lib_nios/divmod.c

   1 /*
   2  * This file is part of GNU CC.
   3  *
   4  * GNU CC is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published
   6  * by the Free Software Foundation; either version 2, or (at your
   7  * option) any later version.
   8  *
   9  * GNU CC 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
  15  * License along with GNU CC; see the file COPYING.  If not, write
  16  * to the Free Software Foundation, 59 Temple Place - Suite 330,
  17  * Boston, MA 02111-1307, USA.
  18  */
  19
  20
  21 #include "math.h"
  22
  23 USItype udivmodsi4 (USItype num, USItype den, word_type modwanted)
  24 {
  25         USItype bit = 1;
  26         USItype res = 0;
  27
  28         while (den < num && bit && !(den & (1L << 31))) {
  29                 den <<= 1;
  30                 bit <<= 1;
  31         }
  32         while (bit) {
  33                 if (num >= den) {
  34                         num -= den;
  35                         res |= bit;
  36                 }
  37                 bit >>= 1;
  38                 den >>= 1;
  39         }
  40         if (modwanted)
  41                 return num;
  42         return res;
  43 }
  44
  45
  46 SItype __divsi3 (SItype a, SItype b)
  47 {
  48         word_type neg = 0;
  49         SItype res;
  50
  51         if (a < 0) {
  52                 a = -a;
  53                 neg = !neg;
  54         }
  55
  56         if (b < 0) {
  57                 b = -b;
  58                 neg = !neg;
  59         }
  60
  61         res = udivmodsi4 (a, b, 0);
  62
  63         if (neg)
  64                 res = -res;
  65
  66         return res;
  67 }
  68
  69
  70 SItype __modsi3 (SItype a, SItype b)
  71 {
  72         word_type neg = 0;
  73         SItype res;
  74
  75         if (a < 0) {
  76                 a = -a;
  77                 neg = 1;
  78         }
  79
  80         if (b < 0)
  81                 b = -b;
  82
  83         res = udivmodsi4 (a, b, 1);
  84
  85         if (neg)
  86                 res = -res;
  87
  88         return res;
  89 }
  90
  91
  92 SItype __udivsi3 (SItype a, SItype b)
  93 {
  94         return udivmodsi4 (a, b, 0);
  95 }
  96
  97
  98 SItype __umodsi3 (SItype a, SItype b)
  99 {
 100         return udivmodsi4 (a, b, 1);
 101 }