linux/arch/m68k/lib/ashldi3.c
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   1/* ashrdi3.c extracted from gcc-2.95.2/libgcc2.c which is: */
   2/* Copyright (C) 1989, 92-98, 1999 Free Software Foundation, Inc.
   3
   4This file is part of GNU CC.
   5
   6GNU CC is free software; you can redistribute it and/or modify
   7it under the terms of the GNU General Public License as published by
   8the Free Software Foundation; either version 2, or (at your option)
   9any later version.
  10
  11GNU CC is distributed in the hope that it will be useful,
  12but WITHOUT ANY WARRANTY; without even the implied warranty of
  13MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14GNU General Public License for more details.
  15
  16You should have received a copy of the GNU General Public License
  17along with GNU CC; see the file COPYING.  If not, write to
  18the Free Software Foundation, 59 Temple Place - Suite 330,
  19Boston, MA 02111-1307, USA.  */
  20
  21#define BITS_PER_UNIT 8
  22
  23typedef          int SItype     __attribute__ ((mode (SI)));
  24typedef unsigned int USItype    __attribute__ ((mode (SI)));
  25typedef          int DItype     __attribute__ ((mode (DI)));
  26typedef int word_type __attribute__ ((mode (__word__)));
  27
  28struct DIstruct {SItype high, low;};
  29
  30typedef union
  31{
  32  struct DIstruct s;
  33  DItype ll;
  34} DIunion;
  35
  36DItype
  37__ashldi3 (DItype u, word_type b)
  38{
  39  DIunion w;
  40  word_type bm;
  41  DIunion uu;
  42
  43  if (b == 0)
  44    return u;
  45
  46  uu.ll = u;
  47
  48  bm = (sizeof (SItype) * BITS_PER_UNIT) - b;
  49  if (bm <= 0)
  50    {
  51      w.s.low = 0;
  52      w.s.high = (USItype)uu.s.low << -bm;
  53    }
  54  else
  55    {
  56      USItype carries = (USItype)uu.s.low >> bm;
  57      w.s.low = (USItype)uu.s.low << b;
  58      w.s.high = ((USItype)uu.s.high << b) | carries;
  59    }
  60
  61  return w.ll;
  62}
  63