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kernel/linux-imx6_3.14.28/arch/m68k/lib/ashrdi3.c 1.65 KB
6b13f685e   김민수   BSP 최초 추가
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  /* ashrdi3.c extracted from gcc-2.7.2/libgcc2.c which is: */
  /* Copyright (C) 1989, 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
  
  This file is part of GNU CC.
  
  GNU CC 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 2, or (at your option)
  any later version.
  
  GNU CC 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 GNU CC; see the file COPYING.  If not, write to
  the Free Software Foundation, 59 Temple Place - Suite 330,
  Boston, MA 02111-1307, USA.  */
  
  #define BITS_PER_UNIT 8
  
  typedef		 int SItype	__attribute__ ((mode (SI)));
  typedef unsigned int USItype	__attribute__ ((mode (SI)));
  typedef		 int DItype	__attribute__ ((mode (DI)));
  typedef int word_type __attribute__ ((mode (__word__)));
  
  struct DIstruct {SItype high, low;};
  
  typedef union
  {
    struct DIstruct s;
    DItype ll;
  } DIunion;
  
  DItype
  __ashrdi3 (DItype u, word_type b)
  {
    DIunion w;
    word_type bm;
    DIunion uu;
  
    if (b == 0)
      return u;
  
    uu.ll = u;
  
    bm = (sizeof (SItype) * BITS_PER_UNIT) - b;
    if (bm <= 0)
      {
        /* w.s.high = 1..1 or 0..0 */
        w.s.high = uu.s.high >> (sizeof (SItype) * BITS_PER_UNIT - 1);
        w.s.low = uu.s.high >> -bm;
      }
    else
      {
        USItype carries = (USItype)uu.s.high << bm;
        w.s.high = uu.s.high >> b;
        w.s.low = ((USItype)uu.s.low >> b) | carries;
      }
  
    return w.ll;
  }