On Wednesday 21 January 2009 20:07, Michael Marcin wrote:
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.
Agreed. I'm under the impression that Joel wants to get 5x through a DSEL-based code generator. I'm not sure it's worthwhile in the general case. It may be worthwhile in highly specialized cases. -Dave