src/arch/mips/ashldi3.c

   1 /*
   2  * This file is part of the coreboot project.
   3  *
   4  * Copyright (C) 2014 Google, Inc.
   5  *
   6  * Based on linux arch/mips/lib/ashldi3.c
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; version 2 of the License.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  */
  17
  18 #ifndef __ORDER_LITTLE_ENDIAN__
  19 #errror "What endian are you!?"
  20 #endif
  21
  22 typedef unsigned int word_type;
  23 long long __ashldi3(long long u, word_type b);
  24
  25 struct DWstruct {
  26         int low, high;
  27 };
  28 typedef union {
  29         struct DWstruct s;
  30         long long ll;
  31 } DWunion;
  32
  33 long long __ashldi3(long long u, word_type b)
  34 {
  35         DWunion uu, w;
  36         word_type bm;
  37
  38         if (b == 0)
  39                 return u;
  40
  41         uu.ll = u;
  42         bm = 32 - b;
  43
  44         if (bm <= 0) {
  45                 w.s.low = 0;
  46                 w.s.high = (unsigned int) uu.s.low << -bm;
  47         } else {
  48                 const unsigned int carries = (unsigned int) uu.s.low >> bm;
  49
  50                 w.s.low = (unsigned int) uu.s.low << b;
  51                 w.s.high = ((unsigned int) uu.s.high << b) | carries;
  52         }
  53
  54         return w.ll;
  55 }