LXR linux/arch/blackfin/lib/ashrdi3.c

   1/*
   2 * File:         arch/blackfin/lib/ashrdi3.c
   3 * Based on:
   4 * Author:
   5 *
   6 * Created:
   7 * Description:
   8 *
   9 * Modified:
  10 *               Copyright 2004-2006 Analog Devices Inc.
  11 *
  12 * Bugs:         Enter bugs at http://blackfin.uclinux.org/
  13 *
  14 * This program is free software; you can redistribute it and/or modify
  15 * it under the terms of the GNU General Public License as published by
  16 * the Free Software Foundation; either version 2 of the License, or
  17 * (at your option) any later version.
  18 *
  19 * This program is distributed in the hope that it will be useful,
  20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22 * GNU General Public License for more details.
  23 *
  24 * You should have received a copy of the GNU General Public License
  25 * along with this program; if not, see the file COPYING, or write
  26 * to the Free Software Foundation, Inc.,
  27 * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  28 */
  29
  30#include "gcclib.h"
  31
  32#ifdef CONFIG_ARITHMETIC_OPS_L1
  33DItype __ashrdi3(DItype u, word_type b)__attribute__((l1_text));
  34#endif
  35
  36DItype __ashrdi3(DItype u, word_type b)
  37{
  38        DIunion w;
  39        word_type bm;
  40        DIunion uu;
  41
  42        if (b == 0)
  43                return u;
  44
  45        uu.ll = u;
  46
  47        bm = (sizeof(SItype) * BITS_PER_UNIT) - b;
  48        if (bm <= 0) {
  49                /* w.s.high = 1..1 or 0..0 */
  50                w.s.high = uu.s.high >> (sizeof(SItype) * BITS_PER_UNIT - 1);
  51                w.s.low = uu.s.high >> -bm;
  52        } else {
  53                USItype carries = (USItype) uu.s.high << bm;
  54                w.s.high = uu.s.high >> b;
  55                w.s.low = ((USItype) uu.s.low >> b) | carries;
  56        }
  57
  58        return w.ll;
  59}
  60