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/* Generic streaming support for basic data types.

   Copyright 2011 Free Software Foundation, Inc.

   Contributed by Diego Novillo <dnovillo@google.com>

This file is part of GCC.

GCC 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.

GCC 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 GCC; see the file COPYING3.  If not see

<http://www.gnu.org/licenses/>.  */

#include "config.h"

#include "system.h"

#include "coretypes.h"

#include "data-streamer.h"

/* Pack WORK into BP in a variant of uleb format.  */

void

bp_pack_var_len_unsigned (struct bitpack_d *bp, unsigned HOST_WIDE_INT work)

{

  do

    {

      unsigned int half_byte = (work & 0x7);

      work >>= 3;

      if (work != 0)

        /* More half_bytes to follow.  */

        half_byte |= 0x8;

      bp_pack_value (bp, half_byte, 4);

    }

  while (work != 0);

}

/* Pack WORK into BP in a variant of sleb format.  */

void

bp_pack_var_len_int (struct bitpack_d *bp, HOST_WIDE_INT work)

{

  int more, half_byte;

  do

    {

      half_byte = (work & 0x7);

      /* arithmetic shift */

      work >>= 3;

      more = !((work == 0 && (half_byte & 0x4) == 0)

               || (work == -1 && (half_byte & 0x4) != 0));

      if (more)

        half_byte |= 0x8;

      bp_pack_value (bp, half_byte, 4);

    }

  while (more);

}

/* Unpack VAL from BP in a variant of uleb format.  */

unsigned HOST_WIDE_INT

bp_unpack_var_len_unsigned (struct bitpack_d *bp)

{

  unsigned HOST_WIDE_INT result = 0;

  int shift = 0;

  unsigned HOST_WIDE_INT half_byte;

  while (true)

    {

      half_byte = bp_unpack_value (bp, 4);

      result |= (half_byte & 0x7) << shift;

      shift += 3;

      if ((half_byte & 0x8) == 0)

        return result;

    }

}

/* Unpack VAL from BP in a variant of sleb format.  */

HOST_WIDE_INT

bp_unpack_var_len_int (struct bitpack_d *bp)

{

  HOST_WIDE_INT result = 0;

  int shift = 0;

  unsigned HOST_WIDE_INT half_byte;

  while (true)

    {

      half_byte = bp_unpack_value (bp, 4);

      result |= (half_byte & 0x7) << shift;

      shift += 3;

      if ((half_byte & 0x8) == 0)

        {

          if ((shift < HOST_BITS_PER_WIDE_INT) && (half_byte & 0x4))

            result |= - ((HOST_WIDE_INT)1 << shift);

          return result;

        }

    }

}