[Libre-soc-dev] New instruction

[lkcl]

(top-posting to preserve message, hope you don't mind alain)

we shouuuuld already have that covered, through v3.0


Floating Round to Integer Nearest X-form

4.6.7.3 Floating Round to Integer Instructions

v3.0C p163



On Tuesday, March 2, 2021, Alain D D Williams <addw at phcomp.co.uk> wrote:
> This is one for the TODO bucket but it does suggest that a look at what
other
> processor vendors are doing might be useful.
>
> ARMv8.3-A has a new instruction that is supposed to make Javascript 0.5%
to 2% faster.
>
> FJCVTZS - Floating-point Javascript Convert to Signed fixed-point,
rounding toward Zero.
>
> It converts Javascript numbers (doubles - IEEE754 64 bit) to 32 bit int
and
> sets the condition registers on overflow, ... especially good when doing
AES &
> SHA256 (not that I thought that a lot of that was done in Javascript, but
> apparently it is).
>
>
https://developer.arm.com/documentation/dui0801/g/A64-Floating-point-Instructions/FJCVTZS
>
>
https://community.arm.com/developer/ip-products/processors/b/processors-ip-blog/posts/armv8-a-architecture-2016-additions
>
> https://bugzilla.mozilla.org/show_bug.cgi?id=1433126
>
> https://www.worksonarm.com/blog/woa-issue-70/
>
> --
> Alain Williams
> Linux/GNU Consultant - Mail systems, Web sites, Networking, Programmer,
IT Lecturer.
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