1 /* Operations with affine combinations of trees.
2 Copyright (C) 2005-2021 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 class aff_comb_elt
32 {
33 public:
34 /* The value of the element. */
35 tree val;
36
37 /* Its coefficient in the combination. */
38 widest_int coef;
39 };
40
41 class aff_tree
42 {
43 public:
44 /* Type of the result of the combination. */
45 tree type;
46
47 /* Constant offset. */
48 poly_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 class 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 class name_expansion;
68
69 void aff_combination_const (aff_tree *, tree, const poly_widest_int &);
70 void aff_combination_elt (aff_tree *, tree, tree);
71 void aff_combination_scale (aff_tree *, const widest_int &);
72 void aff_combination_mult (aff_tree *, aff_tree *, aff_tree *);
73 void aff_combination_add (aff_tree *, aff_tree *);
74 void aff_combination_add_elt (aff_tree *, tree, const widest_int &);
75 void aff_combination_remove_elt (aff_tree *, unsigned);
76 void aff_combination_convert (aff_tree *, tree);
77 void tree_to_aff_combination (tree, tree, aff_tree *);
78 tree aff_combination_to_tree (aff_tree *);
79 void unshare_aff_combination (aff_tree *);
80 bool aff_combination_constant_multiple_p (aff_tree *, aff_tree *,
81 poly_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 *, poly_widest_int *);
86 void free_affine_expand_cache (hash_map<tree, name_expansion *> **);
87 bool aff_comb_cannot_overlap_p (aff_tree *, const poly_widest_int &,
88 const poly_widest_int &);
89
90 /* Debugging functions. */
91 void debug_aff (aff_tree *);
92
93 /* Return AFF's type. */
94 inline tree
aff_combination_type(aff_tree * aff)95 aff_combination_type (aff_tree *aff)
96 {
97 return aff->type;
98 }
99
100 /* Return true if AFF is actually ZERO. */
101 inline bool
aff_combination_zero_p(aff_tree * aff)102 aff_combination_zero_p (aff_tree *aff)
103 {
104 if (!aff)
105 return true;
106
107 if (aff->n == 0 && known_eq (aff->offset, 0))
108 return true;
109
110 return false;
111 }
112
113 /* Return true if AFF is actually const. */
114 inline bool
aff_combination_const_p(aff_tree * aff)115 aff_combination_const_p (aff_tree *aff)
116 {
117 return (aff == NULL || aff->n == 0);
118 }
119
120 /* Return true iff AFF contains one (negated) singleton variable. Users need
121 to make sure AFF points to a valid combination. */
122 inline bool
aff_combination_singleton_var_p(aff_tree * aff)123 aff_combination_singleton_var_p (aff_tree *aff)
124 {
125 return (aff->n == 1
126 && known_eq (aff->offset, 0)
127 && (aff->elts[0].coef == 1 || aff->elts[0].coef == -1));
128 }
129 #endif /* GCC_TREE_AFFINE_H */
130