gcc/rtx-vector-builder.h

   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