[libre-riscv-dev] div/mod algorithm written in python

Luke Kenneth Casson Leighton lkcl at lkcl.net
Wed Jul 24 11:26:17 BST 2019


On Wed, Jul 24, 2019 at 9:28 AM Luke Kenneth Casson Leighton
<lkcl at lkcl.net> wrote:

> jacob what's the setup for RSQRT, i'm getting consistent answers of zero.
>
> changing this from 3 to 2 gives some non-zero answers
>
>         with m.Else():  # DivPipeCoreOperation.RSqrtRem
>             m.d.comb += self.o.compare_lhs.eq(
>                 1 << (self.core_config.fract_width * 3))

ok it now "works".  of course, now, 1/3 of test_core.py unit tests
completely fail, however the answers from FPRSQRT are now reasonably
sensible.

i have absolutely no idea how to "fix" this, jacob - you'll need to look at it.

l.



More information about the libre-riscv-dev mailing list