divmodhi3.c revision 1.1.1.1.8.2
1/* Libgcc Target specific implementation - Emulating div and mod. 2 Copyright (C) 2012-2013 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 29unsigned short 30udivmodhi4 (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 56short 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 82short 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 105short 106__udivhi3 (short a, short b) 107{ 108 return udivmodhi4 (a, b, 0); 109} 110 111short 112__umodhi3 (short a, short b) 113{ 114 return udivmodhi4 (a, b, 1); 115} 116