Intel® C++ Compiler 19.0 Developer Guide and Reference
This topic only applies when targeting Intel® Many Integrated Core Architecture (Intel® MIC Architecture).
Unlike the IA-32 and Intel® 64 architectures, the Intel® MIC Architecture requires all data accesses to be properly aligned according to their size, otherwise the program may behave unpredictably.
For example, an integer variable, which requires four bytes of storage, has to be allocated on an address that is a multiple of four. Likewise, a double-precsion floating point variable, which requires eight bytes of storage, has to be allocated on an address that is a multiple of eight.