Function _mm_mask_fmadd_sd
#[target_feature(enable = "avx512f")]
pub const fn _mm_mask_fmadd_sd(a: __m128d, k: __mmask8, b: __m128d, c: __m128d) -> __m128dMultiply the lower double-precision (64-bit) floating-point elements in a and b, and add the intermediate result to the lower element in c. Store the result in the lower element of dst using writemask k (the element is copied from a when mask bit 0 is not set), and copy the upper element from a to the upper element of dst.