What is the difference between _m_empty and _mm_em

问题:

While I was looking for MMX functions, I noticed that two of them, _m_empty and _mm_empty, have exactly the same definition.

So why do they both exist ? Is one of them older than the other ? Is there a difference that is not mentioned in the manual ?

回答1:

Differences would/should be pointed out in the documentation. The MSDN is more precise. They explicitly mention this:

A synonym for _mm_empty is _m_empty.