float32ToCommonNaN
if ( aSig ) return commonNaNToFloat64( float32ToCommonNaN( a ) );
if ( aSig ) return commonNaNToFloat64( float32ToCommonNaN( a ) );
if ( aSig ) return commonNaNToFloatx80( float32ToCommonNaN( a ) );
if ( aSig ) return commonNaNToFloat128( float32ToCommonNaN( a ) );