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

Jacob Lifshay programmerjake at gmail.com
Fri Mar 27 21:29:15 GMT 2020


On Fri, Mar 27, 2020, 12:21 Luke Kenneth Casson Leighton <lkcl at lkcl.net>
wrote:

> FP is a little more challenging because they use "words" to describe
> most aspects of the hardware.  oh wait!  Appendix A p775 v3.0B
> contains FP to rounding algorithms, and a few more besides.
>
> i would not be at all surprised if, should we do document-parsing, we
> had an entire simulator for the integer V3.0 system in a week, and the
> hardware in around 2.


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.

Jacob

Jacob


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