Method urem

ext/src/llvm/APInt.cpp:1692–1728

}

APInt APInt::urem(const APInt &RHS) const {
  assert(BitWidth == RHS.BitWidth && "Bit widths must be the same");
  if (isSingleWord()) {
    assert(RHS.U.VAL != 0 && "Remainder by zero?");
    return APInt(BitWidth, U.VAL % RHS.U.VAL);
  }

  // Get some facts about the LHS
  unsigned lhsWords = getNumWords(getActiveBits());

  // Get some facts about the RHS
  unsigned rhsBits = RHS.getActiveBits();
  unsigned rhsWords = getNumWords(rhsBits);
  assert(rhsWords && "Performing remainder operation by zero ???");

  // Check the degenerate cases
  if (lhsWords == 0)
    // 0 % Y ===> 0
    return APInt(BitWidth, 0);
  if (rhsBits == 1)
    // X % 1 ===> 0
    return APInt(BitWidth, 0);
  if (lhsWords < rhsWords || this->ult(RHS))
    // X % Y ===> X, iff X < Y
    return *this;
  if (*this == RHS)
    // X % X == 0;
    return APInt(BitWidth, 0);
  if (lhsWords == 1)
    // All high words are zero, just use native remainder
    return APInt(BitWidth, U.pVal[0] % RHS.U.pVal[0]);

  // We have to compute it the hard way. Invoke the Knuth divide algorithm.
  APInt Remainder(BitWidth, 0);
  divide(U.pVal, lhsWords, RHS.U.pVal, rhsWords, nullptr, Remainder.U.pVal);
  return Remainder;
}

uint64_t APInt::urem(uint64_t RHS) const {
  assert(RHS != 0 && "Remainder by zero?");