lib/lshrdi3.c

   1 /*
   2  * lib/lshrdi3.c
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, see the file COPYING, or write
  16  * to the Free Software Foundation, Inc.
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/libgcc.h>
  21
  22 long long notrace __lshrdi3(long long u, word_type b)
  23 {
  24         DWunion uu, w;
  25         word_type bm;
  26
  27         if (b == 0)
  28                 return u;
  29
  30         uu.ll = u;
  31         bm = 32 - b;
  32
  33         if (bm <= 0) {
  34                 w.s.high = 0;
  35                 w.s.low = (unsigned int) uu.s.high >> -bm;
  36         } else {
  37                 const unsigned int carries = (unsigned int) uu.s.high << bm;
  38
  39                 w.s.high = (unsigned int) uu.s.high >> b;
  40                 w.s.low = ((unsigned int) uu.s.low >> b) | carries;
  41         }
  42
  43         return w.ll;
  44 }
  45 EXPORT_SYMBOL(__lshrdi3);