quietNaNFrom method

Implementation

FloatingPoint quietNaNFrom(FloatingPoint source) {
  if (!supportsSignalingNaNs) {
    return _constant(valuePopulator().nan, sign: source.sign);
  }

  final targetFractionWidth = mantissa.width - (explicitJBit ? 1 : 0);
  final sourceFractionWidth =
      source.mantissa.width - (source.explicitJBit ? 1 : 0);
  final targetPayloadWidth = max(0, targetFractionWidth - 1);
  final sourcePayloadWidth = max(0, sourceFractionWidth - 1);
  late final Logic quietMantissa;
  if (targetFractionWidth == 0) {
    quietMantissa = Const(1, width: mantissa.width);
  } else if (targetPayloadWidth == 0) {
    quietMantissa = [
      if (explicitJBit) Const(1),
      Const(1),
    ].swizzle();
  } else {
    Logic payload;
    if (sourcePayloadWidth == 0) {
      payload = Const(0, width: targetPayloadWidth);
    } else {
      payload = source.mantissa.getRange(0, sourcePayloadWidth);
      payload = payload.width > targetPayloadWidth
          ? payload.getRange(0, targetPayloadWidth)
          : payload.zeroExtend(targetPayloadWidth);
    }
    quietMantissa = [
      if (explicitJBit) Const(1),
      Const(1),
      payload,
    ].swizzle();
  }
  final quiet = clone(name: 'quietNaN');
  quiet.sign <= source.sign;
  quiet.exponent <= Const(valuePopulator().nan.exponent);
  quiet.mantissa <= quietMantissa;
  return quiet;
}