binutils-gdb/gas/bit_fix.h

/* bit_fix.h
   Copyright (C) 1987-2017 Free Software Foundation, Inc.

   This file is part of GAS, the GNU Assembler.

   GAS is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3, or (at your option)
   any later version.

   GAS is distributed in the hope that it will be useful, but WITHOUT
   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
   or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
   License for more details.

   You should have received a copy of the GNU General Public License
   along with GAS; see the file COPYING.  If not, write to the Free
   Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
   02110-1301, USA.  */

/* The bit_fix was implemented to support machines that need variables
   to be inserted in bitfields other than 1, 2 and 4 bytes.
   Furthermore it gives us a possibility to mask in bits in the symbol
   when it's fixed in the object code and check the symbols limits.

   The or-mask is used to set the huffman bits in displacements for the
   ns32k port.
   The acbi, addqi, movqi, cmpqi instruction requires an assembler that
   can handle bitfields.  Ie. handle an expression, evaluate it and insert
   the result in some bitfield.  (eg: 5 bits in a short field of an opcode).  */

#ifndef __bit_fix_h__
#define __bit_fix_h__

struct bit_fix {
  int fx_bit_size;		/* Length of bitfield */
  int fx_bit_offset;		/* Bit offset to bitfield */
  long fx_bit_base;		/* Where do we apply the bitfix.
				   If this is zero, default is assumed.  */
  long fx_bit_base_adj;		/* Adjustment of base */
  long fx_bit_max;		/* Signextended max for bitfield */
  long fx_bit_min;		/* Signextended min for bitfield */
  long fx_bit_add;		/* Or mask, used for huffman prefix */
};
typedef struct bit_fix bit_fixS;

#endif /* __bit_fix_h__ */