Function _mm512_extractf64x4_pd 

pub fn _mm512_extractf64x4_pd(a: __m512d, const IMM8: i32) -> __m256d

Available on x86-64 and target feature avx512f only.

Extract 256 bits (composed of 4 packed double-precision (64-bit) floating-point elements) from a, selected with imm8, and store the result in dst.

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