gas/bit_fix.h

   1 /* bit_fix.h
   2    Copyright 1987, 1992, 2000, 2001, 2003 Free Software Foundation, Inc.
   3
   4    This file is part of GAS, the GNU Assembler.
   5
   6    GAS is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2, or (at your option)
   9    any later version.
  10
  11    GAS is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with GAS; see the file COPYING.  If not, write to the Free
  18    Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
  19    02110-1301, USA.  */
  20
  21 /* The bit_fix was implemented to support machines that need variables
  22    to be inserted in bitfields other than 1, 2 and 4 bytes.
  23    Furthermore it gives us a possibility to mask in bits in the symbol
  24    when it's fixed in the objectcode and check the symbols limits.
  25
  26    The or-mask is used to set the huffman bits in displacements for the
  27    ns32k port.
  28    The acbi, addqi, movqi, cmpqi instruction requires an assembler that
  29    can handle bitfields.  Ie. handle an expression, evaluate it and insert
  30    the result in some bitfield.  (eg: 5 bits in a short field of an opcode)
  31    */
  32
  33 #ifndef __bit_fix_h__
  34 #define __bit_fix_h__
  35
  36 struct bit_fix {
  37   int fx_bit_size;              /* Length of bitfield */
  38   int fx_bit_offset;            /* Bit offset to bitfield */
  39   long fx_bit_base;             /* Where do we apply the bitfix.
  40                                    If this is zero, default is assumed.  */
  41   long fx_bit_base_adj;         /* Adjustment of base */
  42   long fx_bit_max;              /* Signextended max for bitfield */
  43   long fx_bit_min;              /* Signextended min for bitfield */
  44   long fx_bit_add;              /* Or mask, used for huffman prefix */
  45 };
  46 typedef struct bit_fix bit_fixS;
  47
  48 #endif /* __bit_fix_h__ */