Function _mm512_insertf64x4

#[target_feature(enable = "avx512f")]
pub const fn _mm512_insertf64x4(a: __m512d, b: __m256d, IMM8: i32) -> __m512d

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

Intel's documentation