1/* A class for building vector tree constants.
2   Copyright (C) 2017-2020 Free Software Foundation, Inc.
3
4This file is part of GCC.
5
6GCC is free software; you can redistribute it and/or modify it under
7the terms of the GNU General Public License as published by the Free
8Software Foundation; either version 3, or (at your option) any later
9version.
10
11GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12WARRANTY; 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#ifndef GCC_TREE_VECTOR_BUILDER_H
21#define GCC_TREE_VECTOR_BUILDER_H
22
23#include "vector-builder.h"
24
25/* This class is used to build VECTOR_CSTs from a sequence of elements.
26   See vector_builder for more details.  */
27class tree_vector_builder : public vector_builder<tree, tree,
28						  tree_vector_builder>
29{
30  typedef vector_builder<tree, tree, tree_vector_builder> parent;
31  friend class vector_builder<tree, tree, tree_vector_builder>;
32
33public:
34  tree_vector_builder () : m_type (0) {}
35  tree_vector_builder (tree, unsigned int, unsigned int);
36  tree build ();
37
38  tree type () const { return m_type; }
39
40  void new_vector (tree, unsigned int, unsigned int);
41
42private:
43  bool equal_p (const_tree, const_tree) const;
44  bool allow_steps_p () const;
45  bool integral_p (const_tree) const;
46  wide_int step (const_tree, const_tree) const;
47  tree apply_step (tree, unsigned int, const wide_int &) const;
48  bool can_elide_p (const_tree) const;
49  void note_representative (tree *, tree);
50
51  static poly_uint64 shape_nelts (const_tree t)
52    { return TYPE_VECTOR_SUBPARTS (t); }
53  static poly_uint64 nelts_of (const_tree t)
54    { return VECTOR_CST_NELTS (t); }
55  static unsigned int npatterns_of (const_tree t)
56    { return VECTOR_CST_NPATTERNS (t); }
57  static unsigned int nelts_per_pattern_of (const_tree t)
58    { return VECTOR_CST_NELTS_PER_PATTERN (t); }
59
60  tree m_type;
61};
62
63/* Create a new builder for a vector of type TYPE.  Initially encode the
64   value as NPATTERNS interleaved patterns with NELTS_PER_PATTERN elements
65   each.  */
66
67inline
68tree_vector_builder::tree_vector_builder (tree type, unsigned int npatterns,
69					  unsigned int nelts_per_pattern)
70{
71  new_vector (type, npatterns, nelts_per_pattern);
72}
73
74/* Start building a new vector of type TYPE.  Initially encode the value
75   as NPATTERNS interleaved patterns with NELTS_PER_PATTERN elements each.  */
76
77inline void
78tree_vector_builder::new_vector (tree type, unsigned int npatterns,
79				 unsigned int nelts_per_pattern)
80{
81  m_type = type;
82  parent::new_vector (TYPE_VECTOR_SUBPARTS (type), npatterns,
83		      nelts_per_pattern);
84}
85
86/* Return true if elements I1 and I2 are equal.  */
87
88inline bool
89tree_vector_builder::equal_p (const_tree elt1, const_tree elt2) const
90{
91  return operand_equal_p (elt1, elt2, OEP_BITWISE);
92}
93
94/* Return true if a stepped representation is OK.  We don't allow
95   linear series for anything other than integers, to avoid problems
96   with rounding.  */
97
98inline bool
99tree_vector_builder::allow_steps_p () const
100{
101  return INTEGRAL_TYPE_P (TREE_TYPE (m_type));
102}
103
104/* Return true if ELT can be interpreted as an integer.  */
105
106inline bool
107tree_vector_builder::integral_p (const_tree elt) const
108{
109  return TREE_CODE (elt) == INTEGER_CST;
110}
111
112/* Return the value of element ELT2 minus the value of element ELT1.
113   Both elements are known to be INTEGER_CSTs.  */
114
115inline wide_int
116tree_vector_builder::step (const_tree elt1, const_tree elt2) const
117{
118  return wi::to_wide (elt2) - wi::to_wide (elt1);
119}
120
121/* Return true if we can drop element ELT, even if the retained elements
122   are different.  Return false if this would mean losing overflow
123   information.  */
124
125inline bool
126tree_vector_builder::can_elide_p (const_tree elt) const
127{
128  return !CONSTANT_CLASS_P (elt) || !TREE_OVERFLOW (elt);
129}
130
131/* Record that ELT2 is being elided, given that ELT1_PTR points to the last
132   encoded element for the containing pattern.  */
133
134inline void
135tree_vector_builder::note_representative (tree *elt1_ptr, tree elt2)
136{
137  if (CONSTANT_CLASS_P (elt2) && TREE_OVERFLOW (elt2))
138    {
139      gcc_assert (operand_equal_p (*elt1_ptr, elt2, 0));
140      if (!TREE_OVERFLOW (elt2))
141	*elt1_ptr = elt2;
142    }
143}
144
145#endif
146