Method convertFromStringSpecials

ext/src/llvm/APFloat.cpp:2793–2861

}

bool IEEEFloat::convertFromStringSpecials(StringRef str) {
  const size_t MIN_NAME_SIZE = 3;

  if (str.size() < MIN_NAME_SIZE)
    return false;

  if (str.equals("inf") || str.equals("INFINITY") || str.equals("+Inf")) {
    makeInf(false);
    return true;
  }

  bool IsNegative = str.front() == '-';
  if (IsNegative) {
    str = str.drop_front();
    if (str.size() < MIN_NAME_SIZE)
      return false;

    if (str.equals("inf") || str.equals("INFINITY") || str.equals("Inf")) {
      makeInf(true);
      return true;
    }
  }

  // If we have a 's' (or 'S') prefix, then this is a Signaling NaN.
  bool IsSignaling = str.front() == 's' || str.front() == 'S';
  if (IsSignaling) {
    str = str.drop_front();
    if (str.size() < MIN_NAME_SIZE)
      return false;
  }

  if (str.startswith("nan") || str.startswith("NaN")) {
    str = str.drop_front(3);

    // A NaN without payload.
    if (str.empty()) {
      makeNaN(IsSignaling, IsNegative);
      return true;
    }

    // Allow the payload to be inside parentheses.
    if (str.front() == '(') {
      // Parentheses should be balanced (and not empty).
      if (str.size() <= 2 || str.back() != ')')
        return false;

      str = str.slice(1, str.size() - 1);
    }

    // Determine the payload number's radix.
    unsigned Radix = 10;
    if (str[0] == '0') {
      if (str.size() > 1 && tolower(str[1]) == 'x') {
        str = str.drop_front(2);
        Radix = 16;
      } else
        Radix = 8;
    }