pub unsafe fn _mm256_mask_compress_pd(
    src: __m256d,
    k: u8,
    a: __m256d
) -> __m256d
🔬 This is a nightly-only experimental API. (stdsimd)
This is supported on x86-64 and target feature avx512f,avx512vl only.
Expand description

Contiguously store the active double-precision (64-bit) floating-point elements in a (those with their respective bit set in writemask k) to dst, and pass through the remaining elements from src.

Intel’s documentation