Dot product

Single precision floating point.
System V AMD64 ABI convention.


sses_dot:
    movaps xmm0, [rdi]
    mulps xmm0, [rsi]
    haddps xmm0, xmm0
    haddps xmm0, xmm0
    ret

>>53
Microhoth has been using a (subset?) of POSIX threads as far back as maybe Windows xp?
No, they have their own threads API which is commonly known as Winthreads. It's completely different from POSIX threads.

Does this look like pthread_create(3) to you?

http://msdn.microsoft.com/en-us/library/ms682453%28v=vs.85%29.aspx

Perhaps you're thinking of BSD sockets, which they more or less support through Winsock. They also have User-Mode Scheduled cooperative-threading worker threads for building very fast task schedulers.