gcc/rtx-vector-builder.h

   1 /* A class for building vector rtx constants.
   2    Copyright (C) 2017-2019 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, machine_mode,
  28                                                  rtx_vector_builder>
  29 {
  30   typedef vector_builder<rtx, machine_mode, rtx_vector_builder> parent;
  31   friend class vector_builder<rtx, machine_mode, rtx_vector_builder>;
  32
  33 public:
  34   rtx_vector_builder () : m_mode (VOIDmode) {}
  35   rtx_vector_builder (machine_mode, unsigned int, unsigned int);
  36   rtx build (rtvec);
  37   rtx build ();
  38
  39   machine_mode mode () const { return m_mode; }
  40
  41   void new_vector (machine_mode, unsigned int, unsigned int);
  42
  43 private:
  44   bool equal_p (rtx, rtx) const;
  45   bool allow_steps_p () const;
  46   bool integral_p (rtx) const;
  47   wide_int step (rtx, rtx) const;
  48   rtx apply_step (rtx, unsigned int, const wide_int &) const;
  49   bool can_elide_p (rtx) const { return true; }
  50   void note_representative (rtx *, rtx) {}
  51
  52   static poly_uint64 shape_nelts (machine_mode mode)
  53     { return GET_MODE_NUNITS (mode); }
  54   static poly_uint64 nelts_of (const_rtx x)
  55     { return CONST_VECTOR_NUNITS (x); }
  56   static unsigned int npatterns_of (const_rtx x)
  57     { return CONST_VECTOR_NPATTERNS (x); }
  58   static unsigned int nelts_per_pattern_of (const_rtx x)
  59     { return CONST_VECTOR_NELTS_PER_PATTERN (x); }
  60
  61   rtx find_cached_value ();
  62
  63   machine_mode m_mode;
  64 };
  65
  66 /* Create a new builder for a vector of mode MODE.  Initially encode the
  67    value as NPATTERNS interleaved patterns with NELTS_PER_PATTERN elements
  68    each.  */
  69
  70 inline
  71 rtx_vector_builder::rtx_vector_builder (machine_mode mode,
  72                                         unsigned int npatterns,
  73                                         unsigned int nelts_per_pattern)
  74 {
  75   new_vector (mode, npatterns, nelts_per_pattern);
  76 }
  77
  78 /* Start building a new vector of mode MODE.  Initially encode the value
  79    as NPATTERNS interleaved patterns with NELTS_PER_PATTERN elements each.  */
  80
  81 inline void
  82 rtx_vector_builder::new_vector (machine_mode mode, unsigned int npatterns,
  83                                 unsigned int nelts_per_pattern)
  84 {
  85   m_mode = mode;
  86   parent::new_vector (GET_MODE_NUNITS (mode), npatterns, nelts_per_pattern);
  87 }
  88
  89 /* Return true if elements ELT1 and ELT2 are equal.  */
  90
  91 inline bool
  92 rtx_vector_builder::equal_p (rtx elt1, rtx elt2) const
  93 {
  94   return rtx_equal_p (elt1, elt2);
  95 }
  96
  97 /* Return true if a stepped representation is OK.  We don't allow
  98    linear series for anything other than integers, to avoid problems
  99    with rounding.  */
 100
 101 inline bool
 102 rtx_vector_builder::allow_steps_p () const
 103 {
 104   return is_a <scalar_int_mode> (GET_MODE_INNER (m_mode));
 105 }
 106
 107 /* Return true if element ELT can be interpreted as an integer.  */
 108
 109 inline bool
 110 rtx_vector_builder::integral_p (rtx elt) const
 111 {
 112   return CONST_SCALAR_INT_P (elt);
 113 }
 114
 115 /* Return the value of element ELT2 minus the value of element ELT1.
 116    Both elements are known to be CONST_SCALAR_INT_Ps.  */
 117
 118 inline wide_int
 119 rtx_vector_builder::step (rtx elt1, rtx elt2) const
 120 {
 121   return wi::sub (rtx_mode_t (elt2, GET_MODE_INNER (m_mode)),
 122                   rtx_mode_t (elt1, GET_MODE_INNER (m_mode)));
 123 }
 124
 125 #endif