libgcc/config/cr16/divmodhi3.c

   1 /* Libgcc Target specific implementation - Emulating div and mod.
   2    Copyright (C) 2012-2017 Free Software Foundation, Inc.
   3    Contributed by KPIT Cummins Infosystems Limited.
   4
   5    This file is part of GCC.
   6
   7    GCC is free software; you can redistribute it and/or modify it
   8    under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3, or (at your option)
  10    any later version.
  11
  12    GCC is distributed in the hope that it will be useful, but WITHOUT
  13    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  14    or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
  15    License for more details.
  16
  17    Under Section 7 of GPL version 3, you are granted additional
  18    permissions described in the GCC Runtime Library Exception, version
  19    3.1, as published by the Free Software Foundation.
  20
  21    You should have received a copy of the GNU General Public License and
  22    a copy of the GCC Runtime Library Exception along with this program;
  23    see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  24    <http://www.gnu.org/licenses/>.  */
  25
  26
  27 /* Emulate the division and modulus operation.  */
  28
  29 unsigned short
  30 udivmodhi4 (unsigned short num, unsigned short den, short modwanted)
  31 {
  32   unsigned short bit = 1;
  33   unsigned short res = 0;
  34
  35   while (den < num && bit && !(den & (1 << 15)))
  36     {
  37       den <<= 1;
  38       bit <<= 1;
  39     }
  40   while (bit)
  41     {
  42       if (num >= den)
  43         {
  44           num -= den;
  45           res |= bit;
  46         }
  47       bit >>= 1;
  48       den >>= 1;
  49     }
  50
  51   if (modwanted)
  52     return num;
  53   return res;
  54 }
  55
  56 short
  57 __divhi3 (short a, short b)
  58 {
  59   short neg = 0;
  60   short res;
  61
  62   if (a < 0)
  63     {
  64       a = -a;
  65       neg = !neg;
  66     }
  67
  68   if (b < 0)
  69     {
  70       b = -b;
  71       neg = !neg;
  72     }
  73
  74   res = udivmodhi4 (a, b, 0);
  75
  76   if (neg)
  77     res = -res;
  78
  79   return res;
  80 }
  81
  82 short
  83 __modhi3 (short a, short b)
  84 {
  85   short neg = 0;
  86   short res;
  87
  88   if (a < 0)
  89     {
  90       a = -a;
  91       neg = 1;
  92     }
  93
  94   if (b < 0)
  95     b = -b;
  96
  97   res = udivmodhi4 (a, b, 1);
  98
  99   if (neg)
 100     res = -res;
 101
 102   return res;
 103 }
 104
 105 short
 106 __udivhi3 (short a, short b)
 107 {
 108   return udivmodhi4 (a, b, 0);
 109 }
 110
 111 short
 112 __umodhi3 (short a, short b)
 113 {
 114   return udivmodhi4 (a, b, 1);
 115 }