1 //#include "math.h" 2 // Arithmatic functions using add & subtract 3 4 unsigned long mult_u(register unsigned long var1, register unsigned long var2) 5 { 6 7 register unsigned long var_out = 0; 8 9 while (var2 > 0) 10 { 11 12 if (var2 & 0x01) 13 { 14 var_out += var1; 15 } 16 var2 >>= 1; 17 var1 <<= 1; 18 } 19 return var_out; 20 21 }// mult_u 22 23 unsigned long ldiv_mod_u(register unsigned long a, register unsigned long b, unsigned long * mod) 24 { 25 register unsigned long div = b; 26 register unsigned long res = 0; 27 register unsigned long bit = 0x1; 28 29 if (!div) 30 { 31 *mod = 0; 32 return 0xffffffff ; // Div by 0 33 } 34 35 if (a < b) 36 { 37 *mod = a; 38 return 0; // It won't even go once 39 } 40 41 while(!(div & 0x80000000)) 42 { 43 div <<= 1; 44 bit <<= 1; 45 } 46 47 while (bit) 48 { 49 if (div <= a) 50 { 51 res |= bit; 52 a -= div; 53 } 54 div >>= 1; 55 bit >>= 1; 56 } 57 *mod = a; 58 return res; 59 }// ldiv_mod_u 60 61 62 unsigned ldiv_u(register unsigned a, register unsigned b) 63 { 64 register unsigned div = b << 16; 65 register unsigned res = 0; 66 register unsigned bit = 0x10000; 67 68 while (bit) 69 { 70 div >>= 1; 71 bit >>= 1; 72 if (div < a) 73 { 74 res |= bit; 75 a -= div; 76 } 77 } 78 79 return res; 80 } 81 82 83
