Extract Biased Exponent
Returns the exponent of a decimal floating-point value as an integer.
long __d64_biased_exponent (_Decimal64);
long __d128_biased_exponent (_Decimal128);
Returns special values for infinity, quiet NaN, and signalling NaN, as listed in Table 1.
For finite values, the result is DFP_BIASED_EXPONENT_FINITE plus the exponent bias (398 for _Decimal64, 6176 for _Decimal128) plus the actual exponent.