gcc/config/tilepro/tilepro-multiply.h

   1 /* Header for constant multiple table for TILEPro.
   2    Copyright (C) 2011-2014 Free Software Foundation, Inc.
   3    Contributed by Walter Lee (walt@tilera.com)
   4
   5    This file is part of GCC.
   6
   7    GCC is free software; you can redistribute it and/or modify it
   8    under the terms of the GNU General Public License as published
   9    by the Free Software Foundation; either version 3, or (at your
  10    option) any later version.
  11
  12    GCC is distributed in the hope that it will be useful, but WITHOUT
  13    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  14    or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
  15    License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with GCC; see the file COPYING3.  If not see
  19    <http://www.gnu.org/licenses/>.  */
  20
  21 #ifndef GCC_TILEPRO_MULTIPLY_H
  22 #define GCC_TILEPRO_MULTIPLY_H
  23
  24 /* A node of a tilepro_multiply_insn_seq, corresponding to a single
  25    machine instruction such as 'add', 's1a', or an shl by a
  26    constant.  */
  27 struct tilepro_multiply_insn_seq_entry
  28 {
  29   /* Which operation this node performs (e.g. an add or sub).  Don't
  30      use this directly, call get_opcode() table to get a
  31      insn_code.  */
  32   unsigned char compressed_opcode;
  33
  34   /* The left-hand side of this expression tree.
  35      If equal to 0, it refers to 'zero'.
  36      If equal to 1, it refers to the original input to the multiply
  37      operation.
  38      Otherwise, subtract two and it is an index into the containing
  39      tilepro_multiply_insn_seq's 'op' array. Since it can only point
  40      to some value that has already been computed it will always point
  41      to an earlier entry in the array.  */
  42   unsigned char lhs;
  43
  44   /* This is like lhs, but for the right-hand side. However, for shift
  45      opcodes this is a shift count rather than an operand index.  */
  46   unsigned char rhs;
  47 };
  48
  49 /* Maximum size of op array.  */
  50 #define tilepro_multiply_insn_seq_MAX_OPERATIONS 4
  51
  52 /* This defines a DAG describing how to multiply by a constant in
  53    terms of one or more machine instructions.  */
  54 struct tilepro_multiply_insn_seq
  55 {
  56   /* The constant factor by which this expression tree multiplies its
  57      input.  */
  58   int multiplier;
  59
  60   /* The nodes of the parse tree. These are ordered so that
  61      instructions can be emitted in the same order that they appear in
  62      this array.  Entry entry in this array can only refer to earlier
  63      entries in the array.  */
  64   struct tilepro_multiply_insn_seq_entry
  65     op[tilepro_multiply_insn_seq_MAX_OPERATIONS];
  66
  67 };
  68
  69 /* A mapping from the compressed opcode to the corresponding enum
  70    insn_code.  */
  71 extern const enum insn_code tilepro_multiply_insn_seq_decode_opcode[];
  72
  73 /* Table mapping constant int multipliers to an expression tree that
  74    efficiently performs that multiplication.  This is sorted by its
  75    'multiplier' field so a binary search can look for matches.  */
  76 extern const struct tilepro_multiply_insn_seq
  77   tilepro_multiply_insn_seq_table[];
  78
  79 /* The number of elements in multiply_insn_seq_table.  */
  80 extern const int tilepro_multiply_insn_seq_table_size;
  81
  82 #endif /* !GCC_TILEPRO_MULTIPLY_H */