Re: [PATCH v3 0/6] target/riscv: support Zfh, Zfhmin extension v0.1

[Frank Chang]

On Sun, Oct 17, 2021 at 2:03 AM Richard Henderson <richard.henderson@linaro.org> wrote:

On 10/16/21 2:07 AM, frank.chang@sifive.com wrote:
> Changelog:
>
> v3:
>    * Use the renamed softfloat min/max APIs: *_minimum_number()
>      and *_maximum_number().
>    * Pick softfloat min/max APIs based on CPU privilege spec version.

So... Given that Zfh 0.1 post-dates F 2.2, does that mean that Zfh should always use the
2019 functions?

Hi Richard,

That's what I thought, but Zfh spec says:

"This chapter describes the Zfh standard extension for 16-bit half-precision binary floating-point

instructions compliant with the IEEE 754-2008 arithmetic standard. The Zfh extension depends on
the single-precision floating-point extension, F."

The spec doesn't illustrate too much about how fmin.h/fmax.h should behave,

so that's why I took the same approach just like fmin and fmax for RVF in my other patchset.

 

If that's not acceptable, I can change back to use IEEE 754-2019 for Zfh extension.

Thanks,

Frank Chang

r~