Intel® C++ Compiler 16.0 User and Reference Guide
This topic only applies to Intel® Many Integrated Core Architecture (Intel® MIC Architecture).
These scalar intrinsic prototypes are available in the immintrin.h header file. There are 17 scalar intrinsics, some of which perform bit-related operations. Many of these intrinsics perform the same operation of different operand sizes.
All scalar intrinsics are abstractions of processor instructions. These intrinsics allow you to specify the underlying implementation (instruction selection) of an algorithm, yet leave instruction scheduling and register allocation to the compiler.