Function core_arch::x86::_mm256_zextsi128_si256

pub unsafe fn _mm256_zextsi128_si256(a: __m128i) -> __m256i

This is supported on x86 and target feature avx,sse2 only.

Constructs a 256-bit integer vector from a 128-bit integer vector. The lower 128 bits contain the value of the source vector. The upper 128 bits are set to zero.

Intel's documentation