gcc/lower-subreg.h

   1 /* Target-dependent costs for lower-subreg.c.
   2    Copyright (C) 2012-2017 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 LOWER_SUBREG_H
  21 #define LOWER_SUBREG_H 1
  22
  23 /* Information about whether, and where, lower-subreg should be applied.  */
  24 struct lower_subreg_choices {
  25   /* A boolean vector for move splitting that is indexed by mode and is
  26      true for each mode that is to have its copies split.  */
  27   bool move_modes_to_split[MAX_MACHINE_MODE];
  28
  29   /* True if zero-extensions from word_mode to twice_word_mode should
  30      be split.  */
  31   bool splitting_zext;
  32
  33   /* Index X is true if twice_word_mode shifts by X + BITS_PER_WORD
  34      should be split.  */
  35   bool splitting_ashift[MAX_BITS_PER_WORD];
  36   bool splitting_lshiftrt[MAX_BITS_PER_WORD];
  37   bool splitting_ashiftrt[MAX_BITS_PER_WORD];
  38
  39   /* True if there is at least one mode that is worth splitting.  */
  40   bool something_to_do;
  41 };
  42
  43 /* Target-specific information for the subreg lowering pass.  */
  44 struct target_lower_subreg {
  45   /* An integer mode that is twice as wide as word_mode.  */
  46   scalar_int_mode_pod x_twice_word_mode;
  47
  48   /* What we have decided to do when optimizing for size (index 0)
  49      and speed (index 1).  */
  50   struct lower_subreg_choices x_choices[2];
  51 };
  52
  53 extern struct target_lower_subreg default_target_lower_subreg;
  54 #if SWITCHABLE_TARGET
  55 extern struct target_lower_subreg *this_target_lower_subreg;
  56 #else
  57 #define this_target_lower_subreg (&default_target_lower_subreg)
  58 #endif
  59
  60 #endif