Re: [Boost-users] [multi-array] Performance? Difference from GIL or uBLAS?

From: joel falcou (joel.falcou_at_[hidden])
Date: 2008-08-07 15:58:10

> When intel came out with it's first SIMD instruction set I was happy
to
> try them on my application. It was a failure. Because even if
one
> instruction executes on 3 data locations it's cost was 3 CPU
cycles. Three
> integer instructions cost 1 cycle each. Also with
SIMD you had to load the
> registers first. <snip>

MMX and SSE were rather a disaster on this point.
Acually, I learn
to play with SIMD using Altivec on PowerPC and that's a complete different
deal. SSSE3 and upcoming SSE4 are ratehr good too.

> And,
Yes, optimizing at this level is a rare situation.
I will be curious
to know which kind of IP algorithm need those but this is maybe a topic
that should go private instead of adding noise to the list.