Re: Fixed Point (Chapter 13): Clarification Request


Krste Asanovic
 

On Fri, 07 Aug 2020 14:48:34 -0700, "CDS" <cohen.steed@...> said:
| Thank you for the response, Andrew.
| Given that these operations are intended to be conveniences, in the first place (hence: vector), the
| addition of a required macro for inclusion could be considered a basic element. Fixed point is almost
| always going to be used in conjunction with other data formats, and the conversion, as you say, could
| be two instructions - or it could be one.

I disagree with "almost always" unless you refer to mixing integer and
fixed-point. There are certainly many use cases with no
floating-point.

| The confusion my team and I are having with fixed point is not so much with the implementation, but the
| use-case. If we're going to have fixed-point in RISC-V, how about we look at how it's used and build
| that? Barring a (possibly necessary) overhaul, making the specification optional *entirely* -
| separating it out from the rest of vector, may be a compelling
| option.

Fixed-point is widely used, and if anything, interest is growing in
low-precision fixed-point. Fixed-point codecs continue to be
widespread also.

I'm having trouble understanding your viewpoint here.

Krste



|

Join tech-vector-ext@lists.riscv.org to automatically receive all group messages.