Function _mm256_blend_pd

pub unsafe fn _mm256_blend_pd(
    a: __m256d,
    b: __m256d,
    const IMM4: i32,
) -> __m256d

Available on (x86 or x86-64) and target feature avx and x86 only.

Blends packed double-precision (64-bit) floating-point elements from a and b using control mask imm8.

Intel’s documentation