree *);
  70 void aff_combination_const (aff_tree *, tree, const widest_int &);
  71 void aff_combination_elt (aff_tree *, tree, tree);
  72 void aff_combination_scale (aff_tree *, const widest_int &);
  73 void aff_combination_mult (aff_tree *, aff_tree *, aff_tree *);
  74 void aff_combination_add (aff_tree *, aff_tree *);
  75 void aff_combination_add_elt (aff_tree *, tree, const widest_int &);
  76 void aff_combination_remove_elt (aff_tree *, unsigned);
  77 void aff_combination_convert (aff_tree *, tree);
  78 void tree_to_aff_combination (tree, tree, aff_tree *);
  79 tree aff_combination_to_tree (aff_tree *);
  80 void unshare_aff_combination (aff_tree *);
  81 bool aff_combination_constant_multiple_p (aff_tree *, aff_tree *, widest_int *);
  82 void aff_combination_expand (aff_tree *, hash_map<tree, name_expansion *> **);
  83 void tree_to_aff_combination_expand (tree, tree, aff_tree *,
  84                                      hash_map<tree, name_expansion *> **);
  85 tree get_inner_reference_aff (tree, aff_tree *, widest_int *);
  86 void free_affine_expand_cache (hash_map<tree, name_expansion *> **);
  87 bool aff_comb_cannot_overlap_p (aff_tree *, const widest_int &,
  88                                 const widest_int &);
  89
  90 /* Debugging functions.  */
  91 void debug_aff (aff_tree *);
  92
  93 /* Return true if AFF is actually ZERO.  */
  94 static inline bool
  95 aff_combination_zero_p (aff_tree *aff)
  96 {
  97   if (!aff)
  98     return true;
  99
 100   if (aff->n == 0 && aff->offset == 0)
 101     return true;
 102
 103   return false;
 104 }
 105
 106 #endif /* GCC_TREE_AFFINE_H */