Function totalExponent

ext/src/llvm/APFloat.cpp:284–333

This is ugly and needs cleaning up, but I don't immediately see how whilst remaining safe. */

/* This is ugly and needs cleaning up, but I don't immediately see
   how whilst remaining safe.  */
static Expected<int> totalExponent(StringRef::iterator p,
                                   StringRef::iterator end,
                                   int exponentAdjustment) {
  int unsignedExponent;
  bool negative, overflow;
  int exponent = 0;

  if (p == end)
    return createError("Exponent has no digits");

  negative = *p == '-';
  if (*p == '-' || *p == '+') {
    p++;
    if (p == end)
      return createError("Exponent has no digits");
  }

  unsignedExponent = 0;
  overflow = false;
  for (; p != end; ++p) {
    unsigned int value;

    value = decDigitValue(*p);
    if (value >= 10U)
      return createError("Invalid character in exponent");

    unsignedExponent = unsignedExponent * 10 + value;
    if (unsignedExponent > 32767) {
      overflow = true;
      break;
    }
  }

  if (exponentAdjustment > 32767 || exponentAdjustment < -32768)
    overflow = true;

  if (!overflow) {
    exponent = unsignedExponent;
    if (negative)
      exponent = -exponent;
    exponent += exponentAdjustment;
    if (exponent > 32767 || exponent < -32768)
      overflow = true;
  }

  if (overflow)
    exponent = negative ? -32768: 32767;

  return exponent;
}

static Expected<StringRef::iterator>
skipLeadingZeroesAndAnyDot(StringRef::iterator begin, StringRef::iterator end,