Function _mm512_mask_compressstoreu_ps 

pub unsafe fn _mm512_mask_compressstoreu_ps(
    base_addr: *mut f32,
    k: u16,
    a: __m512,
)

Contiguously store the active single-precision (32-bit) floating-point elements in a (those with their respective bit set in writemask k) to unaligned memory at base_addr.

Intel’s documentation