rtx-vector-builder.h revision 1.1.1.2 
1/* A class for building vector rtx constants.
2   Copyright (C) 2017-2019 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_RTX_VECTOR_BUILDER_H
21#define GCC_RTX_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 rtx_vector_builder : public vector_builder<rtx, rtx_vector_builder>
28{
29  typedef vector_builder<rtx, rtx_vector_builder> parent;
30  friend class vector_builder<rtx, rtx_vector_builder>;
31
32public:
33  rtx_vector_builder () : m_mode (VOIDmode) {}
34  rtx_vector_builder (machine_mode, unsigned int, unsigned int);
35  rtx build (rtvec);
36  rtx build ();
37
38  machine_mode mode () const { return m_mode; }
39
40  void new_vector (machine_mode, unsigned int, unsigned int);
41
42private:
43  bool equal_p (rtx, rtx) const;
44  bool allow_steps_p () const;
45  bool integral_p (rtx) const;
46  wide_int step (rtx, rtx) const;
47  rtx apply_step (rtx, unsigned int, const wide_int &) const;
48  bool can_elide_p (rtx) const { return true; }
49  void note_representative (rtx *, rtx) {}
50
51  rtx find_cached_value ();
52
53  machine_mode m_mode;
54};
55
56/* Create a new builder for a vector of mode MODE.  Initially encode the
57   value as NPATTERNS interleaved patterns with NELTS_PER_PATTERN elements
58   each.  */
59
60inline
61rtx_vector_builder::rtx_vector_builder (machine_mode mode,
62					unsigned int npatterns,
63					unsigned int nelts_per_pattern)
64{
65  new_vector (mode, npatterns, nelts_per_pattern);
66}
67
68/* Start building a new vector of mode MODE.  Initially encode the value
69   as NPATTERNS interleaved patterns with NELTS_PER_PATTERN elements each.  */
70
71inline void
72rtx_vector_builder::new_vector (machine_mode mode, unsigned int npatterns,
73				unsigned int nelts_per_pattern)
74{
75  m_mode = mode;
76  parent::new_vector (GET_MODE_NUNITS (mode), npatterns, nelts_per_pattern);
77}
78
79/* Return true if elements ELT1 and ELT2 are equal.  */
80
81inline bool
82rtx_vector_builder::equal_p (rtx elt1, rtx elt2) const
83{
84  return rtx_equal_p (elt1, elt2);
85}
86
87/* Return true if a stepped representation is OK.  We don't allow
88   linear series for anything other than integers, to avoid problems
89   with rounding.  */
90
91inline bool
92rtx_vector_builder::allow_steps_p () const
93{
94  return is_a <scalar_int_mode> (GET_MODE_INNER (m_mode));
95}
96
97/* Return true if element ELT can be interpreted as an integer.  */
98
99inline bool
100rtx_vector_builder::integral_p (rtx elt) const
101{
102  return CONST_SCALAR_INT_P (elt);
103}
104
105/* Return the value of element ELT2 minus the value of element ELT1.
106   Both elements are known to be CONST_SCALAR_INT_Ps.  */
107
108inline wide_int
109rtx_vector_builder::step (rtx elt1, rtx elt2) const
110{
111  return wi::sub (rtx_mode_t (elt2, GET_MODE_INNER (m_mode)),
112		  rtx_mode_t (elt1, GET_MODE_INNER (m_mode)));
113}
114
115#endif
116