Re: [boost] [OT?] SIMD and Auto-Vectorization (was Re: How to structurate libraries ?)

Subject: Re: [boost] [OT?] SIMD and Auto-Vectorization (was Re: How to structurate libraries ?)
From: Michael Marcin (mike.marcin_at_[hidden])
Date: 2009-01-21 21:07:58

David A. Greene wrote:
> On Wednesday 21 January 2009 03:11, David Abrahams wrote:
>> on Tue Jan 20 2009, "David A. Greene" <greened-AT-obbligato.org> wrote:
>>> When you're talking "optimal," you're setting a pretty dang high bar.
>> I don't have to care about "optimal" if the difference between a
>> suboptimal use of SIMD and not using it at all is an order of magnitude.
> 
> Well, the whole discussion is about "optimal."  If one doesn't care about 
> "optimal" then a compiler will do just fine all the time and there's no need 
> for a DSEL, asm or ugly gcc intrinsics.
> 

What if we replace optimal with optimized?

Surely library code than gives a 4x speedup is desirable to have even if 
you can hand generate code that gives you a 5x. Getting a 4x speedup 
over naive simd-less in simple vector operations and still being able to 
concentrate on the problem at hand instead of low level optimization 
details sounds fantastic to me.

-- 
Michael Marcin