This is the mail archive of the mailing list for the glibc project.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [RFC][PATCH 0/2] aarch64: Add optimized ASIMD versions of sinf/cosf

On Tuesday 13 June 2017 11:19 PM, Wilco Dijkstra wrote:
> I don't see the point of asking him to do that. It would be a significant amount of
> work which would be wasted once Szabolcs posts his implementation.

Here's what Szabolcs said about his sinf/cosf work:

>> the plan is the next release cycle (i plan to post powf
>> first, then work on sinf/cosf, possibly sin/cos too, then
>> look at vector versions once the vector abi is in gcc).

which seems to indicate that he has not even started.  I guess it is
Ashwin's call now as to whether he finds it worthwhile spending time to
work on it and then have it (probably) superseded later.

> What I'd like to ask Ashwin is which benchmarks show a speedup due to
> his patch and whether it is essential they get a speedup this release
> (rather than a larger speedup later). I don't recall seeing sinf/cosf in profiles
> in popular benchmarks, so I don't understand the urgency of doing this now.

I don't understand the point of the question.  Why is an intermediate
speedup undesirable?  At the very least it will help Ashwin get his
first patch into glibc, which is a great thing too since that means we
have another contributor in our fold.

> What I think would be useful is to start collecting real traces of actual applications
> or large benchmarks like SPEC and creating representative microbenchmarks
> using that data.

We had a benchmarking BoF back in 2015 and I had made notes then to help
track the long term goals we desire from such an exercise:


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]