Function _mm_getexp_sh
#[target_feature(enable = "avx512fp16")]
pub fn _mm_getexp_sh(a: __m128h, b: __m128h) -> __m128hConvert the exponent of the lower half-precision (16-bit) floating-point element in b to a half-precision
(16-bit) floating-point number representing the integer exponent, store the result in the lower element
of dst, and copy the upper 7 packed elements from a to the upper elements of dst. This intrinsic essentially
calculates floor(log2(x)) for the lower element.