Re: Vector Task Group minutes 2020/5/15
I believe it is provably not possible for our vectors to have more thantoggle quoted message Show quoted text
two of the following properties:
1. The datapath can be sliced into multiple slices to improve wiring
such that corresponding elements of different sizes reside in the
2. Memory accesses containing enough contiguous bytes to fill the
datapath width corresponding to one vector can spread evenly
across the slices when loading or storing a vector group of two,
four, or eight vector registers.
3. The operation corresponding to storing a register group at one
element width and loading back the same number of bytes into a
register group of the same size but with a different element width
results in exactly the same register position for all bytes.
The SLEN solution we've had for some time allows for #1 and #2. We're
discussing requiring "cast" operations in place of having property #3.
I wonder whether we should look again at giving up property #2 instead.
It would cost additional logic in wide, sliced datapaths to keep up
memory bandwidth. But the damage might be less than requiring casts and
the potential of splitting the ecosystem?
On 5/15/20 11:55 AM, Krste Asanovic wrote: