1/* Operations with affine combinations of trees.
2   Copyright (C) 2005-2015 Free Software Foundation, Inc.
3
4This file is part of GCC.
5
6GCC is free software; you can redistribute it and/or modify it
7under the terms of the GNU General Public License as published by the
8Free Software Foundation; either version 3, or (at your option) any
9later version.
10
11GCC is distributed in the hope that it will be useful, but WITHOUT
12ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14for more details.
15
16You should have received a copy of the GNU General Public License
17along 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
33struct 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
42struct 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
67struct name_expansion;
68
69widest_int wide_int_ext_for_comb (const widest_int &, aff_tree *);
70void aff_combination_const (aff_tree *, tree, const widest_int &);
71void aff_combination_elt (aff_tree *, tree, tree);
72void aff_combination_scale (aff_tree *, const widest_int &);
73void aff_combination_mult (aff_tree *, aff_tree *, aff_tree *);
74void aff_combination_add (aff_tree *, aff_tree *);
75void aff_combination_add_elt (aff_tree *, tree, const widest_int &);
76void aff_combination_remove_elt (aff_tree *, unsigned);
77void aff_combination_convert (aff_tree *, tree);
78void tree_to_aff_combination (tree, tree, aff_tree *);
79tree aff_combination_to_tree (aff_tree *);
80void unshare_aff_combination (aff_tree *);
81bool aff_combination_constant_multiple_p (aff_tree *, aff_tree *, widest_int *);
82void aff_combination_expand (aff_tree *, hash_map<tree, name_expansion *> **);
83void tree_to_aff_combination_expand (tree, tree, aff_tree *,
84				     hash_map<tree, name_expansion *> **);
85tree get_inner_reference_aff (tree, aff_tree *, widest_int *);
86void free_affine_expand_cache (hash_map<tree, name_expansion *> **);
87bool aff_comb_cannot_overlap_p (aff_tree *, const widest_int &,
88				const widest_int &);
89
90/* Debugging functions.  */
91void debug_aff (aff_tree *);
92
93/* Return true if AFF is actually ZERO.  */
94static inline bool
95aff_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 */
107