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/*

picoChip GCC support for 32-bit logical shift right.

Copyright (C) 2003, 2004, 2005, 2008, 2009  Free Software Foundation, Inc.

Contributed by Picochip Ltd.

Maintained by Daniel Towner (daniel.towner@picochip.com)

This file 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.

This file 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.

Under Section 7 of GPL version 3, you are granted additional

permissions described in the GCC Runtime Library Exception, version

3.1, as published by the Free Software Foundation.

You should have received a copy of the GNU General Public License and

a copy of the GCC Runtime Library Exception along with this program;

see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see

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

typedef int HItype __attribute__ ((mode (HI)));

typedef unsigned int UHItype __attribute__ ((mode (HI)));

typedef unsigned int USItype __attribute__ ((mode (SI)));

typedef struct USIstruct {

  UHItype low, high;

} USIstruct;

typedef union USIunion {

  USItype l;

  USIstruct s;

} USIunion;

USItype __lshrsi3(USIunion value, HItype count) {

  USIunion result;

  int temp;

  /* Ignore a zero count until we get into the (count < 16)

     clause. This is slightly slower when shifting by zero, but faster

     and smaller in all other cases (due to the better scheduling

     opportunities available by putting the test near computational

     instructions. */

  if (count < 16) {

    /* Shift low and high words by the count. */

    result.s.low = value.s.low >> count;

    result.s.high = value.s.high >> count;

    /* There is now a hole in the upper `count' bits of the low

       word. Shift the lower `count' bits of the upper word into the

       low word. This only works when count isn't zero. */

    if (count != 0) {

      temp = value.s.high << (16 - count);

      result.s.low |= temp;

    }

  } else {

    /* Shift the upper word of the source into the lower word of the

       result, and zero the result's upper word. Note that we actually

       ned to shift by (count - 16), but as we are only using the

       bottom 4 bits, this is equivalent to shifting by count. */

    result.s.low = value.s.high >> count;

    result.s.high = 0;

  }

  return result.l;

}