Function frexp

external/astc-encoder/Source/astcenc_vecmathlib.h:542–553

* @brief Extract mantissa and exponent of a float value. * * @param a The input value. * @param[out] exp The output exponent. * * @return The mantissa. */

 * @return The mantissa.
 */
static ASTCENC_SIMD_INLINE vfloat4 frexp(vfloat4 a, vint4& exp)
{
	// Interpret the bits as an integer
	vint4 ai = float_as_int(a);

	// Extract and unbias the exponent
	exp = (lsr<23>(ai) & 0xFF) - 126;

	// Extract and unbias the mantissa
	vint4 manti = (ai &  static_cast<int>(0x807FFFFF)) | 0x3F000000;
	return int_as_float(manti);
}

/**
 * @brief Convert float to 16-bit LNS.