>Which is a language extension and not a C feature. In line assembler has always been C feature. I also fail to see the point of mentioning intrinsics being ex

>Which is a language extension and not a C feature. In line assembler has always been C feature. I also fail to see the point of mentioning intrinsics being extension. Do you have an example of a compiler, which does not support cache prefetch on a platform that supports them? >I would say you would need to make use of Data.Vector.Unboxed I believe you are missing my point. The run-time layout of this type is not known in the first place. Making it unboxed may or may not change its layout to another unknown one. If you need a specific change, and not a change for the sake of change - there is nothing you can do. In C, I might want this to be a 12 byte type if I access the values sequentially and a 16 byte if randomly. In Haskell you can either have it boxed (and you have an order of magnitude more cache misses) or have either 12 or 16 byte in unboxed, but you cannot tell which one and if you wanted another one - tough cookies. >Haskell tools can also improve if its acceptance in the industry keeps increasing. And if they do we will discuss them then.