[Bench!][Mir] +54%..+185% performance boost for Mersenne Twister.

[Ilya Yaroshenko via Digitalmars-d]

On Wednesday, 14 December 2016 at 00:18:06 UTC, Joseph Rushton 
Wakeling wrote:
> Cool.  Last question: IIUC you use the private `_z` parameter 
> as a cache for the most recent `data[index]` value (and AFAICT 
> that's the only use it has).  Is there a good reason for doing 
> this, rather than just setting `z = data[index]` inside 
> `opCall` (where `z` is the local parameter inside the method)?

Because memory access locality. z is always hot.