// Division and Modulo without / and % word divmod(word dividend, word divisor, word* rem) { word quotient = 1; word neg = 1; if ((dividend>0 &&divisor<0)||(dividend<0 && divisor>0)) neg = -1; // Convert to positive word tempdividend = (dividend < 0) ? -dividend : dividend; word tempdivisor = (divisor < 0) ? -divisor : divisor; if (tempdivisor == tempdividend) { *rem = 0; return 1*neg; } else if (tempdividend < tempdivisor) { if (dividend < 0) *rem = tempdividend*neg; else *rem = tempdividend; return 0; } while (tempdivisor<<1 <= tempdividend) { tempdivisor = tempdivisor << 1; quotient = quotient << 1; } // Call division recursively if(dividend < 0) quotient = quotient*neg + divmod(-(tempdividend-tempdivisor), divisor, rem); else quotient = quotient*neg + divmod(tempdividend-tempdivisor, divisor, rem); return quotient; } word division(word dividend, word divisor) { word rem = 0; return divmod(dividend, divisor, &rem); } word modulo(word dividend, word divisor) { word rem = 0; divmod(dividend, divisor, &rem); return rem; } // Unsigned Division and Modulo without / and % word MATH_divmodU(word dividend, word divisor, word mod) { word quotient = 0; word remainder = 0; if(divisor == 0) return 0; word i; for(i = 31 ; i >= 0 ; i--) { quotient = quotient << 1; remainder = remainder << 1; remainder = remainder | ((unsigned) (dividend & (1 << i)) >> i); if((unsigned int) remainder >= (unsigned int) divisor) { remainder = remainder - divisor; quotient = quotient | 1; } if (i == 0) if (mod == 1) return remainder; else return quotient; } return 0; } // Unsigned positive integer division word MATH_divU(word dividend, word divisor) { return MATH_divmodU(dividend, divisor, 0); } // Unsigned positive integer modulo word MATH_modU(word dividend, word divisor) { return MATH_divmodU(dividend, divisor, 1); }