Function _mm_shrdi_epi64 

pub fn _mm_shrdi_epi64(a: __m128i, b: __m128i, const IMM8: i32) -> __m128i

Available on x86-64 and target feature avx512vbmi2 and target feature avx512vl only.

Concatenate packed 64-bit integers in b and a producing an intermediate 128-bit result. Shift the result right by imm8 bits, and store the lower 64-bits in dst.

Intel’s documentation