Fast array copy. SIMD manual or automatic?

[tcak via Digitalmars-d-learn]

I have two char arrays at the size of 16KB. I will copy a part of 
data between them again and again.

arrayA[0 .. dataLen] = arrayB[0 .. dataLen];


Does the compiler generate code that uses SIMD operations 
(128-bits memory copy) automatically, or do I need to do anything 
special for this?