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## _mm512_castsi256_si512

# Function _mm512_castsi256_si512

1.89.0 (const: unstable) · Source

    pub fn _mm512_castsi256_si512(a: __m256i) -> __m512i

Available on x86-64 and target feature `avx512f` only.
Expand description

Cast vector of type __m256i to type __m512i; the upper 256 bits of the result are indeterminate.

In the Intel documentation, the upper bits are declared to be “undefined”. This is not equivalent to `mem::MaybeUninit`; instead, these bits are non-deterministically set to some valid value. In practice, this is typically equivalent to `mem::zeroed`.

This intrinsic is only used for compilation and does not generate any instructions, thus it has zero latency.

Intel’s documentation