[Libre-soc-dev] New instruction

[lkcl]

Floating Round to Integer Toward Zero X-form
friz FRT,FRB (Rc=0)

lol.  great name.  friz.  like the hairdo.  my numbers have been frizzed :)


On Tuesday, March 2, 2021, lkcl <luke.leighton at gmail.com> wrote:
> (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.
>> +44 (0) 787 668 0256  https://www.phcomp.co.uk/
>> Parliament Hill Computers Ltd. Registration Information:
https://www.phcomp.co.uk/Contact.html
>> #include <std_disclaimer.h>
>>