pub unsafe fn _mm512_inserti64x4(
    a: __m512i,
    b: __m256i,
    const IMM8: i32
) -> __m512i
🔬 This is a nightly-only experimental API. (stdsimd #48556)
Available on x86-64 and target feature avx512f only.
Expand description

Copy a to dst, then insert 256 bits (composed of 4 packed 64-bit integers) from b into dst at the location specified by imm8.

Intel’s documentation