1 /* A class for building vector rtx constants.
2    Copyright (C) 2017-2018 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 under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 3, or (at your option) any later
9 version.
10 
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 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 #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.  */
27 class 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 
32 public:
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 
42 private:
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 
60 inline
61 rtx_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 
71 inline void
72 rtx_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 
81 inline bool
82 rtx_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 
91 inline bool
92 rtx_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 
99 inline bool
100 rtx_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 
108 inline wide_int
109 rtx_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