RFR(L): Vector API Compare Intrinsics

[John Rose]

On Mar 9, 2018, at 10:51 AM, Lupusoru, Razvan A <razvan.a.lupusoru at intel.com> wrote:
> 
> Instead of "toArray" on masks, what do you think of replacing/adding "intoArray"? That way we can also intrinsify that easily without making the creation of array part of semantics.

I wonder if it would be better to have a mask to vector conversion.
That seems to be useful in its own right, and a shorter conceptual
distance, than a direct intoArray.  Then the vector can do the intoArray.

It seems to me that the usual representations of masks as either
vectors (themselves) or special vector-associated registers lead
to two natural abstract methods, one for converting a mask to a
vector, and one for converting it to a packed bitmask.  The latter
peaks at 64 lanes, but that's enough for most uses today.