Intel® C++ Compiler 16.0 User and Reference Guide
Moves integer values from unaligned memory location to a destination vector. The corresponding Intel® AVX instruction isVMOVDQU.
extern __m256i _mm256_loadu_si256(__m256i const *a);  | 
*a  | 
      pointer to a memory location that can hold constant integer values | 
Loads integer values from the 256-bit unaligned memory location pointed to by *a, into a destination integer vector, which is returned by the intrinsic.
A 256-bit vector with integer values.