Re: [Qemu-devel] [PATCH v4 00/22] re-factor softfloat and add fp16 functions

[Laurent Vivier <laurent@vivier.eu>]

Le 13/02/2018 à 16:51, Peter Maydell a écrit :
> On 6 February 2018 at 16:47, Alex Bennée <alex.bennee@linaro.org> wrote:
>> Hi,
>>
>> The main change is applying the __attribute__((flatten)) to some of
>> the public functions that show up in Emilio's dbt-benchmark. This
>> seems to be a cleaner solution that squashing inlines higher up the
>> chain and still leaves the chance for re-use for the less widely used
>> functions. The results are an improvement over v3 by some margin:
>>
>>                          NBench score; higher is better
>>
>>     5 +-+-----------+-------------+------------+-------------+-----------+-+
>>       |                     ****### %%%%  +++                              |
>>   4.5 +-+...................*..*..#.%..%..****##..%%%%+ system-2.5       +-+
>>       |                     *  *  # %  %  *  * #  %  %      master         |
>>     4 +-+...................*..*..#.%..%..*..*.#..%..%softfloat-v3       +-+
>>   3.5 +-+...................*..*..#.%..%..*..*.#..%..%softfloat-%%%%.....+-+
>>       |                     *  *  # %  %  *  * #  %  %  * *  #  %  %       |
>>     3 +-+...................*..*..#.%..%..*..*.#..%..%..*.*..#..%..%.....+-+
>>       |                     *  *  #+%  %  *  * #$$$  %  * *  #  %  %       |
>>   2.5 +-+........####.......*..*..#$$..%..*..*.#..$..%..*.*..#..%..%.....+-+
>>       |       ****  #  %%%  *  *  # $  %  *  * #  $  %  * *  #$$$  %       |
>>     2 +-+.....*..*..#..%.%..*..*..#.$..%..*..*.#..$..%..*.*..#..$..%.....+-+
>>       |       *  *  #  % %  *  *  # $  %  *  * #  $  %  * *  #  $  %       |
>>   1.5 +-+.....*..*..#$$$.%..*..*..#.$..%..*..*.#..$..%..*.*..#..$..%.....+-+
>>     1 +-+.....*..*..#..$.%..*..*..#.$..%..*..*.#..$..%..*.*..#..$..%.....+-+
>>       |       *  *  #  $ %  *  *  # $  %  *  * #  $  %  * *  #  $  %       |
>>   0.5 +-+.....*..*..#..$.%..*..*..#.$..%..*..*.#..$..%..*.*..#..$..%.....+-+
>>       |       *  *  #  $ %  *  *  # $  %  *  * #  $  %  * *  #  $  %       |
>>     0 +-+-----****###$$$%%--****###$$%%%--****##$$$%%%--***###$$$%%%-----+-+
>>                  FOURIER     NEURAL NETLU DECOMPOSITION    gmean
>>
>> Slightly easier to read PNG:
>>
>>     https://i.imgur.com/XEeL0bC.png
>>
>> I think it's pretty ready for a merge. Shall I submit a pull myself or
>> does it make sense going via someone else? According to MAINTAINERS
>> Peter and Aurelien are responsible for this code...
> 
> I had some nits but I think the best thing to do is if you fix those
> and then just send a pull request for this.

Just to be sure no one has missed that:

https://bellard.org/libbf/

I'm wondering if it can help for this work.

Thanks,
Laurent