[libre-riscv-dev] extremely busy crowdsupply update started

Luke Kenneth Casson Leighton lkcl at lkcl.net
Fri Mar 27 21:32:01 GMT 2020


On Fri, Mar 27, 2020 at 9:29 PM Jacob Lifshay <programmerjake at gmail.com> wrote:

> I haven't looked at the specific FP algorithms the Power spec specifies
> yet, but assuming they are like how IEEE 754 is specified, they specify it
> in terms of infinite-precision real numbers, which are not mappable to
> hardware without additional conversion to integer/fixed-point operations.

it appears to be bit-numbered sections of the incoming data.  like this:

If (FRB)1:11 < 897 and (FRB)1:63 > 0 then
     Do
         If FPSCRUE = 0 then goto Disabled Exponent Underflow
         If FPSCRUE = 1 then goto Enabled Exponent Underflow
     End



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